[GUI] Add detachable console window (#91)

Add a Split button to detach the emulator console into a resizable window.

The detached console keeps search, auto-scroll, copy, and clear controls. The main console hides while detached and restores when the split window closes if it was previously open.

.editorconfig

@@ -14,7 +14,7 @@ indent_size = 4
 indent_style = space
 tab_width = 4
 
-[*.{md,json,yml,props,csproj}]
+[*.{md,json,yml,xml,props,csproj}]
 
 indent_size = 2
 tab_width = 2

.github/ISSUE_TEMPLATE/game-compatibility.yml

@@ -16,6 +16,11 @@ body:
         Example title:
         Demon’s Souls (PPSA01341)
 
+        **Before reporting:**
+        - Test the game on a **fresh build from `main`**, not an old release.
+        - Copy the **exact commit SHA** shown at the top of the log.
+        - `DEBUG` and `TRACE` lines are diagnostic context, not errors by themselves; report the last milestone or the first `WARNING`, `ERROR`, or `CRITICAL` line connected to the stop.
+
   - type: input
     id: game_name
     attributes:
@@ -73,11 +78,20 @@ body:
     id: logs
     attributes:
       label: Log File
-      description: Drag and drop your log file here, or click to browse
+      description: Attach the **full** log file (`.log`, `.txt`, or `.zip`). Do not paste only a fragment — the maintainer needs the complete log from launch to crash.
     validations:
-      required: false
+      required: true
       accept: ".log,.txt,.zip"
 
+  - type: input
+    id: last_milestone_first_error
+    attributes:
+      label: Last Milestone / First Error
+      description: Paste the **last useful milestone line** or the **first `WARNING`, `ERROR`, or `CRITICAL` line connected to the stop** from the log. `DEBUG`/`TRACE` lines do not count unless a real error follows them.
+      placeholder: "e.g. CpuEngine: native-only  OR  [ERROR] Native backend FAILED: ..."
+    validations:
+      required: true
+
   - type: dropdown
     id: operating_system
     attributes:
@@ -119,7 +133,8 @@ body:
     id: emulator_version
     attributes:
       label: Emulator Version / Commit
-      placeholder: e.g. v0.0.1 / a1b2c3d
+      description: Copy the **exact short SHA** from the top of the log. Do not enter just `0.0.1` without a commit hash.
+      placeholder: e.g. a1b2c3d
     validations:
       required: true
 

.github/workflows/workflow.yml

@@ -9,11 +9,17 @@ on:
       - "**"
     paths-ignore:
       - "**/*.md"
+      - "**/*.png"
+      - "**/*.jpeg"
+      - "**/*.jpg"
   pull_request:
     branches:
       - main
     paths-ignore:
       - "**/*.md"
+      - "**/*.png"
+      - "**/*.jpeg"
+      - "**/*.jpg"
   workflow_dispatch:
 
 permissions:
@@ -120,7 +126,7 @@ jobs:
     needs:
       - init
       - build
-    if: github.event_name == 'push' || github.event_name == 'workflow_dispatch'
+    if: github.event_name == 'workflow_dispatch' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
     runs-on: ubuntu-latest
     permissions:
       contents: write

.gitignore

@@ -26,6 +26,7 @@ arm64/
 *.userosscache
 *.sln.docstates
 
+.packages
 packages/
 *.nupkg
 .nuget/
@@ -36,3 +37,6 @@ packages/
 Thumbs.db
 Desktop.ini
 ehthumbs.db
+
+.vs/
+.idea/

Directory.Build.props

@@ -32,4 +32,18 @@ SPDX-License-Identifier: GPL-2.0-or-later
     <DebugType>none</DebugType>
     <DebugSymbols>false</DebugSymbols>
   </PropertyGroup>
+
+  <!-- Build provenance surfaced by SharpEmu.Logging.BuildInfo as a banner at the
+       top of the log. Populated from GitHub Actions environment variables when
+       building in CI; empty locally. -->
+  <ItemGroup>
+    <AssemblyMetadata Include="SharpEmu.BuildConfiguration" Value="$(Configuration)" />
+    <AssemblyMetadata Condition="'$(GITHUB_SHA)' != ''" Include="SharpEmu.BuildSha" Value="$(GITHUB_SHA)" />
+    <AssemblyMetadata Condition="'$(GITHUB_REF_NAME)' != ''" Include="SharpEmu.BuildBranch" Value="$(GITHUB_REF_NAME)" />
+    <AssemblyMetadata Condition="'$(GITHUB_REF)' != ''" Include="SharpEmu.BuildRef" Value="$(GITHUB_REF)" />
+    <AssemblyMetadata Condition="'$(GITHUB_EVENT_NAME)' != ''" Include="SharpEmu.BuildEventName" Value="$(GITHUB_EVENT_NAME)" />
+    <AssemblyMetadata Condition="'$(GITHUB_REPOSITORY)' != ''" Include="SharpEmu.BuildRepository" Value="$(GITHUB_REPOSITORY)" />
+    <AssemblyMetadata Condition="'$(GITHUB_SERVER_URL)' != ''" Include="SharpEmu.BuildServerUrl" Value="$(GITHUB_SERVER_URL)" />
+    <AssemblyMetadata Condition="'$(GITHUB_RUN_ID)' != ''" Include="SharpEmu.BuildRunId" Value="$(GITHUB_RUN_ID)" />
+  </ItemGroup>
 </Project>

Directory.Packages.props

@@ -1,16 +1,22 @@
-<!--
+<!--
 Copyright (C) 2026 SharpEmu Emulator Project
 SPDX-License-Identifier: GPL-2.0-or-later
 -->
-
 <Project>
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
   </PropertyGroup>
   <ItemGroup>
+    <PackageVersion Include="Avalonia" Version="11.3.18" />
+    <PackageVersion Include="Avalonia.Desktop" Version="11.3.18" />
+    <PackageVersion Include="Avalonia.Fonts.Inter" Version="11.3.18" />
+    <PackageVersion Include="Avalonia.Themes.Fluent" Version="11.3.18" />
     <PackageVersion Include="Iced" Version="1.21.0" />
     <PackageVersion Include="Silk.NET.Vulkan" Version="2.23.0" />
+    <PackageVersion Include="Silk.NET.Vulkan.Extensions.EXT" Version="2.23.0" />
     <PackageVersion Include="Silk.NET.Vulkan.Extensions.KHR" Version="2.23.0" />
     <PackageVersion Include="Silk.NET.Windowing" Version="2.23.0" />
+    <!-- Transitive of Avalonia.Desktop; pinned to fix GHSA-xrw6-gwf8-vvr9 -->
+    <PackageVersion Include="Tmds.DBus.Protocol" Version="0.21.3" />
   </ItemGroup>
-</Project>
+</Project>

LICENSES/MIT.txt

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 Alex Barney
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

REUSE.toml

@@ -3,13 +3,21 @@ version = 1
 [[annotations]]
 path = [
     "REUSE.toml",
+    "nuget.config",
     "global.json",
     "**/packages.lock.json",
     "scripts/ps5_names.txt",
     "src/SharpEmu.HLE/Aerolib/aerolib.bin",
     "_logs/**",
-    ".github/images/**"
+    ".github/images/**",
+    "assets/images/**"
 ]
 precedence = "aggregate"
 SPDX-FileCopyrightText = "SharpEmu Emulator Project"
 SPDX-License-Identifier = "GPL-2.0-or-later"
+
+[[annotations]]
+path = "src/SharpEmu.GUI/Atrac9/**"
+precedence = "aggregate"
+SPDX-FileCopyrightText = "2018 Alex Barney"
+SPDX-License-Identifier = "MIT"

SharpEmu.slnx

@@ -7,6 +7,7 @@ SPDX-License-Identifier: GPL-2.0-or-later
   <Folder Name="/src/">
     <Project Path="src/SharpEmu.CLI/SharpEmu.CLI.csproj" />
     <Project Path="src/SharpEmu.Core/SharpEmu.Core.csproj" />
+    <Project Path="src/SharpEmu.GUI/SharpEmu.GUI.csproj" />
     <Project Path="src/SharpEmu.HLE/SharpEmu.HLE.csproj" />
     <Project Path="src/SharpEmu.Libs/SharpEmu.Libs.csproj" />
     <Project Path="src/SharpEmu.Logging/SharpEmu.Logging.csproj" />

nuget.config

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<configuration>
+  <config>
+    <add key="globalPackagesFolder" value=".packages" />
+  </config>
+
+  <packageSources>
+    <clear />
+    <add key="Nuget" value="https://api.nuget.org/v3/index.json" />
+  </packageSources>
+
+  <packageSourceMapping>
+    <packageSource key="Nuget">
+      <package pattern="*" />
+    </packageSource>
+  </packageSourceMapping>
+</configuration>

src/SharpEmu.CLI/Program.cs

@@ -3,6 +3,7 @@
 
 using SharpEmu.Core.Runtime;
 using SharpEmu.Core.Cpu;
+using SharpEmu.GUI;
 using SharpEmu.HLE;
 using SharpEmu.Logging;
 using System.Runtime.InteropServices;
@@ -24,12 +25,45 @@ internal static partial class Program
     private const ulong PROCESS_CREATION_MITIGATION_POLICY2_CET_USER_SHADOW_STACKS_ALWAYS_OFF = 0x00000002UL << 28;
     private const ulong PROCESS_CREATION_MITIGATION_POLICY2_USER_CET_SET_CONTEXT_IP_VALIDATION_ALWAYS_OFF = 0x00000002UL << 32;
     private const ulong PROCESS_CREATION_MITIGATION_POLICY2_XTENDED_CONTROL_FLOW_GUARD_ALWAYS_OFF = 0x00000002UL << 40;
+    private const int ATTACH_PARENT_PROCESS = -1;
+    private const int STD_OUTPUT_HANDLE = -11;
+    private const int STD_ERROR_HANDLE = -12;
+    private const uint GENERIC_READ = 0x80000000;
+    private const uint GENERIC_WRITE = 0x40000000;
+    private const uint FILE_SHARE_READ = 0x00000001;
+    private const uint FILE_SHARE_WRITE = 0x00000002;
+    private const uint OPEN_EXISTING = 3;
 
+    [STAThread]
     private static int Main(string[] args)
     {
+        try
+        {
+            return Run(args);
+        }
+        finally
+        {
+            SharpEmuLog.Shutdown();
+        }
+    }
+
+    private static int Run(string[] args)
+    {
+        args = NormalizeInternalArguments(args, out var isMitigatedChild);
+        if (args.Length == 0 && !isMitigatedChild)
+        {
+            // No arguments: open the desktop frontend. Any argument selects
+            // the classic CLI behavior below.
+            return GuiLauncher.Run();
+        }
+
+        // The executable uses the GUI subsystem, so CLI mode has to connect
+        // itself to a console before the first write.
+        EnsureCliConsole();
+        UseUtf8ConsoleOutput();
+
         Console.Error.WriteLine($"[DEBUG] SharpEmu starting with {args.Length} args");
 
-        args = NormalizeInternalArguments(args, out var isMitigatedChild);
         if (!isMitigatedChild && TryRunMitigatedChild(args, out var childExitCode))
         {
             return childExitCode;
@@ -43,9 +77,11 @@ internal static partial class Program
 
         SharpEmuLog.MinimumLevel = logLevel;
 
+        Log.Info(BuildInfo.Banner);
+
         ebootPath = Path.GetFullPath(ebootPath);
         Console.Error.WriteLine($"[DEBUG] Full path: {ebootPath}");
-        
+
         if (!File.Exists(ebootPath))
         {
             Log.Error($"EBOOT file was not found: {ebootPath}");
@@ -101,6 +137,100 @@ internal static partial class Program
         return result == OrbisGen2Result.ORBIS_GEN2_OK ? 0 : 4;
     }
 
+    private static void EnsureCliConsole()
+    {
+        if (!OperatingSystem.IsWindows())
+        {
+            return;
+        }
+
+        // Standard handles already provided (pipes or file redirection, e.g.
+        // when the GUI or a script launches us): use them as-is.
+        if (IsHandleValid(GetStdHandle(STD_OUTPUT_HANDLE)) && IsHandleValid(GetStdHandle(STD_ERROR_HANDLE)))
+        {
+            return;
+        }
+
+        // Prefer the console of the parent process (interactive terminal);
+        // create one only when started with arguments but no terminal at all
+        // (e.g. a shortcut), so usage and errors remain visible.
+        if (!AttachConsole(ATTACH_PARENT_PROCESS) && GetConsoleWindow() == 0)
+        {
+            _ = AllocConsole();
+        }
+
+        RebindStdHandleToConsole(STD_OUTPUT_HANDLE);
+        RebindStdHandleToConsole(STD_ERROR_HANDLE);
+    }
+
+    /// <summary>
+    /// Makes console writes UTF-8 so the GUI's pipe reader (and any modern
+    /// terminal) decodes non-ASCII text correctly. Without this, redirected
+    /// output falls back to the OS ANSI code page and characters like "—"
+    /// arrive mangled.
+    /// </summary>
+    private static void UseUtf8ConsoleOutput()
+    {
+        try
+        {
+            // Also recreates the redirected Console.Out/Error writers with
+            // the new encoding.
+            Console.OutputEncoding = Encoding.UTF8;
+            return;
+        }
+        catch (Exception)
+        {
+            // No attached console (GUI-subsystem child with piped output):
+            // wrap the raw handles instead.
+        }
+
+        if (Console.IsOutputRedirected)
+        {
+            Console.SetOut(new StreamWriter(
+                Console.OpenStandardOutput(),
+                new UTF8Encoding(encoderShouldEmitUTF8Identifier: false))
+            {
+                AutoFlush = true,
+            });
+        }
+
+        if (Console.IsErrorRedirected)
+        {
+            Console.SetError(new StreamWriter(
+                Console.OpenStandardError(),
+                new UTF8Encoding(encoderShouldEmitUTF8Identifier: false))
+            {
+                AutoFlush = true,
+            });
+        }
+    }
+
+    private static void RebindStdHandleToConsole(int stdHandle)
+    {
+        if (IsHandleValid(GetStdHandle(stdHandle)) || GetConsoleWindow() == 0)
+        {
+            return;
+        }
+
+        var conOut = CreateFileW(
+            "CONOUT$",
+            GENERIC_READ | GENERIC_WRITE,
+            FILE_SHARE_READ | FILE_SHARE_WRITE,
+            0,
+            OPEN_EXISTING,
+            0,
+            0);
+        if (IsHandleValid(conOut))
+        {
+            _ = SetStdHandle(stdHandle, conOut);
+        }
+    }
+
+    private static bool IsHandleValid(nint handle)
+    {
+        return handle != 0 && handle != -1;
+    }
+
     private static string[] NormalizeInternalArguments(string[] args, out bool isMitigatedChild)
     {
         isMitigatedChild = false;
@@ -670,4 +800,32 @@ internal static partial class Program
     [DllImport("kernel32.dll", SetLastError = true)]
     [return: MarshalAs(UnmanagedType.Bool)]
     private static extern bool CloseHandle(nint handle);
+
+    [DllImport("kernel32.dll")]
+    private static extern nint GetConsoleWindow();
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool AttachConsole(int processId);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool AllocConsole();
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    private static extern nint GetStdHandle(int stdHandle);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool SetStdHandle(int stdHandle, nint handle);
+
+    [DllImport("kernel32.dll", EntryPoint = "CreateFileW", SetLastError = true, CharSet = CharSet.Unicode)]
+    private static extern nint CreateFileW(
+        string fileName,
+        uint desiredAccess,
+        uint shareMode,
+        nint securityAttributes,
+        uint creationDisposition,
+        uint flagsAndAttributes,
+        nint templateFile);
 }

src/SharpEmu.CLI/SharpEmu.CLI.csproj

@@ -7,11 +7,14 @@ SPDX-License-Identifier: GPL-2.0-or-later
 
   <ItemGroup>
     <ProjectReference Include="..\SharpEmu.Core\SharpEmu.Core.csproj" />
+    <ProjectReference Include="..\SharpEmu.GUI\SharpEmu.GUI.csproj" />
     <ProjectReference Include="..\SharpEmu.Logging\SharpEmu.Logging.csproj" />
   </ItemGroup>
 
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <!-- GUI subsystem so starting without arguments opens the frontend with no
+         console window; CLI mode re-attaches to the parent terminal's console. -->
+    <OutputType>WinExe</OutputType>
     <AssemblyName>SharpEmu</AssemblyName>
     <RuntimeIdentifiers>win-x64;linux-x64;osx-arm64</RuntimeIdentifiers>
     <SelfContained>true</SelfContained>
@@ -30,6 +33,15 @@ SPDX-License-Identifier: GPL-2.0-or-later
     <RestorePackagesWithLockFile>true</RestorePackagesWithLockFile>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(RuntimeIdentifier)' == 'win-x64' Or '$(RuntimeIdentifier)' == ''">
+    <ApplicationIcon>..\..\assets\images\SharpEmu.ico</ApplicationIcon>
+    <Win32Icon>..\..\assets\images\SharpEmu.ico</Win32Icon>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <NoWarn>$(NoWarn);1591</NoWarn>
+  </PropertyGroup>
+  
   <ItemGroup>
     <Content Include="..\..\LICENSE.txt">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
@@ -38,4 +50,17 @@ SPDX-License-Identifier: GPL-2.0-or-later
     </Content>
   </ItemGroup>
 
+  <!-- Keep glfw as a loose file next to the executable; every other native
+       library is embedded into the single-file bundle. -->
+  <Target Name="KeepGlfwOutsideSingleFile" AfterTargets="ComputeResolvedFilesToPublishList">
+    <ItemGroup>
+      <_GlfwPublishFiles Include="@(ResolvedFileToPublish)"
+                         Condition="$([System.String]::Copy('%(ResolvedFileToPublish.Filename)').StartsWith('glfw'))" />
+      <ResolvedFileToPublish Remove="@(_GlfwPublishFiles)" />
+      <ResolvedFileToPublish Include="@(_GlfwPublishFiles)">
+        <ExcludeFromSingleFile>true</ExcludeFromSingleFile>
+      </ResolvedFileToPublish>
+    </ItemGroup>
+  </Target>
+
 </Project>

src/SharpEmu.CLI/packages.lock.json

@@ -8,6 +8,105 @@
         "resolved": "10.0.3",
         "contentHash": "0B6nZyCHWXnvmlB559oduOspVdNOnpNXPjhpWVMovLPAsDVG7A4jJR9rzECf67JUzxP8/ee/wA8clwIzJcWNFA=="
       },
+      "Avalonia.Angle.Windows.Natives": {
+        "type": "Transitive",
+        "resolved": "2.1.25547.20250602",
+        "contentHash": "ZL0VLc4s9rvNNFt19Pxm5UNAkmKNylugAwJPX9ulXZ6JWs/l6XZihPWWTyezaoNOVyEPU8YbURtW7XMAtqXH5A=="
+      },
+      "Avalonia.BuildServices": {
+        "type": "Transitive",
+        "resolved": "11.3.2",
+        "contentHash": "qHDToxto1e3hci5YqbG9n0Ty8mlp3zBUN5wT66wKqaDVzXyQ0do3EnRILd4Ke9jpvsktaPpgE0YjEk7hornryQ=="
+      },
+      "Avalonia.FreeDesktop": {
+        "type": "Transitive",
+        "resolved": "11.3.18",
+        "contentHash": "aUwv8BNruRUOaUfMu4U3uibIUS60/rSHgGOhd8zBkLkpxY3JFJvgRbeq5ZzHIyKXCuKi18PO00YHAgCarp3wdw==",
+        "dependencies": {
+          "Avalonia": "11.3.18",
+          "Tmds.DBus.Protocol": "0.21.3"
+        }
+      },
+      "Avalonia.Native": {
+        "type": "Transitive",
+        "resolved": "11.3.18",
+        "contentHash": "8g53DROFW6wVJAnTsE1Iu5bdZO5r0oqxbdbMQODs1QDYCK2IU/y/x/vQVKCYOvqxl4tXkzU9tExv8XqSGPWthQ==",
+        "dependencies": {
+          "Avalonia": "11.3.18"
+        }
+      },
+      "Avalonia.Remote.Protocol": {
+        "type": "Transitive",
+        "resolved": "11.3.18",
+        "contentHash": "vw+6ZfgTuu72dA9aVWn6u56t2nrBd5MoMU0wo/qI9XJAl/c0oYYphIvwLvJP1JorubQY4UE3d0ac8ULBhrGBiA=="
+      },
+      "Avalonia.Skia": {
+        "type": "Transitive",
+        "resolved": "11.3.18",
+        "contentHash": "/B4aXmNRNjG8I5U/a1xJI+bIi0XO6DDzS3mBrIKlVnJRY2CyZiUeESRQXLnIU77Z9TvqkUROs+D47s085YjFtA==",
+        "dependencies": {
+          "Avalonia": "11.3.18",
+          "HarfBuzzSharp": "8.3.1.1",
+          "HarfBuzzSharp.NativeAssets.Linux": "8.3.1.1",
+          "HarfBuzzSharp.NativeAssets.WebAssembly": "8.3.1.1",
+          "SkiaSharp": "2.88.9",
+          "SkiaSharp.NativeAssets.Linux": "2.88.9",
+          "SkiaSharp.NativeAssets.WebAssembly": "2.88.9"
+        }
+      },
+      "Avalonia.Win32": {
+        "type": "Transitive",
+        "resolved": "11.3.18",
+        "contentHash": "eioUHkM2PeLPETd1aEks3rvb9plbba6buIrNdrqCpwE/qgHKUjvRNBd5mUQfAbGgTLiAes524gB8uUMDhrsJVQ==",
+        "dependencies": {
+          "Avalonia": "11.3.18",
+          "Avalonia.Angle.Windows.Natives": "2.1.25547.20250602"
+        }
+      },
+      "Avalonia.X11": {
+        "type": "Transitive",
+        "resolved": "11.3.18",
+        "contentHash": "m4Ki/G5Dovnq+6QzfS0iGbK8V77Q6oTjToMLOB0CxPCCrl3Oxywh6kIjuGJDPaN6kopMmjxlNShyQf+vPYL+JA==",
+        "dependencies": {
+          "Avalonia": "11.3.18",
+          "Avalonia.FreeDesktop": "11.3.18",
+          "Avalonia.Skia": "11.3.18"
+        }
+      },
+      "HarfBuzzSharp": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "tLZN66oe/uiRPTZfrCU4i8ScVGwqHNh5MHrXj0yVf4l7Mz0FhTGnQ71RGySROTmdognAs0JtluHkL41pIabWuQ==",
+        "dependencies": {
+          "HarfBuzzSharp.NativeAssets.Win32": "8.3.1.1",
+          "HarfBuzzSharp.NativeAssets.macOS": "8.3.1.1"
+        }
+      },
+      "HarfBuzzSharp.NativeAssets.Linux": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "3EZ1mpIiKWRLL5hUYA82ZHteeDIVaEA/Z0rA/wU6tjx6crcAkJnBPwDXZugBSfo8+J3EznvRJf49uMsqYfKrHg=="
+      },
+      "HarfBuzzSharp.NativeAssets.macOS": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "jbtCsgftcaFLCA13tVKo5iWdElJScrulLTKJre36O4YQTIlwDtPPqhRZNk+Y0vv4D1gxbscasGRucUDfS44ofQ=="
+      },
+      "HarfBuzzSharp.NativeAssets.WebAssembly": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "loJweK2u/mH/3C2zBa0ggJlITIszOkK64HLAZB7FUT670dTg965whLFYHDQo69NmC4+d9UN0icLC9VHidXaVCA=="
+      },
+      "HarfBuzzSharp.NativeAssets.Win32": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "UsJtQsfAJoFDZrXc4hCUfRPMqccfKZ0iumJ/upcUjz/cmsTgVFGNEL5yaJWmkqsuFYdMWbj/En5/kS4PFl9hBA=="
+      },
+      "MicroCom.Runtime": {
+        "type": "Transitive",
+        "resolved": "0.11.0",
+        "contentHash": "MEnrZ3UIiH40hjzMDsxrTyi8dtqB5ziv3iBeeU4bXsL/7NLSal9F1lZKpK+tfBRnUoDSdtcW3KufE4yhATOMCA=="
+      },
       "Microsoft.DotNet.PlatformAbstractions": {
         "type": "Transitive",
         "resolved": "3.1.6",
@@ -59,6 +158,38 @@
           "Silk.NET.Windowing.Common": "2.23.0"
         }
       },
+      "SkiaSharp": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "3MD5VHjXXieSHCleRLuaTXmL2pD0mB7CcOB1x2kA1I4bhptf4e3R27iM93264ZYuAq6mkUyX5XbcxnZvMJYc1Q==",
+        "dependencies": {
+          "SkiaSharp.NativeAssets.Win32": "2.88.9",
+          "SkiaSharp.NativeAssets.macOS": "2.88.9"
+        }
+      },
+      "SkiaSharp.NativeAssets.Linux": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "cWSaJKVPWAaT/WIn9c8T5uT/l4ETwHxNJTkEOtNKjphNo8AW6TF9O32aRkxqw3l8GUdUo66Bu7EiqtFh/XG0Zg==",
+        "dependencies": {
+          "SkiaSharp": "2.88.9"
+        }
+      },
+      "SkiaSharp.NativeAssets.macOS": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "Nv5spmKc4505Ep7oUoJ5vp3KweFpeNqxpyGDWyeEPTX2uR6S6syXIm3gj75dM0YJz7NPvcix48mR5laqs8dPuA=="
+      },
+      "SkiaSharp.NativeAssets.WebAssembly": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "kt06RccBHSnAs2wDYdBSfsjIDbY3EpsOVqnlDgKdgvyuRA8ZFDaHRdWNx1VHjGgYzmnFCGiTJBnXFl5BqGwGnA=="
+      },
+      "SkiaSharp.NativeAssets.Win32": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "wb2kYgU7iy84nQLYZwMeJXixvK++GoIuECjU4ECaUKNuflyRlJKyiRhN1MAHswvlvzuvkrjRWlK0Za6+kYQK7w=="
+      },
       "Ultz.Native.GLFW": {
         "type": "Transitive",
         "resolved": "3.4.0",
@@ -73,6 +204,17 @@
           "SharpEmu.Logging": "[1.0.0, )"
         }
       },
+      "sharpemu.gui": {
+        "type": "Project",
+        "dependencies": {
+          "Avalonia": "[11.3.18, )",
+          "Avalonia.Desktop": "[11.3.18, )",
+          "Avalonia.Fonts.Inter": "[11.3.18, )",
+          "Avalonia.Themes.Fluent": "[11.3.18, )",
+          "SharpEmu.Logging": "[1.0.0, )",
+          "Tmds.DBus.Protocol": "[0.21.3, )"
+        }
+      },
       "sharpemu.hle": {
         "type": "Project"
       },
@@ -81,6 +223,7 @@
         "dependencies": {
           "SharpEmu.HLE": "[1.0.0, )",
           "Silk.NET.Vulkan": "[2.23.0, )",
+          "Silk.NET.Vulkan.Extensions.EXT": "[2.23.0, )",
           "Silk.NET.Vulkan.Extensions.KHR": "[2.23.0, )",
           "Silk.NET.Windowing": "[2.23.0, )"
         }
@@ -88,6 +231,48 @@
       "sharpemu.logging": {
         "type": "Project"
       },
+      "Avalonia": {
+        "type": "CentralTransitive",
+        "requested": "[11.3.18, )",
+        "resolved": "11.3.18",
+        "contentHash": "2C4UxhWUObWGgYKWic1x5BMMWGJP6SElb91WeOxs+X/iR26rtkqpxFFwwo50FXS9AyYnHfk8QKXDEfe7oT/kZA==",
+        "dependencies": {
+          "Avalonia.BuildServices": "11.3.2",
+          "Avalonia.Remote.Protocol": "11.3.18",
+          "MicroCom.Runtime": "0.11.0"
+        }
+      },
+      "Avalonia.Desktop": {
+        "type": "CentralTransitive",
+        "requested": "[11.3.18, )",
+        "resolved": "11.3.18",
+        "contentHash": "bilMPa5vYiis6fbNovb6esKytBnOCEGojBa1XFegLCRHCP6g6PvZwS0XF/YOAGkENRlHG8dI7lohOpQ9bIkq1g==",
+        "dependencies": {
+          "Avalonia": "11.3.18",
+          "Avalonia.Native": "11.3.18",
+          "Avalonia.Skia": "11.3.18",
+          "Avalonia.Win32": "11.3.18",
+          "Avalonia.X11": "11.3.18"
+        }
+      },
+      "Avalonia.Fonts.Inter": {
+        "type": "CentralTransitive",
+        "requested": "[11.3.18, )",
+        "resolved": "11.3.18",
+        "contentHash": "27u6hB3Y2Ue586yjfeVakberY73VNQXtuKwe/P927XG1QPlhsfmOyifLHDDpSHG85Zl1x/Xv9IZ3+tk9FnjcZQ==",
+        "dependencies": {
+          "Avalonia": "11.3.18"
+        }
+      },
+      "Avalonia.Themes.Fluent": {
+        "type": "CentralTransitive",
+        "requested": "[11.3.18, )",
+        "resolved": "11.3.18",
+        "contentHash": "+Q/TJoynD0zNuu5w2gD+xcTl7GNKJFxlPYAndRLs/mTDrNbbsvv/271WyIysbMPsXSjCyBDp7RCZzQkpD6x5Bg==",
+        "dependencies": {
+          "Avalonia": "11.3.18"
+        }
+      },
       "Iced": {
         "type": "CentralTransitive",
         "requested": "[1.21.0, )",
@@ -103,6 +288,16 @@
           "Silk.NET.Core": "2.23.0"
         }
       },
+      "Silk.NET.Vulkan.Extensions.EXT": {
+        "type": "CentralTransitive",
+        "requested": "[2.23.0, )",
+        "resolved": "2.23.0",
+        "contentHash": "+Oth189ksRiL6HvGCwIdnsYHawqrbO8y49u1H61z3wsfcHhQZeVDYe/wF5LD7fk3NcdgDvwFD3mLm1QWhdZySw==",
+        "dependencies": {
+          "Silk.NET.Core": "2.23.0",
+          "Silk.NET.Vulkan": "2.23.0"
+        }
+      },
       "Silk.NET.Vulkan.Extensions.KHR": {
         "type": "CentralTransitive",
         "requested": "[2.23.0, )",
@@ -122,9 +317,61 @@
           "Silk.NET.Windowing.Common": "2.23.0",
           "Silk.NET.Windowing.Glfw": "2.23.0"
         }
+      },
+      "Tmds.DBus.Protocol": {
+        "type": "CentralTransitive",
+        "requested": "[0.21.3, )",
+        "resolved": "0.21.3",
+        "contentHash": "hDwB8WsQoyALQKqIbwzS68UKdlnafDm4T/DkO/JrA/YIneP/rKv96SxYPVXeh3FP4i/SXfShrYftKLtciJAIlw=="
       }
     },
     "net10.0/linux-x64": {
+      "Avalonia.Angle.Windows.Natives": {
+        "type": "Transitive",
+        "resolved": "2.1.25547.20250602",
+        "contentHash": "ZL0VLc4s9rvNNFt19Pxm5UNAkmKNylugAwJPX9ulXZ6JWs/l6XZihPWWTyezaoNOVyEPU8YbURtW7XMAtqXH5A=="
+      },
+      "Avalonia.Native": {
+        "type": "Transitive",
+        "resolved": "11.3.18",
+        "contentHash": "8g53DROFW6wVJAnTsE1Iu5bdZO5r0oqxbdbMQODs1QDYCK2IU/y/x/vQVKCYOvqxl4tXkzU9tExv8XqSGPWthQ==",
+        "dependencies": {
+          "Avalonia": "11.3.18"
+        }
+      },
+      "HarfBuzzSharp.NativeAssets.Linux": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "3EZ1mpIiKWRLL5hUYA82ZHteeDIVaEA/Z0rA/wU6tjx6crcAkJnBPwDXZugBSfo8+J3EznvRJf49uMsqYfKrHg=="
+      },
+      "HarfBuzzSharp.NativeAssets.macOS": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "jbtCsgftcaFLCA13tVKo5iWdElJScrulLTKJre36O4YQTIlwDtPPqhRZNk+Y0vv4D1gxbscasGRucUDfS44ofQ=="
+      },
+      "HarfBuzzSharp.NativeAssets.Win32": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "UsJtQsfAJoFDZrXc4hCUfRPMqccfKZ0iumJ/upcUjz/cmsTgVFGNEL5yaJWmkqsuFYdMWbj/En5/kS4PFl9hBA=="
+      },
+      "SkiaSharp.NativeAssets.Linux": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "cWSaJKVPWAaT/WIn9c8T5uT/l4ETwHxNJTkEOtNKjphNo8AW6TF9O32aRkxqw3l8GUdUo66Bu7EiqtFh/XG0Zg==",
+        "dependencies": {
+          "SkiaSharp": "2.88.9"
+        }
+      },
+      "SkiaSharp.NativeAssets.macOS": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "Nv5spmKc4505Ep7oUoJ5vp3KweFpeNqxpyGDWyeEPTX2uR6S6syXIm3gj75dM0YJz7NPvcix48mR5laqs8dPuA=="
+      },
+      "SkiaSharp.NativeAssets.Win32": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "wb2kYgU7iy84nQLYZwMeJXixvK++GoIuECjU4ECaUKNuflyRlJKyiRhN1MAHswvlvzuvkrjRWlK0Za6+kYQK7w=="
+      },
       "Ultz.Native.GLFW": {
         "type": "Transitive",
         "resolved": "3.4.0",
@@ -132,6 +379,52 @@
       }
     },
     "net10.0/osx-arm64": {
+      "Avalonia.Angle.Windows.Natives": {
+        "type": "Transitive",
+        "resolved": "2.1.25547.20250602",
+        "contentHash": "ZL0VLc4s9rvNNFt19Pxm5UNAkmKNylugAwJPX9ulXZ6JWs/l6XZihPWWTyezaoNOVyEPU8YbURtW7XMAtqXH5A=="
+      },
+      "Avalonia.Native": {
+        "type": "Transitive",
+        "resolved": "11.3.18",
+        "contentHash": "8g53DROFW6wVJAnTsE1Iu5bdZO5r0oqxbdbMQODs1QDYCK2IU/y/x/vQVKCYOvqxl4tXkzU9tExv8XqSGPWthQ==",
+        "dependencies": {
+          "Avalonia": "11.3.18"
+        }
+      },
+      "HarfBuzzSharp.NativeAssets.Linux": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "3EZ1mpIiKWRLL5hUYA82ZHteeDIVaEA/Z0rA/wU6tjx6crcAkJnBPwDXZugBSfo8+J3EznvRJf49uMsqYfKrHg=="
+      },
+      "HarfBuzzSharp.NativeAssets.macOS": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "jbtCsgftcaFLCA13tVKo5iWdElJScrulLTKJre36O4YQTIlwDtPPqhRZNk+Y0vv4D1gxbscasGRucUDfS44ofQ=="
+      },
+      "HarfBuzzSharp.NativeAssets.Win32": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "UsJtQsfAJoFDZrXc4hCUfRPMqccfKZ0iumJ/upcUjz/cmsTgVFGNEL5yaJWmkqsuFYdMWbj/En5/kS4PFl9hBA=="
+      },
+      "SkiaSharp.NativeAssets.Linux": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "cWSaJKVPWAaT/WIn9c8T5uT/l4ETwHxNJTkEOtNKjphNo8AW6TF9O32aRkxqw3l8GUdUo66Bu7EiqtFh/XG0Zg==",
+        "dependencies": {
+          "SkiaSharp": "2.88.9"
+        }
+      },
+      "SkiaSharp.NativeAssets.macOS": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "Nv5spmKc4505Ep7oUoJ5vp3KweFpeNqxpyGDWyeEPTX2uR6S6syXIm3gj75dM0YJz7NPvcix48mR5laqs8dPuA=="
+      },
+      "SkiaSharp.NativeAssets.Win32": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "wb2kYgU7iy84nQLYZwMeJXixvK++GoIuECjU4ECaUKNuflyRlJKyiRhN1MAHswvlvzuvkrjRWlK0Za6+kYQK7w=="
+      },
       "Ultz.Native.GLFW": {
         "type": "Transitive",
         "resolved": "3.4.0",
@@ -139,6 +432,52 @@
       }
     },
     "net10.0/win-x64": {
+      "Avalonia.Angle.Windows.Natives": {
+        "type": "Transitive",
+        "resolved": "2.1.25547.20250602",
+        "contentHash": "ZL0VLc4s9rvNNFt19Pxm5UNAkmKNylugAwJPX9ulXZ6JWs/l6XZihPWWTyezaoNOVyEPU8YbURtW7XMAtqXH5A=="
+      },
+      "Avalonia.Native": {
+        "type": "Transitive",
+        "resolved": "11.3.18",
+        "contentHash": "8g53DROFW6wVJAnTsE1Iu5bdZO5r0oqxbdbMQODs1QDYCK2IU/y/x/vQVKCYOvqxl4tXkzU9tExv8XqSGPWthQ==",
+        "dependencies": {
+          "Avalonia": "11.3.18"
+        }
+      },
+      "HarfBuzzSharp.NativeAssets.Linux": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "3EZ1mpIiKWRLL5hUYA82ZHteeDIVaEA/Z0rA/wU6tjx6crcAkJnBPwDXZugBSfo8+J3EznvRJf49uMsqYfKrHg=="
+      },
+      "HarfBuzzSharp.NativeAssets.macOS": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "jbtCsgftcaFLCA13tVKo5iWdElJScrulLTKJre36O4YQTIlwDtPPqhRZNk+Y0vv4D1gxbscasGRucUDfS44ofQ=="
+      },
+      "HarfBuzzSharp.NativeAssets.Win32": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "UsJtQsfAJoFDZrXc4hCUfRPMqccfKZ0iumJ/upcUjz/cmsTgVFGNEL5yaJWmkqsuFYdMWbj/En5/kS4PFl9hBA=="
+      },
+      "SkiaSharp.NativeAssets.Linux": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "cWSaJKVPWAaT/WIn9c8T5uT/l4ETwHxNJTkEOtNKjphNo8AW6TF9O32aRkxqw3l8GUdUo66Bu7EiqtFh/XG0Zg==",
+        "dependencies": {
+          "SkiaSharp": "2.88.9"
+        }
+      },
+      "SkiaSharp.NativeAssets.macOS": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "Nv5spmKc4505Ep7oUoJ5vp3KweFpeNqxpyGDWyeEPTX2uR6S6syXIm3gj75dM0YJz7NPvcix48mR5laqs8dPuA=="
+      },
+      "SkiaSharp.NativeAssets.Win32": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "wb2kYgU7iy84nQLYZwMeJXixvK++GoIuECjU4ECaUKNuflyRlJKyiRhN1MAHswvlvzuvkrjRWlK0Za6+kYQK7w=="
+      },
       "Ultz.Native.GLFW": {
         "type": "Transitive",
         "resolved": "3.4.0",

src/SharpEmu.Core/Cpu/CpuDispatcher.cs

@@ -7,11 +7,14 @@ using SharpEmu.Core.Cpu.Native;
 using SharpEmu.Core.Loader;
 using SharpEmu.Core.Memory;
 using SharpEmu.HLE;
+using SharpEmu.Logging;
 
 namespace SharpEmu.Core.Cpu;
 
 public sealed class CpuDispatcher : ICpuDispatcher, IDisposable
 {
+    private static readonly SharpEmuLogger Log = SharpEmuLog.For("Dispatcher");
+
     private enum EntryFrameKind
     {
         ProcessEntry,
@@ -80,8 +83,8 @@ public sealed class CpuDispatcher : ICpuDispatcher, IDisposable
         string processImageName = "eboot.bin",
         CpuExecutionOptions executionOptions = default)
     {
-        Console.Error.WriteLine("[DISPATCHER] === DispatchEntry START ===");
+        Log.Debug("=== DispatchEntry START ===");
-        Console.Error.WriteLine($"[DISPATCHER] entryPoint=0x{entryPoint:X16}, generation={generation}");
+        Log.Debug($"entryPoint=0x{entryPoint:X16}, generation={generation}");
 
         try
         {
@@ -89,8 +92,7 @@ public sealed class CpuDispatcher : ICpuDispatcher, IDisposable
         }
         catch (Exception ex)
         {
-            Console.Error.WriteLine($"[DISPATCHER] FATAL EXCEPTION in DispatchEntry: {ex.GetType().Name}: {ex.Message}");
+            Log.Critical($"FATAL EXCEPTION in DispatchEntry: {ex.GetType().Name}: {ex.Message}", ex);
-            Console.Error.WriteLine($"[DISPATCHER] Stack trace: {ex.StackTrace}");
             throw;
         }
     }
@@ -103,8 +105,8 @@ public sealed class CpuDispatcher : ICpuDispatcher, IDisposable
         string moduleName = "module",
         CpuExecutionOptions executionOptions = default)
     {
-        Console.Error.WriteLine("[DISPATCHER] === DispatchModuleInitializer START ===");
+        Log.Debug("=== DispatchModuleInitializer START ===");
-        Console.Error.WriteLine($"[DISPATCHER] moduleInit=0x{entryPoint:X16}, generation={generation}, module={moduleName}");
+        Log.Debug($"moduleInit=0x{entryPoint:X16}, generation={generation}, module={moduleName}");
 
         try
         {
@@ -119,8 +121,7 @@ public sealed class CpuDispatcher : ICpuDispatcher, IDisposable
         }
         catch (Exception ex)
         {
-            Console.Error.WriteLine($"[DISPATCHER] FATAL EXCEPTION in DispatchModuleInitializer: {ex.GetType().Name}: {ex.Message}");
+            Log.Critical($"FATAL EXCEPTION in DispatchModuleInitializer: {ex.GetType().Name}: {ex.Message}", ex);
-            Console.Error.WriteLine($"[DISPATCHER] Stack trace: {ex.StackTrace}");
             throw;
         }
     }
@@ -134,7 +135,7 @@ public sealed class CpuDispatcher : ICpuDispatcher, IDisposable
         CpuExecutionOptions executionOptions = default,
         EntryFrameKind frameKind = EntryFrameKind.ProcessEntry)
     {
-        Console.Error.WriteLine("[DISPATCHER] DispatchEntryCore STARTING...");
+        Log.Debug("DispatchEntryCore STARTING...");
 
         LastEntryPoint = entryPoint;
         LastTrapInfo = null;
@@ -306,7 +307,7 @@ public sealed class CpuDispatcher : ICpuDispatcher, IDisposable
             LastMilestoneLog,
             Environment.NewLine,
             $"CpuEngine native-only failed: {backendError}");
-        Console.Error.WriteLine($"[DISPATCHER] Native backend FAILED: {backendError}");
+        Log.Error($"Native backend FAILED: {backendError}");
         return FailEarly(
             OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_IMPLEMENTED,
             CpuExitReason.NativeBackendUnavailable);
@@ -415,8 +416,8 @@ public sealed class CpuDispatcher : ICpuDispatcher, IDisposable
 
         const ulong entryParamsSize = 0x20;
         var entryParamsAddress = AlignDown(argv0Address - entryParamsSize, 16);
-        if (!TryWriteUInt32(context, entryParamsAddress + 0x00, 1) ||
+        if (!context.TryWriteUInt32(entryParamsAddress + 0x00, 1) ||
-            !TryWriteUInt32(context, entryParamsAddress + 0x04, 0) ||
+            !context.TryWriteUInt32(entryParamsAddress + 0x04, 0) ||
             !context.TryWriteUInt64(entryParamsAddress + 0x08, argv0Address) ||
             !context.TryWriteUInt64(entryParamsAddress + 0x10, 0) ||
             !context.TryWriteUInt64(entryParamsAddress + 0x18, 0))
@@ -456,13 +457,6 @@ public sealed class CpuDispatcher : ICpuDispatcher, IDisposable
         return value & ~(alignment - 1);
     }
 
-    private static bool TryWriteUInt32(CpuContext context, ulong address, uint value)
-    {
-        Span<byte> buffer = stackalloc byte[sizeof(uint)];
-        BinaryPrimitives.WriteUInt32LittleEndian(buffer, value);
-        return context.Memory.TryWrite(address, buffer);
-    }
-
     private static string BuildEntryFrameDiagnostic(
         ulong entryPoint,
         CpuContext context,

src/SharpEmu.Core/Cpu/Native/DirectExecutionBackend.Diagnostics.cs

@@ -2,20 +2,35 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.InteropServices;
 using System.Threading;
 using SharpEmu.HLE;
+using SharpEmu.Logging;
 
 namespace SharpEmu.Core.Cpu.Native;
 
 public sealed partial class DirectExecutionBackend
 {
+	private static readonly ConcurrentDictionary<ulong, byte> _knownExecutablePages = new();
 
-	private void RecordRecentImportTrace(string traceLine)
+	private void RecordRecentImportTrace(
+		long dispatchIndex,
+		string nid,
+		ulong returnRip,
+		ulong arg0,
+		ulong arg1,
+		ulong arg2)
 	{
-		_recentImportTrace[_recentImportTraceWriteIndex] = traceLine;
+		_recentImportTrace[_recentImportTraceWriteIndex] = new RecentImportTraceEntry(
+			dispatchIndex,
+			nid,
+			returnRip,
+			arg0,
+			arg1,
+			arg2);
 		_recentImportTraceWriteIndex = (_recentImportTraceWriteIndex + 1) % _recentImportTrace.Length;
 		if (_recentImportTraceCount < _recentImportTrace.Length)
 		{
@@ -29,15 +44,17 @@ public sealed partial class DirectExecutionBackend
 		{
 			return;
 		}
-		Console.Error.WriteLine($"[LOADER][INFO]   Recent import calls ({_recentImportTraceCount}):");
+		Log.Info($"   Recent import calls ({_recentImportTraceCount}):");
 		int num = (_recentImportTraceWriteIndex - _recentImportTraceCount + _recentImportTrace.Length) % _recentImportTrace.Length;
 		for (int i = 0; i < _recentImportTraceCount; i++)
 		{
 			int num2 = (num + i) % _recentImportTrace.Length;
-			string text = _recentImportTrace[num2];
+			var entry = _recentImportTrace[num2];
-			if (!string.IsNullOrEmpty(text))
+			if (!string.IsNullOrEmpty(entry.Nid))
 			{
-				Console.Error.WriteLine("[LOADER][INFO]     " + text);
+				Log.Info(
+					$"     #{entry.DispatchIndex} nid={entry.Nid} ret=0x{entry.ReturnRip:X16} " +
+					$"rdi=0x{entry.Arg0:X16} rsi=0x{entry.Arg1:X16} rdx=0x{entry.Arg2:X16}");
 			}
 		}
 	}
@@ -75,12 +92,12 @@ public sealed partial class DirectExecutionBackend
 						list.Add(num7);
 						if (num2 < 32)
 						{
-							Console.Error.WriteLine($"[LOADER][INFO] Suspicious unresolved pointer: slot=0x{num7:X16} value=0x{value2:X16}");
+							Log.Info($"Suspicious unresolved pointer: slot=0x{num7:X16} value=0x{value2:X16}");
 							num2++;
 						}
 						if (num >= 16384)
 						{
-							Console.Error.WriteLine($"[LOADER][WARNING] Suspicious unresolved pointer scan reached cap ({16384}); truncating.");
+							Log.Warning($"Suspicious unresolved pointer scan reached cap ({16384}); truncating.");
 							return list;
 						}
 					}
@@ -90,7 +107,7 @@ public sealed partial class DirectExecutionBackend
 		}
 		if (num != 0)
 		{
-			Console.Error.WriteLine($"[LOADER][WARNING] Suspicious unresolved pointer hits: {num}");
+			Log.Warning($"Suspicious unresolved pointer hits: {num}");
 		}
 		return list;
 	}
@@ -105,18 +122,18 @@ public sealed partial class DirectExecutionBackend
 		Span<byte> destination = stackalloc byte[128];
 		if (!cpuContext.Memory.TryRead(returnRip, destination))
 		{
-			Console.Error.WriteLine($"[LOADER][TRACE] Import#{dispatchIndex} return-rip probe: unreadable @0x{returnRip:X16}");
+			Log.Debug($"Import#{dispatchIndex} return-rip probe: unreadable @0x{returnRip:X16}");
 			return;
 		}
 		string value = BitConverter.ToString(destination.ToArray()).Replace("-", " ");
-		Console.Error.WriteLine($"[LOADER][TRACE] Import#{dispatchIndex} return-rip bytes @0x{returnRip:X16}: {value}");
+		Log.Debug($"Import#{dispatchIndex} return-rip bytes @0x{returnRip:X16}: {value}");
 		if (destination[0] == byte.MaxValue && (destination[1] == 21 || destination[1] == 37))
 		{
 			int num = BitConverter.ToInt32(destination.Slice(2, 4));
 			ulong num2 = returnRip + 6 + (ulong)num;
 			if (cpuContext.TryReadUInt64(num2, out var value2))
 			{
-				Console.Error.WriteLine($"[LOADER][TRACE] Import#{dispatchIndex} return-rip slot: [0x{num2:X16}] = 0x{value2:X16}");
+				Log.Debug($"Import#{dispatchIndex} return-rip slot: [0x{num2:X16}] = 0x{value2:X16}");
 			}
 		}
 		if (destination[0] == 72 && destination[1] == 139 && destination[2] == 5)
@@ -125,7 +142,7 @@ public sealed partial class DirectExecutionBackend
 			ulong num4 = returnRip + 7 + (ulong)num3;
 			if (cpuContext.TryReadUInt64(num4, out var value3))
 			{
-				Console.Error.WriteLine($"[LOADER][TRACE] Import#{dispatchIndex} return-rip mov-slot: [0x{num4:X16}] = 0x{value3:X16}");
+				Log.Debug($"Import#{dispatchIndex} return-rip mov-slot: [0x{num4:X16}] = 0x{value3:X16}");
 			}
 		}
 		for (int i = 0; i + 6 <= destination.Length; i++)
@@ -137,7 +154,7 @@ public sealed partial class DirectExecutionBackend
 				ulong num7 = num6 + 6 + (ulong)num5;
 				if (cpuContext.TryReadUInt64(num7, out var value4))
 				{
-					Console.Error.WriteLine($"[LOADER][TRACE] Import#{dispatchIndex} near-indirect @{num6:X16}: slot=0x{num7:X16} val=0x{value4:X16}");
+					Log.Debug($"Import#{dispatchIndex} near-indirect @{num6:X16}: slot=0x{num7:X16} val=0x{value4:X16}");
 				}
 			}
 		}
@@ -152,7 +169,7 @@ public sealed partial class DirectExecutionBackend
 			int rel32 = BitConverter.ToInt32(destination.Slice(i + 1, 4));
 			ulong callRip = returnRip + (ulong)i;
 			ulong target = unchecked((ulong)((long)(callRip + 5) + rel32));
-			Console.Error.WriteLine($"[LOADER][TRACE] Import#{dispatchIndex} near-call @{callRip:X16}: target=0x{target:X16}");
+			Log.Debug($"Import#{dispatchIndex} near-call @{callRip:X16}: target=0x{target:X16}");
 			for (int importIndex = 0; importIndex < _importEntries.Length; importIndex++)
 			{
 				if (_importEntries[importIndex].Address != target)
@@ -163,21 +180,21 @@ public sealed partial class DirectExecutionBackend
 				string nid = _importEntries[importIndex].Nid;
 				if (_moduleManager.TryGetExport(nid, out var export))
 				{
-					Console.Error.WriteLine(
+					Log.Debug(
-						$"[LOADER][TRACE] Import#{dispatchIndex} near-call import: index={importIndex} {export.LibraryName}:{export.Name} ({nid})");
+						$"Import#{dispatchIndex} near-call import: index={importIndex} {export.LibraryName}:{export.Name} ({nid})");
 				}
 				else
 				{
-					Console.Error.WriteLine(
+					Log.Debug(
-						$"[LOADER][TRACE] Import#{dispatchIndex} near-call import: index={importIndex} nid={nid}");
+						$"Import#{dispatchIndex} near-call import: index={importIndex} nid={nid}");
 				}
 				break;
 			}
 
 			if (cpuContext.Memory.TryRead(target, targetBytes))
 			{
-				Console.Error.WriteLine(
+				Log.Debug(
-					$"[LOADER][TRACE] Import#{dispatchIndex} near-call target bytes @0x{target:X16}: " +
+					$"Import#{dispatchIndex} near-call target bytes @0x{target:X16}: " +
 					BitConverter.ToString(targetBytes.ToArray()).Replace("-", " "));
 				if (targetBytes[0] == 0xFF && targetBytes[1] == 0x25)
 				{
@@ -185,8 +202,8 @@ public sealed partial class DirectExecutionBackend
 					ulong slot = unchecked((ulong)((long)(target + 6) + slotRel32));
 					if (cpuContext.TryReadUInt64(slot, out var slotTarget))
 					{
-						Console.Error.WriteLine(
+						Log.Debug(
-							$"[LOADER][TRACE] Import#{dispatchIndex} near-call PLT slot: [0x{slot:X16}] = 0x{slotTarget:X16}");
+							$"Import#{dispatchIndex} near-call PLT slot: [0x{slot:X16}] = 0x{slotTarget:X16}");
 						for (int importIndex = 0; importIndex < _importEntries.Length; importIndex++)
 						{
 							if (_importEntries[importIndex].Address != slotTarget)
@@ -197,13 +214,13 @@ public sealed partial class DirectExecutionBackend
 							string nid = _importEntries[importIndex].Nid;
 							if (_moduleManager.TryGetExport(nid, out var export))
 							{
-								Console.Error.WriteLine(
+								Log.Debug(
-									$"[LOADER][TRACE] Import#{dispatchIndex} near-call PLT import: index={importIndex} {export.LibraryName}:{export.Name} ({nid})");
+									$"Import#{dispatchIndex} near-call PLT import: index={importIndex} {export.LibraryName}:{export.Name} ({nid})");
 							}
 							else
 							{
-								Console.Error.WriteLine(
+								Log.Debug(
-									$"[LOADER][TRACE] Import#{dispatchIndex} near-call PLT import: index={importIndex} nid={nid}");
+									$"Import#{dispatchIndex} near-call PLT import: index={importIndex} nid={nid}");
 							}
 							break;
 						}
@@ -302,11 +319,24 @@ public sealed partial class DirectExecutionBackend
 
 	private unsafe static bool IsExecutableAddress(ulong address)
 	{
+		var pageAddress = address & ~0xFFFUL;
+		if (_knownExecutablePages.ContainsKey(pageAddress))
+		{
+			return true;
+		}
+
 		if (VirtualQuery((void*)address, out var lpBuffer, (nuint)sizeof(MEMORY_BASIC_INFORMATION64)) == 0)
 		{
 			return false;
 		}
-		return lpBuffer.State == 4096 && IsExecutableProtection(lpBuffer.Protect);
+
+		var executable = lpBuffer.State == 4096 && IsExecutableProtection(lpBuffer.Protect);
+		if (executable)
+		{
+			_knownExecutablePages.TryAdd(pageAddress, 0);
+		}
+
+		return executable;
 	}
 
 	private static ulong AlignUp(ulong value, ulong alignment)

src/SharpEmu.Core/Cpu/Native/DirectExecutionBackend.Exceptions.cs

@@ -15,6 +15,9 @@ namespace SharpEmu.Core.Cpu.Native;
 
 public sealed partial class DirectExecutionBackend
 {
+	private const ulong LazyCommitWindowBytes = 0x0200_0000UL;
+	private static int _lazyCommitTraceCount;
+
 	private unsafe void SetupExceptionHandler()
 	{
 		if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_DISABLE_RAW_HANDLER"), "1", StringComparison.Ordinal))
@@ -100,6 +103,15 @@ public sealed partial class DirectExecutionBackend
 			ulong rip = ReadCtxU64(contextRecord, 248);
 			ulong rsp = ReadCtxU64(contextRecord, 152);
 
+			// Thread-mode probe: a hardware exception raised while this thread is inside
+			// the managed import gateway means the VEH->managed reentry happened from
+			// cooperative GC mode — a ReversePInvokeBadTransition candidate.
+			if (LogThreadMode && _threadModeGatewayDepth > 0)
+			{
+				TraceThreadMode(
+					$"veh_in_gateway code=0x{exceptionCode:X8} rip=0x{rip:X16} gateway_depth={_threadModeGatewayDepth}");
+			}
+
 			if (exceptionCode == 3221225477u && TryHandleLazyCommittedPage(exceptionRecord, rip, rsp))
 			{
 				return -1;
@@ -911,7 +923,21 @@ public sealed partial class DirectExecutionBackend
 
 		ulong pageBase = faultAddress & 0xFFFFFFFFFFFFF000uL;
 		uint commitProtect = ResolveLazyCommitProtection(accessType, mbi.AllocationProtect);
-		Console.Error.WriteLine($"[LOADER][TRACE] lazy-query: fault=0x{faultAddress:X16} owner={owner} rip=0x{rip:X16} rsp=0x{rsp:X16} state=0x{mbi.State:X08} base=0x{mbi.BaseAddress:X16} size=0x{mbi.RegionSize:X16} alloc=0x{mbi.AllocationProtect:X08} prot=0x{mbi.Protect:X08}");
+		int traceIndex = Interlocked.Increment(ref _lazyCommitTraceCount);
+		bool traceLazyCommit = ShouldTraceLazyCommit(traceIndex);
+		if (traceLazyCommit)
+		{
+			Console.Error.WriteLine($"[LOADER][TRACE] lazy-query#{traceIndex}: fault=0x{faultAddress:X16} owner={owner} rip=0x{rip:X16} rsp=0x{rsp:X16} state=0x{mbi.State:X08} base=0x{mbi.BaseAddress:X16} size=0x{mbi.RegionSize:X16} alloc=0x{mbi.AllocationProtect:X08} prot=0x{mbi.Protect:X08}");
+		}
+
+		if (mbi.State == 4096 && IsAccessCompatible(accessType, mbi.Protect))
+		{
+			if (traceLazyCommit)
+			{
+				Console.Error.WriteLine($"[LOADER][TRACE] lazy-commit-race#{traceIndex}: fault=0x{faultAddress:X16} protect=0x{mbi.Protect:X08}");
+			}
+			return true;
+		}
 
 		bool committed = false;
 		ulong committedBase = 0;
@@ -919,14 +945,25 @@ public sealed partial class DirectExecutionBackend
 
 		if (mbi.State == 65536)
 		{
-			ulong largeBase = faultAddress & 0xFFFFFFFFFFE00000uL;
+			if (TryGetLazyCommitWindow(faultAddress, mbi.BaseAddress, mbi.RegionSize, out var windowBase, out var windowSize) &&
-			if (TryReserveThenCommit(largeBase, 2097152uL, largeBase, 2097152uL, commitProtect))
+				TryReserveThenCommit(windowBase, windowSize, windowBase, windowSize, commitProtect))
 			{
 				committed = true;
-				committedBase = largeBase;
+				committedBase = windowBase;
-				committedSize = 2097152uL;
+				committedSize = windowSize;
 			}
 			else
+			{
+				ulong largeBase = faultAddress & 0xFFFFFFFFFFE00000uL;
+				if (TryReserveThenCommit(largeBase, 2097152uL, largeBase, 2097152uL, commitProtect))
+				{
+					committed = true;
+					committedBase = largeBase;
+					committedSize = 2097152uL;
+				}
+			}
+
+			if (!committed)
 			{
 				ulong region64kBase = faultAddress & 0xFFFFFFFFFFFF0000uL;
 				if (TryReserveThenCommit(region64kBase, 65536uL, region64kBase, 65536uL, commitProtect))
@@ -949,7 +986,10 @@ public sealed partial class DirectExecutionBackend
 			}
 
 			TryCommitRange(pageBase + 4096, 4096uL, commitProtect);
-			Console.Error.WriteLine($"[LOADER][TRACE] lazy-reserve-commit: addr=0x{committedBase:X16} size=0x{committedSize:X16} access={accessType} protect=0x{commitProtect:X8}");
+			if (traceLazyCommit)
+			{
+				Console.Error.WriteLine($"[LOADER][TRACE] lazy-reserve-commit#{traceIndex}: addr=0x{committedBase:X16} size=0x{committedSize:X16} access={accessType} protect=0x{commitProtect:X8}");
+			}
 			return true;
 		}
 
@@ -958,14 +998,25 @@ public sealed partial class DirectExecutionBackend
 			return false;
 		}
 
-		ulong largeCommitBase = faultAddress & 0xFFFFFFFFFFE00000uL;
+		if (TryGetLazyCommitWindow(faultAddress, mbi.BaseAddress, mbi.RegionSize, out var commitWindowBase, out var commitWindowSize) &&
-		if (TryCommitRange(largeCommitBase, 2097152uL, commitProtect))
+			TryCommitRange(commitWindowBase, commitWindowSize, commitProtect))
 		{
 			committed = true;
-			committedBase = largeCommitBase;
+			committedBase = commitWindowBase;
-			committedSize = 2097152uL;
+			committedSize = commitWindowSize;
 		}
 		else
+		{
+			ulong largeCommitBase = faultAddress & 0xFFFFFFFFFFE00000uL;
+			if (TryCommitRange(largeCommitBase, 2097152uL, commitProtect))
+			{
+				committed = true;
+				committedBase = largeCommitBase;
+				committedSize = 2097152uL;
+			}
+		}
+
+		if (!committed)
 		{
 			ulong region64kBase = faultAddress & 0xFFFFFFFFFFFF0000uL;
 			if (TryCommitRange(region64kBase, 65536uL, commitProtect))
@@ -994,9 +1045,46 @@ public sealed partial class DirectExecutionBackend
 		}
 
 		TryCommitRange(pageBase + 4096, 4096uL, commitProtect);
-		Console.Error.WriteLine($"[LOADER][TRACE] lazy-commit: addr=0x{committedBase:X16} size=0x{committedSize:X16} access={accessType} protect=0x{commitProtect:X8}");
+		if (traceLazyCommit)
+		{
+			Console.Error.WriteLine($"[LOADER][TRACE] lazy-commit#{traceIndex}: addr=0x{committedBase:X16} size=0x{committedSize:X16} access={accessType} protect=0x{commitProtect:X8}");
+		}
 		return true;
 
+		static bool TryGetLazyCommitWindow(ulong fault, ulong regionBase, ulong regionSize, out ulong baseAddress, out ulong length)
+		{
+			baseAddress = 0;
+			length = 0;
+			if (regionSize == 0 || ulong.MaxValue - regionBase < regionSize)
+			{
+				return false;
+			}
+
+			ulong regionEnd = regionBase + regionSize;
+			ulong windowBase = fault & ~(LazyCommitWindowBytes - 1);
+			if (windowBase < regionBase)
+			{
+				windowBase = regionBase;
+			}
+
+			if (windowBase >= regionEnd)
+			{
+				return false;
+			}
+
+			ulong windowEnd = Math.Min(regionEnd, windowBase + LazyCommitWindowBytes);
+			ulong windowSize = windowEnd - windowBase;
+			windowSize &= 0xFFFFFFFFFFFFF000uL;
+			if (windowSize == 0)
+			{
+				return false;
+			}
+
+			baseAddress = windowBase;
+			length = windowSize;
+			return true;
+		}
+
 		static unsafe bool TryCommitRange(ulong baseAddress, ulong length, uint protection)
 		{
 			if (length == 0)
@@ -1023,6 +1111,49 @@ public sealed partial class DirectExecutionBackend
 			}
 			return TryCommitRange(commitAddress, commitSize, protection);
 		}
+
+		static bool IsAccessCompatible(ulong accessType, uint protection)
+		{
+			const uint pageNoAccess = 0x01;
+			const uint pageReadOnly = 0x02;
+			const uint pageReadWrite = 0x04;
+			const uint pageWriteCopy = 0x08;
+			const uint pageExecute = 0x10;
+			const uint pageExecuteRead = 0x20;
+			const uint pageExecuteReadWrite = 0x40;
+			const uint pageExecuteWriteCopy = 0x80;
+			const uint pageGuard = 0x100;
+			const uint accessMask = 0xFF;
+
+			if ((protection & pageGuard) != 0)
+			{
+				return false;
+			}
+
+			uint access = protection & accessMask;
+			if (access == pageNoAccess)
+			{
+				return false;
+			}
+
+			return accessType switch
+			{
+				0 => access is pageReadOnly or pageReadWrite or pageWriteCopy or pageExecuteRead or pageExecuteReadWrite or pageExecuteWriteCopy,
+				1 => access is pageReadWrite or pageWriteCopy or pageExecuteReadWrite or pageExecuteWriteCopy,
+				8 => access is pageExecute or pageExecuteRead or pageExecuteReadWrite or pageExecuteWriteCopy,
+				_ => false
+			};
+		}
+	}
+
+	private static bool ShouldTraceLazyCommit(int traceIndex)
+	{
+		if (string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_LAZY_COMMIT"), "1", StringComparison.Ordinal))
+		{
+			return true;
+		}
+
+		return traceIndex <= 16 || traceIndex % 256 == 0;
 	}
 
 	private static uint ResolveLazyCommitProtection(ulong accessType, uint allocationProtect)

src/SharpEmu.Core/Cpu/Native/DirectExecutionBackend.Imports.cs

@@ -14,8 +14,21 @@ namespace SharpEmu.Core.Cpu.Native;
 
 public sealed partial class DirectExecutionBackend
 {
+	private readonly object _importResultLogSampleGate = new();
+	private readonly Dictionary<string, int> _importResultLogSamples = new(StringComparer.Ordinal);
+
 	private static ulong ImportDispatchGatewayManaged(nint backendHandle, int importIndex, nint argPackPtr)
 	{
+		if (LogThreadMode)
+		{
+			_threadModeGatewayCalls++;
+			_threadModeGatewayDepth++;
+			if (!_threadModeGatewayFirstLogged)
+			{
+				_threadModeGatewayFirstLogged = true;
+				TraceThreadMode($"gateway_first import={importIndex} total={_threadModeGatewayCalls}");
+			}
+		}
 		try
 		{
 			if (!(GCHandle.FromIntPtr(backendHandle).Target is DirectExecutionBackend directExecutionBackend))
@@ -33,6 +46,13 @@ public sealed partial class DirectExecutionBackend
 				$"[LOADER][ERROR] ImportDispatchGatewayManaged exception: {ex.GetType().Name}: {ex.Message}");
 			return 18446744071562199298uL;
 		}
+		finally
+		{
+			if (LogThreadMode)
+			{
+				_threadModeGatewayDepth--;
+			}
+		}
 	}
 
 	private unsafe static int RawVectoredHandlerManaged(void* exceptionInfo)
@@ -66,6 +86,12 @@ public sealed partial class DirectExecutionBackend
 			WriteCtxU64(contextRecord, 152, nextRsp);
 			WriteCtxU64(contextRecord, 248, returnRip);
 			Interlocked.Increment(ref _rawSentinelRecoveries);
+			if (LogThreadMode)
+			{
+				TraceThreadMode(
+					$"sentinel_recover rip=0x{value:X16} -> 0x{returnRip:X16} rsp=0x{rsp:X16} -> 0x{nextRsp:X16} " +
+					$"gateway_depth={_threadModeGatewayDepth}");
+			}
 			return -1;
 		}
 		return 0;
@@ -73,8 +99,11 @@ public sealed partial class DirectExecutionBackend
 
 	private unsafe ulong DispatchImport(int importIndex, nint argPackPtr)
 	{
-		long num = Interlocked.Increment(ref _importDispatchCount);
+		long num = NextImportDispatchIndex();
-		MarkExecutionProgress();
+		if ((num & 0x3F) == 0)
+		{
+			MarkExecutionProgress();
+		}
 		var cpuContext = ActiveCpuContext;
 		if (cpuContext == null)
 		{
@@ -93,6 +122,18 @@ public sealed partial class DirectExecutionBackend
 			Console.Error.WriteLine($"[LOADER][TRACE] Raw sentinel recoveries: {num2} (last import index={importIndex})");
 			_lastReportedRawSentinelRecoveries = num2;
 		}
+		// Leaf imports take a scalar-only fast path that reads its own operands and
+		// intentionally bypasses the SysV variadic XMM marshalling below. This is safe
+		// only while the leaf set contains no float-variadic or float-returning function.
+		// The constraint and the audited list live on IsLeafImport — do not add a
+		// function that consumes xmm0-7 args or returns in xmm0 to the leaf set;
+		// such functions must stay on the full gateway path below.
+		if (IsLeafImport(importStubEntry.Nid) &&
+			TryDispatchLeafImport(cpuContext, importStubEntry, argPackPtr, num, out var leafResult))
+		{
+			return leafResult;
+		}
+
 		cpuContext.Rip = importStubEntry.Address;
 		cpuContext[CpuRegister.Rdi] = *(ulong*)argPackPtr;
 		cpuContext[CpuRegister.Rsi] = *(ulong*)(argPackPtr + 8);
@@ -106,6 +147,17 @@ public sealed partial class DirectExecutionBackend
 		cpuContext[CpuRegister.R13] = *(ulong*)(argPackPtr + 72);
 		cpuContext[CpuRegister.R14] = *(ulong*)(argPackPtr + 80);
 		cpuContext[CpuRegister.R15] = *(ulong*)(argPackPtr + 88);
+		// The trampoline spills the SysV variadic XMM save area (xmm0..xmm7) into the
+		// 0x80 bytes immediately below the GP argpack, so variadic float args (printf
+		// %f, and powf/logf inputs) reach the handler. xmm{i} is at argPackPtr-0x80+i*16.
+		for (var xmmIndex = 0; xmmIndex < 8; xmmIndex++)
+		{
+			var xmmSlot = argPackPtr - 0x80 + (xmmIndex * 16);
+			cpuContext.SetXmmRegister(
+				xmmIndex,
+				*(ulong*)xmmSlot,
+				*(ulong*)(xmmSlot + 8));
+		}
 		cpuContext[CpuRegister.Rsp] = (ulong)argPackPtr + 96uL;
 		ulong value = cpuContext[CpuRegister.Rdi];
 		ulong value2 = cpuContext[CpuRegister.Rsi];
@@ -120,6 +172,7 @@ public sealed partial class DirectExecutionBackend
 		ulong value7 = cpuContext[CpuRegister.R14];
 		ulong value8 = cpuContext[CpuRegister.R15];
 		ulong num7 = *(ulong*)(argPackPtr + 96);
+		var isGuestWorker = GuestThreadExecution.IsGuestThread;
 		if (!IsLikelyReturnAddress(num7))
 		{
 			for (int i = 1; i <= 4; i++)
@@ -134,19 +187,29 @@ public sealed partial class DirectExecutionBackend
 				}
 			}
 		}
-		TrackDistinctImportNid(importStubEntry.Nid);
+		if (_activeGuestThreadState is { } activeGuestThreadState)
-		var probeImportReturn = Environment.GetEnvironmentVariable("SHARPEMU_PROBE_IMPORT_RET");
+		{
-		if (!string.IsNullOrWhiteSpace(probeImportReturn) &&
+			Interlocked.Increment(ref activeGuestThreadState.ImportCount);
-			(string.Equals(probeImportReturn, "*", StringComparison.Ordinal) ||
+			Volatile.Write(ref activeGuestThreadState.LastImportNid, importStubEntry.Nid);
-			 string.Equals(probeImportReturn, importStubEntry.Nid, StringComparison.Ordinal)))
+			Volatile.Write(ref activeGuestThreadState.LastReturnRip, num7);
+		}
+		if (_logStrlenBursts)
+		{
+			TrackDistinctImportNid(importStubEntry.Nid);
+			TrackStrlenPrelude(importStubEntry.Nid, num, num7);
+		}
+		if (!string.IsNullOrWhiteSpace(_probeImportReturn) &&
+			(string.Equals(_probeImportReturn, "*", StringComparison.Ordinal) ||
+			 string.Equals(_probeImportReturn, importStubEntry.Nid, StringComparison.Ordinal)))
 		{
 			ProbeReturnRip(num7, num);
 		}
-		TrackStrlenPrelude(importStubEntry.Nid, num, num7);
+		if (_logGuestContext)
-		TraceGuestContext(
+		{
-			$"import dispatch={num} nid={importStubEntry.Nid} ret=0x{num7:X16} managed={Environment.CurrentManagedThreadId} guest=0x{GuestThreadExecution.CurrentGuestThreadHandle:X16} fiber=0x{GuestThreadExecution.CurrentFiberAddress:X16} active={HasActiveExecutionThread}");
+			TraceGuestContext(
-		bool logBootstrap = string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_BOOTSTRAP"), "1", StringComparison.Ordinal);
+				$"import dispatch={num} nid={importStubEntry.Nid} ret=0x{num7:X16} managed={Environment.CurrentManagedThreadId} guest=0x{GuestThreadExecution.CurrentGuestThreadHandle:X16} fiber=0x{GuestThreadExecution.CurrentFiberAddress:X16} active={HasActiveExecutionThread}");
-		if (logBootstrap && string.Equals(importStubEntry.Nid, RuntimeStubNids.BootstrapBridge, StringComparison.Ordinal))
+		}
+		if (_logBootstrap && string.Equals(importStubEntry.Nid, RuntimeStubNids.BootstrapBridge, StringComparison.Ordinal))
 		{
 			string symbolText = "<unreadable>";
 			if (TryReadAsciiZ(value2, 256, out var sym))
@@ -156,36 +219,56 @@ public sealed partial class DirectExecutionBackend
 			Console.Error.WriteLine(
 				$"[LOADER][TRACE] bootstrap_call#{num}: op=0x{value:X16} sym_ptr=0x{value2:X16} sym='{symbolText}' out_ptr=0x{num3:X16} ret=0x{num7:X16}");
 		}
-		if (!ActiveForcedGuestExit && ShouldForceGuestExitOnImportLoop(importStubEntry.Nid, num7, num, value, value2) && TryForceGuestExitToHostStub(argPackPtr, num, num7, importStubEntry.Nid))
+		if (!isGuestWorker &&
+			!ActiveForcedGuestExit &&
+			ShouldForceGuestExitOnImportLoop(importStubEntry.Nid, num7, num, value, value2) &&
+			TryForceGuestExitToHostStub(argPackPtr, num, num7, importStubEntry.Nid))
 		{
 			cpuContext[CpuRegister.Rax] = 1uL;
 			return 1uL;
 		}
+		// Backend teardown in progress: unwind this worker to the host instead of
+		// dispatching. RunGuestThread parks it as Blocked with no wake handler, its
+		// host thread exits, and RequestGuestThreadTeardown can finish before any
+		// executable memory is freed.
+		if (isGuestWorker &&
+			_guestTeardownRequested &&
+			TryYieldGuestThreadToHostStub(argPackPtr, num, num7, importStubEntry.Nid, "backend teardown"))
+		{
+			cpuContext[CpuRegister.Rax] = 0uL;
+			return 0uL;
+		}
 		bool flag0 = ShouldSuppressStrlenTrace(importStubEntry.Nid);
 		bool flag = num7 >= 2156221920u && num7 <= 2156225024u;
 		bool flag2 = num7 >= 2156351360u && num7 <= 2156352080u;
 		bool flag3 = num >= 1020 && num <= 1040;
-		bool logAllImports = string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_ALL_IMPORTS"), "1", StringComparison.Ordinal);
+		bool flag4 = !string.IsNullOrWhiteSpace(_importFilter);
-		string importFilter = Environment.GetEnvironmentVariable("SHARPEMU_LOG_IMPORT_FILTER");
-		bool flag4 = !string.IsNullOrWhiteSpace(importFilter);
 		bool flag5 = false;
-		ExportedFunction matchedExport = null;
+		ExportedFunction? matchedExport = importStubEntry.Export;
-		if (_moduleManager.TryGetExport(importStubEntry.Nid, out ExportedFunction export))
+		bool periodicTrace = num <= 128 ||
+			(num >= 240 && num <= 400) ||
+			(num >= 900 && num <= 1300) ||
+			num % 100000 == 0L ||
+			(importStubEntry.Nid == "tsvEmnenz48" && (num <= 256 || num % 1000 == 0L)) ||
+			(importStubEntry.Nid == "rTXw65xmLIA" && (num <= 256 || num % 128 == 0)) ||
+			flag ||
+			flag2 ||
+			flag3;
+		if (matchedExport is not null)
 		{
-			matchedExport = export;
 			if (flag4)
 			{
-				flag5 = export.LibraryName.Contains(importFilter, StringComparison.OrdinalIgnoreCase)
+				flag5 = matchedExport.LibraryName.Contains(_importFilter!, StringComparison.OrdinalIgnoreCase)
-					|| export.Name.Contains(importFilter, StringComparison.OrdinalIgnoreCase)
+					|| matchedExport.Name.Contains(_importFilter!, StringComparison.OrdinalIgnoreCase)
-					|| importStubEntry.Nid.Contains(importFilter, StringComparison.OrdinalIgnoreCase);
+					|| importStubEntry.Nid.Contains(_importFilter!, StringComparison.OrdinalIgnoreCase);
 			}
 		}
 		else if (flag4)
 		{
-			flag5 = importStubEntry.Nid.Contains(importFilter, StringComparison.OrdinalIgnoreCase);
+			flag5 = importStubEntry.Nid.Contains(_importFilter!, StringComparison.OrdinalIgnoreCase);
 		}
-		bool flag6 = logAllImports || flag5;
+		bool flag6 = _logAllImports || flag5;
-		if (!flag0 && (flag6 || num <= 128 || (num >= 240 && num <= 400) || (num >= 900 && num <= 1300) || num % 100000 == 0L || (importStubEntry.Nid == "tsvEmnenz48" && (num <= 256 || num % 1000 == 0L)) || (importStubEntry.Nid == "rTXw65xmLIA" && (num <= 256 || num % 128 == 0)) || flag || flag2 || flag3))
+		if (!flag0 && (flag6 || periodicTrace))
 		{
 			if (matchedExport != null)
 			{
@@ -218,9 +301,15 @@ public sealed partial class DirectExecutionBackend
 				Console.Error.Flush();
 			}
 		}
-		if (!flag0)
+		if (!flag0 && !isGuestWorker)
 		{
-			RecordRecentImportTrace($"#{num} nid={importStubEntry.Nid} ret=0x{num7:X16} rdi=0x{cpuContext[CpuRegister.Rdi]:X16} rsi=0x{cpuContext[CpuRegister.Rsi]:X16} rdx=0x{cpuContext[CpuRegister.Rdx]:X16}");
+			RecordRecentImportTrace(
+				num,
+				importStubEntry.Nid,
+				num7,
+				cpuContext[CpuRegister.Rdi],
+				cpuContext[CpuRegister.Rsi],
+				cpuContext[CpuRegister.Rdx]);
 		}
 		if (importStubEntry.Nid == "8zTFvBIAIN8" && num <= 256)
 		{
@@ -247,11 +336,11 @@ public sealed partial class DirectExecutionBackend
 					Console.Error.WriteLine($"[LOADER][TRACE] ImportStack#{num}: rsp=0x{num9:X16} [0]=0x{value9:X16} [8]=0x{value10:X16} [10]=0x{value11:X16} [18]=0x{value12:X16} [20]=0x{value13:X16} [28]=0x{value14:X16} [30]=0x{value15:X16} [38]=0x{value16:X16} [40]=0x{value17:X16}");
 				}
 			}
-			if (flag6 && string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_IMPORT_FRAMES"), "1", StringComparison.Ordinal))
+			if (flag6 && _logImportFrames)
 			{
 				TraceImportFrameChain(cpuContext, num);
 			}
-			if (flag6 && string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_IMPORT_RECENT"), "1", StringComparison.Ordinal))
+			if (flag6 && _logImportRecent)
 			{
 				DumpRecentImportTrace();
 			}
@@ -262,7 +351,7 @@ public sealed partial class DirectExecutionBackend
 		}
 		if (importStubEntry.Nid == "Ou3iL1abvng")
 		{
-			if (string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_STACK_CHK"), "1", StringComparison.Ordinal))
+			if (_logStackCheck)
 			{
 				var savedGuardAddress = value4 >= 0x10 ? value4 - 0x10 : 0;
 				var guardKnown = TryReadUInt64Compat(value3, out var guardValue);
@@ -296,14 +385,41 @@ public sealed partial class DirectExecutionBackend
 				{
 					orbisGen2Result = DispatchBootstrapBridge();
 				}
-				else if (string.Equals(importStubEntry.Nid, RuntimeStubNids.KernelDynlibDlsym, StringComparison.Ordinal))
+				else if (string.Equals(importStubEntry.Nid, RuntimeStubNids.KernelDynlibDlsym, StringComparison.Ordinal) ||
+					string.Equals(importStubEntry.Nid, "LwG8g3niqwA", StringComparison.Ordinal))
 				{
 					orbisGen2Result = DispatchKernelDynlibDlsym();
 				}
-				else
+				else if (string.Equals(importStubEntry.Nid, "r8mvOaWdi28", StringComparison.Ordinal))
 				{
-					dispatchResolved = _moduleManager.TryDispatch(importStubEntry.Nid, cpuContext, out orbisGen2Result);
+					orbisGen2Result = DispatchIl2CppApiLookupSymbol();
 				}
+				else if (importStubEntry.Export is { } cachedExport &&
+					(cachedExport.Target & cpuContext.TargetGeneration) != 0)
+				{
+					cpuContext.ClearRaxWriteFlag();
+					var returnValue = cachedExport.Function(cpuContext);
+					if (!cpuContext.WasRaxWritten)
+					{
+						cpuContext[CpuRegister.Rax] = unchecked((ulong)returnValue);
+					}
+					orbisGen2Result = (OrbisGen2Result)returnValue;
+				}
+                else if (importStubEntry.Export is { } mismatchedExport)
+                {
+                    dispatchResolved = true;
+                    orbisGen2Result = OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_IMPLEMENTED;
+                    cpuContext[CpuRegister.Rax] = unchecked((ulong)(int)orbisGen2Result);
+                    Console.Error.WriteLine(
+                        $"[LOADER][WARN] Import#{num} not implemented for generation {cpuContext.TargetGeneration}: " +
+                        $"nid={importStubEntry.Nid} targets={mismatchedExport.Target} ret=0x{num7:X16}");
+                }
+                else
+                {
+                    dispatchResolved = false;
+                    orbisGen2Result = OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+                    cpuContext[CpuRegister.Rax] = unchecked((ulong)(int)orbisGen2Result);
+                }
 			}
 			finally
 			{
@@ -318,7 +434,9 @@ public sealed partial class DirectExecutionBackend
 			if (!dispatchResolved)
 			{
 				LastError = "Missing HLE export for NID: " + importStubEntry.Nid;
-				Console.Error.WriteLine($"[LOADER][WARN] Import#{num} unresolved: nid={importStubEntry.Nid} ret=0x{num7:X16}");
+				Console.Error.WriteLine(
+					$"[LOADER][WARN] Import#{num} unresolved: nid={importStubEntry.Nid} ret=0x{num7:X16} " +
+					$"rdi=0x{value:X16} rsi=0x{value2:X16} rdx=0x{num3:X16} rcx=0x{num4:X16} r8=0x{num5:X16} r9=0x{num6:X16}");
 				if (importStubEntry.Nid == "L-Q3LEjIbgA")
 				{
 					string value18 = string.Join(" ", importStubEntry.Nid.Select(delegate (char c)
@@ -337,9 +455,12 @@ public sealed partial class DirectExecutionBackend
 			}
 			else if (orbisGen2Result != OrbisGen2Result.ORBIS_GEN2_OK)
 			{
-				Console.Error.WriteLine(
+				if (ShouldLogImportResult(importStubEntry.Nid, orbisGen2Result))
-					$"[LOADER][WARN] Import#{num} result: {orbisGen2Result} ({importStubEntry.Nid}) " +
+				{
-					$"rdi=0x{value:X16} rsi=0x{value2:X16} rdx=0x{num3:X16} rcx=0x{num4:X16} ret=0x{num7:X16}");
+					Console.Error.WriteLine(
+						$"[LOADER][WARN] Import#{num} result: {orbisGen2Result} ({importStubEntry.Nid}) " +
+						$"rdi=0x{value:X16} rsi=0x{value2:X16} rdx=0x{num3:X16} rcx=0x{num4:X16} ret=0x{num7:X16}");
+				}
 			}
 			cpuContext[CpuRegister.Rbx] = value3;
 			cpuContext[CpuRegister.Rbp] = value4;
@@ -349,11 +470,36 @@ public sealed partial class DirectExecutionBackend
 			cpuContext[CpuRegister.R15] = value8;
 			cpuContext[CpuRegister.Rdi] = value;
 			cpuContext[CpuRegister.Rsi] = value2;
-			if (GuestThreadExecution.TryConsumeCurrentEntryExit(out var exitStatus, out var exitReason))
+			if (GuestThreadExecution.TryConsumeCurrentContextTransfer(out var transferTarget))
 			{
-				if (TryCompleteGuestEntryToHostStub(argPackPtr, num, num7, importStubEntry.Nid, exitReason, exitStatus))
+				if (!TryPrepareGuestContextTransfer(
+						transferTarget,
+						out var transferFrame,
+						out var transferStub,
+						out var transferError))
 				{
-					cpuContext[CpuRegister.Rax] = unchecked((ulong)exitStatus);
+					LastError = transferError ?? "failed to prepare guest context transfer";
+					ActiveForcedGuestExit = true;
+					cpuContext[CpuRegister.Rax] = 18446744071562199298uL;
+					return cpuContext[CpuRegister.Rax];
+				}
+
+				*(ulong*)(argPackPtr + 96) = unchecked((ulong)transferStub);
+				if (string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_FIBER"), "1", StringComparison.Ordinal))
+				{
+					Console.Error.WriteLine(
+						$"[LOADER][TRACE] fiber.context-transfer rip=0x{transferTarget.Rip:X16} " +
+						$"rsp=0x{transferTarget.Rsp:X16} guest=0x{GuestThreadExecution.CurrentGuestThreadHandle:X16} " +
+						$"fiber=0x{GuestThreadExecution.CurrentFiberAddress:X16}");
+				}
+
+				return unchecked((ulong)transferFrame);
+			}
+			if (GuestThreadExecution.TryConsumeCurrentEntryExit(out var exitValue, out var exitReason))
+			{
+				if (TryCompleteGuestEntryToHostStub(argPackPtr, num, num7, importStubEntry.Nid, exitReason, exitValue))
+				{
+					cpuContext[CpuRegister.Rax] = exitValue;
 				}
 				else
 				{
@@ -361,9 +507,27 @@ public sealed partial class DirectExecutionBackend
 					cpuContext[CpuRegister.Rax] = 18446744071562199298uL;
 				}
 			}
-			if (GuestThreadExecution.TryConsumeCurrentThreadBlock(out var blockReason) &&
+			if (GuestThreadExecution.TryConsumeCurrentThreadBlock(
+					out var blockReason,
+					out var blockContinuation,
+					out var hasBlockContinuation,
+					out var blockWakeKey,
+					out var blockResumeHandler,
+					out var blockWakeHandler,
+					out var blockDeadlineTimestamp) &&
 				TryYieldGuestThreadToHostStub(argPackPtr, num, num7, importStubEntry.Nid, blockReason))
 			{
+				if (hasBlockContinuation)
+				{
+					RegisterBlockedGuestThreadContinuation(
+						GuestThreadExecution.CurrentGuestThreadHandle,
+						blockContinuation,
+						blockWakeKey,
+						blockResumeHandler,
+						blockWakeHandler,
+						blockDeadlineTimestamp);
+				}
+
 				cpuContext[CpuRegister.Rax] = 0uL;
 			}
 			if (flag || flag2 || flag3)
@@ -374,16 +538,384 @@ public sealed partial class DirectExecutionBackend
 					Console.Error.Flush();
 				}
 			}
+			// Publish the handler's XMM0 back into the argpack's xmm0 save slot; the
+			// trampoline epilogue reloads it into the guest's XMM0, delivering float/double
+			// return values (powf/logf/wcstod). Harmless for int/pointer returns (XMM is
+			// volatile across a SysV call, so the guest never relies on a preserved XMM0).
+			cpuContext.GetXmmRegister(0, out var returnXmm0Low, out var returnXmm0High);
+			*(ulong*)(argPackPtr - 0x80) = returnXmm0Low;
+			*(ulong*)(argPackPtr - 0x80 + 8) = returnXmm0High;
 			return cpuContext[CpuRegister.Rax];
 		}
 		catch (Exception ex)
 		{
 			LastError = $"HLE dispatch error for {importStubEntry.Nid}: {ex.GetType().Name}: {ex.Message}";
+			Console.Error.WriteLine($"[LOADER][ERROR] {LastError}");
+			Console.Error.WriteLine($"[LOADER][ERROR] {ex.StackTrace}");
 			cpuContext[CpuRegister.Rax] = 18446744071562199298uL;
 			return 18446744071562199298uL;
 		}
 	}
 
+	private unsafe bool TryDispatchLeafImport(
+		CpuContext cpuContext,
+		ImportStubEntry importStubEntry,
+		nint argPackPtr,
+		long dispatchIndex,
+		out ulong result)
+	{
+		result = 0;
+		if (importStubEntry.Export is not { } export ||
+			(export.Target & cpuContext.TargetGeneration) == 0)
+		{
+			return false;
+		}
+
+		var arg0 = *(ulong*)argPackPtr;
+		var returnRip = *(ulong*)(argPackPtr + 96);
+		cpuContext.Rip = importStubEntry.Address;
+		cpuContext[CpuRegister.Rdi] = arg0;
+		cpuContext[CpuRegister.Rsi] = *(ulong*)(argPackPtr + 8);
+		cpuContext[CpuRegister.Rdx] = *(ulong*)(argPackPtr + 16);
+		cpuContext[CpuRegister.Rcx] = *(ulong*)(argPackPtr + 24);
+		cpuContext[CpuRegister.R8] = *(ulong*)(argPackPtr + 32);
+		cpuContext[CpuRegister.R9] = *(ulong*)(argPackPtr + 40);
+		cpuContext[CpuRegister.Rbx] = *(ulong*)(argPackPtr + 48);
+		cpuContext[CpuRegister.Rbp] = *(ulong*)(argPackPtr + 56);
+		cpuContext[CpuRegister.R12] = *(ulong*)(argPackPtr + 64);
+		cpuContext[CpuRegister.R13] = *(ulong*)(argPackPtr + 72);
+		cpuContext[CpuRegister.R14] = *(ulong*)(argPackPtr + 80);
+		cpuContext[CpuRegister.R15] = *(ulong*)(argPackPtr + 88);
+		cpuContext[CpuRegister.Rsp] = (ulong)argPackPtr + 96uL;
+
+		if (_activeGuestThreadState is { } activeGuestThreadState)
+		{
+			Interlocked.Increment(ref activeGuestThreadState.ImportCount);
+			Volatile.Write(ref activeGuestThreadState.LastImportNid, importStubEntry.Nid);
+			Volatile.Write(ref activeGuestThreadState.LastReturnRip, returnRip);
+		}
+		if (dispatchIndex % 100000 == 0)
+		{
+			Console.Error.WriteLine(
+				$"[LOADER][TRACE] Import#{dispatchIndex}: {export.LibraryName}:{export.Name} ({importStubEntry.Nid}) " +
+				$"rdi=0x{arg0:X16} rsi=0x{cpuContext[CpuRegister.Rsi]:X16} " +
+				$"rdx=0x{cpuContext[CpuRegister.Rdx]:X16} rcx=0x{cpuContext[CpuRegister.Rcx]:X16} " +
+				$"ret=0x{returnRip:X16}");
+		}
+
+		int returnValue;
+		if (IsNoBlockLeafImport(importStubEntry.Nid))
+		{
+			cpuContext.ClearRaxWriteFlag();
+			returnValue = export.Function(cpuContext);
+			if (!cpuContext.WasRaxWritten)
+			{
+				cpuContext[CpuRegister.Rax] = unchecked((ulong)returnValue);
+			}
+		}
+		else
+		{
+			var previousImportCallFrame = GuestThreadExecution.EnterImportCallFrame(
+				returnRip,
+				(ulong)argPackPtr + 104uL,
+				ActiveGuestReturnSlotAddress);
+			try
+			{
+				cpuContext.ClearRaxWriteFlag();
+				returnValue = export.Function(cpuContext);
+				if (!cpuContext.WasRaxWritten)
+				{
+					cpuContext[CpuRegister.Rax] = unchecked((ulong)returnValue);
+				}
+			}
+			finally
+			{
+				GuestThreadExecution.RestoreImportCallFrame(previousImportCallFrame);
+			}
+		}
+
+		if (returnValue != (int)OrbisGen2Result.ORBIS_GEN2_OK)
+		{
+			var returnResult = (OrbisGen2Result)returnValue;
+			if (ShouldLogImportResult(importStubEntry.Nid, returnResult))
+			{
+				Console.Error.WriteLine(
+					$"[LOADER][WARN] Import#{dispatchIndex} result: {returnResult} ({importStubEntry.Nid}) " +
+					$"rdi=0x{arg0:X16} rsi=0x{cpuContext[CpuRegister.Rsi]:X16} " +
+					$"rdx=0x{cpuContext[CpuRegister.Rdx]:X16} rcx=0x{cpuContext[CpuRegister.Rcx]:X16} " +
+					$"r8=0x{cpuContext[CpuRegister.R8]:X16} r9=0x{cpuContext[CpuRegister.R9]:X16} " +
+					$"ret=0x{returnRip:X16}");
+			}
+		}
+
+		if (GuestThreadExecution.TryConsumeCurrentThreadBlock(
+				out var blockReason,
+				out var blockContinuation,
+				out var hasBlockContinuation,
+				out var blockWakeKey,
+				out var blockResumeHandler,
+				out var blockWakeHandler,
+				out var blockDeadlineTimestamp) &&
+			TryYieldGuestThreadToHostStub(argPackPtr, dispatchIndex, returnRip, importStubEntry.Nid, blockReason))
+		{
+			if (hasBlockContinuation)
+			{
+				RegisterBlockedGuestThreadContinuation(
+					GuestThreadExecution.CurrentGuestThreadHandle,
+					blockContinuation,
+					blockWakeKey,
+					blockResumeHandler,
+					blockWakeHandler,
+					blockDeadlineTimestamp);
+			}
+
+			cpuContext[CpuRegister.Rax] = 0uL;
+		}
+
+		result = cpuContext[CpuRegister.Rax];
+		return true;
+	}
+
+	// Subset of the leaf set that additionally skips the import-call-frame
+	// bookkeeping. The same scalar-only (no XMM args, no XMM return) constraint
+	// as IsLeafImport applies — see the note there before adding entries.
+	// NOTE: this filter is only consulted after IsLeafImport accepts the NID;
+	// entries listed here but not in IsLeafImport (scePadRead, scePadOpen,
+	// sceUserServiceGetEvent, sceUserServiceGetPlatformPrivacySetting,
+	// pthread_mutex_trylock) currently take the full gateway path.
+	private static bool IsNoBlockLeafImport(string nid) =>
+		nid is
+			"8aI7R7WaOlc" or // sceAmprCommandBufferConstructor
+			"a8uLzYY--tM" or // sceAmprAprCommandBufferConstructor
+			"Qs1xtplKo0U" or // sceAmprAprCommandBufferDestructor
+			"GuchCTefuZw" or // sceAmprCommandBufferDestructor
+			"N-FSPA4S3nI" or // sceAmprCommandBufferSetBuffer
+			"baQO9ez2gL4" or // sceAmprCommandBufferReset
+			"ULvXMDz56po" or // sceAmprCommandBufferClearBuffer
+			"mQ16-QdKv7k" or // sceAmprAprCommandBufferReadFile
+			"vWU-odnS+fU" or // sceAmprMeasureCommandSizeReadFile
+			"sSAUCCU1dv4" or // sceAmprMeasureCommandSizeWriteKernelEventQueue_04_00
+			"C+IEj+BsAFM" or // sceAmprMeasureCommandSizeWriteAddressOnCompletion
+			"tZDDEo2tE5k" or // sceAmprCommandBufferGetSize
+			"GnxKOHEawhk" or // sceAmprCommandBufferGetCurrentOffset
+			"H896Pt-yB4I" or // sceAmprCommandBufferWriteKernelEventQueue_04_00
+			"sJXyWHjP-F8" or // sceAmprCommandBufferWriteAddressOnCompletion
+			"ASoW5WE-UPo" or // sceKernelAprSubmitCommandBufferAndGetResult
+			"rqwFKI4PAiM" or // sceKernelAprWaitCommandBuffer
+			"eE4Szl8sil8" or // sceKernelAprSubmitCommandBuffer
+			"qvMUCyyaCSI" or // sceKernelAprSubmitCommandBufferAndGetId
+			"Q2V+iqvjgC0" or // vsnprintf
+			"q1cHNfGycLI" or // scePadRead
+			"xk0AcarP3V4" or // scePadOpen
+			"yH17Q6NWtVg" or // sceUserServiceGetEvent
+			"D-CzAxQL0XI" or // sceUserServiceGetPlatformPrivacySetting
+			"K-jXhbt2gn4";   // pthread_mutex_trylock (scePthreadMutexTrylock is upoVrzMHFeE)
+
+	private bool ShouldLogImportResult(string nid, OrbisGen2Result result)
+	{
+		var resultValue = unchecked((int)result);
+		if (resultValue > 0)
+		{
+			return false;
+		}
+
+		var expectedFileProbeMiss =
+			result == OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND &&
+			IsExpectedFileProbeNotFoundNid(nid);
+		var expectedTimedWaitTimeout =
+			string.Equals(nid, "27bAgiJmOh0", StringComparison.Ordinal) &&
+			unchecked((int)result) == 60;
+		var expectedEqueueTimeout =
+			string.Equals(nid, "fzyMKs9kim0", StringComparison.Ordinal) &&
+			result == OrbisGen2Result.ORBIS_GEN2_ERROR_TIMED_OUT;
+		var expectedMutexTrylockBusy =
+			string.Equals(nid, "K-jXhbt2gn4", StringComparison.Ordinal) &&
+			result == OrbisGen2Result.ORBIS_GEN2_ERROR_BUSY;
+		var expectedUserServiceNoEvent =
+			string.Equals(nid, "yH17Q6NWtVg", StringComparison.Ordinal) &&
+			resultValue == unchecked((int)0x80960007);
+		var expectedPrivacyInvalidParameter =
+			string.Equals(nid, "D-CzAxQL0XI", StringComparison.Ordinal) &&
+			resultValue == unchecked((int)0x80960009);
+		if (!expectedFileProbeMiss &&
+			!expectedTimedWaitTimeout &&
+			!expectedEqueueTimeout &&
+			!expectedMutexTrylockBusy &&
+			!expectedUserServiceNoEvent &&
+			!expectedPrivacyInvalidParameter)
+		{
+			return true;
+		}
+
+		if (!ShouldLogExpectedImportResults())
+		{
+			return false;
+		}
+
+		var key = nid + "\0" + resultValue;
+		int count;
+		lock (_importResultLogSampleGate)
+		{
+			_importResultLogSamples.TryGetValue(key, out count);
+			count++;
+			_importResultLogSamples[key] = count;
+		}
+
+		return count <= 8 || count % 10000 == 0;
+	}
+
+	private static bool ShouldLogExpectedImportResults() =>
+		string.Equals(
+			Environment.GetEnvironmentVariable("SHARPEMU_LOG_EXPECTED_IMPORT_RESULTS"),
+			"1",
+			StringComparison.Ordinal);
+
+	private static bool IsExpectedFileProbeNotFoundNid(string nid) =>
+		nid is
+			"eV9wAD2riIA" or // sceKernelStat
+			"1G3lF1Gg1k8" or // sceKernelOpen
+			"gEpBkcwxUjw";   // sceKernelAprResolveFilepathsToIdsAndFileSizes
+
+	// LEAF-IMPORT REGISTRATION — scalar-only constraint.
+	//
+	// TryDispatchLeafImport is a fast path that never copies the trampoline's XMM
+	// save area into CpuContext and never publishes an XMM0 return back to the
+	// guest (see DispatchImport). Every NID listed here must therefore satisfy BOTH:
+	//   1. no float/double parameters (nothing passed in xmm0..xmm7), and
+	//   2. no float/double return value (nothing returned in xmm0).
+	// Integer/pointer arguments and returns only. va_list-based functions
+	// (vsnprintf) are safe: SysV va_list floats are read from the caller-built
+	// reg_save_area in guest memory, not from the callee's incoming XMM registers.
+	//
+	// If a function that consumes XMM arguments or returns in xmm0 (e.g. powf,
+	// logf, wcstod, sceVideoOutColorSettingsSetGamma_) is ever added here, its
+	// float arguments will silently arrive stale and its return value will be
+	// dropped. Such functions must stay on the full gateway path — do not list them.
+	//
+	// Audited 2026-07-11 (PR #59): every NID below maps to a registered
+	// SysAbiExport whose handler neither reads nor writes CpuContext XMM state
+	// and whose known guest signature is integer/pointer only.
+	private bool IsLeafImport(string nid)
+	{
+		if (nid == "1jfXLRVzisc") // sceKernelUsleep
+		{
+			return !_logUsleep;
+		}
+
+		return nid is
+			"9UK1vLZQft4" or // scePthreadMutexLock
+			"tn3VlD0hG60" or // scePthreadMutexUnlock
+			"7H0iTOciTLo" or // pthread_mutex_lock
+			"2Z+PpY6CaJg" or // pthread_mutex_unlock
+			"8aI7R7WaOlc" or // sceAmprCommandBufferConstructor
+			"zgXifHT9ErY" or // sceVideoOutIsFlipPending
+			"V++UgBtQhn0" or // sceAgcGetDataPacketPayloadAddress
+			"qj7QZpgr9Uw" or // sceAgcUnknownQj7QZpgr9Uw (unknown NID; observed scalar: command-buffer pointer in, packet address out)
+			"LtTouSCZjHM" or // sceAgcCbNop
+			"k3GhuSNmBLU" or // sceAgcCbDispatch
+			"UZbQjYAwwXM" or // sceAgcCbSetShRegistersDirect
+			"JrtiDtKeS38" or // sceAgcAcbResetQueue
+			"cFazmnXpJOE" or // sceAgcAcbEventWrite
+			"KT-hTp-Ch14" or // sceAgcAcbAcquireMem
+			"htn36gPnBk4" or // sceAgcAcbWaitRegMem
+			"eZ4+17OQz4Q" or // sceAgcAcbWriteData
+			"j3EtxFkSIhQ" or // sceAgcAcbDispatchIndirect
+			"gSRnr79F8tQ" or // sceAgcDriverSubmitAcb
+			"i1jyy49AjXU" or // sceAgcDcbWriteData
+			"VmW0Tdpy420" or // sceAgcDcbWaitRegMem
+			"WmAc2MEj6Io" or // sceAgcDcbDmaData
+			"rUuVjyR+Rd4" or // sceAgcDcbGetLodStatsGetSize
+			"vuSXe69VILM" or // sceAgcDcbGetLodStats
+			"RmaJwLtc8rY" or // sceAgcDcbSetBaseIndirectArgs
+			"CtB+A9-VxO0" or // sceAgcDcbDispatchIndirect
+			"+kSrjIVxKFE" or // sceAgcDcbPushMarker
+			"H7uZqCoNuWk" or // sceAgcDcbPopMarker
+			"IxYiarKlXxM" or // sceAgcDmaDataPatchSetDstAddressOrOffset
+			"3KDcnM3lrcU" or // sceAgcWaitRegMemPatchAddress
+			"0fWWK5uG9rQ" or // sceAgcQueueEndOfPipeActionPatchAddress
+			"a8uLzYY--tM" or // sceAmprAprCommandBufferConstructor
+			"Qs1xtplKo0U" or // sceAmprAprCommandBufferDestructor
+			"GuchCTefuZw" or // sceAmprCommandBufferDestructor
+			"N-FSPA4S3nI" or // sceAmprCommandBufferSetBuffer
+			"baQO9ez2gL4" or // sceAmprCommandBufferReset
+			"ULvXMDz56po" or // sceAmprCommandBufferClearBuffer
+			"mQ16-QdKv7k" or // sceAmprAprCommandBufferReadFile
+			"vWU-odnS+fU" or // sceAmprMeasureCommandSizeReadFile
+			"sSAUCCU1dv4" or // sceAmprMeasureCommandSizeWriteKernelEventQueue_04_00
+			"C+IEj+BsAFM" or // sceAmprMeasureCommandSizeWriteAddressOnCompletion
+			"tZDDEo2tE5k" or // sceAmprCommandBufferGetSize
+			"GnxKOHEawhk" or // sceAmprCommandBufferGetCurrentOffset
+			"H896Pt-yB4I" or // sceAmprCommandBufferWriteKernelEventQueue_04_00
+			"sJXyWHjP-F8" or // sceAmprCommandBufferWriteAddressOnCompletion
+			"ASoW5WE-UPo" or // sceKernelAprSubmitCommandBufferAndGetResult
+			"rqwFKI4PAiM" or // sceKernelAprWaitCommandBuffer
+			"eE4Szl8sil8" or // sceKernelAprSubmitCommandBuffer
+			"qvMUCyyaCSI" or // sceKernelAprSubmitCommandBufferAndGetId
+			"Vo5V8KAwCmk" or // sceSystemServiceHideSplashScreen
+			"TywrFKCoLGY" or // sceSaveDataInitialize3
+			"dyIhnXq-0SM" or // sceSaveDataDirNameSearch
+			"ZP4e7rlzOUk" or // sceSaveDataMount3
+			"ERKzksauAJA" or // sceSaveDataDialogGetStatus
+			"KK3Bdg1RWK0" or // sceSaveDataDialogUpdateStatus
+			"en7gNVnh878" or // sceSaveDataDialogIsReadyToDisplay
+			"jO8DM8oyego" or // sceNpEntitlementAccessInitialize
+			"TFyU+KFBv54" or // sceNpEntitlementAccessGetAddcontEntitlementInfoList
+			"27bAgiJmOh0" or // pthread_cond_timedwait
+			"iQw3iQPhvUQ" or // sceNetCtlCheckCallback
+			"Q2V+iqvjgC0" or // vsnprintf
+			"j4ViWNHEgww" or // strlen
+			"5jNubw4vlAA" or // strnlen
+			"LHMrG7e8G78" or // wcslen
+			"WkkeywLJcgU" or // wcslen
+			"Ovb2dSJOAuE" or // strcmp
+			"aesyjrHVWy4" or // strncmp
+			"pNtJdE3x49E" or // wcscmp
+			"fV2xHER+bKE" or // wcscoll
+			"E8wCoUEbfzk" or // wcsncmp
+			"Q3VBxCXhUHs" or // memcpy
+			"+P6FRGH4LfA" or // memmove
+			"DfivPArhucg" or // memcmp
+			"ytQULN-nhL4" or // pthread_rwlock_init
+			"6ULAa0fq4jA" or // scePthreadRwlockInit
+			"1471ajPzxh0" or // pthread_rwlock_destroy
+			"BB+kb08Tl9A" or // scePthreadRwlockDestroy
+			"iGjsr1WAtI0" or // pthread_rwlock_rdlock
+			"Ox9i0c7L5w0" or // scePthreadRwlockRdlock
+			"sIlRvQqsN2Y" or // pthread_rwlock_wrlock
+			"mqdNorrB+gI" or // scePthreadRwlockWrlock
+			"EgmLo6EWgso" or // pthread_rwlock_unlock
+			"+L98PIbGttk" or // scePthreadRwlockUnlock
+			"aI+OeCz8xrQ" or // scePthreadSelf
+			"EotR8a3ASf4" or // pthread_self
+			"eoht7mQOCmo" or // scePthreadGetspecific
+			"0-KXaS70xy4" or // pthread_getspecific
+			"+BzXYkqYeLE" or // scePthreadSetspecific
+			"WrOLvHU0yQM" or // pthread_setspecific
+			"vz+pg2zdopI" or // sceKernelGetEventUserData
+			"mJ7aghmgvfc" or // sceKernelGetEventId
+			"23CPPI1tyBY" or // sceKernelGetEventFilter
+			"kwGyyjohI50" or // sceKernelGetEventData
+			// _Getpctype is a per-character ctype table lookup; the embedded mcpp preprocessor
+			// re-fetches the table pointer on every isdigit()/isalpha() check, so classifying a
+			// large input legitimately calls it hundreds of thousands of times back-to-back -
+			// real, finite work that would otherwise trip the loop guard.
+			"sUP1hBaouOw";   // _Getpctype
+	}
+
+	private long NextImportDispatchIndex()
+	{
+		if (!ReferenceEquals(_importCounterOwner, this) ||
+			_nextImportDispatchIndex >= _importDispatchBlockEnd)
+		{
+			var blockEnd = Interlocked.Add(ref _importDispatchCount, ImportDispatchBlockSize);
+			_importCounterOwner = this;
+			_nextImportDispatchIndex = blockEnd - ImportDispatchBlockSize + 1;
+			_importDispatchBlockEnd = blockEnd + 1;
+		}
+
+		return _nextImportDispatchIndex++;
+	}
+
 	private void TraceImportFrameChain(CpuContext context, long dispatchIndex)
 	{
 		var frame = context[CpuRegister.Rbp];
@@ -431,7 +963,7 @@ public sealed partial class DirectExecutionBackend
 		return true;
 	}
 
-	private unsafe bool TryCompleteGuestEntryToHostStub(nint argPackPtr, long dispatchIndex, ulong returnRip, string nid, string reason, int status)
+	private unsafe bool TryCompleteGuestEntryToHostStub(nint argPackPtr, long dispatchIndex, ulong returnRip, string nid, string reason, ulong value)
 	{
 		ulong hostExit = ActiveEntryReturnSentinelRip;
 		if (hostExit < 65536 || !TryPatchActiveGuestReturnSlot(hostExit))
@@ -447,7 +979,7 @@ public sealed partial class DirectExecutionBackend
 			return false;
 		}
 		Console.Error.WriteLine(
-			$"[LOADER][INFO] Guest entry exit at import#{dispatchIndex}: nid={nid} ret=0x{returnRip:X16} reason={reason} status={status}");
+			$"[LOADER][INFO] Guest entry exit at import#{dispatchIndex}: nid={nid} ret=0x{returnRip:X16} reason={reason} value=0x{value:X16}");
 		return true;
 	}
 
@@ -469,8 +1001,11 @@ public sealed partial class DirectExecutionBackend
 
 		ActiveGuestThreadYieldRequested = true;
 		ActiveGuestThreadYieldReason = string.IsNullOrWhiteSpace(reason) ? nid : reason;
-		Console.Error.WriteLine(
+		if (_logGuestThreads)
-			$"[LOADER][INFO] Guest thread yield at import#{dispatchIndex}: nid={nid} ret=0x{returnRip:X16} reason={ActiveGuestThreadYieldReason}");
+		{
+			Console.Error.WriteLine(
+				$"[LOADER][INFO] Guest thread yield at import#{dispatchIndex}: nid={nid} ret=0x{returnRip:X16} reason={ActiveGuestThreadYieldReason}");
+		}
 		return true;
 	}
 
@@ -488,7 +1023,7 @@ public sealed partial class DirectExecutionBackend
 		{
 			return false;
 		}
-		if (string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_DISABLE_IMPORT_LOOP_GUARD"), "1", StringComparison.Ordinal))
+		if (_disableImportLoopGuard || _importLoopGuardSeconds <= 0)
 		{
 			return false;
 		}
@@ -503,6 +1038,10 @@ public sealed partial class DirectExecutionBackend
 			_importNidHashCache[nid] = value;
 		}
 		RecordImportLoopSignature(value, returnRip, BuildImportLoopSignature(value, returnRip, arg0, arg1));
+		if ((dispatchIndex & 0x3F) != 0)
+		{
+			return false;
+		}
 		if (!HasRepeatingImportLoopPattern())
 		{
 			if (_importLoopPatternHits > 0)
@@ -520,14 +1059,13 @@ public sealed partial class DirectExecutionBackend
 			_importLoopPatternStartTimestamp = Stopwatch.GetTimestamp();
 		}
 		_importLoopPatternHits++;
-		var guardSeconds = GetImportLoopGuardSeconds();
+		if (_importLoopPatternHits < 6)
-		if (guardSeconds <= 0 || _importLoopPatternHits < 6)
 		{
 			return false;
 		}
 
 		var elapsedTicks = Stopwatch.GetTimestamp() - _importLoopPatternStartTimestamp;
-		return elapsedTicks >= (long)(guardSeconds * Stopwatch.Frequency);
+		return elapsedTicks >= (long)(_importLoopGuardSeconds * Stopwatch.Frequency);
 	}
 
 	private static bool IsImportLoopGuardBoundary(string nid) =>
@@ -778,8 +1316,11 @@ public sealed partial class DirectExecutionBackend
 			cpuContext[CpuRegister.Rax] = 18446744073709551615uL;
 			return OrbisGen2Result.ORBIS_GEN2_OK;
 		}
-		if (!TryResolveRuntimeSymbolAddress(symbolName, out var resolvedAddress))
+		if (!TryResolveRuntimeSymbolAddress(symbolName, out var resolvedAddress) &&
+			!TryResolveRuntimeSymbolAlias(symbolName, out resolvedAddress))
 		{
+			Console.Error.WriteLine(
+				$"[LOADER][WARN] sceKernelDlsym failed: handle=0x{cpuContext[CpuRegister.Rdi]:X} symbol='{symbolName}'");
 			cpuContext[CpuRegister.Rax] = 18446744073709551615uL;
 			return OrbisGen2Result.ORBIS_GEN2_OK;
 		}
@@ -792,6 +1333,62 @@ public sealed partial class DirectExecutionBackend
 		return OrbisGen2Result.ORBIS_GEN2_OK;
 	}
 
+	private bool TryResolveRuntimeSymbolAlias(string symbolName, out ulong address)
+	{
+		address = 0;
+		var alias = symbolName switch
+		{
+			"scriptingGetMem" => "malloc",
+			"scriptingFreeMem" => "free",
+			"scriptingRealloc" => "realloc",
+			"scriptingCalloc" => "calloc",
+			_ => null,
+		};
+
+		return alias != null && TryResolveRuntimeSymbolAddress(alias, out address);
+	}
+
+	private OrbisGen2Result DispatchIl2CppApiLookupSymbol()
+	{
+		var cpuContext = ActiveCpuContext;
+		if (cpuContext == null)
+		{
+			return OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+		}
+
+		var symbolNameAddress = cpuContext[CpuRegister.Rdi];
+		var outputAddress = cpuContext[CpuRegister.Rsi];
+		if (!TryReadAsciiZ(symbolNameAddress, 512, out var symbolName) ||
+			outputAddress == 0 ||
+			!TryResolveIl2CppApiAddress(symbolName, out var resolvedAddress) ||
+			!TryWriteUInt64Compat(outputAddress, resolvedAddress))
+		{
+			Console.Error.WriteLine(
+				$"[LOADER][WARN] il2cpp_api_lookup_symbol failed: name='{symbolName}' out=0x{outputAddress:X16}");
+			if (outputAddress != 0)
+			{
+				_ = TryWriteUInt64Compat(outputAddress, 0);
+			}
+
+			cpuContext[CpuRegister.Rax] = ulong.MaxValue;
+			return OrbisGen2Result.ORBIS_GEN2_OK;
+		}
+
+		cpuContext[CpuRegister.Rax] = 0;
+		return OrbisGen2Result.ORBIS_GEN2_OK;
+	}
+
+	private bool TryResolveIl2CppApiAddress(string symbolName, out ulong address)
+	{
+		if (TryResolveRuntimeSymbolAddress(symbolName, out address))
+		{
+			return true;
+		}
+
+		return Aerolib.Instance.TryGetByExportName(symbolName, out var symbol) &&
+			TryResolveRuntimeSymbolAddress(symbol.Nid, out address);
+	}
+
 	private OrbisGen2Result DispatchBootstrapBridge()
 	{
 		var cpuContext = ActiveCpuContext;
@@ -810,8 +1407,7 @@ public sealed partial class DirectExecutionBackend
 		{
 			return result;
 		}
-		bool logBootstrap = string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_BOOTSTRAP"), "1", StringComparison.Ordinal);
+		if (_logBootstrap)
-		if (logBootstrap)
 		{
 			Console.Error.WriteLine(
 				$"[LOADER][TRACE] bootstrap_dispatch: handle=0x{bridgeHandle:X16} symbol='{symbolName}' out=0x{outputAddress:X16} rax=0x{cpuContext[CpuRegister.Rax]:X16}");

src/SharpEmu.Core/Cpu/Native/DirectExecutionBackend.NativeWorker.cs

@@ -0,0 +1,582 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using System.Threading;
+using SharpEmu.HLE;
+
+namespace SharpEmu.Core.Cpu.Native;
+
+public sealed partial class DirectExecutionBackend
+{
+	// Guest entry stubs must not run above CLR-managed frames on a CLR-created thread:
+	// the suspension/stack-walk machinery then has to traverse a frame chain that is
+	// interleaved with guest stubs carrying no CLR unwind info, and any window in which
+	// the thread-mode bookkeeping disagrees with the actual stack (import dispatch, VEH
+	// redirection) fail-fasts the runtime — the audio_output_thread ~7th-cycle
+	// "attempted to call a UnmanagedCallersOnly method from managed code" crash.
+	//
+	// Guest execution therefore runs on dedicated raw OS threads whose run loop is
+	// emitted native code. While guest code executes there is not a single managed
+	// frame on the thread and it sits in preemptive mode, so the GC ignores it
+	// entirely. The only managed activity on the thread is the reverse-P/Invoke import
+	// dispatch and the per-run prologue/epilogue, which the CLR supports on foreign
+	// threads (lazy attach, preemptive between calls). The managed orchestrator
+	// (RunGuestThread / the main execution thread) parks in a preemptive wait for the
+	// duration of the run, so its own frame chain is never walked across guest frames.
+	private static readonly bool NativeGuestWorkersDisabled =
+		string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_DISABLE_NATIVE_GUEST_WORKERS"), "1", StringComparison.Ordinal);
+
+	private readonly object _nativeWorkerGate = new();
+	private readonly List<NativeGuestExecutor> _allNativeWorkers = new();
+	private readonly Stack<NativeGuestExecutor> _idleNativeWorkers = new();
+	private bool _nativeWorkersDisposed;
+	private int _nativeWorkerCreationFailedLogged;
+
+	private const uint StackSizeParamIsAReservation = 0x00010000u;
+
+	[DllImport("kernel32.dll", SetLastError = true)]
+	private static extern nint CreateThread(
+		nint lpThreadAttributes,
+		nuint dwStackSize,
+		nint lpStartAddress,
+		nint lpParameter,
+		uint dwCreationFlags,
+		out uint lpThreadId);
+
+	[DllImport("kernel32.dll", SetLastError = true)]
+	private static extern uint WaitForSingleObject(nint hHandle, uint dwMilliseconds);
+
+	// Runs an emitted guest entry stub. Preferred path is a pooled native worker
+	// thread; falls back to the historical inline calli (guest frames above this
+	// thread's managed frames) when workers are disabled or unavailable.
+	//
+	// Callers set the Active* thread-statics before emitting the stub and read the
+	// yield/forced-exit flags right after this returns, so the worker outcome is
+	// copied back into this thread's statics before returning.
+	private unsafe int RunGuestEntryStub(void* entryStub, ulong hostRspSlot)
+	{
+		var worker = RentNativeGuestExecutor();
+		if (worker is null)
+		{
+			TlsSetValue(_hostRspSlotTlsIndex, (nint)hostRspSlot);
+			return CallNativeEntry(entryStub);
+		}
+		try
+		{
+			var state = _activeGuestThreadState;
+			var nativeReturn = worker.Run(
+				_activeCpuContext!,
+				state,
+				GuestThreadExecution.CurrentGuestThreadHandle,
+				_activeEntryReturnSentinelRip,
+				_activeGuestReturnSlotAddress,
+				(nint)hostRspSlot,
+				(nint)entryStub,
+				state?.AffinityMask ?? 0,
+				out var yieldRequested,
+				out var yieldReason,
+				out var forcedExit);
+			_activeGuestThreadYieldRequested = yieldRequested;
+			_activeGuestThreadYieldReason = yieldReason;
+			_activeForcedGuestExit = forcedExit;
+			return nativeReturn;
+		}
+		finally
+		{
+			ReturnNativeGuestExecutor(worker);
+		}
+	}
+
+	private NativeGuestExecutor? RentNativeGuestExecutor()
+	{
+		if (NativeGuestWorkersDisabled)
+		{
+			return null;
+		}
+		lock (_nativeWorkerGate)
+		{
+			if (_nativeWorkersDisposed)
+			{
+				return null;
+			}
+			if (_idleNativeWorkers.Count > 0)
+			{
+				return _idleNativeWorkers.Pop();
+			}
+		}
+		var worker = NativeGuestExecutor.TryCreate(this);
+		if (worker is null)
+		{
+			if (Interlocked.Exchange(ref _nativeWorkerCreationFailedLogged, 1) == 0)
+			{
+				Console.Error.WriteLine(
+					"[LOADER][WARN] Failed to create a native guest worker thread; falling back to inline guest execution.");
+			}
+			return null;
+		}
+		lock (_nativeWorkerGate)
+		{
+			if (_nativeWorkersDisposed)
+			{
+				worker.Dispose();
+				return null;
+			}
+			_allNativeWorkers.Add(worker);
+		}
+		return worker;
+	}
+
+	private void ReturnNativeGuestExecutor(NativeGuestExecutor worker)
+	{
+		lock (_nativeWorkerGate)
+		{
+			if (!_nativeWorkersDisposed)
+			{
+				_idleNativeWorkers.Push(worker);
+				return;
+			}
+		}
+		worker.Dispose();
+	}
+
+	private void DisposeNativeGuestExecutors()
+	{
+		NativeGuestExecutor[] workers;
+		lock (_nativeWorkerGate)
+		{
+			if (_nativeWorkersDisposed)
+			{
+				return;
+			}
+			_nativeWorkersDisposed = true;
+			workers = _allNativeWorkers.ToArray();
+			_allNativeWorkers.Clear();
+			_idleNativeWorkers.Clear();
+		}
+		foreach (var worker in workers)
+		{
+			worker.Dispose();
+		}
+	}
+
+	// A pooled raw OS thread that executes guest entry stubs. The run loop is emitted
+	// native code (no CLR unwind info required — nothing ever unwinds through it):
+	//
+	//   loop: WaitForSingleObject(work);
+	//         if (*stopFlag) { SetEvent(done); ExitThread(0); }
+	//         rax = RunPrologue(self);      // managed: binds per-run ambient, returns stub
+	//         if (rax != 0) eax = rax();    // guest entry stub — zero managed frames below
+	//         RunEpilogue(self, eax);       // managed: captures outcome, restores ambient
+	//         SetEvent(done); goto loop;
+	//
+	// Workers carry no per-guest identity of their own: the prologue rebinds guest TLS,
+	// the host-RSP slot, the Active* thread-statics and the GuestThreadExecution ambient
+	// on every run, so a worker can be reused for any guest thread.
+	private sealed unsafe class NativeGuestExecutor : IDisposable
+	{
+		private const uint LoopStubSize = 512u;
+		private const uint WorkerStackReservation = 4u * 1024u * 1024u;
+
+		private static nint _waitForSingleObjectAddress;
+		private static nint _setEventAddress;
+		private static nint _exitThreadAddress;
+
+		private readonly DirectExecutionBackend _backend;
+		private readonly AutoResetEvent _workAvailable = new(false);
+		private readonly AutoResetEvent _workCompleted = new(false);
+		private GCHandle _selfHandle;
+		private void* _controlBlock;
+		private void* _loopStub;
+		private nint _threadHandle;
+		private uint _nativeThreadId;
+
+		// Single in-flight run; publication is ordered by the work/done event pair.
+		private CpuContext? _runContext;
+		private GuestThreadState? _runState;
+		private ulong _runGuestThreadHandle;
+		private ulong _runSentinelRip;
+		private ulong _runReturnSlotAddress;
+		private nint _runHostRspSlot;
+		private nint _runEntryStub;
+		private ulong _runAffinityMask;
+		private int _runNativeResult;
+		private bool _runYieldRequested;
+		private string? _runYieldReason;
+		private bool _runForcedExit;
+		private bool _runPrologueFailed;
+
+		// Prologue -> epilogue carry, only touched on the worker thread.
+		private DirectExecutionBackend? _prevBackend;
+		private CpuContext? _prevContext;
+		private ulong _prevSentinel;
+		private ulong _prevReturnSlot;
+		private bool _prevForcedExit;
+		private bool _prevYieldRequested;
+		private string? _prevYieldReason;
+		private GuestThreadState? _prevState;
+		private ulong _prevGuestThreadHandle;
+		private nint _prevHostRspSlot;
+		private int _prevHostThreadId;
+		private bool _entered;
+
+		private NativeGuestExecutor(DirectExecutionBackend backend)
+		{
+			_backend = backend;
+		}
+
+		public static NativeGuestExecutor? TryCreate(DirectExecutionBackend backend)
+		{
+			if (!EnsureKernel32Exports())
+			{
+				return null;
+			}
+			var executor = new NativeGuestExecutor(backend);
+			if (!executor.Initialize())
+			{
+				executor.Dispose();
+				return null;
+			}
+			return executor;
+		}
+
+		private static bool EnsureKernel32Exports()
+		{
+			if (_exitThreadAddress != 0)
+			{
+				return _waitForSingleObjectAddress != 0 && _setEventAddress != 0;
+			}
+			nint kernel32 = GetModuleHandle("kernel32.dll");
+			if (kernel32 == 0)
+			{
+				return false;
+			}
+			_waitForSingleObjectAddress = GetProcAddress(kernel32, "WaitForSingleObject");
+			_setEventAddress = GetProcAddress(kernel32, "SetEvent");
+			_exitThreadAddress = GetProcAddress(kernel32, "ExitThread");
+			return _waitForSingleObjectAddress != 0 && _setEventAddress != 0 && _exitThreadAddress != 0;
+		}
+
+		private bool Initialize()
+		{
+			_selfHandle = GCHandle.Alloc(this);
+			_controlBlock = VirtualAlloc(null, 4096u, 12288u, 4u);
+			if (_controlBlock == null)
+			{
+				return false;
+			}
+			_loopStub = VirtualAlloc(null, LoopStubSize, 12288u, 64u);
+			if (_loopStub == null)
+			{
+				return false;
+			}
+
+			var prologuePtr = (nint)(delegate* unmanaged<nint, nint>)&RunPrologue;
+			var epiloguePtr = (nint)(delegate* unmanaged<nint, int, void>)&RunEpilogue;
+			var executorHandle = GCHandle.ToIntPtr(_selfHandle);
+			var workHandle = _workAvailable.SafeWaitHandle.DangerousGetHandle();
+			var doneHandle = _workCompleted.SafeWaitHandle.DangerousGetHandle();
+
+			byte* code = (byte*)_loopStub;
+			int offset = 0;
+			void Emit(byte value) => code[offset++] = value;
+			void EmitMovRcxImm64(ulong value)
+			{
+				Emit(0x48); Emit(0xB9);
+				*(ulong*)(code + offset) = value;
+				offset += sizeof(ulong);
+			}
+			void EmitMovRaxImm64(ulong value)
+			{
+				Emit(0x48); Emit(0xB8);
+				*(ulong*)(code + offset) = value;
+				offset += sizeof(ulong);
+			}
+			void EmitCallRax()
+			{
+				Emit(0xFF); Emit(0xD0);
+			}
+			void EmitSetDoneEvent()
+			{
+				EmitMovRcxImm64((ulong)doneHandle);
+				EmitMovRaxImm64((ulong)_setEventAddress);
+				EmitCallRax();
+			}
+
+			// Thread entry leaves RSP ≡ 8 (mod 16); after this every call below happens
+			// at RSP ≡ 0 with shadow space available.
+			Emit(0x48); Emit(0x83); Emit(0xEC); Emit(0x28); // sub rsp, 0x28
+			int loopStart = offset;
+			EmitMovRcxImm64((ulong)workHandle);
+			Emit(0xBA);                                     // mov edx, INFINITE
+			*(uint*)(code + offset) = 0xFFFFFFFFu;
+			offset += sizeof(uint);
+			EmitMovRaxImm64((ulong)_waitForSingleObjectAddress);
+			EmitCallRax();
+			EmitMovRaxImm64((ulong)_controlBlock);
+			Emit(0x83); Emit(0x38); Emit(0x00);             // cmp dword [rax], 0
+			Emit(0x0F); Emit(0x85);                         // jne stop
+			int stopJump = offset;
+			offset += sizeof(int);
+			EmitMovRcxImm64((ulong)executorHandle);
+			EmitMovRaxImm64((ulong)prologuePtr);
+			EmitCallRax();                                  // rax = entry stub, or 0 on failure
+			Emit(0x48); Emit(0x85); Emit(0xC0);             // test rax, rax
+			Emit(0x0F); Emit(0x84);                         // je skipEntry
+			int skipJump = offset;
+			offset += sizeof(int);
+			EmitCallRax();                                  // guest entry stub -> eax
+			int skipEntryOffset = offset;
+			Emit(0x89); Emit(0xC2);                         // mov edx, eax
+			EmitMovRcxImm64((ulong)executorHandle);
+			EmitMovRaxImm64((ulong)epiloguePtr);
+			EmitCallRax();
+			EmitSetDoneEvent();
+			Emit(0xE9);                                     // jmp loop
+			*(int*)(code + offset) = loopStart - (offset + sizeof(int));
+			offset += sizeof(int);
+			int stopOffset = offset;
+			// Signal done so a Run() racing teardown cannot park forever; a stopped
+			// worker is never re-rented, so the stale signal is unobservable.
+			EmitSetDoneEvent();
+			Emit(0x31); Emit(0xC9);                         // xor ecx, ecx
+			EmitMovRaxImm64((ulong)_exitThreadAddress);
+			EmitCallRax();
+			Emit(0xCC);                                     // int3 (ExitThread never returns)
+			*(int*)(code + stopJump) = stopOffset - (stopJump + sizeof(int));
+			*(int*)(code + skipJump) = skipEntryOffset - (skipJump + sizeof(int));
+
+			uint oldProtect = 0;
+			if (!VirtualProtect(_loopStub, LoopStubSize, 32u, &oldProtect))
+			{
+				return false;
+			}
+			FlushInstructionCache(GetCurrentProcess(), _loopStub, LoopStubSize);
+			_threadHandle = CreateThread(
+				0,
+				WorkerStackReservation,
+				(nint)_loopStub,
+				0,
+				StackSizeParamIsAReservation,
+				out _nativeThreadId);
+			if (_threadHandle == 0)
+			{
+				return false;
+			}
+			if (LogThreadMode)
+			{
+				TraceThreadMode($"worker_created native_tid={_nativeThreadId} loop=0x{(ulong)_loopStub:X16}");
+			}
+			return true;
+		}
+
+		public int Run(
+			CpuContext context,
+			GuestThreadState? state,
+			ulong guestThreadHandle,
+			ulong sentinelRip,
+			ulong returnSlotAddress,
+			nint hostRspSlot,
+			nint entryStub,
+			ulong affinityMask,
+			out bool yieldRequested,
+			out string? yieldReason,
+			out bool forcedExit)
+		{
+			_runContext = context;
+			_runState = state;
+			_runGuestThreadHandle = guestThreadHandle;
+			_runSentinelRip = sentinelRip;
+			_runReturnSlotAddress = returnSlotAddress;
+			_runHostRspSlot = hostRspSlot;
+			_runEntryStub = entryStub;
+			_runAffinityMask = affinityMask;
+			_runPrologueFailed = true;
+			_runYieldRequested = false;
+			_runYieldReason = null;
+			_runForcedExit = false;
+			_workAvailable.Set();
+			_workCompleted.WaitOne();
+			_runContext = null;
+			_runState = null;
+			yieldRequested = _runYieldRequested;
+			yieldReason = _runYieldReason;
+			forcedExit = _runForcedExit;
+			if (_runPrologueFailed)
+			{
+				throw new InvalidOperationException("Native guest worker failed to bind the run ambient (prologue fault)");
+			}
+			return _runNativeResult;
+		}
+
+		[UnmanagedCallersOnly]
+		private static nint RunPrologue(nint executorHandle)
+		{
+			try
+			{
+				var executor = (NativeGuestExecutor)GCHandle.FromIntPtr(executorHandle).Target!;
+				return executor.EnterRun();
+			}
+			catch (Exception ex)
+			{
+				try
+				{
+					Console.Error.WriteLine(
+						$"[LOADER][ERROR] Native guest worker prologue failed: {ex.GetType().Name}: {ex.Message}");
+				}
+				catch
+				{
+				}
+				return 0;
+			}
+		}
+
+		[UnmanagedCallersOnly]
+		private static void RunEpilogue(nint executorHandle, int nativeResult)
+		{
+			try
+			{
+				var executor = (NativeGuestExecutor)GCHandle.FromIntPtr(executorHandle).Target!;
+				executor.ExitRun(nativeResult);
+			}
+			catch (Exception ex)
+			{
+				try
+				{
+					Console.Error.WriteLine(
+						$"[LOADER][ERROR] Native guest worker epilogue failed: {ex.GetType().Name}: {ex.Message}");
+				}
+				catch
+				{
+				}
+			}
+		}
+
+		private nint EnterRun()
+		{
+			var backend = _backend;
+			_prevBackend = _activeExecutionBackend;
+			_prevContext = _activeCpuContext;
+			_prevSentinel = _activeEntryReturnSentinelRip;
+			_prevReturnSlot = _activeGuestReturnSlotAddress;
+			_prevForcedExit = _activeForcedGuestExit;
+			_prevYieldRequested = _activeGuestThreadYieldRequested;
+			_prevYieldReason = _activeGuestThreadYieldReason;
+			_prevState = _activeGuestThreadState;
+			_prevHostRspSlot = TlsGetValue(backend._hostRspSlotTlsIndex);
+			_prevGuestThreadHandle = GuestThreadExecution.EnterGuestThread(_runGuestThreadHandle);
+			_entered = true;
+			_activeExecutionBackend = backend;
+			_activeCpuContext = _runContext;
+			_activeEntryReturnSentinelRip = _runSentinelRip;
+			_activeGuestReturnSlotAddress = _runReturnSlotAddress;
+			_activeForcedGuestExit = false;
+			_activeGuestThreadYieldRequested = false;
+			_activeGuestThreadYieldReason = null;
+			_activeGuestThreadState = _runState;
+			backend.BindTlsBase(_runContext!);
+			TlsSetValue(backend._hostRspSlotTlsIndex, _runHostRspSlot);
+			if (_runState is { } state)
+			{
+				_prevHostThreadId = Volatile.Read(ref state.HostThreadId);
+				Volatile.Write(ref state.HostThreadId, unchecked((int)GetCurrentThreadId()));
+			}
+			if (_runAffinityMask != 0)
+			{
+				backend.ApplyGuestThreadAffinity(_runAffinityMask);
+			}
+			_runPrologueFailed = false;
+			if (LogThreadMode)
+			{
+				TraceThreadMode(
+					$"worker_enter guest=0x{_runGuestThreadHandle:X16} stub=0x{(ulong)_runEntryStub:X16}");
+			}
+			return _runEntryStub;
+		}
+
+		private void ExitRun(int nativeResult)
+		{
+			_runNativeResult = nativeResult;
+			_runYieldRequested = _activeGuestThreadYieldRequested;
+			_runYieldReason = _activeGuestThreadYieldReason;
+			_runForcedExit = _activeForcedGuestExit;
+			if (!_entered)
+			{
+				return;
+			}
+			_entered = false;
+			if (_runState is { } state)
+			{
+				Volatile.Write(ref state.HostThreadId, _prevHostThreadId);
+			}
+			TlsSetValue(_backend._hostRspSlotTlsIndex, _prevHostRspSlot);
+			GuestThreadExecution.RestoreGuestThread(_prevGuestThreadHandle);
+			_activeExecutionBackend = _prevBackend;
+			_activeCpuContext = _prevContext;
+			_activeEntryReturnSentinelRip = _prevSentinel;
+			_activeGuestReturnSlotAddress = _prevReturnSlot;
+			_activeForcedGuestExit = _prevForcedExit;
+			_activeGuestThreadYieldRequested = _prevYieldRequested;
+			_activeGuestThreadYieldReason = _prevYieldReason;
+			_activeGuestThreadState = _prevState;
+			_prevBackend = null;
+			_prevContext = null;
+			_prevState = null;
+			_prevYieldReason = null;
+			if (LogThreadMode)
+			{
+				TraceThreadMode(
+					$"worker_exit guest=0x{_runGuestThreadHandle:X16} result=0x{nativeResult:X8} yield={_runYieldRequested}");
+			}
+		}
+
+		public void Dispose()
+		{
+			if (_controlBlock != null)
+			{
+				*(int*)_controlBlock = 1;
+			}
+			try
+			{
+				_workAvailable.Set();
+			}
+			catch (ObjectDisposedException)
+			{
+			}
+			var exited = _threadHandle == 0;
+			if (_threadHandle != 0)
+			{
+				exited = WaitForSingleObject(_threadHandle, 1000u) == 0u;
+				CloseHandle(_threadHandle);
+				_threadHandle = 0;
+			}
+			if (!exited)
+			{
+				// The worker is still parked in guest code (teardown should have unwound
+				// it first). Leak the stub, control block, events and GC handle rather
+				// than have the thread execute freed memory.
+				Console.Error.WriteLine(
+					$"[LOADER][WARN] Native guest worker tid={_nativeThreadId} did not stop; leaking its run loop.");
+				return;
+			}
+			if (_loopStub != null)
+			{
+				VirtualFree(_loopStub, 0u, 32768u);
+				_loopStub = null;
+			}
+			if (_controlBlock != null)
+			{
+				VirtualFree(_controlBlock, 0u, 32768u);
+				_controlBlock = null;
+			}
+			if (_selfHandle.IsAllocated)
+			{
+				_selfHandle.Free();
+			}
+			_workAvailable.Dispose();
+			_workCompleted.Dispose();
+		}
+	}
+}

src/SharpEmu.Core/Loader/SelfLoader.cs

@@ -10,11 +10,13 @@ using SharpEmu.Core;
 using SharpEmu.Core.Cpu;
 using SharpEmu.Core.Memory;
 using SharpEmu.HLE;
+using SharpEmu.Logging;
 
 namespace SharpEmu.Core.Loader;
 
 public sealed class SelfLoader : ISelfLoader
 {
+    private static readonly SharpEmuLogger Log = SharpEmuLog.For("Loader");
     private const uint SelfMagic = 0x4F153D1D;
     private const ulong SelfSegmentFlag = 0x800;
     private const int PageSize = 0x1000;
@@ -155,7 +157,7 @@ public sealed class SelfLoader : ISelfLoader
         }
 
         var tlsModuleId = _nextTlsModuleId == 0 ? 1u : _nextTlsModuleId;
-        Console.Error.WriteLine($"[LOADER][TLS] load_start clear={clearVirtualMemory} next={_nextTlsModuleId} assigned={tlsModuleId}");
+        Log.Debug($"TLS load_start clear={clearVirtualMemory} next={_nextTlsModuleId} assigned={tlsModuleId}");
 
         var loadContext = ParseLayout(imageData);
         var elfHeader = ReadUnmanaged<ElfHeader>(imageData, loadContext.ElfOffset);
@@ -255,7 +257,7 @@ public sealed class SelfLoader : ISelfLoader
         {
             _nextTlsModuleId++;
         }
-        Console.Error.WriteLine($"[LOADER][TLS] load_done assigned={tlsModuleId} next={_nextTlsModuleId}");
+        Log.Debug($"TLS load_done assigned={tlsModuleId} next={_nextTlsModuleId}");
 
         return new SelfImage(
             loadContext.IsSelf,
@@ -403,15 +405,15 @@ public sealed class SelfLoader : ISelfLoader
 
             var virtualAddress = header.VirtualAddress + imageBase;
 
-            Console.Error.WriteLine($"[LOADER] Segment {index}: VAddr=0x{virtualAddress:X16}, FileSize=0x{header.FileSize:X}, MemSize=0x{header.MemorySize:X}, Align=0x{header.Alignment:X}");
+            Log.Debug($"Segment {index}: VAddr=0x{virtualAddress:X16}, FileSize=0x{header.FileSize:X}, MemSize=0x{header.MemorySize:X}, Align=0x{header.Alignment:X}");
             if (header.Alignment > 1)
             {
                 var vaddrMod = virtualAddress % header.Alignment;
                 var offsetMod = header.Offset % header.Alignment;
                 if (vaddrMod != offsetMod)
                 {
-                    Console.Error.WriteLine(
+                    Log.Warning(
-                        $"[LOADER] WARNING: Segment {index} ELF alignment mismatch! " +
+                        $"Segment {index} ELF alignment mismatch! " +
                         $"VAddr=0x{virtualAddress:X}, Offset=0x{header.Offset:X}, Align=0x{header.Alignment:X}, " +
                         $"VAddr%Align=0x{vaddrMod:X}, Offset%Align=0x{offsetMod:X}");
                 }
@@ -671,13 +673,13 @@ public sealed class SelfLoader : ISelfLoader
             {
                 if (descriptor.ValueKind == RelocationValueKind.TlsModuleId)
                 {
-                    Console.Error.WriteLine(
+                    Log.Debug(
-                        $"[LOADER][TLS] Patching DTPMOD64 at 0x{descriptor.TargetAddress:X} with module id 0x{targetValue:X}");
+                        $"Patching DTPMOD64 at 0x{descriptor.TargetAddress:X} with module id 0x{targetValue:X}");
                 }
                 else
                 {
-                    Console.Error.WriteLine($"[LOADER] !!! CRITICAL !!! Patching address 0x{descriptor.TargetAddress:X} with INVALID value 0x{targetValue:X} for NID {descriptor.ImportNid ?? "(null)"}");
+                    Log.Warning($"!!! CRITICAL !!! Patching address 0x{descriptor.TargetAddress:X} with INVALID value 0x{targetValue:X} for NID {descriptor.ImportNid ?? "(null)"}");
-                    Console.Error.WriteLine($"[LOADER]   SymbolValue=0x{descriptor.SymbolValue:X}, Addend=0x{descriptor.Addend:X}, StubAddress=0x{(addressesByNid.TryGetValue(descriptor.ImportNid ?? "", out var sa) ? sa : 0):X}");
+                    Log.Warning($"  SymbolValue=0x{descriptor.SymbolValue:X}, Addend=0x{descriptor.Addend:X}, StubAddress=0x{(addressesByNid.TryGetValue(descriptor.ImportNid ?? "", out var sa) ? sa : 0):X}");
                 }
             }
 
@@ -689,8 +691,8 @@ public sealed class SelfLoader : ISelfLoader
             if (descriptor.TargetAddress >= 0x00000008030FC300UL &&
                 descriptor.TargetAddress <= 0x00000008030FC3F0UL)
             {
-                Console.Error.WriteLine(
+                Log.Debug(
-                    $"[LOADER][RELOC] target=0x{descriptor.TargetAddress:X16} value=0x{targetValue:X16} addend=0x{descriptor.Addend:X} nid={(descriptor.ImportNid ?? "<sym>")}");
+                    $"[RELOC] target=0x{descriptor.TargetAddress:X16} value=0x{targetValue:X16} addend=0x{descriptor.Addend:X} nid={(descriptor.ImportNid ?? "<sym>")}");
             }
         }
 
@@ -783,15 +785,15 @@ public sealed class SelfLoader : ISelfLoader
         {
             if (IsFocusRelocationOffset(relocation.Offset, imageBase))
             {
-                Console.Error.WriteLine(
+                Log.Debug(
-                    $"[LOADER][FOCUS][SCAN] off=0x{relocation.Offset:X16} type={relocation.Type} sym={relocation.SymbolIndex} addend=0x{relocation.Addend:X}");
+                    $"[FOCUS][SCAN] off=0x{relocation.Offset:X16} type={relocation.Type} sym={relocation.SymbolIndex} addend=0x{relocation.Addend:X}");
             }
 
             if (!IsSupportedRelocationType(relocation.Type))
             {
                 if (IsFocusRelocationOffset(relocation.Offset, imageBase))
                 {
-                    Console.Error.WriteLine($"[LOADER][FOCUS][SKIP] unsupported type={relocation.Type}");
+                    Log.Debug($"[FOCUS][SKIP] unsupported type={relocation.Type}");
                 }
                 continue;
             }
@@ -800,7 +802,7 @@ public sealed class SelfLoader : ISelfLoader
             {
                 if (IsFocusRelocationOffset(relocation.Offset, imageBase))
                 {
-                    Console.Error.WriteLine("[LOADER][FOCUS][SKIP] target address not mapped");
+                    Log.Debug("[FOCUS][SKIP] target address not mapped");
                 }
                 continue;
             }
@@ -840,7 +842,7 @@ public sealed class SelfLoader : ISelfLoader
             {
                 if (targetAddress >= FocusRelocGuestStart && targetAddress <= FocusRelocGuestEnd)
                 {
-                    Console.Error.WriteLine($"[LOADER][FOCUS][SKIP] symbol read failed index={symbolIndex}");
+                    Log.Debug($"[FOCUS][SKIP] symbol read failed index={symbolIndex}");
                 }
                 continue;
             }
@@ -852,10 +854,9 @@ public sealed class SelfLoader : ISelfLoader
                 var symbolAddress = ResolveMappedAddressOrFallback(virtualMemory, symbol.Value, imageBase);
                 if (symbolAddress == 0)
                 {
-                    Console.Error.WriteLine(
+                    Log.Warning(
-                        $"[LOADER] Skipping local relocation with invalid symbol value 0x{symbol.Value:X} " +
+                        $"Skipping local relocation with invalid symbol value 0x{symbol.Value:X} " +
                         $"at target 0x{targetAddress:X16}, type={relocation.Type}, sym={symbolIndex}");
-                    continue;
                 }
 
                 descriptors.Add(new RelocationDescriptor(
@@ -873,10 +874,9 @@ public sealed class SelfLoader : ISelfLoader
                 var symbolAddress = ResolveMappedAddressOrFallback(virtualMemory, symbol.Value, imageBase);
                 if (symbolAddress == 0)
                 {
-                    Console.Error.WriteLine(
+                    Log.Warning(
-                        $"[LOADER] Skipping relocation with invalid symbol value 0x{symbol.Value:X} " +
+                        $"Skipping relocation with invalid symbol value 0x{symbol.Value:X} " +
                         $"at target 0x{targetAddress:X16}, type={relocation.Type}, sym={symbolIndex}");
-                    continue;
                 }
 
                 descriptors.Add(new RelocationDescriptor(
@@ -893,7 +893,7 @@ public sealed class SelfLoader : ISelfLoader
             {
                 if (targetAddress >= FocusRelocGuestStart && targetAddress <= FocusRelocGuestEnd)
                 {
-                    Console.Error.WriteLine($"[LOADER][FOCUS][SKIP] bind={symbolBind} not importable");
+                    Log.Debug($"[FOCUS][SKIP] bind={symbolBind} not importable");
                 }
                 continue;
             }
@@ -902,7 +902,7 @@ public sealed class SelfLoader : ISelfLoader
             {
                 if (targetAddress >= FocusRelocGuestStart && targetAddress <= FocusRelocGuestEnd)
                 {
-                    Console.Error.WriteLine($"[LOADER][FOCUS][SKIP] symbol name read failed offset={symbol.NameOffset}");
+                    Log.Debug($"[FOCUS][SKIP] symbol name read failed offset={symbol.NameOffset}");
                 }
                 continue;
             }
@@ -950,8 +950,8 @@ public sealed class SelfLoader : ISelfLoader
 
         if (sectionSymbols > 0 || dynamicSymbols > 0)
         {
-            Console.Error.WriteLine(
+            Log.Info(
-                $"[LOADER] Runtime symbol index populated: section={sectionSymbols}, dynamic={dynamicSymbols}, total={runtimeSymbols.Count}");
+                $"Runtime symbol index populated: section={sectionSymbols}, dynamic={dynamicSymbols}, total={runtimeSymbols.Count}");
         }
     }
 
@@ -1025,8 +1025,8 @@ public sealed class SelfLoader : ISelfLoader
 
         if (preInitializers.Count != 0 || initializers.Count != 0)
         {
-            Console.Error.WriteLine(
+            Log.Info(
-                $"[LOADER] Initializers discovered: preinit={preInitializers.Count}, init={initializers.Count}");
+                $"Initializers discovered: preinit={preInitializers.Count}, init={initializers.Count}");
         }
     }
 
@@ -1409,8 +1409,8 @@ public sealed class SelfLoader : ISelfLoader
 
         var requiredBytes = checked((ulong)orderedImportNids.Count * ImportStubSlotSize);
         var mapSize = AlignUp(Math.Max(requiredBytes, (ulong)PageSize), PageSize);
-        Console.Error.WriteLine(
+        Log.Debug(
-            $"[LOADER] CreateImportStubMapping: nids={orderedImportNids.Count}, required=0x{requiredBytes:X}, map_size=0x{mapSize:X}");
+            $"CreateImportStubMapping: nids={orderedImportNids.Count}, required=0x{requiredBytes:X}, map_size=0x{mapSize:X}");
         if (mapSize > int.MaxValue)
         {
             throw new NotSupportedException("Import stub mapping exceeds 2 GB and is not supported.");
@@ -1842,16 +1842,16 @@ public sealed class SelfLoader : ISelfLoader
         tableBytes = GC.AllocateUninitializedArray<byte>((int)size);
 
         var guestAddr = location + imageBase;
-        Console.Error.WriteLine($"[LOADER] TryLoadTableBytes: trying guest address 0x{guestAddr:X}");
+        Log.Debug($"TryLoadTableBytes: trying guest address 0x{guestAddr:X}");
         if (virtualMemory.TryRead(guestAddr, tableBytes))
         {
-            Console.Error.WriteLine($"[LOADER] TryLoadTableBytes: loaded from guest memory at 0x{guestAddr:X}");
+            Log.Debug($"TryLoadTableBytes: loaded from guest memory at 0x{guestAddr:X}");
             return true;
         }
 
         if (virtualMemory.TryRead(location, tableBytes))
         {
-            Console.Error.WriteLine($"[LOADER] TryLoadTableBytes: loaded from absolute guest address 0x{location:X}");
+            Log.Debug($"TryLoadTableBytes: loaded from absolute guest address 0x{location:X}");
             return true;
         }
 
@@ -1859,11 +1859,11 @@ public sealed class SelfLoader : ISelfLoader
         {
             var slice = elfData.Slice((int)location, (int)size);
             tableBytes = slice.ToArray();
-            Console.Error.WriteLine($"[LOADER] TryLoadTableBytes: loaded from elfData as file offset at 0x{location:X}");
+            Log.Debug($"TryLoadTableBytes: loaded from elfData as file offset at 0x{location:X}");
             return true;
         }
 
-        Console.Error.WriteLine($"[LOADER] TryLoadTableBytes: FAILED for location 0x{location:X}");
+        Log.Warning($"TryLoadTableBytes: FAILED for location 0x{location:X}");
         tableBytes = Array.Empty<byte>();
         return false;
     }
@@ -1920,17 +1920,17 @@ public sealed class SelfLoader : ISelfLoader
 
     private static ulong ResolveMappedAddressOrFallback(IVirtualMemory virtualMemory, ulong address, ulong imageBase)
     {
-        Console.Error.WriteLine($"[LOADER][TEST] ResolveMappedAddressOrFallback addr=0x{address:X} imageBase=0x{imageBase:X16}");
+        Log.Debug($"ResolveMappedAddressOrFallback addr=0x{address:X} imageBase=0x{imageBase:X16}");
 
         if (address == 0)
         {
-            Console.Error.WriteLine("[LOADER][TEST] -> return 0 (null)");
+            Log.Debug("-> return 0 (null)");
             return 0;
         }
 
         if (TryResolveMappedAddress(virtualMemory, address, imageBase, 1, out var resolved))
         {
-            Console.Error.WriteLine($"[LOADER][TEST] -> resolved raw 0x{resolved:X16}");
+            Log.Debug($"-> resolved raw 0x{resolved:X16}");
             return resolved;
         }
 
@@ -1939,18 +1939,18 @@ public sealed class SelfLoader : ISelfLoader
             var rebased = address + imageBase;
             if (TryResolveMappedAddress(virtualMemory, rebased, imageBase, 1, out var resolvedRebased))
             {
-                Console.Error.WriteLine($"[LOADER][TEST] -> resolved rebased 0x{resolvedRebased:X16}");
+                Log.Debug($"-> resolved rebased 0x{resolvedRebased:X16}");
                 return resolvedRebased;
             }
         }
 
         if (address < 0x10000)
         {
-            Console.Error.WriteLine($"[LOADER][TEST] -> reject small 0x{address:X}");
+            Log.Debug($"-> reject small 0x{address:X}");
             return 0;
         }
 
-        Console.Error.WriteLine($"[LOADER][TEST] -> fallback raw 0x{address:X}");
+        Log.Debug($"-> fallback raw 0x{address:X}");
         return address;
     }
 

src/SharpEmu.Core/Memory/PhysicalVirtualMemory.cs

@@ -4,14 +4,19 @@
 using System.Runtime.InteropServices;
 using SharpEmu.Core.Loader;
 using SharpEmu.HLE;
+using SharpEmu.Logging;
 
 namespace SharpEmu.Core.Memory;
 
 public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryAllocator, IDisposable
 {
-    private readonly object _gate = new();
+    private static readonly SharpEmuLogger Log = SharpEmuLog.For("VMEM");
+
+    private readonly ReaderWriterLockSlim _gate = new(LockRecursionPolicy.SupportsRecursion);
     private readonly object _guestAllocationGate = new();
+    private readonly object _allocationSearchHintGate = new();
     private readonly List<MemoryRegion> _regions = new();
+    private readonly Dictionary<(ulong DesiredAddress, ulong Alignment, bool Executable), ulong> _allocationSearchHints = new();
     private readonly Dictionary<ulong, ProgramHeaderFlags> _pageProtections = new();
     private bool _disposed;
     private const ulong PageSize = 0x1000;
@@ -19,7 +24,8 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
     private const ulong GuestAllocationArenaSize = 0x0100_0000;
     private const ulong GuestAllocationArenaStartOffset = PageSize;
     private const ulong LargeDataReserveThreshold = 0x4000_0000UL; // 1 GiB
-    private const ulong LazyReservePrimeBytes = 0x5000_0000UL; // 1.25 GiB
+    private const ulong FullCommitRegionLimit = 4UL << 30;
+    private const ulong DefaultLazyReservePrimeBytes = 0x0400_0000UL; // 64 MiB
     private const ulong LazyReservePrimeChunkBytes = 0x0200_0000UL; // 32 MiB
 
     private const uint MEM_COMMIT = 0x1000;
@@ -35,6 +41,7 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
 
     private ulong _guestAllocationArenaBase;
     private ulong _guestAllocationOffset;
+    private static readonly ulong LazyReservePrimeBytes = ResolveLazyReservePrimeBytes();
 
     [DllImport("kernel32.dll", SetLastError = true)]
     private static extern void* VirtualAlloc(void* lpAddress, nuint dwSize, uint flAllocationType, uint flProtect);
@@ -51,7 +58,11 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
     private static extern nuint VirtualQuery(void* lpAddress, out MemoryBasicInformation64 lpBuffer, nuint dwLength);
 
     [DllImport("kernel32.dll")]
-    private static extern void FlushInstructionCache(void* hProcess, void* lpBaseAddress, nuint dwSize);
+    private static extern void* GetCurrentProcess();
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool FlushInstructionCache(void* hProcess, void* lpBaseAddress, nuint dwSize);
 
     public bool TryAllocateAtExact(ulong desiredAddress, ulong size, bool executable, out ulong actualAddress)
     {
@@ -78,9 +89,10 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
             return false;
         }
 
-        lock (_gate)
+        _gate.EnterWriteLock();
+        try
         {
-            _regions.Add(new MemoryRegion
+            InsertRegionSorted(new MemoryRegion
             {
                 VirtualAddress = actualAddress,
                 Size = alignedSize,
@@ -89,9 +101,13 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
                 Protection = protection
             });
         }
+        finally
+        {
+            _gate.ExitWriteLock();
+        }
 
         var allocationKind = executable ? "executable memory" : "data memory";
-        Console.Error.WriteLine($"[VMEM] Allocated exact {allocationKind}: 0x{actualAddress:X16} - 0x{actualAddress + alignedSize:X16} ({alignedSize} bytes)");
+        TraceVmem($"Allocated exact {allocationKind}: 0x{actualAddress:X16} - 0x{actualAddress + alignedSize:X16} ({alignedSize} bytes)");
         return true;
     }
 
@@ -105,7 +121,9 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
         var protection = executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
         var allocationType = MEM_COMMIT | MEM_RESERVE;
         var reservedOnly = false;
-        var preferReserveOnly = !executable && alignedSize >= LargeDataReserveThreshold;
+        var preferReserveOnly = !executable &&
+            alignedSize >= LargeDataReserveThreshold &&
+            alignedSize > FullCommitRegionLimit;
 
         void* result = null;
         if (preferReserveOnly)
@@ -134,7 +152,7 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
                 throw new InvalidOperationException($"Failed to allocate exact mapping at 0x{desiredAddress:X16} ({alignedSize} bytes)");
             }
 
-            Console.Error.WriteLine($"[VMEM] Could not allocate at 0x{desiredAddress:X16}, trying any address...");
+            TraceVmem($"Could not allocate at 0x{desiredAddress:X16}, trying any address...");
             result = VirtualAlloc(null, (nuint)alignedSize, allocationType, protection);
 
             if (result == null)
@@ -188,12 +206,12 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
                     lazyPrimeState = committedBytes == primeBytes
                         ? $"ok:{committedBytes:X}"
                         : $"partial:{committedBytes:X}/{primeBytes:X}";
-                    Console.Error.WriteLine($"[VMEM] Primed lazy region: 0x{actualAddress:X16} - 0x{actualAddress + committedBytes:X16} ({committedBytes} bytes)");
+                    TraceVmem($"Primed lazy region: 0x{actualAddress:X16} - 0x{actualAddress + committedBytes:X16} ({committedBytes} bytes)");
                 }
                 else
                 {
                     lazyPrimeState = $"fail:{primeBytes:X}";
-                    Console.Error.WriteLine($"[VMEM] Failed to prime lazy region at 0x{actualAddress:X16} ({primeBytes} bytes), continuing with on-demand commit");
+                    TraceVmem($"Failed to prime lazy region at 0x{actualAddress:X16} ({primeBytes} bytes), continuing with on-demand commit");
                 }
             }
             else
@@ -202,9 +220,10 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
             }
         }
 
-        lock (_gate)
+        _gate.EnterWriteLock();
+        try
         {
-            _regions.Add(new MemoryRegion
+            InsertRegionSorted(new MemoryRegion
             {
                 VirtualAddress = actualAddress,
                 Size = alignedSize,
@@ -213,11 +232,15 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
                 Protection = protection
             });
         }
+        finally
+        {
+            _gate.ExitWriteLock();
+        }
 
         var allocationKind = reservedOnly
             ? "reserved data memory (lazy commit)"
             : (executable ? "executable memory" : "data memory");
-        Console.Error.WriteLine($"[VMEM] Allocated {allocationKind}: 0x{actualAddress:X16} - 0x{actualAddress + alignedSize:X16} ({alignedSize} bytes) lazy_prime={lazyPrimeState}");
+        TraceVmem($"Allocated {allocationKind}: 0x{actualAddress:X16} - 0x{actualAddress + alignedSize:X16} ({alignedSize} bytes) lazy_prime={lazyPrimeState}");
 
         return actualAddress;
     }
@@ -237,7 +260,8 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
 
         var alignedSize = AlignUp(size, PageSize);
         var effectiveAlignment = Math.Max(PageSize, alignment == 0 ? PageSize : alignment);
-        var cursor = AlignUp(desiredAddress, effectiveAlignment);
+        var requestedCursor = AlignUp(desiredAddress, effectiveAlignment);
+        var cursor = GetAllocationSearchCursor(desiredAddress, requestedCursor, effectiveAlignment, executable);
 
         for (var attempt = 0; attempt < 0x10000; attempt++)
         {
@@ -257,6 +281,7 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
                 actualAddress = AllocateAt(cursor, alignedSize, executable, allowAlternative: false);
                 if (actualAddress == cursor)
                 {
+                    UpdateAllocationSearchCursor(desiredAddress, effectiveAlignment, executable, actualAddress + alignedSize);
                     return true;
                 }
 
@@ -315,7 +340,8 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
     {
         lock (_guestAllocationGate)
         {
-            lock (_gate)
+            _gate.EnterWriteLock();
+            try
             {
                 foreach (var region in _regions)
                 {
@@ -323,6 +349,14 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
                 }
                 _regions.Clear();
                 _pageProtections.Clear();
+                lock (_allocationSearchHintGate)
+                {
+                    _allocationSearchHints.Clear();
+                }
+            }
+            finally
+            {
+                _gate.ExitWriteLock();
             }
 
             _guestAllocationArenaBase = 0;
@@ -343,7 +377,8 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
         var mapEnd = AlignUp(segmentEnd, PageSize);
         var mapSize = checked(mapEnd - mapStart);
 
-        lock (_gate)
+        _gate.EnterWriteLock();
+        try
         {
             var existingRegion = FindRegion(mapStart, mapSize);
             if (existingRegion == null)
@@ -374,7 +409,11 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
 
             ApplySegmentProtection(mapStart, mapEnd, protection);
 
-            Console.Error.WriteLine($"[VMEM] Mapped segment: 0x{virtualAddress:X16} - 0x{virtualAddress + memorySize:X16} (file: {fileData.Length} bytes, prot: {protection})");
+            TraceVmem($"Mapped segment: 0x{virtualAddress:X16} - 0x{virtualAddress + memorySize:X16} (file: {fileData.Length} bytes, prot: {protection})");
+        }
+        finally
+        {
+            _gate.ExitWriteLock();
         }
     }
 
@@ -419,13 +458,14 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
 
         if ((flags & ProgramHeaderFlags.Execute) != 0)
         {
-            FlushInstructionCache(null, (void*)address, (nuint)size);
+            FlushInstructionCache(GetCurrentProcess(), (void*)address, (nuint)size);
         }
     }
 
     public IReadOnlyList<VirtualMemoryRegion> SnapshotRegions()
     {
-        lock (_gate)
+        _gate.EnterReadLock();
+        try
         {
             var snapshot = new VirtualMemoryRegion[_regions.Count];
             for (var i = 0; i < _regions.Count; i++)
@@ -440,96 +480,240 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
             }
             return snapshot;
         }
+        finally
+        {
+            _gate.ExitReadLock();
+        }
     }
 
     public bool TryRead(ulong virtualAddress, Span<byte> destination)
     {
-        lock (_gate)
+        var requiresExclusiveAccess = false;
+        _gate.EnterReadLock();
+        try
         {
-            foreach (var region in _regions)
+            var region = FindRegion(virtualAddress, (ulong)destination.Length);
+            if (region is not null &&
+                TryResolveRegionOffset(
+                    virtualAddress,
+                    (ulong)destination.Length,
+                    region,
+                    out var offset))
             {
-                if (TryResolveRegionOffset(virtualAddress, (ulong)destination.Length, region, out var offset))
+                var srcPtr = (void*)(region.VirtualAddress + offset);
+                if (destination.IsEmpty)
                 {
-                    var srcPtr = (void*)(region.VirtualAddress + offset);
+                    return true;
-                    if (destination.IsEmpty)
+                }
-                    {
-                        return true;
-                    }
 
+                if (region.IsReservedOnly)
+                {
                     if (!EnsureRangeCommitted((ulong)srcPtr, (ulong)destination.Length, region))
                     {
                         return false;
                     }
+                }
 
-                    if (!TryTemporarilyProtectForRead((ulong)srcPtr, (ulong)destination.Length, region, out var touchedPages))
+                if (!CanReadWithoutProtectionChange((ulong)srcPtr, (ulong)destination.Length, region))
+                {
+                    requiresExclusiveAccess = true;
+                }
+                else
+                {
+                    fixed (byte* destPtr = destination)
                     {
-                        return false;
+                        Buffer.MemoryCopy(srcPtr, destPtr, (nuint)destination.Length, (nuint)destination.Length);
-                    }
-
-                    try
-                    {
-                        fixed (byte* destPtr = destination)
-                        {
-                            Buffer.MemoryCopy(srcPtr, destPtr, (nuint)destination.Length, (nuint)destination.Length);
-                        }
-                    }
-                    finally
-                    {
-                        RestorePageProtections(touchedPages);
                     }
 
                     return true;
                 }
             }
+        }
+        finally
+        {
+            _gate.ExitReadLock();
+        }
+
+        if (!requiresExclusiveAccess)
+        {
             return false;
         }
+
+        _gate.EnterWriteLock();
+        try
+        {
+            return TryReadExclusive(virtualAddress, destination);
+        }
+        finally
+        {
+            _gate.ExitWriteLock();
+        }
     }
 
     public bool TryWrite(ulong virtualAddress, ReadOnlySpan<byte> source)
     {
-        lock (_gate)
+        var requiresExclusiveAccess = false;
+        _gate.EnterReadLock();
+        try
         {
-            foreach (var region in _regions)
+            var region = FindRegion(virtualAddress, (ulong)source.Length);
+            if (region is not null &&
+                TryResolveRegionOffset(
+                    virtualAddress,
+                    (ulong)source.Length,
+                    region,
+                    out var offset))
             {
-                if (TryResolveRegionOffset(virtualAddress, (ulong)source.Length, region, out var offset))
+                var destPtr = (void*)(region.VirtualAddress + offset);
+                if (source.IsEmpty)
                 {
-                    var destPtr = (void*)(region.VirtualAddress + offset);
+                    return true;
-                    if (source.IsEmpty)
+                }
-                    {
-                        return true;
-                    }
 
+                if (region.IsReservedOnly)
+                {
                     if (!EnsureRangeCommitted((ulong)destPtr, (ulong)source.Length, region))
                     {
                         return false;
                     }
+                }
 
-                    if (!VirtualProtect(destPtr, (nuint)source.Length, PAGE_EXECUTE_READWRITE, out var oldProtect))
+                if (!CanWriteWithoutProtectionChange((ulong)destPtr, (ulong)source.Length, region))
+                {
+                    requiresExclusiveAccess = true;
+                }
+                else
+                {
+                    fixed (byte* srcPtr = source)
                     {
-                        return false;
+                        Buffer.MemoryCopy(srcPtr, destPtr, (nuint)source.Length, (nuint)source.Length);
-                    }
-
-                    try
-                    {
-                        fixed (byte* srcPtr = source)
-                        {
-                            Buffer.MemoryCopy(srcPtr, destPtr, (nuint)source.Length, (nuint)source.Length);
-                        }
-                    }
-                    finally
-                    {
-                        VirtualProtect(destPtr, (nuint)source.Length, oldProtect, out _);
-                        if (IsExecutableProtection(oldProtect))
-                        {
-                            FlushInstructionCache(null, destPtr, (nuint)source.Length);
-                        }
                     }
 
                     return true;
                 }
             }
+        }
+        finally
+        {
+            _gate.ExitReadLock();
+        }
+
+        if (!requiresExclusiveAccess)
+        {
             return false;
         }
+
+        _gate.EnterWriteLock();
+        try
+        {
+            return TryWriteExclusive(virtualAddress, source);
+        }
+        finally
+        {
+            _gate.ExitWriteLock();
+        }
+    }
+
+    private bool TryReadExclusive(ulong virtualAddress, Span<byte> destination)
+    {
+        var region = FindRegion(virtualAddress, (ulong)destination.Length);
+        if (region is not null &&
+            TryResolveRegionOffset(
+                virtualAddress,
+                (ulong)destination.Length,
+                region,
+                out var offset))
+        {
+            var srcPtr = (void*)(region.VirtualAddress + offset);
+            if (!EnsureRangeCommitted((ulong)srcPtr, (ulong)destination.Length, region))
+            {
+                return false;
+            }
+
+            if (CanReadWithoutProtectionChange((ulong)srcPtr, (ulong)destination.Length, region))
+            {
+                fixed (byte* destPtr = destination)
+                {
+                    Buffer.MemoryCopy(srcPtr, destPtr, (nuint)destination.Length, (nuint)destination.Length);
+                }
+
+                return true;
+            }
+
+            if (!TryTemporarilyProtectForRead((ulong)srcPtr, (ulong)destination.Length, region, out var touchedPages))
+            {
+                return false;
+            }
+
+            try
+            {
+                fixed (byte* destPtr = destination)
+                {
+                    Buffer.MemoryCopy(srcPtr, destPtr, (nuint)destination.Length, (nuint)destination.Length);
+                }
+            }
+            finally
+            {
+                RestorePageProtections(touchedPages);
+            }
+
+            return true;
+        }
+
+        return false;
+    }
+
+    private bool TryWriteExclusive(ulong virtualAddress, ReadOnlySpan<byte> source)
+    {
+        var region = FindRegion(virtualAddress, (ulong)source.Length);
+        if (region is not null &&
+            TryResolveRegionOffset(
+                virtualAddress,
+                (ulong)source.Length,
+                region,
+                out var offset))
+        {
+            var destPtr = (void*)(region.VirtualAddress + offset);
+            if (!EnsureRangeCommitted((ulong)destPtr, (ulong)source.Length, region))
+            {
+                return false;
+            }
+
+            if (CanWriteWithoutProtectionChange((ulong)destPtr, (ulong)source.Length, region))
+            {
+                fixed (byte* srcPtr = source)
+                {
+                    Buffer.MemoryCopy(srcPtr, destPtr, (nuint)source.Length, (nuint)source.Length);
+                }
+
+                return true;
+            }
+
+            if (!VirtualProtect(destPtr, (nuint)source.Length, PAGE_EXECUTE_READWRITE, out var oldProtect))
+            {
+                return false;
+            }
+
+            try
+            {
+                fixed (byte* srcPtr = source)
+                {
+                    Buffer.MemoryCopy(srcPtr, destPtr, (nuint)source.Length, (nuint)source.Length);
+                }
+            }
+            finally
+            {
+                VirtualProtect(destPtr, (nuint)source.Length, oldProtect, out _);
+                if (IsExecutableProtection(oldProtect))
+                {
+                    FlushInstructionCache(GetCurrentProcess(), destPtr, (nuint)source.Length);
+                }
+            }
+
+            return true;
+        }
+
+        return false;
     }
 
     public bool TryWriteUInt64(ulong virtualAddress, ulong value)
@@ -541,45 +725,76 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
 
     public void* GetPointer(ulong virtualAddress)
     {
-        lock (_gate)
+        _gate.EnterReadLock();
+        try
         {
-            foreach (var region in _regions)
+            return FindRegion(virtualAddress, 1) is not null
-            {
+                ? (void*)virtualAddress
-                if (virtualAddress >= region.VirtualAddress &&
+                : null;
-                    virtualAddress < region.VirtualAddress + region.Size)
+        }
-                {
+        finally
-                    return (void*)virtualAddress;
+        {
-                }
+            _gate.ExitReadLock();
-            }
-            return null;
         }
     }
 
     public bool IsAccessible(ulong virtualAddress, ulong size)
     {
-        lock (_gate)
+        _gate.EnterReadLock();
+        try
         {
-            foreach (var region in _regions)
+            return FindRegion(virtualAddress, size) is not null;
-            {
+        }
-                if (TryResolveRegionOffset(virtualAddress, size, region, out _))
+        finally
-                {
+        {
-                    return true;
+            _gate.ExitReadLock();
-                }
-            }
-            return false;
         }
     }
 
     private MemoryRegion? FindRegion(ulong address, ulong size)
     {
-        foreach (var region in _regions)
+        var low = 0;
+        var high = _regions.Count - 1;
+        MemoryRegion? candidate = null;
+        while (low <= high)
         {
-            if (TryResolveRegionOffset(address, size, region, out _))
+            var middle = low + ((high - low) >> 1);
+            var region = _regions[middle];
+            if (region.VirtualAddress <= address)
             {
-                return region;
+                candidate = region;
+                low = middle + 1;
+            }
+            else
+            {
+                high = middle - 1;
             }
         }
-        return null;
+
+        return candidate is not null &&
+            TryResolveRegionOffset(address, size, candidate, out _)
+                ? candidate
+                : null;
+    }
+
+    private void InsertRegionSorted(MemoryRegion region)
+    {
+        var low = 0;
+        var high = _regions.Count;
+        while (low < high)
+        {
+            var middle = low + ((high - low) >> 1);
+            if (_regions[middle].VirtualAddress < region.VirtualAddress)
+            {
+                low = middle + 1;
+            }
+            else
+            {
+                high = middle;
+            }
+        }
+
+        _regions.Insert(low, region);
     }
 
     private bool TryGetOverlappingRegionEnd(ulong address, ulong size, out ulong overlapEnd)
@@ -591,21 +806,67 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
         }
 
         var end = address + size;
-        lock (_gate)
+        _gate.EnterReadLock();
+        try
         {
             foreach (var region in _regions)
             {
                 var regionEnd = region.VirtualAddress + region.Size;
+                if (region.VirtualAddress >= end)
+                {
+                    break;
+                }
+
+                if (regionEnd <= address)
+                {
+                    continue;
+                }
+
                 if (address < regionEnd && region.VirtualAddress < end)
                 {
                     overlapEnd = Math.Max(overlapEnd, regionEnd);
                 }
             }
         }
+        finally
+        {
+            _gate.ExitReadLock();
+        }
 
         return overlapEnd != 0;
     }
 
+    private ulong GetAllocationSearchCursor(
+        ulong desiredAddress,
+        ulong requestedCursor,
+        ulong alignment,
+        bool executable)
+    {
+        lock (_allocationSearchHintGate)
+        {
+            var key = (desiredAddress, alignment, executable);
+            if (_allocationSearchHints.TryGetValue(key, out var hintedCursor) &&
+                hintedCursor > requestedCursor)
+            {
+                return AlignUp(hintedCursor, alignment);
+            }
+        }
+
+        return requestedCursor;
+    }
+
+    private void UpdateAllocationSearchCursor(
+        ulong desiredAddress,
+        ulong alignment,
+        bool executable,
+        ulong nextCursor)
+    {
+        lock (_allocationSearchHintGate)
+        {
+            _allocationSearchHints[(desiredAddress, alignment, executable)] = AlignUp(nextCursor, alignment);
+        }
+    }
+
     private static bool TryResolveRegionOffset(ulong address, ulong size, MemoryRegion region, out ulong offset)
     {
         offset = 0;
@@ -633,6 +894,44 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
         return protection is PAGE_EXECUTE or PAGE_EXECUTE_READ or PAGE_EXECUTE_READWRITE or PAGE_EXECUTE_WRITECOPY;
     }
 
+    private bool CanReadWithoutProtectionChange(ulong address, ulong size, MemoryRegion region) =>
+        CanAccessWithoutProtectionChange(address, size, region, write: false);
+
+    private bool CanWriteWithoutProtectionChange(ulong address, ulong size, MemoryRegion region) =>
+        CanAccessWithoutProtectionChange(address, size, region, write: true);
+
+    private bool CanAccessWithoutProtectionChange(ulong address, ulong size, MemoryRegion region, bool write)
+    {
+        var startPage = AlignDown(address, PageSize);
+        var endPage = AlignUp(address + size, PageSize);
+        for (var pageAddress = startPage; pageAddress < endPage; pageAddress += PageSize)
+        {
+            if (_pageProtections.TryGetValue(pageAddress, out var flags))
+            {
+                if (write ? (flags & ProgramHeaderFlags.Write) == 0 : (flags & ProgramHeaderFlags.Read) == 0)
+                {
+                    return false;
+                }
+            }
+            else if (write ? !IsWritableProtection(region.Protection) : !IsReadableProtection(region.Protection))
+            {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    private static bool IsReadableProtection(uint protection)
+    {
+        return protection is PAGE_READONLY or PAGE_READWRITE or PAGE_EXECUTE_READ or PAGE_EXECUTE_READWRITE;
+    }
+
+    private static bool IsWritableProtection(uint protection)
+    {
+        return protection is PAGE_READWRITE or PAGE_EXECUTE_READWRITE;
+    }
+
     private static uint GetCommitProtection(MemoryRegion region)
     {
         return region.IsExecutable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
@@ -649,15 +948,26 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
         var endPage = AlignUp(address + size, PageSize);
         var commitProtection = GetCommitProtection(region);
 
-        for (var pageAddress = startPage; pageAddress < endPage; pageAddress += PageSize)
+        var pageAddress = startPage;
+        while (pageAddress < endPage)
         {
             if (VirtualQuery((void*)pageAddress, out var info, (nuint)sizeof(MemoryBasicInformation64)) == 0)
             {
                 return false;
             }
 
+            var queriedEnd = info.RegionSize > ulong.MaxValue - info.BaseAddress
+                ? ulong.MaxValue
+                : info.BaseAddress + info.RegionSize;
+            var rangeEnd = Math.Min(endPage, queriedEnd);
+            if (rangeEnd <= pageAddress)
+            {
+                return false;
+            }
+
             if (info.State == MEM_COMMIT)
             {
+                pageAddress = rangeEnd;
                 continue;
             }
 
@@ -666,10 +976,13 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
                 return false;
             }
 
-            if (VirtualAlloc((void*)pageAddress, (nuint)PageSize, MEM_COMMIT, commitProtection) == null)
+            var commitSize = rangeEnd - pageAddress;
+            if (VirtualAlloc((void*)pageAddress, (nuint)commitSize, MEM_COMMIT, commitProtection) == null)
             {
                 return false;
             }
+
+            pageAddress = rangeEnd;
         }
 
         return true;
@@ -722,6 +1035,29 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
         return checked((value + mask) & ~mask);
     }
 
+    private static ulong ResolveLazyReservePrimeBytes()
+    {
+        var configured = Environment.GetEnvironmentVariable("SHARPEMU_LAZY_RESERVE_PRIME_MB");
+        if (ulong.TryParse(configured, out var megabytes))
+        {
+            return megabytes == 0
+                ? 0
+                : checked(Math.Min(megabytes, 4096UL) * 1024UL * 1024UL);
+        }
+
+        return DefaultLazyReservePrimeBytes;
+    }
+
+    private static void TraceVmem(string message)
+    {
+        if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_VMEM"), "1", StringComparison.Ordinal))
+        {
+            return;
+        }
+
+        Log.Debug(message);
+    }
+
     public void Dispose()
     {
         if (!_disposed)

src/SharpEmu.Core/Runtime/SharpEmuRuntime.cs

@@ -10,15 +10,20 @@ using SharpEmu.HLE;
 using SharpEmu.Libs.VideoOut;
 using SharpEmu.Libs.Kernel;
 using SharpEmu.Libs.AppContent;
+using SharpEmu.Libs.SaveData;
+using SharpEmu.Logging;
 using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using System.IO;
 
 namespace SharpEmu.Core.Runtime;
 
 public sealed class SharpEmuRuntime : ISharpEmuRuntime
 {
+    private static readonly SharpEmuLogger Log = SharpEmuLog.For("Runtime");
+
     private readonly record struct LoadedModuleImage(string Path, SelfImage Image);
 
     private static readonly HashSet<string> PreloadSkipModules = new(StringComparer.OrdinalIgnoreCase)
@@ -127,7 +132,7 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
     {
         var normalizedEbootPath = Path.GetFullPath(ebootPath);
         using var app0Binding = BindApp0Root(normalizedEbootPath);
-        Console.Error.WriteLine($"[RUNTIME] Loading: {ebootPath}");
+        Log.Info($"Loading: {ebootPath}");
         LastExecutionDiagnostics = null;
         LastExecutionTrace = null;
         LastSessionSummary = null;
@@ -136,9 +141,11 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
         KernelModuleRegistry.Reset();
         var image = LoadImage(normalizedEbootPath);
         VideoOutExports.ConfigureApplicationInfo(image.Title, image.TitleId, image.Version);
+        SaveDataExports.ConfigureApplicationInfo(image.TitleId);
+        LogAppBundleInfo(normalizedEbootPath, image);
         RegisterLoadedModule(normalizedEbootPath, image, isMain: true, isSystemModule: false);
         KernelRuntimeCompatExports.ConfigureProcessProcParamAddress(image.ProcParamAddress);
-        Console.Error.WriteLine($"[RUNTIME] Entry: 0x{image.EntryPoint:X16}");
+        Log.Info($"Entry: 0x{image.EntryPoint:X16}");
         var generation = image.ElfHeader.AbiVersion == 2 ? Generation.Gen5 : Generation.Gen4;
         var activeImportStubs = new Dictionary<ulong, string>(image.ImportStubs);
         var activeRuntimeSymbols = new Dictionary<string, ulong>(image.RuntimeSymbols, StringComparer.Ordinal);
@@ -161,7 +168,7 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
             processImageName);
         if (initializerResult is { } failedInitializerResult)
         {
-            Console.Error.WriteLine($"[RUNTIME] Initializer dispatch failed: {failedInitializerResult}");
+            Log.Error($"Initializer dispatch failed: {failedInitializerResult}");
             LastExecutionTrace = _cpuDispatcher.LastImportResolutionTrace;
             LastMilestoneLog = _cpuDispatcher.LastMilestoneLog;
             LastSessionSummary = BuildSessionSummary(_cpuDispatcher.LastSessionSummary);
@@ -169,8 +176,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
             return failedInitializerResult;
         }
 
-        Console.Error.WriteLine($"[RUNTIME] Dispatching, gen: {generation}");
+        Log.Info($"Dispatching, gen: {generation}");
-        Console.Error.WriteLine($"[RUNTIME] About to call DispatchEntry with entryPoint=0x{image.EntryPoint:X16}");
+        Log.Debug($"About to call DispatchEntry with entryPoint=0x{image.EntryPoint:X16}");
 
         var result = _cpuDispatcher.DispatchEntry(
             image.EntryPoint,
@@ -180,8 +187,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
             processImageName,
             _cpuExecutionOptions);
 
-        Console.Error.WriteLine($"[RUNTIME] DispatchEntry returned: {result}");
+        Log.Info($"DispatchEntry returned: {result}");
-        Console.Error.WriteLine($"[RUNTIME] Dispatch result: {result}");
+        Log.Info($"Dispatch result: {result}");
         LastExecutionTrace = _cpuDispatcher.LastImportResolutionTrace;
         LastMilestoneLog = _cpuDispatcher.LastMilestoneLog;
         LastSessionSummary = BuildSessionSummary(_cpuDispatcher.LastSessionSummary);
@@ -352,6 +359,66 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
         return result;
     }
 
+    private static void LogAppBundleInfo(string ebootPath, SelfImage image)
+    {
+        var executableName = Path.GetFileName(ebootPath);
+        if (string.IsNullOrWhiteSpace(executableName))
+        {
+            executableName = "eboot.bin";
+        }
+
+        var displayName = string.IsNullOrWhiteSpace(image.Title) ? "(unknown)" : image.Title!.Trim();
+        var titleId = string.IsNullOrWhiteSpace(image.TitleId) ? "(unknown)" : image.TitleId!.Trim();
+        var version = string.IsNullOrWhiteSpace(image.Version) ? "(unknown)" : image.Version!.Trim();
+        var contentId = ResolveContentId(Path.GetDirectoryName(ebootPath)) ?? "(unknown)";
+
+        var builder = new StringBuilder();
+        builder.AppendLine("App bundle info:");
+        builder.AppendLine($"- Display name: {displayName}");
+        builder.AppendLine($"- Version: {version}");
+        builder.AppendLine($"- Title ID: {titleId}");
+        builder.AppendLine($"- Content ID: {contentId}");
+        builder.AppendLine($"- Executable: {executableName}");
+        builder.Append("- Platform: PlayStation 5");
+        Log.Info(builder.ToString());
+    }
+
+    private static string? ResolveContentId(string? bundleRoot)
+    {
+        if (string.IsNullOrEmpty(bundleRoot))
+        {
+            return null;
+        }
+
+        foreach (var candidate in new[]
+        {
+            Path.Combine(bundleRoot, "sce_sys", "param.json"),
+            Path.Combine(bundleRoot, "param.json"),
+        })
+        {
+            if (!File.Exists(candidate))
+            {
+                continue;
+            }
+
+            try
+            {
+                using var doc = System.Text.Json.JsonDocument.Parse(File.ReadAllBytes(candidate));
+                if (doc.RootElement.TryGetProperty("contentId", out var contentId))
+                {
+                    return contentId.GetString();
+                }
+            }
+            catch (Exception ex) when (ex is IOException or System.Text.Json.JsonException)
+            {
+            }
+
+            break;
+        }
+
+        return null;
+    }
+
     private static App0BindingScope? BindApp0Root(string normalizedEbootPath)
     {
         const string app0VariableName = "SHARPEMU_APP0_DIR";
@@ -432,8 +499,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
                 moduleName = $"module#{i}";
             }
 
-            Console.Error.WriteLine(
+            Log.Info(
-                $"[RUNTIME] Starting module {moduleName}: dt_init=0x{initEntryPoint:X16}");
+                $"Starting module {moduleName}: dt_init=0x{initEntryPoint:X16}");
 
             var result = _cpuDispatcher.DispatchModuleInitializer(
                 initEntryPoint,
@@ -444,8 +511,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
                 _cpuExecutionOptions);
             if (result != OrbisGen2Result.ORBIS_GEN2_OK)
             {
-                Console.Error.WriteLine(
+                Log.Error(
-                    $"[RUNTIME] Module start failed: {moduleName} -> {result}");
+                    $"Module start failed: {moduleName} -> {result}");
                 return result;
             }
         }
@@ -466,8 +533,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
             return null;
         }
 
-        Console.Error.WriteLine(
+        Log.Info(
-            $"[RUNTIME] Running initializers for {label}: preinit={image.PreInitializerFunctions.Count}, init={image.InitializerFunctions.Count}");
+            $"Running initializers for {label}: preinit={image.PreInitializerFunctions.Count}, init={image.InitializerFunctions.Count}");
 
         var result = RunInitializerList(
             $"{label}:preinit",
@@ -506,8 +573,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
                 continue;
             }
 
-            Console.Error.WriteLine(
+            Log.Debug(
-                $"[RUNTIME]   Initializer {label}[{i}] -> 0x{initializerAddress:X16}");
+                $"  Initializer {label}[{i}] -> 0x{initializerAddress:X16}");
 
             var result = _cpuDispatcher.DispatchEntry(
                 initializerAddress,
@@ -541,6 +608,7 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
         {
             Path.Combine(ebootDirectory, "sce_module"),
             Path.Combine(ebootDirectory, "sce_modules"),
+            Path.Combine(ebootDirectory, "Media", "Modules"),
         }
         .Distinct(StringComparer.OrdinalIgnoreCase)
         .Where(Directory.Exists)
@@ -552,7 +620,9 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
         }
 
         var allModulePaths = moduleDirectories
-            .SelectMany(Directory.EnumerateFiles)
+            .SelectMany(directory => Directory
+                .EnumerateFiles(directory)
+                .OrderBy(path => path, StringComparer.OrdinalIgnoreCase))
             .Where(path =>
             {
                 var extension = Path.GetExtension(path);
@@ -560,7 +630,6 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
                        string.Equals(extension, ".sprx", StringComparison.OrdinalIgnoreCase);
             })
             .Distinct(StringComparer.OrdinalIgnoreCase)
-            .OrderBy(path => path, StringComparer.OrdinalIgnoreCase)
             .ToArray();
 
         var modulePaths = allModulePaths
@@ -573,7 +642,7 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
             .ToArray();
         if (skippedModules.Length > 0)
         {
-            Console.Error.WriteLine($"[RUNTIME] Skipping {skippedModules.Length} core module(s): {string.Join(", ", skippedModules)}");
+            Log.Info($"Skipping {skippedModules.Length} core module(s): {string.Join(", ", skippedModules)}");
         }
 
         if (modulePaths.Length == 0)
@@ -581,8 +650,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
             return loadedImages;
         }
 
-        Console.Error.WriteLine($"[RUNTIME] Module search directories: {string.Join(", ", moduleDirectories)}");
+        Log.Debug($"Module search directories: {string.Join(", ", moduleDirectories)}");
-        Console.Error.WriteLine($"[RUNTIME] Loading {modulePaths.Length} module(s)...");
+        Log.Info($"Loading {modulePaths.Length} module(s)...");
         var loadedModules = 0;
         var failedModules = 0;
         var mergedImportCount = 0;
@@ -617,18 +686,18 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
                 loadedImages.Add(new LoadedModuleImage(modulePath, moduleImage));
                 loadedModules++;
 
-                Console.Error.WriteLine(
+                Log.Info(
-                    $"[RUNTIME] Loaded module {Path.GetFileName(modulePath)}: entry=0x{moduleImage.EntryPoint:X16}, imports={moduleImage.ImportStubs.Count}, symbols={moduleImage.RuntimeSymbols.Count}");
+                    $"Loaded module {Path.GetFileName(modulePath)}: entry=0x{moduleImage.EntryPoint:X16}, imports={moduleImage.ImportStubs.Count}, symbols={moduleImage.RuntimeSymbols.Count}");
             }
             catch (Exception ex)
             {
                 failedModules++;
-                Console.Error.WriteLine($"[RUNTIME] Module load failed: {modulePath} ({ex.GetType().Name}: {ex.Message})");
+                Log.Error($"Module load failed: {modulePath} ({ex.GetType().Name}: {ex.Message})", ex);
             }
         }
 
-        Console.Error.WriteLine(
+        Log.Info(
-            $"[RUNTIME] Module preload summary: loaded={loadedModules}, failed={failedModules}, merged_imports={mergedImportCount}, merged_symbols={mergedSymbolCount}");
+            $"Module preload summary: loaded={loadedModules}, failed={failedModules}, merged_imports={mergedImportCount}, merged_symbols={mergedSymbolCount}");
         return loadedImages;
     }
 
@@ -648,8 +717,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
 
         if (rebound != 0 || unresolved != 0)
         {
-            Console.Error.WriteLine(
+            Log.Info(
-                $"[RUNTIME] Imported data rebind: rebound={rebound}, unresolved={unresolved}");
+                $"Imported data rebind: rebound={rebound}, unresolved={unresolved}");
         }
     }
 
@@ -681,8 +750,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
             {
                 if (logRebind)
                 {
-                    Console.Error.WriteLine(
+                    Log.Warning(
-                        $"[RUNTIME] Imported data unresolved: nid={relocation.Nid} target=0x{relocation.TargetAddress:X16} addend=0x{unchecked((ulong)relocation.Addend):X16}");
+                        $"Imported data unresolved: nid={relocation.Nid} target=0x{relocation.TargetAddress:X16} addend=0x{unchecked((ulong)relocation.Addend):X16}");
                 }
 
                 unresolved++;
@@ -694,8 +763,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
             {
                 if (logRebind)
                 {
-                    Console.Error.WriteLine(
+                    Log.Error(
-                        $"[RUNTIME] Imported data write-failed: nid={relocation.Nid} target=0x{relocation.TargetAddress:X16} value=0x{reboundValue:X16}");
+                        $"Imported data write-failed: nid={relocation.Nid} target=0x{relocation.TargetAddress:X16} value=0x{reboundValue:X16}");
                 }
 
                 unresolved++;
@@ -704,8 +773,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
 
             if (logRebind)
             {
-                Console.Error.WriteLine(
+                Log.Debug(
-                    $"[RUNTIME] Imported data rebound: nid={relocation.Nid} target=0x{relocation.TargetAddress:X16} value=0x{reboundValue:X16}");
+                    $"Imported data rebound: nid={relocation.Nid} target=0x{relocation.TargetAddress:X16} value=0x{reboundValue:X16}");
             }
 
             rebound++;
@@ -741,8 +810,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
             {
                 if (!string.Equals(existingNid, nid, StringComparison.Ordinal))
                 {
-                    Console.Error.WriteLine(
+                    Log.Warning(
-                        $"[RUNTIME] Import stub conflict at 0x{address:X16}: keep={existingNid}, skip={nid} ({Path.GetFileName(modulePath)})");
+                        $"Import stub conflict at 0x{address:X16}: keep={existingNid}, skip={nid} ({Path.GetFileName(modulePath)})");
                 }
 
                 continue;
@@ -851,8 +920,8 @@ public sealed class SharpEmuRuntime : ISharpEmuRuntime
             image.EntryPoint,
             isMain,
             isSystemModule);
-        Console.Error.WriteLine(
+        Log.Info(
-            $"[RUNTIME] Registered module handle={handle} name={Path.GetFileName(modulePath)} base=0x{baseAddress:X16} size=0x{size:X16}");
+            $"Registered module handle={handle} name={Path.GetFileName(modulePath)} base=0x{baseAddress:X16} size=0x{size:X16}");
     }
 
     private static bool TryComputeImageRange(SelfImage image, out ulong baseAddress, out ulong size)

src/SharpEmu.Core/SharpEmu.Core.csproj

@@ -1,4 +1,4 @@
-<!--
+<!--
 Copyright (C) 2026 SharpEmu Emulator Project
 SPDX-License-Identifier: GPL-2.0-or-later
 -->
@@ -14,6 +14,10 @@ SPDX-License-Identifier: GPL-2.0-or-later
     <PackageReference Include="Iced" />
   </ItemGroup>
 
+  <PropertyGroup>
+    <NoWarn>$(NoWarn);1591</NoWarn>
+  </PropertyGroup>
+
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>

src/SharpEmu.Core/packages.lock.json

@@ -72,6 +72,7 @@
         "dependencies": {
           "SharpEmu.HLE": "[1.0.0, )",
           "Silk.NET.Vulkan": "[2.23.0, )",
+          "Silk.NET.Vulkan.Extensions.EXT": "[2.23.0, )",
           "Silk.NET.Vulkan.Extensions.KHR": "[2.23.0, )",
           "Silk.NET.Windowing": "[2.23.0, )"
         }
@@ -88,6 +89,16 @@
           "Silk.NET.Core": "2.23.0"
         }
       },
+      "Silk.NET.Vulkan.Extensions.EXT": {
+        "type": "CentralTransitive",
+        "requested": "[2.23.0, )",
+        "resolved": "2.23.0",
+        "contentHash": "+Oth189ksRiL6HvGCwIdnsYHawqrbO8y49u1H61z3wsfcHhQZeVDYe/wF5LD7fk3NcdgDvwFD3mLm1QWhdZySw==",
+        "dependencies": {
+          "Silk.NET.Core": "2.23.0",
+          "Silk.NET.Vulkan": "2.23.0"
+        }
+      },
       "Silk.NET.Vulkan.Extensions.KHR": {
         "type": "CentralTransitive",
         "requested": "[2.23.0, )",

src/SharpEmu.GUI/App.axaml

@@ -0,0 +1,198 @@
+<!--
+Copyright (C) 2026 SharpEmu Emulator Project
+SPDX-License-Identifier: GPL-2.0-or-later
+-->
+
+<Application xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             x:Class="SharpEmu.GUI.App"
+             RequestedThemeVariant="Dark">
+
+  <Application.Resources>
+    <Color x:Key="SystemAccentColor">#7C5CFC</Color>
+
+    <LinearGradientBrush x:Key="BgBrush" StartPoint="0%,0%" EndPoint="100%,100%">
+      <GradientStop Offset="0" Color="#12151F" />
+      <GradientStop Offset="0.55" Color="#0D1017" />
+      <GradientStop Offset="1" Color="#0B0D14" />
+    </LinearGradientBrush>
+
+    <SolidColorBrush x:Key="ChromeBrush" Color="#090C12" />
+    <SolidColorBrush x:Key="CardBrush" Color="#141924" />
+    <SolidColorBrush x:Key="CardBorderBrush" Color="#232B3A" />
+    <SolidColorBrush x:Key="ElevatedBrush" Color="#1B2230" />
+    <SolidColorBrush x:Key="TextBrush" Color="#E8ECF4" />
+    <SolidColorBrush x:Key="MutedBrush" Color="#8B94A7" />
+    <SolidColorBrush x:Key="FaintBrush" Color="#5A6478" />
+    <SolidColorBrush x:Key="AccentBrush" Color="#7C5CFC" />
+    <SolidColorBrush x:Key="AccentHoverBrush" Color="#8F73FF" />
+    <SolidColorBrush x:Key="DangerBrush" Color="#E5484D" />
+    <SolidColorBrush x:Key="DangerHoverBrush" Color="#F2555A" />
+    <SolidColorBrush x:Key="SuccessBrush" Color="#46C46B" />
+    <SolidColorBrush x:Key="TileHoverBrush" Color="#1A2130" />
+    <SolidColorBrush x:Key="TileSelectedBrush" Color="#212A3F" />
+  </Application.Resources>
+
+  <Application.Styles>
+    <FluentTheme />
+
+    <Style Selector="Window">
+      <Setter Property="FontFamily" Value="Inter, Segoe UI, sans-serif" />
+      <Setter Property="Foreground" Value="{StaticResource TextBrush}" />
+    </Style>
+
+    <Style Selector="Border.card">
+      <Setter Property="Background" Value="{StaticResource CardBrush}" />
+      <Setter Property="BorderBrush" Value="{StaticResource CardBorderBrush}" />
+      <Setter Property="BorderThickness" Value="1" />
+      <Setter Property="CornerRadius" Value="12" />
+      <Setter Property="Padding" Value="16" />
+    </Style>
+
+    <Style Selector="Border.pill">
+      <Setter Property="Background" Value="{StaticResource ElevatedBrush}" />
+      <Setter Property="CornerRadius" Value="999" />
+      <Setter Property="Padding" Value="10,3" />
+    </Style>
+
+    <Style Selector="TextBlock.sectionTitle">
+      <Setter Property="FontSize" Value="11" />
+      <Setter Property="FontWeight" Value="SemiBold" />
+      <Setter Property="LetterSpacing" Value="1.5" />
+      <Setter Property="Foreground" Value="{StaticResource MutedBrush}" />
+    </Style>
+
+    <Style Selector="TextBlock.fieldLabel">
+      <Setter Property="FontSize" Value="12" />
+      <Setter Property="Foreground" Value="{StaticResource MutedBrush}" />
+      <Setter Property="Margin" Value="0,0,0,6" />
+    </Style>
+
+    <Style Selector="TextBox">
+      <Setter Property="CornerRadius" Value="8" />
+    </Style>
+
+    <Style Selector="Button.accent">
+      <Setter Property="Background" Value="{StaticResource AccentBrush}" />
+      <Setter Property="Foreground" Value="White" />
+      <Setter Property="FontWeight" Value="SemiBold" />
+      <Setter Property="Padding" Value="22,10" />
+      <Setter Property="CornerRadius" Value="8" />
+    </Style>
+    <Style Selector="Button.accent:pointerover /template/ ContentPresenter#PART_ContentPresenter">
+      <Setter Property="Background" Value="{StaticResource AccentHoverBrush}" />
+      <Setter Property="Foreground" Value="White" />
+    </Style>
+
+    <Style Selector="Button.danger">
+      <Setter Property="Background" Value="{StaticResource DangerBrush}" />
+      <Setter Property="Foreground" Value="White" />
+      <Setter Property="FontWeight" Value="SemiBold" />
+      <Setter Property="Padding" Value="22,10" />
+      <Setter Property="CornerRadius" Value="8" />
+    </Style>
+    <Style Selector="Button.danger:pointerover /template/ ContentPresenter#PART_ContentPresenter">
+      <Setter Property="Background" Value="{StaticResource DangerHoverBrush}" />
+      <Setter Property="Foreground" Value="White" />
+    </Style>
+
+    <Style Selector="Button.ghost">
+      <Setter Property="Background" Value="Transparent" />
+      <Setter Property="BorderBrush" Value="{StaticResource CardBorderBrush}" />
+      <Setter Property="BorderThickness" Value="1" />
+      <Setter Property="Foreground" Value="{StaticResource TextBrush}" />
+      <Setter Property="Padding" Value="12,7" />
+      <Setter Property="CornerRadius" Value="8" />
+    </Style>
+    <Style Selector="Button.ghost:pointerover /template/ ContentPresenter#PART_ContentPresenter">
+      <Setter Property="Background" Value="{StaticResource ElevatedBrush}" />
+      <Setter Property="Foreground" Value="{StaticResource TextBrush}" />
+    </Style>
+
+    <Style Selector="ToggleButton.ghost">
+      <Setter Property="Background" Value="Transparent" />
+      <Setter Property="BorderBrush" Value="{StaticResource CardBorderBrush}" />
+      <Setter Property="BorderThickness" Value="1" />
+      <Setter Property="Foreground" Value="{StaticResource TextBrush}" />
+      <Setter Property="Padding" Value="12,7" />
+      <Setter Property="CornerRadius" Value="8" />
+    </Style>
+    <Style Selector="ToggleButton.ghost:pointerover /template/ ContentPresenter#PART_ContentPresenter">
+      <Setter Property="Background" Value="{StaticResource ElevatedBrush}" />
+      <Setter Property="Foreground" Value="{StaticResource TextBrush}" />
+    </Style>
+    <Style Selector="ToggleButton.ghost:checked /template/ ContentPresenter#PART_ContentPresenter">
+      <Setter Property="Background" Value="{StaticResource ElevatedBrush}" />
+      <Setter Property="BorderBrush" Value="{StaticResource AccentBrush}" />
+      <Setter Property="Foreground" Value="{StaticResource TextBrush}" />
+    </Style>
+
+    <Style Selector="ContextMenu">
+      <Setter Property="Background" Value="{StaticResource CardBrush}" />
+      <Setter Property="BorderBrush" Value="{StaticResource CardBorderBrush}" />
+      <Setter Property="BorderThickness" Value="1" />
+      <Setter Property="CornerRadius" Value="10" />
+      <Setter Property="Padding" Value="6" />
+    </Style>
+    <Style Selector="ContextMenu MenuItem">
+      <Setter Property="Padding" Value="10,7" />
+      <Setter Property="CornerRadius" Value="7" />
+    </Style>
+    <Style Selector="ContextMenu Separator">
+      <Setter Property="Background" Value="{StaticResource CardBorderBrush}" />
+      <Setter Property="Height" Value="1" />
+      <Setter Property="Margin" Value="8,4" />
+    </Style>
+
+    <Style Selector="ListBox.console">
+      <Setter Property="Background" Value="#0B0E14" />
+      <Setter Property="FontFamily" Value="Cascadia Mono, Consolas, Courier New, monospace" />
+      <Setter Property="FontSize" Value="12" />
+    </Style>
+    <Style Selector="ListBox.console ListBoxItem">
+      <Setter Property="Padding" Value="10,1" />
+      <Setter Property="MinHeight" Value="0" />
+    </Style>
+
+    <!-- Cover-art library grid -->
+    <Style Selector="ListBox.tileGrid ListBoxItem">
+      <Setter Property="Padding" Value="10" />
+      <Setter Property="Margin" Value="5" />
+      <Setter Property="CornerRadius" Value="14" />
+      <Setter Property="Background" Value="Transparent" />
+      <Setter Property="BorderThickness" Value="1" />
+      <Setter Property="BorderBrush" Value="Transparent" />
+      <Setter Property="RenderTransform" Value="translateY(0px)" />
+      <Setter Property="Transitions">
+        <Transitions>
+          <TransformOperationsTransition Property="RenderTransform" Duration="0:0:0.12" />
+        </Transitions>
+      </Setter>
+    </Style>
+    <Style Selector="ListBox.tileGrid ListBoxItem:pointerover">
+      <Setter Property="RenderTransform" Value="translateY(-3px)" />
+    </Style>
+    <Style Selector="ListBox.tileGrid ListBoxItem:pointerover /template/ ContentPresenter#PART_ContentPresenter">
+      <Setter Property="Background" Value="{StaticResource TileHoverBrush}" />
+    </Style>
+    <Style Selector="ListBox.tileGrid ListBoxItem:selected /template/ ContentPresenter#PART_ContentPresenter">
+      <Setter Property="Background" Value="{StaticResource TileSelectedBrush}" />
+      <Setter Property="BorderBrush" Value="{StaticResource AccentBrush}" />
+    </Style>
+    <Style Selector="ListBox.tileGrid ListBoxItem:selected:pointerover /template/ ContentPresenter#PART_ContentPresenter">
+      <Setter Property="Background" Value="{StaticResource TileSelectedBrush}" />
+      <Setter Property="BorderBrush" Value="{StaticResource AccentHoverBrush}" />
+    </Style>
+
+    <Style Selector="Border.coverShadow">
+      <Setter Property="CornerRadius" Value="10" />
+      <Setter Property="BoxShadow" Value="0 6 14 0 #55000000" />
+    </Style>
+    <Style Selector="Border.coverClip">
+      <Setter Property="CornerRadius" Value="10" />
+      <Setter Property="ClipToBounds" Value="True" />
+      <Setter Property="Background" Value="{StaticResource ElevatedBrush}" />
+    </Style>
+  </Application.Styles>
+
+</Application>

src/SharpEmu.GUI/App.axaml.cs

@@ -0,0 +1,26 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using Avalonia;
+using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.Markup.Xaml;
+
+namespace SharpEmu.GUI;
+
+public partial class App : Application
+{
+    public override void Initialize()
+    {
+        AvaloniaXamlLoader.Load(this);
+    }
+
+    public override void OnFrameworkInitializationCompleted()
+    {
+        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
+        {
+            desktop.MainWindow = new MainWindow();
+        }
+
+        base.OnFrameworkInitializationCompleted();
+    }
+}

src/SharpEmu.GUI/Atrac9/Atrac9Config.cs

@@ -0,0 +1,120 @@
+#nullable disable
+using System.IO;
+using LibAtrac9.Utilities;
+
+namespace LibAtrac9
+{
+    /// <summary>
+    /// Stores the configuration data needed to decode or encode an ATRAC9 stream.
+    /// </summary>
+    public class Atrac9Config
+    {
+        /// <summary>
+        /// The 4-byte ATRAC9 configuration data.
+        /// </summary>
+        public byte[] ConfigData { get; }
+
+        /// <summary>
+        /// A 4-bit value specifying one of 16 sample rates.
+        /// </summary>
+        public int SampleRateIndex { get; }
+        /// <summary>
+        /// A 3-bit value specifying one of 6 substream channel mappings.
+        /// </summary>
+        public int ChannelConfigIndex { get; }
+        /// <summary>
+        /// An 11-bit value containing the average size of a single frame.
+        /// </summary>
+        public int FrameBytes { get; }
+        /// <summary>
+        /// A 2-bit value indicating how many frames are in each superframe.
+        /// </summary>
+        public int SuperframeIndex { get; }
+
+        /// <summary>
+        /// The channel mapping used by the ATRAC9 stream.
+        /// </summary>
+        public ChannelConfig ChannelConfig { get; }
+        /// <summary>
+        /// The total number of channels in the ATRAC9 stream.
+        /// </summary>
+        public int ChannelCount { get; }
+        /// <summary>
+        /// The sample rate of the ATRAC9 stream.
+        /// </summary>
+        public int SampleRate { get; }
+        /// <summary>
+        /// Indicates whether the ATRAC9 stream has a <see cref="SampleRateIndex"/> of 8 or above.
+        /// </summary>
+        public bool HighSampleRate { get; }
+
+        /// <summary>
+        /// The number of frames in each superframe.
+        /// </summary>
+        public int FramesPerSuperframe { get; }
+        /// <summary>
+        /// The number of samples in one frame as an exponent of 2.
+        /// <see cref="FrameSamples"/> = 2^<see cref="FrameSamplesPower"/>.
+        /// </summary>
+        public int FrameSamplesPower { get; }
+        /// <summary>
+        /// The number of samples in one frame.
+        /// </summary>
+        public int FrameSamples { get; }
+        /// <summary>
+        /// The number of bytes in one superframe.
+        /// </summary>
+        public int SuperframeBytes { get; }
+        /// <summary>
+        /// The number of samples in one superframe.
+        /// </summary>
+        public int SuperframeSamples { get; }
+
+        /// <summary>
+        /// Reads ATRAC9 configuration data and calculates the stream parameters from it.
+        /// </summary>
+        /// <param name="configData">The processed ATRAC9 configuration.</param>
+        public Atrac9Config(byte[] configData)
+        {
+            if (configData == null || configData.Length != 4)
+            {
+                throw new InvalidDataException("Config data must be 4 bytes long");
+            }
+
+            ReadConfigData(configData, out int a, out int b, out int c, out int d);
+            SampleRateIndex = a;
+            ChannelConfigIndex = b;
+            FrameBytes = c;
+            SuperframeIndex = d;
+            ConfigData = configData;
+
+            FramesPerSuperframe = 1 << SuperframeIndex;
+            SuperframeBytes = FrameBytes << SuperframeIndex;
+            ChannelConfig = Tables.ChannelConfig[ChannelConfigIndex];
+
+            ChannelCount = ChannelConfig.ChannelCount;
+            SampleRate = Tables.SampleRates[SampleRateIndex];
+            HighSampleRate = SampleRateIndex > 7;
+            FrameSamplesPower = Tables.SamplingRateIndexToFrameSamplesPower[SampleRateIndex];
+            FrameSamples = 1 << FrameSamplesPower;
+            SuperframeSamples = FrameSamples * FramesPerSuperframe;
+        }
+
+        private static void ReadConfigData(byte[] configData, out int sampleRateIndex, out int channelConfigIndex, out int frameBytes, out int superframeIndex)
+        {
+            var reader = new BitReader(configData);
+
+            int header = reader.ReadInt(8);
+            sampleRateIndex = reader.ReadInt(4);
+            channelConfigIndex = reader.ReadInt(3);
+            int validationBit = reader.ReadInt(1);
+            frameBytes = reader.ReadInt(11) + 1;
+            superframeIndex = reader.ReadInt(2);
+
+            if (header != 0xFE || validationBit != 0)
+            {
+                throw new InvalidDataException("ATRAC9 Config Data is invalid");
+            }
+        }
+    }
+}

src/SharpEmu.GUI/Atrac9/Atrac9Decoder.cs

@@ -0,0 +1,128 @@
+#nullable disable
+using System;
+using LibAtrac9.Utilities;
+
+namespace LibAtrac9
+{
+    /// <summary>
+    /// Decodes an ATRAC9 stream into 16-bit PCM.
+    /// </summary>
+    public class Atrac9Decoder
+    {
+        /// <summary>
+        /// The config data for the current ATRAC9 stream.
+        /// </summary>
+        public Atrac9Config Config { get; private set; }
+
+        private Frame Frame { get; set; }
+        private BitReader Reader { get; set; }
+        private bool _initialized;
+
+        /// <summary>
+        /// Sets up the decoder to decode an ATRAC9 stream based on the information in <paramref name="configData"/>.
+        /// </summary>
+        /// <param name="configData">A 4-byte value containing information about the ATRAC9 stream.</param>
+        public void Initialize(byte[] configData)
+        {
+            Config = new Atrac9Config(configData);
+            Frame = new Frame(Config);
+            Reader = new BitReader(null);
+            _initialized = true;
+        }
+
+        /// <summary>
+        /// Decodes one superframe of ATRAC9 data.
+        /// </summary>
+        /// <param name="atrac9Data">The ATRAC9 data to decode. The array must be at least
+        /// <see cref="Config"/>.<see cref="Atrac9Config.SuperframeBytes"/> bytes long.</param>
+        /// <param name="pcmOut">A buffer that the decoded PCM data will be placed in.
+        /// The array must have dimensions of at least [<see cref="Config"/>.<see cref="Atrac9Config.ChannelCount"/>]
+        /// [<see cref="Config"/>.<see cref="Atrac9Config.SuperframeSamples"/>].</param>
+        public void Decode(byte[] atrac9Data, short[][] pcmOut)
+        {
+            if (!_initialized) throw new InvalidOperationException("Decoder must be initialized before decoding.");
+
+            ValidateDecodeBuffers(atrac9Data, pcmOut);
+            Reader.SetBuffer(atrac9Data);
+            DecodeSuperFrame(pcmOut);
+        }
+
+        private void ValidateDecodeBuffers(byte[] atrac9Buffer, short[][] pcmBuffer)
+        {
+            if (atrac9Buffer == null) throw new ArgumentNullException(nameof(atrac9Buffer));
+            if (pcmBuffer == null) throw new ArgumentNullException(nameof(pcmBuffer));
+
+            if (atrac9Buffer.Length < Config.SuperframeBytes)
+            {
+                throw new ArgumentException("ATRAC9 buffer is too small");
+            }
+
+            if (pcmBuffer.Length < Config.ChannelCount)
+            {
+                throw new ArgumentException("PCM buffer is too small");
+            }
+
+            for (int i = 0; i < Config.ChannelCount; i++)
+            {
+                if (pcmBuffer[i]?.Length < Config.SuperframeSamples)
+                {
+                    throw new ArgumentException("PCM buffer is too small");
+                }
+            }
+        }
+
+        private void DecodeSuperFrame(short[][] pcmOut)
+        {
+            for (int i = 0; i < Config.FramesPerSuperframe; i++)
+            {
+                Frame.FrameIndex = i;
+                DecodeFrame(Reader, Frame);
+                PcmFloatToShort(pcmOut, i * Config.FrameSamples);
+                Reader.AlignPosition(8);
+            }
+        }
+
+        private void PcmFloatToShort(short[][] pcmOut, int start)
+        {
+            int endSample = start + Config.FrameSamples;
+            int channelNum = 0;
+            foreach (Block block in Frame.Blocks)
+            {
+                foreach (Channel channel in block.Channels)
+                {
+                    double[] pcmSrc = channel.Pcm;
+                    short[] pcmDest = pcmOut[channelNum++];
+                    for (int d = 0, s = start; s < endSample; d++, s++)
+                    {
+                        double sample = pcmSrc[d];
+                        // Not using Math.Round because it's ~20x slower on 64-bit
+                        int roundedSample = (int)Math.Floor(sample + 0.5);
+                        pcmDest[s] = Helpers.Clamp16(roundedSample);
+                    }
+                }
+            }
+        }
+
+        private static void DecodeFrame(BitReader reader, Frame frame)
+        {
+            Unpack.UnpackFrame(reader, frame);
+
+            foreach (Block block in frame.Blocks)
+            {
+                Quantization.DequantizeSpectra(block);
+                Stereo.ApplyIntensityStereo(block);
+                Quantization.ScaleSpectrum(block);
+                BandExtension.ApplyBandExtension(block);
+                ImdctBlock(block);
+            }
+        }
+
+        private static void ImdctBlock(Block block)
+        {
+            foreach (Channel channel in block.Channels)
+            {
+                channel.Mdct.RunImdct(channel.Spectra, channel.Pcm);
+            }
+        }
+    }
+}

src/SharpEmu.GUI/Atrac9/Atrac9Rng.cs

@@ -0,0 +1,34 @@
+#nullable disable
+namespace LibAtrac9
+{
+    /// <summary>
+    /// An Xorshift RNG used by the ATRAC9 codec
+    /// </summary>
+    internal class Atrac9Rng
+    {
+        private ushort _stateA;
+        private ushort _stateB;
+        private ushort _stateC;
+        private ushort _stateD;
+
+        public Atrac9Rng(ushort seed)
+        {
+            int startValue = 0x4D93 * (seed ^ (seed >> 14));
+
+            _stateA = (ushort)(3 - startValue);
+            _stateB = (ushort)(2 - startValue);
+            _stateC = (ushort)(1 - startValue);
+            _stateD = (ushort)(0 - startValue);
+        }
+
+        public ushort Next()
+        {
+            ushort t = (ushort)(_stateD ^ (_stateD << 5));
+            _stateD = _stateC;
+            _stateC = _stateB;
+            _stateB = _stateA;
+            _stateA = (ushort)(t ^ _stateA ^ ((t ^ (_stateA >> 5)) >> 4));
+            return _stateA;
+        }
+    }
+}

src/SharpEmu.GUI/Atrac9/BandExtension.cs

@@ -0,0 +1,373 @@
+#nullable disable
+using System;
+
+namespace LibAtrac9
+{
+    internal static class BandExtension
+    {
+        public static void ApplyBandExtension(Block block)
+        {
+            if (!block.BandExtensionEnabled || !block.HasExtensionData) return;
+
+            foreach (Channel channel in block.Channels)
+            {
+                ApplyBandExtensionChannel(channel);
+            }
+        }
+
+        private static void ApplyBandExtensionChannel(Channel channel)
+        {
+            int groupAUnit = channel.Block.QuantizationUnitCount;
+            int[] scaleFactors = channel.ScaleFactors;
+            double[] spectra = channel.Spectra;
+            double[] scales = channel.BexScales;
+            int[] values = channel.BexValues;
+
+            GetBexBandInfo(out int bandCount, out int groupBUnit, out int groupCUnit, groupAUnit);
+            int totalUnits = Math.Max(groupCUnit, 22);
+
+            int groupABin = Tables.QuantUnitToCoeffIndex[groupAUnit];
+            int groupBBin = Tables.QuantUnitToCoeffIndex[groupBUnit];
+            int groupCBin = Tables.QuantUnitToCoeffIndex[groupCUnit];
+            int totalBins = Tables.QuantUnitToCoeffIndex[totalUnits];
+
+            FillHighFrequencies(spectra, groupABin, groupBBin, groupCBin, totalBins);
+
+            switch (channel.BexMode)
+            {
+                case 0:
+                    int bexQuantUnits = totalUnits - groupAUnit;
+
+                    switch (bandCount)
+                    {
+                        case 3:
+                            scales[0] = BexMode0Bands3[0][values[0]];
+                            scales[1] = BexMode0Bands3[1][values[0]];
+                            scales[2] = BexMode0Bands3[2][values[1]];
+                            scales[3] = BexMode0Bands3[3][values[2]];
+                            scales[4] = BexMode0Bands3[4][values[3]];
+                            break;
+                        case 4:
+                            scales[0] = BexMode0Bands4[0][values[0]];
+                            scales[1] = BexMode0Bands4[1][values[0]];
+                            scales[2] = BexMode0Bands4[2][values[1]];
+                            scales[3] = BexMode0Bands4[3][values[2]];
+                            scales[4] = BexMode0Bands4[4][values[3]];
+                            break;
+                        case 5:
+                            scales[0] = BexMode0Bands5[0][values[0]];
+                            scales[1] = BexMode0Bands5[1][values[1]];
+                            scales[2] = BexMode0Bands5[2][values[1]];
+                            break;
+                    }
+
+                    scales[bexQuantUnits - 1] = Tables.SpectrumScale[scaleFactors[groupAUnit]];
+
+                    AddNoiseToSpectrum(channel, Tables.QuantUnitToCoeffIndex[totalUnits - 1],
+                        Tables.QuantUnitToCoeffCount[totalUnits - 1]);
+                    ScaleBexQuantUnits(spectra, scales, groupAUnit, totalUnits);
+                    break;
+                case 1:
+                    for (int i = groupAUnit; i < totalUnits; i++)
+                    {
+                        scales[i - groupAUnit] = Tables.SpectrumScale[scaleFactors[i]];
+                    }
+
+                    AddNoiseToSpectrum(channel, groupABin, totalBins - groupABin);
+                    ScaleBexQuantUnits(spectra, scales, groupAUnit, totalUnits);
+                    break;
+                case 2:
+                    double groupAScale2 = BexMode2Scale[values[0]];
+                    double groupBScale2 = BexMode2Scale[values[1]];
+
+                    for (int i = groupABin; i < groupBBin; i++)
+                    {
+                        spectra[i] *= groupAScale2;
+                    }
+
+                    for (int i = groupBBin; i < groupCBin; i++)
+                    {
+                        spectra[i] *= groupBScale2;
+                    }
+                    return;
+                case 3:
+                    double rate = Math.Pow(2, BexMode3Rate[values[1]]);
+                    double scale = BexMode3Initial[values[0]];
+                    for (int i = groupABin; i < totalBins; i++)
+                    {
+                        scale *= rate;
+                        spectra[i] *= scale;
+                    }
+                    return;
+                case 4:
+                    double mult = BexMode4Multiplier[values[0]];
+                    double groupAScale4 = 0.7079468 * mult;
+                    double groupBScale4 = 0.5011902 * mult;
+                    double groupCScale4 = 0.3548279 * mult;
+
+                    for (int i = groupABin; i < groupBBin; i++)
+                    {
+                        spectra[i] *= groupAScale4;
+                    }
+
+                    for (int i = groupBBin; i < groupCBin; i++)
+                    {
+                        spectra[i] *= groupBScale4;
+                    }
+
+                    for (int i = groupCBin; i < totalBins; i++)
+                    {
+                        spectra[i] *= groupCScale4;
+                    }
+                    return;
+            }
+        }
+
+        private static void ScaleBexQuantUnits(double[] spectra, double[] scales, int startUnit, int totalUnits)
+        {
+            for (int i = startUnit; i < totalUnits; i++)
+            {
+                for (int k = Tables.QuantUnitToCoeffIndex[i]; k < Tables.QuantUnitToCoeffIndex[i + 1]; k++)
+                {
+                    spectra[k] *= scales[i - startUnit];
+                }
+            }
+        }
+
+        private static void FillHighFrequencies(double[] spectra, int groupABin, int groupBBin, int groupCBin, int totalBins)
+        {
+            for (int i = 0; i < groupBBin - groupABin; i++)
+            {
+                spectra[groupABin + i] = spectra[groupABin - i - 1];
+            }
+
+            for (int i = 0; i < groupCBin - groupBBin; i++)
+            {
+                spectra[groupBBin + i] = spectra[groupBBin - i - 1];
+            }
+
+            for (int i = 0; i < totalBins - groupCBin; i++)
+            {
+                spectra[groupCBin + i] = spectra[groupCBin - i - 1];
+            }
+        }
+
+        private static void AddNoiseToSpectrum(Channel channel, int index, int count)
+        {
+            if (channel.Rng == null)
+            {
+                int[] sf = channel.ScaleFactors;
+                ushort seed = (ushort)(543 * (sf[8] + sf[12] + sf[15] + 1));
+                channel.Rng = new Atrac9Rng(seed);
+            }
+            for (int i = 0; i < count; i++)
+            {
+                channel.Spectra[i + index] = channel.Rng.Next() / 65535.0 * 2.0 - 1.0;
+            }
+        }
+
+        public static void GetBexBandInfo(out int bandCount, out int groupAUnit, out int groupBUnit, int quantUnits)
+        {
+            groupAUnit = BexGroupInfo[quantUnits - 13][0];
+            groupBUnit = BexGroupInfo[quantUnits - 13][1];
+            bandCount = BexGroupInfo[quantUnits - 13][2];
+        }
+
+        public static readonly byte[][] BexGroupInfo =
+        {
+            new byte[] {16, 21, 0},
+            new byte[] {18, 22, 1},
+            new byte[] {20, 22, 2},
+            new byte[] {21, 22, 3},
+            new byte[] {21, 22, 3},
+            new byte[] {23, 24, 4},
+            new byte[] {23, 24, 4},
+            new byte[] {24, 24, 5}
+        };
+
+        // [mode][bands]
+
+        public static readonly byte[][] BexEncodedValueCounts =
+        {
+            new byte[] {0, 0, 0, 4, 4, 2},
+            new byte[] {0, 0, 0, 0, 0, 0},
+            new byte[] {0, 0, 0, 2, 2, 1},
+            new byte[] {0, 0, 0, 2, 2, 2},
+            new byte[] {1, 1, 1, 0, 0, 0}
+        };
+
+        // [mode][bands][valueIndex]
+
+        public static readonly byte[][][] BexDataLengths =
+        {
+            new[] {
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {5, 4, 3, 3},
+                new byte[] {4, 4, 3, 4},
+                new byte[] {4, 5, 0, 0}
+            }, new[] {
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0}
+            }, new[] {
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {6, 6, 0, 0},
+                new byte[] {6, 6, 0, 0},
+                new byte[] {6, 0, 0, 0}
+            }, new[] {
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {4, 4, 0, 0},
+                new byte[] {4, 4, 0, 0},
+                new byte[] {4, 4, 0, 0}
+            }, new[] {
+                new byte[] {3, 0, 0, 0},
+                new byte[] {3, 0, 0, 0},
+                new byte[] {3, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0},
+                new byte[] {0, 0, 0, 0}
+            }
+        };
+
+        public static readonly double[][] BexMode0Bands3 =
+        {
+            new[] {
+                0.000000e+0, 1.988220e-1, 2.514343e-1, 2.960510e-1,
+                3.263550e-1, 3.771362e-1, 3.786926e-1, 4.540405e-1,
+                4.877625e-1, 5.262451e-1, 5.447083e-1, 5.737000e-1,
+                6.212158e-1, 6.222839e-1, 6.560974e-1, 6.896667e-1,
+                7.555542e-1, 7.677917e-1, 7.918091e-1, 7.971497e-1,
+                8.188171e-1, 8.446045e-1, 9.790649e-1, 9.822083e-1,
+                9.846191e-1, 9.859314e-1, 9.863586e-1, 9.863892e-1,
+                9.873352e-1, 9.881287e-1, 9.898682e-1, 9.913330e-1
+            }, new[] {
+                0.000000e+0, 9.982910e-1, 7.592773e-2, 7.179565e-1,
+                9.851379e-1, 5.340271e-1, 9.013672e-1, 6.349182e-1,
+                7.226257e-1, 1.948547e-1, 7.628174e-1, 9.873657e-1,
+                8.112183e-1, 2.715454e-1, 9.734192e-1, 1.443787e-1,
+                4.640198e-1, 3.249207e-1, 3.790894e-1, 8.276367e-2,
+                5.954590e-1, 2.864380e-1, 9.806824e-1, 7.929077e-1,
+                6.292114e-1, 4.887085e-1, 2.905273e-1, 1.301880e-1,
+                3.140869e-1, 5.482483e-1, 4.210815e-1, 1.182861e-1
+            }, new[] {
+                0.000000e+0, 3.155518e-2, 8.581543e-2, 1.364746e-1,
+                1.858826e-1, 2.368469e-1, 2.888184e-1, 3.432617e-1,
+                4.012451e-1, 4.623108e-1, 5.271301e-1, 5.954895e-1,
+                6.681213e-1, 7.448425e-1, 8.245239e-1, 9.097290e-1
+            }, new[] {
+                0.000000e+0, 4.418945e-2, 1.303711e-1, 2.273560e-1,
+                3.395996e-1, 4.735718e-1, 6.267090e-1, 8.003845e-1
+            }, new[] {
+                0.000000e+0, 2.804565e-2, 9.683228e-2, 1.849976e-1,
+                3.005981e-1, 4.470520e-1, 6.168518e-1, 8.007813e-1
+            }
+        };
+
+        public static readonly double[][] BexMode0Bands4 =
+        {
+            new[] {
+                0.000000e+0, 2.708740e-1, 3.479614e-1, 3.578186e-1,
+                5.083618e-1, 5.299072e-1, 5.819092e-1, 6.381836e-1,
+                7.276917e-1, 7.595520e-1, 7.878723e-1, 9.707336e-1,
+                9.713135e-1, 9.736023e-1, 9.759827e-1, 9.832458e-1
+            }, new[] {
+                0.000000e+0, 2.330627e-1, 5.891418e-1, 7.170410e-1,
+                2.036438e-1, 1.613464e-1, 6.668701e-1, 9.481201e-1,
+                9.769897e-1, 5.111694e-1, 3.522644e-1, 8.209534e-1,
+                2.933960e-1, 9.757690e-1, 5.289917e-1, 4.372253e-1
+            }, new[] {
+                0.000000e+0, 4.360962e-2, 1.056519e-1, 1.590576e-1,
+                2.078857e-1, 2.572937e-1, 3.082581e-1, 3.616028e-1,
+                4.191589e-1, 4.792175e-1, 5.438538e-1, 6.125183e-1,
+                6.841125e-1, 7.589417e-1, 8.365173e-1, 9.148254e-1
+            }, new[] {
+                0.000000e+0, 4.074097e-2, 1.164551e-1, 2.077026e-1,
+                3.184509e-1, 4.532166e-1, 6.124268e-1, 7.932129e-1
+            }, new[] {
+                0.000000e+0, 8.880615e-3, 2.932739e-2, 5.593872e-2,
+                8.825684e-2, 1.259155e-1, 1.721497e-1, 2.270813e-1,
+                2.901611e-1, 3.579712e-1, 4.334106e-1, 5.147095e-1,
+                6.023254e-1, 6.956177e-1, 7.952881e-1, 8.977356e-1
+            }
+        };
+
+        public static readonly double[][] BexMode0Bands5 =
+        {
+            new[] {
+                0.000000e+0, 7.379150e-2, 1.806335e-1, 2.687073e-1,
+                3.407898e-1, 4.047546e-1, 4.621887e-1, 5.168762e-1,
+                5.703125e-1, 6.237488e-1, 6.763611e-1, 7.288208e-1,
+                7.808533e-1, 8.337708e-1, 8.874512e-1, 9.418030e-1
+            }, new[] {
+                0.000000e+0, 7.980347e-2, 1.615295e-1, 1.665649e-1,
+                1.822205e-1, 2.185669e-1, 2.292175e-1, 2.456665e-1,
+                2.666321e-1, 3.306580e-1, 3.330688e-1, 3.765259e-1,
+                4.085083e-1, 4.400024e-1, 4.407654e-1, 4.817505e-1,
+                4.924011e-1, 5.320740e-1, 5.893860e-1, 6.131287e-1,
+                6.212463e-1, 6.278076e-1, 6.308899e-1, 7.660828e-1,
+                7.850647e-1, 7.910461e-1, 7.929382e-1, 8.038330e-1,
+                9.834900e-1, 9.846191e-1, 9.852295e-1, 9.862671e-1
+            }, new[] {
+                0.000000e+0, 6.084290e-1, 3.672791e-1, 3.151855e-1,
+                1.488953e-1, 2.571716e-1, 5.103455e-1, 3.311157e-1,
+                5.426025e-2, 4.254456e-1, 7.998352e-1, 7.873230e-1,
+                5.418701e-1, 2.925110e-1, 8.468628e-2, 1.410522e-1,
+                9.819641e-1, 9.609070e-1, 3.530884e-2, 9.729004e-2,
+                5.758362e-1, 9.941711e-1, 7.215576e-1, 7.183228e-1,
+                2.028809e-1, 9.588623e-2, 2.032166e-1, 1.338806e-1,
+                5.003357e-1, 1.874390e-1, 9.804993e-1, 1.107788e-1
+            }
+        };
+
+        public static readonly double[] BexMode2Scale =
+        {
+            4.272461e-4, 1.312256e-3, 2.441406e-3, 3.692627e-3,
+            4.913330e-3, 6.134033e-3, 7.507324e-3, 8.972168e-3,
+            1.049805e-2, 1.223755e-2, 1.406860e-2, 1.599121e-2,
+            1.800537e-2, 2.026367e-2, 2.264404e-2, 2.517700e-2,
+            2.792358e-2, 3.073120e-2, 3.344727e-2, 3.631592e-2,
+            3.952026e-2, 4.275513e-2, 4.608154e-2, 4.968262e-2,
+            5.355835e-2, 5.783081e-2, 6.195068e-2, 6.677246e-2,
+            7.196045e-2, 7.745361e-2, 8.319092e-2, 8.993530e-2,
+            9.759521e-2, 1.056213e-1, 1.138916e-1, 1.236267e-1,
+            1.348267e-1, 1.470337e-1, 1.603394e-1, 1.755676e-1,
+            1.905823e-1, 2.071228e-1, 2.245178e-1, 2.444153e-1,
+            2.658997e-1, 2.897644e-1, 3.146057e-1, 3.450012e-1,
+            3.766174e-1, 4.122620e-1, 4.505615e-1, 4.893799e-1,
+            5.305481e-1, 5.731201e-1, 6.157837e-1, 6.580811e-1,
+            6.985168e-1, 7.435303e-1, 7.865906e-1, 8.302612e-1,
+            8.718567e-1, 9.125671e-1, 9.575806e-1, 9.996643e-1
+        };
+
+        public static readonly double[] BexMode3Initial =
+        {
+            3.491211e-1, 5.371094e-1, 6.782227e-1, 7.910156e-1,
+            9.057617e-1, 1.024902e+0, 1.156250e+0, 1.290527e+0,
+            1.458984e+0, 1.664551e+0, 1.929688e+0, 2.278320e+0,
+            2.831543e+0, 3.659180e+0, 5.257813e+0, 8.373047e+0
+        };
+
+        public static readonly double[] BexMode3Rate =
+        {
+            -2.913818e-1, -2.541504e-1, -1.664429e-1, -1.476440e-1,
+            -1.342163e-1, -1.220703e-1, -1.117554e-1, -1.026611e-1,
+            -9.436035e-2, -8.483887e-2, -7.476807e-2, -6.304932e-2,
+            -4.492188e-2, -2.447510e-2, +1.831055e-4, +4.174805e-2
+        };
+
+        public static readonly double[] BexMode4Multiplier =
+        {
+            3.610229e-2, 1.260681e-1, 2.227478e-1, 3.338318e-1,
+            4.662170e-1, 6.221313e-1, 7.989197e-1, 9.939575e-1
+        };
+    }
+}

src/SharpEmu.GUI/Atrac9/BitAllocation.cs

@@ -0,0 +1,141 @@
+#nullable disable
+using System;
+
+namespace LibAtrac9
+{
+    internal static class BitAllocation
+    {
+        public static void CreateGradient(Block block)
+        {
+            int valueCount = block.GradientEndValue - block.GradientStartValue;
+            int unitCount = block.GradientEndUnit - block.GradientStartUnit;
+
+            for (int i = 0; i < block.GradientEndUnit; i++)
+            {
+                block.Gradient[i] = block.GradientStartValue;
+            }
+
+            for (int i = block.GradientEndUnit; i <= block.QuantizationUnitCount; i++)
+            {
+                block.Gradient[i] = block.GradientEndValue;
+            }
+            if (unitCount <= 0) return;
+            if (valueCount == 0) return;
+
+            byte[] curve = Tables.GradientCurves[unitCount - 1];
+            if (valueCount <= 0)
+            {
+                double scale = (-valueCount - 1) / 31.0;
+                int baseVal = block.GradientStartValue - 1;
+                for (int i = block.GradientStartUnit; i < block.GradientEndUnit; i++)
+                {
+                    block.Gradient[i] = baseVal - (int)(curve[i - block.GradientStartUnit] * scale);
+                }
+            }
+            else
+            {
+                double scale = (valueCount - 1) / 31.0;
+                int baseVal = block.GradientStartValue + 1;
+                for (int i = block.GradientStartUnit; i < block.GradientEndUnit; i++)
+                {
+                    block.Gradient[i] = baseVal + (int)(curve[i - block.GradientStartUnit] * scale);
+                }
+            }
+        }
+
+        public static void CalculateMask(Channel channel)
+        {
+            Array.Clear(channel.PrecisionMask, 0, channel.PrecisionMask.Length);
+            for (int i = 1; i < channel.Block.QuantizationUnitCount; i++)
+            {
+                int delta = channel.ScaleFactors[i] - channel.ScaleFactors[i - 1];
+                if (delta > 1)
+                {
+                    channel.PrecisionMask[i] += Math.Min(delta - 1, 5);
+                }
+                else if (delta < -1)
+                {
+                    channel.PrecisionMask[i - 1] += Math.Min(delta * -1 - 1, 5);
+                }
+            }
+        }
+
+        public static void CalculatePrecisions(Channel channel)
+        {
+            Block block = channel.Block;
+
+            if (block.GradientMode != 0)
+            {
+                for (int i = 0; i < block.QuantizationUnitCount; i++)
+                {
+                    channel.Precisions[i] = channel.ScaleFactors[i] + channel.PrecisionMask[i] - block.Gradient[i];
+                    if (channel.Precisions[i] > 0)
+                    {
+                        switch (block.GradientMode)
+                        {
+                            case 1:
+                                channel.Precisions[i] /= 2;
+                                break;
+                            case 2:
+                                channel.Precisions[i] = 3 * channel.Precisions[i] / 8;
+                                break;
+                            case 3:
+                                channel.Precisions[i] /= 4;
+                                break;
+                        }
+                    }
+                }
+            }
+            else
+            {
+                for (int i = 0; i < block.QuantizationUnitCount; i++)
+                {
+                    channel.Precisions[i] = channel.ScaleFactors[i] - block.Gradient[i];
+                }
+            }
+
+            for (int i = 0; i < block.QuantizationUnitCount; i++)
+            {
+                if (channel.Precisions[i] < 1)
+                {
+                    channel.Precisions[i] = 1;
+                }
+            }
+
+            for (int i = 0; i < block.GradientBoundary; i++)
+            {
+                channel.Precisions[i]++;
+            }
+
+            for (int i = 0; i < block.QuantizationUnitCount; i++)
+            {
+                channel.PrecisionsFine[i] = 0;
+                if (channel.Precisions[i] > 15)
+                {
+                    channel.PrecisionsFine[i] = channel.Precisions[i] - 15;
+                    channel.Precisions[i] = 15;
+                }
+            }
+        }
+
+        public static byte[][] GenerateGradientCurves()
+        {
+            byte[] main =
+            {
+                01, 01, 01, 01, 02, 02, 02, 02, 03, 03, 03, 04, 04, 05, 05, 06, 07, 08, 09, 10, 11, 12, 13, 15,
+                16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 26, 27, 27, 28, 28, 28, 29, 29, 29, 29, 30, 30, 30, 30
+            };
+            var curves = new byte[main.Length][];
+
+            for (int length = 1; length <= main.Length; length++)
+            {
+                curves[length - 1] = new byte[length];
+                for (int i = 0; i < length; i++)
+                {
+                    curves[length - 1][i] = main[i * main.Length / length];
+                }
+            }
+            return curves;
+        }
+    }
+}

src/SharpEmu.GUI/Atrac9/Block.cs

@@ -0,0 +1,92 @@
+#nullable disable
+namespace LibAtrac9
+{
+    internal class Block
+    {
+        public Atrac9Config Config { get; }
+        public BlockType BlockType { get; }
+        public int BlockIndex { get; }
+        public Frame Frame { get; }
+
+        public Channel[] Channels { get; }
+        public int ChannelCount { get; }
+
+        public bool FirstInSuperframe { get; set; }
+        public bool ReuseBandParams { get; set; }
+
+        public int BandCount { get; set; }
+        public int StereoBand { get; set; }
+        public int ExtensionBand { get; set; }
+        public int QuantizationUnitCount { get; set; }
+        public int StereoQuantizationUnit { get; set; }
+        public int ExtensionUnit { get; set; }
+        public int QuantizationUnitsPrev { get; set; }
+
+        public int[] Gradient { get; } = new int[31];
+        public int GradientMode { get; set; }
+        public int GradientStartUnit { get; set; }
+        public int GradientStartValue { get; set; }
+        public int GradientEndUnit { get; set; }
+        public int GradientEndValue { get; set; }
+        public int GradientBoundary { get; set; }
+
+        public int PrimaryChannelIndex { get; set; }
+        public int[] JointStereoSigns { get; } = new int[30];
+        public bool HasJointStereoSigns { get; set; }
+        public Channel PrimaryChannel => Channels[PrimaryChannelIndex == 0 ? 0 : 1];
+        public Channel SecondaryChannel => Channels[PrimaryChannelIndex == 0 ? 1 : 0];
+
+        public bool BandExtensionEnabled { get; set; }
+        public bool HasExtensionData { get; set; }
+        public int BexDataLength { get; set; }
+        public int BexMode { get; set; }
+
+        public Block(Frame parentFrame, int blockIndex)
+        {
+            Frame = parentFrame;
+            BlockIndex = blockIndex;
+            Config = parentFrame.Config;
+            BlockType = Config.ChannelConfig.BlockTypes[blockIndex];
+            ChannelCount = BlockTypeToChannelCount(BlockType);
+            Channels = new Channel[ChannelCount];
+            for (int i = 0; i < ChannelCount; i++)
+            {
+                Channels[i] = new Channel(this, i);
+            }
+        }
+
+        public static int BlockTypeToChannelCount(BlockType blockType)
+        {
+            switch (blockType)
+            {
+                case BlockType.Mono:
+                    return 1;
+                case BlockType.Stereo:
+                    return 2;
+                case BlockType.LFE:
+                    return 1;
+                default:
+                    return 0;
+            }
+        }
+    }
+
+    /// <summary>
+    /// An ATRAC9 block (substream) type
+    /// </summary>
+    public enum BlockType
+    {
+        /// <summary>
+        /// Mono ATRAC9 block
+        /// </summary>
+        Mono = 0,
+        /// <summary>
+        /// Stereo ATRAC9 block
+        /// </summary>
+        Stereo = 1,
+        /// <summary>
+        /// Low-frequency effects ATRAC9 block
+        /// </summary>
+        LFE = 2
+    }
+}

src/SharpEmu.GUI/Atrac9/Channel.cs

@@ -0,0 +1,49 @@
+#nullable disable
+using LibAtrac9.Utilities;
+
+namespace LibAtrac9
+{
+    internal class Channel
+    {
+        public Atrac9Config Config { get; }
+        public int ChannelIndex { get; }
+        public bool IsPrimary => Block.PrimaryChannelIndex == ChannelIndex;
+        public Block Block { get; }
+        public Mdct Mdct { get; }
+
+        public double[] Pcm { get; } = new double[256];
+        public double[] Spectra { get; } = new double[256];
+
+        public int CodedQuantUnits { get; set; }
+        public int ScaleFactorCodingMode { get; set; }
+        public int[] ScaleFactors { get; } = new int[31];
+        public int[] ScaleFactorsPrev { get; } = new int[31];
+
+        public int[] Precisions { get; } = new int[30];
+        public int[] PrecisionsFine { get; } = new int[30];
+        public int[] PrecisionMask { get; } = new int[30];
+
+        public int[] SpectraValuesBuffer { get; } = new int[16];
+        public int[] CodebookSet { get; } = new int[30];
+
+        public int[] QuantizedSpectra { get; } = new int[256];
+        public int[] QuantizedSpectraFine { get; } = new int[256];
+
+        public int BexMode { get; set; }
+        public int BexValueCount { get; set; }
+        public int[] BexValues { get; } = new int[4];
+        public double[] BexScales { get; } = new double[6];
+        public Atrac9Rng Rng { get; set; }
+
+        public Channel(Block parentBlock, int channelIndex)
+        {
+            Block = parentBlock;
+            ChannelIndex = channelIndex;
+            Config = parentBlock.Config;
+            Mdct = new Mdct(Config.FrameSamplesPower, Tables.ImdctWindow[Config.FrameSamplesPower - 6]);
+        }
+
+        public void UpdateCodedUnits() =>
+            CodedQuantUnits = IsPrimary ? Block.QuantizationUnitCount : Block.StereoQuantizationUnit;
+    }
+}

src/SharpEmu.GUI/Atrac9/ChannelConfig.cs

@@ -0,0 +1,34 @@
+#nullable disable
+namespace LibAtrac9
+{
+    /// <summary>
+    /// Describes the channel mapping for an ATRAC9 stream
+    /// </summary>
+    public class ChannelConfig
+    {
+        internal ChannelConfig(params BlockType[] blockTypes)
+        {
+            BlockCount = blockTypes.Length;
+            BlockTypes = blockTypes;
+            foreach (BlockType type in blockTypes)
+            {
+                ChannelCount += Block.BlockTypeToChannelCount(type);
+            }
+        }
+
+        /// <summary>
+        /// The number of blocks or substreams in the ATRAC9 stream
+        /// </summary>
+        public int BlockCount { get; }
+
+        /// <summary>
+        /// The type of each block or substream in the ATRAC9 stream
+        /// </summary>
+        public BlockType[] BlockTypes { get; }
+
+        /// <summary>
+        /// The number of channels in the ATRAC9 stream
+        /// </summary>
+        public int ChannelCount { get; }
+    }
+}

src/SharpEmu.GUI/Atrac9/Frame.cs

@@ -0,0 +1,21 @@
+#nullable disable
+namespace LibAtrac9
+{
+    internal class Frame
+    {
+        public Atrac9Config Config { get; }
+        public int FrameIndex { get; set; }
+        public Block[] Blocks { get; }
+
+        public Frame(Atrac9Config config)
+        {
+            Config = config;
+            Blocks = new Block[config.ChannelConfig.BlockCount];
+
+            for (int i = 0; i < config.ChannelConfig.BlockCount; i++)
+            {
+                Blocks[i] = new Block(this, i);
+            }
+        }
+    }
+}

src/SharpEmu.GUI/Atrac9/HuffmanCodebook.cs

@@ -0,0 +1,63 @@
+#nullable disable
+using System;
+using LibAtrac9.Utilities;
+
+namespace LibAtrac9
+{
+    internal class HuffmanCodebook
+    {
+        public HuffmanCodebook(short[] codes, byte[] bits, byte valueCountPower)
+        {
+            Codes = codes;
+            Bits = bits;
+            if (Codes == null || Bits == null) return;
+
+            ValueCount = 1 << valueCountPower;
+            ValueCountPower = valueCountPower;
+            ValueBits = Helpers.Log2(codes.Length) >> valueCountPower;
+            ValueMax = 1 << ValueBits;
+
+            int max = 0;
+            foreach (byte bitSize in bits)
+            {
+                max = Math.Max(max, bitSize);
+            }
+
+            MaxBitSize = max;
+            Lookup = CreateLookupTable();
+        }
+
+        private byte[] CreateLookupTable()
+        {
+            if (Codes == null || Bits == null) return null;
+
+            int tableSize = 1 << MaxBitSize;
+            var dest = new byte[tableSize];
+
+            for (int i = 0; i < Bits.Length; i++)
+            {
+                if (Bits[i] == 0) continue;
+                int unusedBits = MaxBitSize - Bits[i];
+
+                int start = Codes[i] << unusedBits;
+                int length = 1 << unusedBits;
+                int end = start + length;
+
+                for (int j = start; j < end; j++)
+                {
+                    dest[j] = (byte)i;
+                }
+            }
+            return dest;
+        }
+
+        public short[] Codes { get; }
+        public byte[] Bits { get; }
+        public byte[] Lookup { get; }
+        public int ValueCount { get; }
+        public int ValueCountPower { get; }
+        public int ValueBits { get; }
+        public int ValueMax { get; }
+        public int MaxBitSize { get; }
+    }
+}

src/SharpEmu.GUI/Atrac9/LICENSE.txt

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 Alex Barney
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

src/SharpEmu.GUI/Atrac9/Quantization.cs

@@ -0,0 +1,58 @@
+#nullable disable
+using System;
+
+namespace LibAtrac9
+{
+    internal static class Quantization
+    {
+        public static void DequantizeSpectra(Block block)
+        {
+            foreach (Channel channel in block.Channels)
+            {
+                Array.Clear(channel.Spectra, 0, channel.Spectra.Length);
+
+                for (int i = 0; i < channel.CodedQuantUnits; i++)
+                {
+                    DequantizeQuantUnit(channel, i);
+                }
+            }
+        }
+
+        private static void DequantizeQuantUnit(Channel channel, int band)
+        {
+            int subBandIndex = Tables.QuantUnitToCoeffIndex[band];
+            int subBandCount = Tables.QuantUnitToCoeffCount[band];
+            double stepSize = Tables.QuantizerStepSize[channel.Precisions[band]];
+            double stepSizeFine = Tables.QuantizerFineStepSize[channel.PrecisionsFine[band]];
+
+            for (int sb = 0; sb < subBandCount; sb++)
+            {
+                double coarse = channel.QuantizedSpectra[subBandIndex + sb] * stepSize;
+                double fine = channel.QuantizedSpectraFine[subBandIndex + sb] * stepSizeFine;
+                channel.Spectra[subBandIndex + sb] = coarse + fine;
+            }
+        }
+
+        public static void ScaleSpectrum(Block block)
+        {
+            foreach (Channel channel in block.Channels)
+            {
+                ScaleSpectrum(channel);
+            }
+        }
+
+        private static void ScaleSpectrum(Channel channel)
+        {
+            int quantUnitCount = channel.Block.QuantizationUnitCount;
+            double[] spectra = channel.Spectra;
+
+            for (int i = 0; i < quantUnitCount; i++)
+            {
+                for (int sb = Tables.QuantUnitToCoeffIndex[i]; sb < Tables.QuantUnitToCoeffIndex[i + 1]; sb++)
+                {
+                    spectra[sb] *= Tables.SpectrumScale[channel.ScaleFactors[i]];
+                }
+            }
+        }
+    }
+}

src/SharpEmu.GUI/Atrac9/ScaleFactors.cs

@@ -0,0 +1,172 @@
+#nullable disable
+using System;
+using System.IO;
+using LibAtrac9.Utilities;
+
+namespace LibAtrac9
+{
+    internal static class ScaleFactors
+    {
+        public static void Read(BitReader reader, Channel channel)
+        {
+            Array.Clear(channel.ScaleFactors, 0, channel.ScaleFactors.Length);
+
+            channel.ScaleFactorCodingMode = reader.ReadInt(2);
+            if (channel.ChannelIndex == 0)
+            {
+                switch (channel.ScaleFactorCodingMode)
+                {
+                    case 0:
+                        ReadVlcDeltaOffset(reader, channel);
+                        break;
+                    case 1:
+                        ReadClcOffset(reader, channel);
+                        break;
+                    case 2:
+                        if (channel.Block.FirstInSuperframe) throw new InvalidDataException();
+                        ReadVlcDistanceToBaseline(reader, channel, channel.ScaleFactorsPrev, channel.Block.QuantizationUnitsPrev);
+                        break;
+                    case 3:
+                        if (channel.Block.FirstInSuperframe) throw new InvalidDataException();
+                        ReadVlcDeltaOffsetWithBaseline(reader, channel, channel.ScaleFactorsPrev, channel.Block.QuantizationUnitsPrev);
+                        break;
+                }
+            }
+            else
+            {
+                switch (channel.ScaleFactorCodingMode)
+                {
+                    case 0:
+                        ReadVlcDeltaOffset(reader, channel);
+                        break;
+                    case 1:
+                        ReadVlcDistanceToBaseline(reader, channel, channel.Block.Channels[0].ScaleFactors, channel.Block.ExtensionUnit);
+                        break;
+                    case 2:
+                        ReadVlcDeltaOffsetWithBaseline(reader, channel, channel.Block.Channels[0].ScaleFactors, channel.Block.ExtensionUnit);
+                        break;
+                    case 3:
+                        if (channel.Block.FirstInSuperframe) throw new InvalidDataException();
+                        ReadVlcDistanceToBaseline(reader, channel, channel.ScaleFactorsPrev, channel.Block.QuantizationUnitsPrev);
+                        break;
+                }
+            }
+
+            for (int i = 0; i < channel.Block.ExtensionUnit; i++)
+            {
+                if (channel.ScaleFactors[i] < 0 || channel.ScaleFactors[i] > 31)
+                {
+                    throw new InvalidDataException("Scale factor values are out of range.");
+                }
+            }
+
+            Array.Copy(channel.ScaleFactors, channel.ScaleFactorsPrev, channel.ScaleFactors.Length);
+        }
+
+        private static void ReadClcOffset(BitReader reader, Channel channel)
+        {
+            const int maxBits = 5;
+            int[] sf = channel.ScaleFactors;
+            int bitLength = reader.ReadInt(2) + 2;
+            int baseValue = bitLength < maxBits ? reader.ReadInt(maxBits) : 0;
+
+            for (int i = 0; i < channel.Block.ExtensionUnit; i++)
+            {
+                sf[i] = reader.ReadInt(bitLength) + baseValue;
+            }
+        }
+
+        private static void ReadVlcDeltaOffset(BitReader reader, Channel channel)
+        {
+            int weightIndex = reader.ReadInt(3);
+            byte[] weights = ScaleFactorWeights[weightIndex];
+
+            int[] sf = channel.ScaleFactors;
+            int baseValue = reader.ReadInt(5);
+            int bitLength = reader.ReadInt(2) + 3;
+            HuffmanCodebook codebook = Tables.HuffmanScaleFactorsUnsigned[bitLength];
+
+            sf[0] = reader.ReadInt(bitLength);
+
+            for (int i = 1; i < channel.Block.ExtensionUnit; i++)
+            {
+                int delta = Unpack.ReadHuffmanValue(codebook, reader);
+                sf[i] = (sf[i - 1] + delta) & (codebook.ValueMax - 1);
+            }
+
+            for (int i = 0; i < channel.Block.ExtensionUnit; i++)
+            {
+                sf[i] += baseValue - weights[i];
+            }
+        }
+
+        private static void ReadVlcDistanceToBaseline(BitReader reader, Channel channel, int[] baseline, int baselineLength)
+        {
+            int[] sf = channel.ScaleFactors;
+            int bitLength = reader.ReadInt(2) + 2;
+            HuffmanCodebook codebook = Tables.HuffmanScaleFactorsSigned[bitLength];
+            int unitCount = Math.Min(channel.Block.ExtensionUnit, baselineLength);
+
+            for (int i = 0; i < unitCount; i++)
+            {
+                int distance = Unpack.ReadHuffmanValue(codebook, reader, true);
+                sf[i] = (baseline[i] + distance) & 31;
+            }
+
+            for (int i = unitCount; i < channel.Block.ExtensionUnit; i++)
+            {
+                sf[i] = reader.ReadInt(5);
+            }
+        }
+
+        private static void ReadVlcDeltaOffsetWithBaseline(BitReader reader, Channel channel, int[] baseline, int baselineLength)
+        {
+            int[] sf = channel.ScaleFactors;
+            int baseValue = reader.ReadOffsetBinary(5, BitReader.OffsetBias.Negative);
+            int bitLength = reader.ReadInt(2) + 1;
+            HuffmanCodebook codebook = Tables.HuffmanScaleFactorsUnsigned[bitLength];
+            int unitCount = Math.Min(channel.Block.ExtensionUnit, baselineLength);
+
+            sf[0] = reader.ReadInt(bitLength);
+
+            for (int i = 1; i < unitCount; i++)
+            {
+                int delta = Unpack.ReadHuffmanValue(codebook, reader);
+                sf[i] = (sf[i - 1] + delta) & (codebook.ValueMax - 1);
+            }
+
+            for (int i = 0; i < unitCount; i++)
+            {
+                sf[i] += baseValue + baseline[i];
+            }
+
+            for (int i = unitCount; i < channel.Block.ExtensionUnit; i++)
+            {
+                sf[i] = reader.ReadInt(5);
+            }
+        }
+
+        public static readonly byte[][] ScaleFactorWeights =
+        {
+            new byte[] {
+                0, 0, 0, 1, 1, 2, 2, 2, 2, 2, 2, 3, 2, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 6, 6, 7, 7, 8, 10, 12, 12, 12
+            }, new byte[] {
+                3, 2, 2, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 2, 3, 3, 4, 5, 7, 10, 10, 10
+            }, new byte[] {
+                0, 2, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 8, 9, 12, 12, 12
+            }, new byte[] {
+                0, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 7, 8, 8, 10, 11, 11, 12, 13, 13, 13, 13
+            }, new byte[] {
+                0, 2, 2, 3, 3, 4, 4, 5, 4, 5, 5, 5, 5, 6, 7, 8, 8, 8, 8, 9, 9, 9, 10, 10, 11, 12, 12, 13, 13, 14, 14, 14
+            }, new byte[] {
+                1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 4, 4, 5, 6, 7, 7, 9, 11, 11, 11
+            }, new byte[] {
+                0, 5, 8, 10, 11, 11, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 12, 12, 12,
+                12, 13, 15, 15, 15
+            }, new byte[] {
+                0, 2, 3, 4, 5, 6, 6, 7, 7, 8, 8, 8, 9, 9, 10, 10, 10, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13,
+                15, 15, 15
+            }
+        };
+    }
+}

src/SharpEmu.GUI/Atrac9/Stereo.cs

@@ -0,0 +1,34 @@
+#nullable disable
+namespace LibAtrac9
+{
+    internal static class Stereo
+    {
+        public static void ApplyIntensityStereo(Block block)
+        {
+            if (block.BlockType != BlockType.Stereo) return;
+
+            int totalUnits = block.QuantizationUnitCount;
+            int stereoUnits = block.StereoQuantizationUnit;
+            if (stereoUnits >= totalUnits) return;
+
+            Channel source = block.PrimaryChannel;
+            Channel dest = block.SecondaryChannel;
+
+            for (int i = stereoUnits; i < totalUnits; i++)
+            {
+                int sign = block.JointStereoSigns[i];
+                for (int sb = Tables.QuantUnitToCoeffIndex[i]; sb < Tables.QuantUnitToCoeffIndex[i + 1]; sb++)
+                {
+                    if (sign > 0)
+                    {
+                        dest.Spectra[sb] = -source.Spectra[sb];
+                    }
+                    else
+                    {
+                        dest.Spectra[sb] = source.Spectra[sb];
+                    }
+                }
+            }
+        }
+    }
+}

src/SharpEmu.GUI/Atrac9/Tables.cs

@@ -0,0 +1,116 @@
+#nullable disable
+using System;
+using static LibAtrac9.HuffmanCodebooks;
+
+namespace LibAtrac9
+{
+    internal static class Tables
+    {
+        public static int MaxHuffPrecision(bool highSampleRate) => highSampleRate ? 1 : 7;
+        public static int MinBandCount(bool highSampleRate) => highSampleRate ? 1 : 3;
+        public static int MaxExtensionBand(bool highSampleRate) => highSampleRate ? 16 : 18;
+
+        public static readonly int[] SampleRates =
+        {
+            11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000,
+            44100, 48000, 64000, 88200, 96000, 128000, 176400, 192000
+        };
+
+        public static readonly byte[] SamplingRateIndexToFrameSamplesPower = { 6, 6, 7, 7, 7, 8, 8, 8, 6, 6, 7, 7, 7, 8, 8, 8 };
+
+        // From sampling rate index
+        public static readonly byte[] MaxBandCount = { 8, 8, 12, 12, 12, 18, 18, 18, 8, 8, 12, 12, 12, 16, 16, 16 };
+        public static readonly byte[] BandToQuantUnitCount = { 0, 4, 8, 10, 12, 13, 14, 15, 16, 18, 20, 21, 22, 23, 24, 25, 26, 28, 30 };
+
+        public static readonly byte[] QuantUnitToCoeffCount =
+        {
+            02, 02, 02, 02, 02, 02, 02, 02, 04, 04, 04, 04, 08, 08, 08,
+            08, 08, 08, 08, 08, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16
+        };
+
+        public static readonly short[] QuantUnitToCoeffIndex =
+        {
+            0, 2, 4, 6, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
+            64, 72, 80, 88, 96, 112, 128, 144, 160, 176, 192, 208, 224, 240, 256
+        };
+
+        public static readonly byte[] QuantUnitToCodebookIndex =
+        {
+            0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2,
+            2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3
+        };
+
+        public static readonly ChannelConfig[] ChannelConfig =
+        {
+            new ChannelConfig(BlockType.Mono),
+            new ChannelConfig(BlockType.Mono, BlockType.Mono),
+            new ChannelConfig(BlockType.Stereo),
+            new ChannelConfig(BlockType.Stereo, BlockType.Mono, BlockType.LFE, BlockType.Stereo),
+            new ChannelConfig(BlockType.Stereo, BlockType.Mono, BlockType.LFE, BlockType.Stereo, BlockType.Stereo),
+            new ChannelConfig(BlockType.Stereo, BlockType.Stereo)
+        };
+
+        public static readonly HuffmanCodebook[] HuffmanScaleFactorsUnsigned =
+            GenerateHuffmanCodebooks(HuffmanScaleFactorsACodes, HuffmanScaleFactorsABits, HuffmanScaleFactorsGroupSizes);
+        
+        public static readonly HuffmanCodebook[] HuffmanScaleFactorsSigned =
+            GenerateHuffmanCodebooks(HuffmanScaleFactorsBCodes, HuffmanScaleFactorsBBits, HuffmanScaleFactorsGroupSizes);
+
+        public static readonly HuffmanCodebook[][][] HuffmanSpectrum =
+        {
+            GenerateHuffmanCodebooks(HuffmanSpectrumACodes, HuffmanSpectrumABits, HuffmanSpectrumAGroupSizes),
+            GenerateHuffmanCodebooks(HuffmanSpectrumBCodes, HuffmanSpectrumBBits, HuffmanSpectrumBGroupSizes)
+        };
+
+        public static readonly double[][] ImdctWindow = { GenerateImdctWindow(6), GenerateImdctWindow(7), GenerateImdctWindow(8) };
+
+        public static readonly double[] SpectrumScale = Generate(32, SpectrumScaleFunction);
+        public static readonly double[] QuantizerStepSize = Generate(16, QuantizerStepSizeFunction);
+        public static readonly double[] QuantizerFineStepSize = Generate(16, QuantizerFineStepSizeFunction);
+
+        public static readonly byte[][] GradientCurves = BitAllocation.GenerateGradientCurves();
+
+        private static double QuantizerStepSizeFunction(int x) => 2.0 / ((1 << (x + 1)) - 1);
+        private static double QuantizerFineStepSizeFunction(int x) => QuantizerStepSizeFunction(x) / ushort.MaxValue;
+        private static double SpectrumScaleFunction(int x) => Math.Pow(2, x - 15);
+
+        private static double[] GenerateImdctWindow(int frameSizePower)
+        {
+            int frameSize = 1 << frameSizePower;
+            var output = new double[frameSize];
+
+            double[] a1 = GenerateMdctWindow(frameSizePower);
+
+            for (int i = 0; i < frameSize; i++)
+            {
+                output[i] = a1[i] / (a1[frameSize - 1 - i] * a1[frameSize - 1 - i] + a1[i] * a1[i]);
+            }
+            return output;
+        }
+
+        private static double[] GenerateMdctWindow(int frameSizePower)
+        {
+            int frameSize = 1 << frameSizePower;
+            var output = new double[frameSize];
+
+            for (int i = 0; i < frameSize; i++)
+            {
+                output[i] = (Math.Sin(((i + 0.5) / frameSize - 0.5) * Math.PI) + 1.0) * 0.5;
+            }
+
+            return output;
+        }
+
+        private static T[] Generate<T>(int count, Func<int, T> elementGenerator)
+        {
+            var table = new T[count];
+            for (int i = 0; i < count; i++)
+            {
+                table[i] = elementGenerator(i);
+            }
+            return table;
+        }
+
+        
+    }
+}

src/SharpEmu.GUI/Atrac9/Unpack.cs

@@ -0,0 +1,426 @@
+#nullable disable
+using System;
+using System.IO;
+using LibAtrac9.Utilities;
+
+namespace LibAtrac9
+{
+    internal static class Unpack
+    {
+        public static void UnpackFrame(BitReader reader, Frame frame)
+        {
+            foreach (Block block in frame.Blocks)
+            {
+                UnpackBlock(reader, block);
+            }
+        }
+
+        private static void UnpackBlock(BitReader reader, Block block)
+        {
+            ReadBlockHeader(reader, block);
+
+            if (block.BlockType == BlockType.LFE)
+            {
+                UnpackLfeBlock(reader, block);
+            }
+            else
+            {
+                UnpackStandardBlock(reader, block);
+            }
+
+            reader.AlignPosition(8);
+        }
+
+        private static void ReadBlockHeader(BitReader reader, Block block)
+        {
+            bool firstInSuperframe = block.Frame.FrameIndex == 0;
+            block.FirstInSuperframe = !reader.ReadBool();
+            block.ReuseBandParams = reader.ReadBool();
+
+            if (block.FirstInSuperframe != firstInSuperframe)
+            {
+                throw new InvalidDataException();
+            }
+
+            if (firstInSuperframe && block.ReuseBandParams && block.BlockType != BlockType.LFE)
+            {
+                throw new InvalidDataException();
+            }
+        }
+
+        private static void UnpackStandardBlock(BitReader reader, Block block)
+        {
+            Channel[] channels = block.Channels;
+
+            if (!block.ReuseBandParams)
+            {
+                ReadBandParams(reader, block);
+            }
+
+            ReadGradientParams(reader, block);
+            BitAllocation.CreateGradient(block);
+            ReadStereoParams(reader, block);
+            ReadExtensionParams(reader, block);
+
+            foreach (Channel channel in channels)
+            {
+                channel.UpdateCodedUnits();
+
+                ScaleFactors.Read(reader, channel);
+                BitAllocation.CalculateMask(channel);
+                BitAllocation.CalculatePrecisions(channel);
+                CalculateSpectrumCodebookIndex(channel);
+
+                ReadSpectra(reader, channel);
+                ReadSpectraFine(reader, channel);
+            }
+
+            block.QuantizationUnitsPrev = block.BandExtensionEnabled ? block.ExtensionUnit : block.QuantizationUnitCount;
+        }
+
+        private static void ReadBandParams(BitReader reader, Block block)
+        {
+            int minBandCount = Tables.MinBandCount(block.Config.HighSampleRate);
+            int maxExtensionBand = Tables.MaxExtensionBand(block.Config.HighSampleRate);
+            block.BandCount = reader.ReadInt(4);
+            block.BandCount += minBandCount;
+            block.QuantizationUnitCount = Tables.BandToQuantUnitCount[block.BandCount];
+            if (block.BandCount < minBandCount || block.BandCount >
+                Tables.MaxBandCount[block.Config.SampleRateIndex])
+            {
+                return;
+            }
+
+            if (block.BlockType == BlockType.Stereo)
+            {
+                block.StereoBand = reader.ReadInt(4);
+                block.StereoBand += minBandCount;
+                block.StereoQuantizationUnit = Tables.BandToQuantUnitCount[block.StereoBand];
+            }
+            else
+            {
+                block.StereoBand = block.BandCount;
+            }
+
+            block.BandExtensionEnabled = reader.ReadBool();
+            if (block.BandExtensionEnabled)
+            {
+                block.ExtensionBand = reader.ReadInt(4);
+                block.ExtensionBand += minBandCount;
+
+                if (block.ExtensionBand < block.BandCount || block.ExtensionBand > maxExtensionBand)
+                {
+                    throw new InvalidDataException();
+                }
+
+                block.ExtensionUnit = Tables.BandToQuantUnitCount[block.ExtensionBand];
+            }
+            else
+            {
+                block.ExtensionBand = block.BandCount;
+                block.ExtensionUnit = block.QuantizationUnitCount;
+            }
+        }
+
+        private static void ReadGradientParams(BitReader reader, Block block)
+        {
+            block.GradientMode = reader.ReadInt(2);
+            if (block.GradientMode > 0)
+            {
+                block.GradientEndUnit = 31;
+                block.GradientEndValue = 31;
+                block.GradientStartUnit = reader.ReadInt(5);
+                block.GradientStartValue = reader.ReadInt(5);
+            }
+            else
+            {
+                block.GradientStartUnit = reader.ReadInt(6);
+                block.GradientEndUnit = reader.ReadInt(6) + 1;
+                block.GradientStartValue = reader.ReadInt(5);
+                block.GradientEndValue = reader.ReadInt(5);
+            }
+            block.GradientBoundary = reader.ReadInt(4);
+
+            if (block.GradientBoundary > block.QuantizationUnitCount)
+            {
+                throw new InvalidDataException();
+            }
+            if (block.GradientStartUnit < 1 || block.GradientStartUnit >= 48)
+            {
+                throw new InvalidDataException();
+            }
+            if (block.GradientEndUnit < 1 || block.GradientEndUnit >= 48)
+            {
+                throw new InvalidDataException();
+            }
+            if (block.GradientStartUnit > block.GradientEndUnit)
+            {
+                throw new InvalidDataException();
+            }
+            if (block.GradientStartValue < 0 || block.GradientStartValue >= 32)
+            {
+                throw new InvalidDataException();
+            }
+            if (block.GradientEndValue < 0 || block.GradientEndValue >= 32)
+            {
+                throw new InvalidDataException();
+            }
+        }
+
+        private static void ReadStereoParams(BitReader reader, Block block)
+        {
+            if (block.BlockType != BlockType.Stereo) return;
+
+            block.PrimaryChannelIndex = reader.ReadInt(1);
+            block.HasJointStereoSigns = reader.ReadBool();
+            if (block.HasJointStereoSigns)
+            {
+                for (int i = block.StereoQuantizationUnit; i < block.QuantizationUnitCount; i++)
+                {
+                    block.JointStereoSigns[i] = reader.ReadInt(1);
+                }
+            }
+            else
+            {
+                Array.Clear(block.JointStereoSigns, 0, block.JointStereoSigns.Length);
+            }
+        }
+
+        private static void ReadExtensionParams(BitReader reader, Block block)
+        {
+            // ReSharper disable once RedundantAssignment
+            int bexBand = 0;
+            if (block.BandExtensionEnabled)
+            {
+                BandExtension.GetBexBandInfo(out bexBand, out _, out _, block.QuantizationUnitCount);
+                if (block.BlockType == BlockType.Stereo)
+                {
+                    ReadHeader(block.Channels[1]);
+                }
+                else
+                {
+                    reader.Position += 1;
+                }
+            }
+            block.HasExtensionData = reader.ReadBool();
+
+            if (!block.HasExtensionData) return;
+            if (!block.BandExtensionEnabled)
+            {
+                block.BexMode = reader.ReadInt(2);
+                block.BexDataLength = reader.ReadInt(5);
+                reader.Position += block.BexDataLength;
+                return;
+            }
+
+            ReadHeader(block.Channels[0]);
+
+            block.BexDataLength = reader.ReadInt(5);
+            if (block.BexDataLength <= 0) return;
+            int bexDataEnd = reader.Position + block.BexDataLength;
+
+            ReadData(block.Channels[0]);
+
+            if (block.BlockType == BlockType.Stereo)
+            {
+                ReadData(block.Channels[1]);
+            }
+
+            // Make sure we didn't read too many bits
+            if (reader.Position > bexDataEnd)
+            {
+                throw new InvalidDataException();
+            }
+
+            void ReadHeader(Channel channel)
+            {
+                int bexMode = reader.ReadInt(2);
+                channel.BexMode = bexBand > 2 ? bexMode : 4;
+                channel.BexValueCount = BandExtension.BexEncodedValueCounts[channel.BexMode][bexBand];
+            }
+
+            void ReadData(Channel channel)
+            {
+                for (int i = 0; i < channel.BexValueCount; i++)
+                {
+                    int dataLength = BandExtension.BexDataLengths[channel.BexMode][bexBand][i];
+                    channel.BexValues[i] = reader.ReadInt(dataLength);
+                }
+            }
+        }
+
+        private static void CalculateSpectrumCodebookIndex(Channel channel)
+        {
+            Array.Clear(channel.CodebookSet, 0, channel.CodebookSet.Length);
+            int quantUnits = channel.CodedQuantUnits;
+            int[] sf = channel.ScaleFactors;
+
+            if (quantUnits <= 1) return;
+            if (channel.Config.HighSampleRate) return;
+
+            // Temporarily setting this value allows for simpler code by
+            // making the last value a non-special case.
+            int originalScaleTmp = sf[quantUnits];
+            sf[quantUnits] = sf[quantUnits - 1];
+
+            int avg = 0;
+            if (quantUnits > 12)
+            {
+                for (int i = 0; i < 12; i++)
+                {
+                    avg += sf[i];
+                }
+                avg = (avg + 6) / 12;
+            }
+
+            for (int i = 8; i < quantUnits; i++)
+            {
+                int prevSf = sf[i - 1];
+                int nextSf = sf[i + 1];
+                int minSf = Math.Min(prevSf, nextSf);
+                if (sf[i] - minSf >= 3 || sf[i] - prevSf + sf[i] - nextSf >= 3)
+                {
+                    channel.CodebookSet[i] = 1;
+                }
+            }
+
+            for (int i = 12; i < quantUnits; i++)
+            {
+                if (channel.CodebookSet[i] == 0)
+                {
+                    int minSf = Math.Min(sf[i - 1], sf[i + 1]);
+                    if (sf[i] - minSf >= 2 && sf[i] >= avg - (Tables.QuantUnitToCoeffCount[i] == 16 ? 1 : 0))
+                    {
+                        channel.CodebookSet[i] = 1;
+                    }
+                }
+            }
+
+            sf[quantUnits] = originalScaleTmp;
+        }
+
+        private static void ReadSpectra(BitReader reader, Channel channel)
+        {
+            int[] values = channel.SpectraValuesBuffer;
+            Array.Clear(channel.QuantizedSpectra, 0, channel.QuantizedSpectra.Length);
+            int maxHuffPrecision = Tables.MaxHuffPrecision(channel.Config.HighSampleRate);
+
+            for (int i = 0; i < channel.CodedQuantUnits; i++)
+            {
+                int subbandCount = Tables.QuantUnitToCoeffCount[i];
+                int precision = channel.Precisions[i] + 1;
+                if (precision <= maxHuffPrecision)
+                {
+                    HuffmanCodebook huff = Tables.HuffmanSpectrum[channel.CodebookSet[i]][precision][Tables.QuantUnitToCodebookIndex[i]];
+                    int groupCount = subbandCount >> huff.ValueCountPower;
+                    for (int j = 0; j < groupCount; j++)
+                    {
+                        values[j] = ReadHuffmanValue(huff, reader);
+                    }
+
+                    DecodeHuffmanValues(channel.QuantizedSpectra, Tables.QuantUnitToCoeffIndex[i], subbandCount, huff, values);
+                }
+                else
+                {
+                    int subbandIndex = Tables.QuantUnitToCoeffIndex[i];
+                    for (int j = subbandIndex; j < Tables.QuantUnitToCoeffIndex[i + 1]; j++)
+                    {
+                        channel.QuantizedSpectra[j] = reader.ReadSignedInt(precision);
+                    }
+                }
+            }
+        }
+
+        private static void ReadSpectraFine(BitReader reader, Channel channel)
+        {
+            Array.Clear(channel.QuantizedSpectraFine, 0, channel.QuantizedSpectraFine.Length);
+
+            for (int i = 0; i < channel.CodedQuantUnits; i++)
+            {
+                if (channel.PrecisionsFine[i] > 0)
+                {
+                    int overflowBits = channel.PrecisionsFine[i] + 1;
+                    int startSubband = Tables.QuantUnitToCoeffIndex[i];
+                    int endSubband = Tables.QuantUnitToCoeffIndex[i + 1];
+
+                    for (int j = startSubband; j < endSubband; j++)
+                    {
+                        channel.QuantizedSpectraFine[j] = reader.ReadSignedInt(overflowBits);
+                    }
+                }
+            }
+        }
+
+        private static void DecodeHuffmanValues(int[] spectrum, int index, int bandCount, HuffmanCodebook huff, int[] values)
+        {
+            int valueCount = bandCount >> huff.ValueCountPower;
+            int mask = (1 << huff.ValueBits) - 1;
+
+            for (int i = 0; i < valueCount; i++)
+            {
+                int value = values[i];
+                for (int j = 0; j < huff.ValueCount; j++)
+                {
+                    spectrum[index++] = Bit.SignExtend32(value & mask, huff.ValueBits);
+                    value >>= huff.ValueBits;
+                }
+            }
+        }
+
+        public static int ReadHuffmanValue(HuffmanCodebook huff, BitReader reader, bool signed = false)
+        {
+            int code = reader.PeekInt(huff.MaxBitSize);
+            byte value = huff.Lookup[code];
+            int bits = huff.Bits[value];
+            reader.Position += bits;
+            return signed ? Bit.SignExtend32(value, huff.ValueBits) : value;
+        }
+
+        private static void UnpackLfeBlock(BitReader reader, Block block)
+        {
+            Channel channel = block.Channels[0];
+            block.QuantizationUnitCount = 2;
+
+            DecodeLfeScaleFactors(reader, channel);
+            CalculateLfePrecision(channel);
+            channel.CodedQuantUnits = block.QuantizationUnitCount;
+            ReadLfeSpectra(reader, channel);
+        }
+
+        private static void DecodeLfeScaleFactors(BitReader reader, Channel channel)
+        {
+            Array.Clear(channel.ScaleFactors, 0, channel.ScaleFactors.Length);
+            for (int i = 0; i < channel.Block.QuantizationUnitCount; i++)
+            {
+                channel.ScaleFactors[i] = reader.ReadInt(5);
+            }
+        }
+
+        private static void CalculateLfePrecision(Channel channel)
+        {
+            Block block = channel.Block;
+            int precision = block.ReuseBandParams ? 8 : 4;
+            for (int i = 0; i < block.QuantizationUnitCount; i++)
+            {
+                channel.Precisions[i] = precision;
+                channel.PrecisionsFine[i] = 0;
+            }
+        }
+
+        private static void ReadLfeSpectra(BitReader reader, Channel channel)
+        {
+            Array.Clear(channel.QuantizedSpectra, 0, channel.QuantizedSpectra.Length);
+
+            for (int i = 0; i < channel.CodedQuantUnits; i++)
+            {
+                if (channel.Precisions[i] <= 0) continue;
+
+                int precision = channel.Precisions[i] + 1;
+                for (int j = Tables.QuantUnitToCoeffIndex[i]; j < Tables.QuantUnitToCoeffIndex[i + 1]; j++)
+                {
+                    channel.QuantizedSpectra[j] = reader.ReadSignedInt(precision);
+                }
+            }
+        }
+    }
+}

src/SharpEmu.GUI/Atrac9/Utilities/Bit.cs

@@ -0,0 +1,23 @@
+#nullable disable
+namespace LibAtrac9.Utilities
+{
+    internal static class Bit
+    {
+        private static uint BitReverse32(uint value)
+        {
+            value = ((value & 0xaaaaaaaa) >> 1) | ((value & 0x55555555) << 1);
+            value = ((value & 0xcccccccc) >> 2) | ((value & 0x33333333) << 2);
+            value = ((value & 0xf0f0f0f0) >> 4) | ((value & 0x0f0f0f0f) << 4);
+            value = ((value & 0xff00ff00) >> 8) | ((value & 0x00ff00ff) << 8);
+            return (value >> 16) | (value << 16);
+        }
+        private static uint BitReverse32(uint value, int bitCount) => BitReverse32(value) >> (32 - bitCount);
+        public static int BitReverse32(int value, int bitCount) => (int) BitReverse32((uint) value, bitCount);
+
+        public static int SignExtend32(int value, int bits)
+        {
+            int shift = 8 * sizeof(int) - bits;
+            return (value << shift) >> shift;
+        }
+    }
+}

src/SharpEmu.GUI/Atrac9/Utilities/BitReader.cs

@@ -0,0 +1,133 @@
+#nullable disable
+using System;
+using System.Diagnostics;
+
+namespace LibAtrac9.Utilities
+{
+    internal class BitReader
+    {
+        private byte[] Buffer { get; set; }
+        private int LengthBits { get; set; }
+        public int Position { get; set; }
+        private int Remaining => LengthBits - Position;
+
+        public BitReader(byte[] buffer) => SetBuffer(buffer);
+
+        public void SetBuffer(byte[] buffer)
+        {
+            Buffer = buffer;
+            LengthBits = Buffer?.Length * 8 ?? 0;
+            Position = 0;
+        }
+
+        public int ReadInt(int bitCount)
+        {
+            int value = PeekInt(bitCount);
+            Position += bitCount;
+            return value;
+        }
+
+        public int ReadSignedInt(int bitCount)
+        {
+            int value = PeekInt(bitCount);
+            Position += bitCount;
+            return Bit.SignExtend32(value, bitCount);
+        }
+
+        public bool ReadBool() => ReadInt(1) == 1;
+
+        public int ReadOffsetBinary(int bitCount, OffsetBias bias)
+        {
+            int offset = (1 << (bitCount - 1)) - (int)bias;
+            int value = PeekInt(bitCount) - offset;
+            Position += bitCount;
+            return value;
+        }
+
+        public void AlignPosition(int multiple)
+        {
+            Position = Helpers.GetNextMultiple(Position, multiple);
+        }
+
+        public int PeekInt(int bitCount)
+        {
+            Debug.Assert(bitCount >= 0 && bitCount <= 32);
+
+            if (bitCount > Remaining)
+            {
+                if (Position >= LengthBits) return 0;
+
+                int extraBits = bitCount - Remaining;
+                return PeekIntFallback(Remaining) << extraBits;
+            }
+
+            int byteIndex = Position / 8;
+            int bitIndex = Position % 8;
+
+            if (bitCount <= 9 && Remaining >= 16)
+            {
+                int value = Buffer[byteIndex] << 8 | Buffer[byteIndex + 1];
+                value &= 0xFFFF >> bitIndex;
+                value >>= 16 - bitCount - bitIndex;
+                return value;
+            }
+
+            if (bitCount <= 17 && Remaining >= 24)
+            {
+                int value = Buffer[byteIndex] << 16 | Buffer[byteIndex + 1] << 8 | Buffer[byteIndex + 2];
+                value &= 0xFFFFFF >> bitIndex;
+                value >>= 24 - bitCount - bitIndex;
+                return value;
+            }
+
+            if (bitCount <= 25 && Remaining >= 32)
+            {
+                int value = Buffer[byteIndex] << 24 | Buffer[byteIndex + 1] << 16 | Buffer[byteIndex + 2] << 8 | Buffer[byteIndex + 3];
+                value &= (int)(0xFFFFFFFF >> bitIndex);
+                value >>= 32 - bitCount - bitIndex;
+                return value;
+            }
+            return PeekIntFallback(bitCount);
+        }
+
+        private int PeekIntFallback(int bitCount)
+        {
+            int value = 0;
+            int byteIndex = Position / 8;
+            int bitIndex = Position % 8;
+
+            while (bitCount > 0)
+            {
+                if (bitIndex >= 8)
+                {
+                    bitIndex = 0;
+                    byteIndex++;
+                }
+
+                int bitsToRead = Math.Min(bitCount, 8 - bitIndex);
+                int mask = 0xFF >> bitIndex;
+                int currentByte = (mask & Buffer[byteIndex]) >> (8 - bitIndex - bitsToRead);
+
+                value = (value << bitsToRead) | currentByte;
+                bitIndex += bitsToRead;
+                bitCount -= bitsToRead;
+            }
+            return value;
+        }
+
+        /// <summary>
+        /// Specifies the bias of an offset binary value. A positive bias can represent one more
+        /// positive value than negative value, and a negative bias can represent one more
+        /// negative value than positive value.
+        /// </summary>
+        /// <remarks>Example:
+        /// A 4-bit offset binary value with a positive bias can store
+        /// the values 8 through -7 inclusive.
+        /// A 4-bit offset binary value with a positive bias can store
+        /// the values 7 through -8 inclusive.</remarks>
+        public enum OffsetBias
+        {
+            Negative = 0
+        }
+    }
+}

src/SharpEmu.GUI/Atrac9/Utilities/Helpers.cs

@@ -0,0 +1,51 @@
+#nullable disable
+using System.Runtime.CompilerServices;
+
+namespace LibAtrac9.Utilities
+{
+    internal static class Helpers
+    {
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static short Clamp16(int value)
+        {
+            if (value > short.MaxValue)
+                return short.MaxValue;
+            if (value < short.MinValue)
+                return short.MinValue;
+            return (short)value;
+        }
+
+        public static int GetNextMultiple(int value, int multiple)
+        {
+            if (multiple <= 0)
+                return value;
+
+            if (value % multiple == 0)
+                return value;
+
+            return value + multiple - value % multiple;
+        }
+
+        /// <summary>
+        /// Returns the floor of the base 2 logarithm of a specified number.
+        /// </summary>
+        /// <param name="value">The number whose logarithm is to be found.</param>
+        /// <returns>The floor of the base 2 logarithm of <paramref name="value"/>.</returns>
+        public static int Log2(int value)
+        {
+            value |= value >> 1;
+            value |= value >> 2;
+            value |= value >> 4;
+            value |= value >> 8;
+            value |= value >> 16;
+
+            return MultiplyDeBruijnBitPosition[(uint)(value * 0x07C4ACDDU) >> 27];
+        }
+
+        private static readonly int[] MultiplyDeBruijnBitPosition =
+        {
+            0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30,
+            8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31
+        };
+    }
+}

src/SharpEmu.GUI/Atrac9/Utilities/Mdct.cs

@@ -0,0 +1,178 @@
+#nullable disable
+using System;
+using System.Collections.Generic;
+
+namespace LibAtrac9.Utilities
+{
+    internal class Mdct
+    {
+        private int MdctBits { get; }
+        private int MdctSize { get; }
+        private double Scale { get; }
+
+        private static readonly object TableLock = new object();
+        private static int _tableBits = -1;
+        private static readonly List<double[]> SinTables = new List<double[]>();
+        private static readonly List<double[]> CosTables = new List<double[]>();
+        private static readonly List<int[]> ShuffleTables = new List<int[]>();
+
+        private readonly double[] _imdctPrevious;
+        private readonly double[] _imdctWindow;
+
+        private readonly double[] _scratchMdct;
+        private readonly double[] _scratchDct;
+
+        public Mdct(int mdctBits, double[] window, double scale = 1)
+        {
+            SetTables(mdctBits);
+
+            MdctBits = mdctBits;
+            MdctSize = 1 << mdctBits;
+            Scale = scale;
+
+            if (window.Length < MdctSize)
+            {
+                throw new ArgumentException("Window must be as long as the MDCT size.", nameof(window));
+            }
+
+            _imdctPrevious = new double[MdctSize];
+            _scratchMdct = new double[MdctSize];
+            _scratchDct = new double[MdctSize];
+            _imdctWindow = window;
+        }
+
+        private static void SetTables(int maxBits)
+        {
+            lock (TableLock)
+            {
+                if (maxBits > _tableBits)
+                {
+                    for (int i = _tableBits + 1; i <= maxBits; i++)
+                    {
+                        GenerateTrigTables(i, out double[] sin, out double[] cos);
+                        SinTables.Add(sin);
+                        CosTables.Add(cos);
+                        ShuffleTables.Add(GenerateShuffleTable(i));
+                    }
+                    _tableBits = maxBits;
+                }
+            }
+        }
+
+        public void RunImdct(double[] input, double[] output)
+        {
+            if (input.Length < MdctSize)
+            {
+                throw new ArgumentException("Input must be as long as the MDCT size.", nameof(input));
+            }
+
+            if (output.Length < MdctSize)
+            {
+                throw new ArgumentException("Output must be as long as the MDCT size.", nameof(output));
+            }
+
+            int size = MdctSize;
+            int half = size / 2;
+            double[] dctOut = _scratchMdct;
+
+            Dct4(input, dctOut);
+
+            for (int i = 0; i < half; i++)
+            {
+                output[i] = _imdctWindow[i] * dctOut[i + half] + _imdctPrevious[i];
+                output[i + half] = _imdctWindow[i + half] * -dctOut[size - 1 - i] - _imdctPrevious[i + half];
+                _imdctPrevious[i] = _imdctWindow[size - 1 - i] * -dctOut[half - i - 1];
+                _imdctPrevious[i + half] = _imdctWindow[half - i - 1] * dctOut[i];
+            }
+        }
+
+        /// <summary>
+        /// Does a Type-4 DCT.
+        /// </summary>
+        /// <param name="input">The input array containing the time or frequency-domain samples</param>
+        /// <param name="output">The output array that will contain the transformed time or frequency-domain samples</param>
+        private void Dct4(double[] input, double[] output)
+        {
+            int[] shuffleTable = ShuffleTables[MdctBits];
+            double[] sinTable = SinTables[MdctBits];
+            double[] cosTable = CosTables[MdctBits];
+            double[] dctTemp = _scratchDct;
+
+            int size = MdctSize;
+            int lastIndex = size - 1;
+            int halfSize = size / 2;
+
+            for (int i = 0; i < halfSize; i++)
+            {
+                int i2 = i * 2;
+                double a = input[i2];
+                double b = input[lastIndex - i2];
+                double sin = sinTable[i];
+                double cos = cosTable[i];
+                dctTemp[i2] = a * cos + b * sin;
+                dctTemp[i2 + 1] = a * sin - b * cos;
+            }
+            int stageCount = MdctBits - 1;
+
+            for (int stage = 0; stage < stageCount; stage++)
+            {
+                int blockCount = 1 << stage;
+                int blockSizeBits = stageCount - stage;
+                int blockHalfSizeBits = blockSizeBits - 1;
+                int blockSize = 1 << blockSizeBits;
+                int blockHalfSize = 1 << blockHalfSizeBits;
+                sinTable = SinTables[blockHalfSizeBits];
+                cosTable = CosTables[blockHalfSizeBits];
+
+                for (int block = 0; block < blockCount; block++)
+                {
+                    for (int i = 0; i < blockHalfSize; i++)
+                    {
+                        int frontPos = (block * blockSize + i) * 2;
+                        int backPos = frontPos + blockSize;
+                        double a = dctTemp[frontPos] - dctTemp[backPos];
+                        double b = dctTemp[frontPos + 1] - dctTemp[backPos + 1];
+                        double sin = sinTable[i];
+                        double cos = cosTable[i];
+                        dctTemp[frontPos] += dctTemp[backPos];
+                        dctTemp[frontPos + 1] += dctTemp[backPos + 1];
+                        dctTemp[backPos] = a * cos + b * sin;
+                        dctTemp[backPos + 1] = a * sin - b * cos;
+                    }
+                }
+            }
+
+            for (int i = 0; i < MdctSize; i++)
+            {
+                output[i] = dctTemp[shuffleTable[i]] * Scale;
+            }
+        }
+
+        internal static void GenerateTrigTables(int sizeBits, out double[] sin, out double[] cos)
+        {
+            int size = 1 << sizeBits;
+            sin = new double[size];
+            cos = new double[size];
+
+            for (int i = 0; i < size; i++)
+            {
+                double value = Math.PI * (4 * i + 1) / (4 * size);
+                sin[i] = Math.Sin(value);
+                cos[i] = Math.Cos(value);
+            }
+        }
+
+        internal static int[] GenerateShuffleTable(int sizeBits)
+        {
+            int size = 1 << sizeBits;
+            var table = new int[size];
+
+            for (int i = 0; i < size; i++)
+            {
+                table[i] = Bit.BitReverse32(i ^ (i / 2), sizeBits);
+            }
+
+            return table;
+        }
+    }
+}

src/SharpEmu.GUI/ConsoleWindow.cs

@@ -0,0 +1,150 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using Avalonia;
+using Avalonia.Collections;
+using Avalonia.Controls;
+using Avalonia.Controls.Templates;
+using Avalonia.Data;
+using Avalonia.Layout;
+using Avalonia.Media;
+using Avalonia.Platform;
+using Avalonia.Threading;
+using System.Collections.Specialized;
+
+namespace SharpEmu.GUI;
+
+public sealed class ConsoleWindow : Window
+{
+    private readonly AvaloniaList<LogLine> _sourceLines;
+    private readonly AvaloniaList<LogLine> _visibleLines = new();
+    private readonly ListBox _list;
+    private readonly TextBox _searchBox;
+    private readonly CheckBox _autoScrollCheck;
+
+    public ConsoleWindow(
+        AvaloniaList<LogLine> lines,
+        Action clear,
+        bool autoScroll)
+    {
+        _sourceLines = lines;
+        Title = "SharpEmu Console";
+        Width = 980;
+        Height = 620;
+        MinWidth = 520;
+        MinHeight = 320;
+        Background = new SolidColorBrush(Color.Parse("#0D1017"));
+        Icon = new WindowIcon(AssetLoader.Open(new Uri("avares://SharpEmu.GUI/Assets/SharpEmu.ico")));
+
+        _searchBox = new TextBox { Watermark = "Search...", Width = 320, Margin = new Thickness(0, 0, 12, 0) };
+        _autoScrollCheck = new CheckBox
+        {
+            Content = "Auto-scroll",
+            IsChecked = autoScroll,
+            FontSize = 12,
+            Margin = new Thickness(0, 0, 12, 0),
+            VerticalAlignment = VerticalAlignment.Center,
+        };
+        var copyButton = new Button
+        {
+            Classes = { "ghost" },
+            Content = "Copy",
+            Padding = new Thickness(10, 4),
+            Margin = new Thickness(0, 0, 8, 0),
+        };
+        var clearButton = new Button { Classes = { "ghost" }, Content = "Clear", Padding = new Thickness(10, 4) };
+        copyButton.Click += async (_, _) => await CopyAsync();
+        clearButton.Click += (_, _) => clear();
+        _searchBox.TextChanged += (_, _) => RefreshVisibleLines();
+
+        _list = new ListBox
+        {
+            Classes = { "console" },
+            ItemsSource = _visibleLines,
+            BorderThickness = new Thickness(1),
+            BorderBrush = new SolidColorBrush(Color.Parse("#232B3A")),
+            ItemTemplate = new FuncDataTemplate<LogLine>((_, _) =>
+            {
+                var text = new TextBlock { TextWrapping = TextWrapping.NoWrap };
+                text.Bind(TextBlock.TextProperty, new Binding(nameof(LogLine.Text)));
+                text.Bind(TextBlock.ForegroundProperty, new Binding(nameof(LogLine.Brush)));
+                return text;
+            }),
+        };
+
+        Content = new Grid
+        {
+            Margin = new Thickness(12),
+            RowDefinitions = new RowDefinitions("Auto,*"),
+            Children =
+            {
+                new Grid
+                {
+                    Margin = new Thickness(0, 0, 0, 8),
+                    ColumnDefinitions = new ColumnDefinitions("*,Auto,Auto,Auto,Auto"),
+                    Children =
+                    {
+                        new TextBlock
+                        {
+                            Classes = { "sectionTitle" },
+                            Text = "CONSOLE",
+                            VerticalAlignment = VerticalAlignment.Center,
+                        },
+                        _searchBox.WithGridColumn(1),
+                        _autoScrollCheck.WithGridColumn(2),
+                        copyButton.WithGridColumn(3),
+                        clearButton.WithGridColumn(4),
+                    },
+                },
+                _list.WithGridRow(1),
+            },
+        };
+
+        lines.CollectionChanged += OnLinesChanged;
+        Closed += (_, _) => lines.CollectionChanged -= OnLinesChanged;
+        RefreshVisibleLines();
+    }
+
+    private void OnLinesChanged(object? sender, NotifyCollectionChangedEventArgs e)
+    {
+        RefreshVisibleLines();
+        if (_autoScrollCheck.IsChecked == true)
+        {
+            Dispatcher.UIThread.Post(() => (_list.Scroll as ScrollViewer)?.ScrollToEnd());
+        }
+    }
+
+    private void RefreshVisibleLines()
+    {
+        var query = _searchBox.Text ?? string.Empty;
+        _visibleLines.Clear();
+        _visibleLines.AddRange(string.IsNullOrWhiteSpace(query)
+            ? _sourceLines
+            : _sourceLines.Where(line => line.Text.Contains(query, StringComparison.OrdinalIgnoreCase)));
+    }
+
+    private async Task CopyAsync()
+    {
+        if (_visibleLines.Count == 0 || Clipboard is null)
+        {
+            return;
+        }
+
+        await Clipboard.SetTextAsync(string.Join(Environment.NewLine, _visibleLines.Select(line => line.Text)));
+    }
+}
+
+file static class GridExtensions
+{
+    public static T WithGridColumn<T>(this T control, int column) where T : Control
+    {
+        Grid.SetColumn(control, column);
+        return control;
+    }
+
+    public static T WithGridRow<T>(this T control, int row) where T : Control
+    {
+        Grid.SetRow(control, row);
+        return control;
+    }
+}

src/SharpEmu.GUI/DiscordRichPresence.cs

@@ -0,0 +1,252 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.IO.Pipes;
+using System.Text;
+using System.Text.Json;
+
+namespace SharpEmu.GUI;
+
+/// <summary>
+/// Minimal Discord Rich Presence client. Speaks Discord's local IPC
+/// protocol (framed JSON over the discord-ipc-N named pipe) directly, so no
+/// external dependency is needed. All failures are silent: no Discord, no
+/// presence, no impact on the launcher.
+/// </summary>
+public sealed class DiscordRichPresence : IDisposable
+{
+    private const int OpHandshake = 0;
+    private const int OpFrame = 1;
+    private const int MaxFrameBytes = 64 * 1024;
+
+    private static readonly JsonSerializerOptions JsonOptions = new()
+    {
+        DefaultIgnoreCondition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritingNull,
+    };
+
+    private readonly object _gate = new();
+    private readonly string _clientId;
+    private readonly AutoResetEvent _signal = new(false);
+    private readonly Thread _worker;
+
+    private NamedPipeClientStream? _pipe;
+    private PresenceState? _desired;
+    private PresenceState? _sent;
+    private volatile bool _disposed;
+
+    private sealed record PresenceState(string Details, string? State, long? StartUnixSeconds);
+
+    public DiscordRichPresence(string clientId)
+    {
+        _clientId = clientId;
+        _worker = new Thread(WorkerLoop)
+        {
+            IsBackground = true,
+            Name = "DiscordRichPresence",
+        };
+        _worker.Start();
+    }
+
+    /// <summary>
+    /// Requests the given presence; the worker applies it asynchronously and
+    /// retries (with reconnection) until it is delivered or replaced.
+    /// </summary>
+    public void SetPresence(string details, string? state = null, long? startUnixSeconds = null)
+    {
+        lock (_gate)
+        {
+            _desired = new PresenceState(details, state, startUnixSeconds);
+        }
+
+        Trace($"queued details=\"{details}\" state=\"{state}\"");
+        _signal.Set();
+    }
+
+    public void Dispose()
+    {
+        _disposed = true;
+        _signal.Set();
+        ClosePipe();
+    }
+
+    private void WorkerLoop()
+    {
+        while (!_disposed)
+        {
+            // Woken immediately on presence changes; the periodic tick
+            // retries after connection failures (e.g. Discord starts later).
+            _signal.WaitOne(TimeSpan.FromSeconds(15));
+            if (_disposed || _clientId.Length == 0)
+            {
+                continue;
+            }
+
+            PresenceState? desired;
+            lock (_gate)
+            {
+                desired = _desired;
+            }
+
+            if (desired is null || desired == _sent)
+            {
+                continue;
+            }
+
+            try
+            {
+                EnsureConnected();
+                SendActivity(desired);
+                _sent = desired;
+                Trace($"sent details=\"{desired.Details}\" state=\"{desired.State}\"");
+            }
+            catch (Exception exception)
+            {
+                // Connection died (or never existed); reconnect on a later tick.
+                Trace($"send failed: {exception.Message}");
+                ClosePipe();
+                _sent = null;
+            }
+        }
+    }
+
+    private void EnsureConnected()
+    {
+        if (_pipe is { IsConnected: true })
+        {
+            return;
+        }
+
+        ClosePipe();
+        Exception? lastError = null;
+        for (var index = 0; index < 10; index++)
+        {
+            var pipe = new NamedPipeClientStream(
+                ".",
+                $"discord-ipc-{index}",
+                PipeDirection.InOut,
+                PipeOptions.Asynchronous);
+            try
+            {
+                pipe.Connect(500);
+                _pipe = pipe;
+                WriteFrame(OpHandshake, JsonSerializer.Serialize(new
+                {
+                    v = 1,
+                    client_id = _clientId,
+                }));
+
+                // Discord replies with a READY (or error) frame; consume it
+                // so the pipe buffer stays drained.
+                _ = ReadFrame();
+                return;
+            }
+            catch (Exception exception)
+            {
+                lastError = exception;
+                pipe.Dispose();
+                _pipe = null;
+            }
+        }
+
+        throw lastError ?? new IOException("Discord IPC pipe not found.");
+    }
+
+    private void SendActivity(PresenceState presence)
+    {
+        var payload = new Dictionary<string, object?>
+        {
+            ["cmd"] = "SET_ACTIVITY",
+            ["nonce"] = Guid.NewGuid().ToString(),
+            ["args"] = new Dictionary<string, object?>
+            {
+                ["pid"] = Environment.ProcessId,
+                ["activity"] = new Dictionary<string, object?>
+                {
+                    ["details"] = presence.Details,
+                    ["state"] = presence.State,
+                    ["timestamps"] = presence.StartUnixSeconds is { } start
+                        ? new Dictionary<string, object?> { ["start"] = start }
+                        : null,
+                    ["assets"] = new Dictionary<string, object?>
+                    {
+                        ["large_image"] = "logo",
+                        ["large_text"] = "SharpEmu",
+                    },
+                },
+            },
+        };
+
+        WriteFrame(OpFrame, JsonSerializer.Serialize(payload, JsonOptions));
+
+        // Consume Discord's acknowledgement to keep the pipe drained.
+        _ = ReadFrame();
+    }
+
+    private void WriteFrame(int opcode, string json)
+    {
+        var pipe = _pipe ?? throw new IOException("Discord IPC pipe is not connected.");
+        var payload = Encoding.UTF8.GetBytes(json);
+        var frame = new byte[8 + payload.Length];
+        BitConverter.TryWriteBytes(frame.AsSpan(0, 4), opcode);
+        BitConverter.TryWriteBytes(frame.AsSpan(4, 4), payload.Length);
+        payload.CopyTo(frame, 8);
+        pipe.Write(frame, 0, frame.Length);
+        pipe.Flush();
+    }
+
+    private string ReadFrame()
+    {
+        var pipe = _pipe ?? throw new IOException("Discord IPC pipe is not connected.");
+        var header = ReadExactly(pipe, 8);
+        var length = BitConverter.ToInt32(header, 4);
+        if (length is < 0 or > MaxFrameBytes)
+        {
+            throw new IOException($"Discord IPC frame length {length} is out of range.");
+        }
+
+        return Encoding.UTF8.GetString(ReadExactly(pipe, length));
+    }
+
+    private static byte[] ReadExactly(NamedPipeClientStream pipe, int count)
+    {
+        var buffer = new byte[count];
+        var read = 0;
+        while (read < count)
+        {
+            var chunk = pipe.Read(buffer, read, count - read);
+            if (chunk <= 0)
+            {
+                throw new IOException("Discord IPC pipe closed.");
+            }
+
+            read += chunk;
+        }
+
+        return buffer;
+    }
+
+    private static void Trace(string message)
+    {
+        if (string.Equals(
+                Environment.GetEnvironmentVariable("SHARPEMU_LOG_DISCORD"),
+                "1",
+                StringComparison.Ordinal))
+        {
+            Console.Error.WriteLine($"[DISCORD] {message}");
+        }
+    }
+
+    private void ClosePipe()
+    {
+        var pipe = _pipe;
+        _pipe = null;
+        try
+        {
+            pipe?.Dispose();
+        }
+        catch (Exception)
+        {
+            // Best effort; the pipe may already be broken.
+        }
+    }
+}

src/SharpEmu.GUI/EmulatorProcess.cs

@@ -0,0 +1,657 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.ComponentModel;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using System.Text;
+using Microsoft.Win32.SafeHandles;
+
+namespace SharpEmu.GUI;
+
+/// <summary>
+/// Launches the SharpEmu CLI as a child process with the same CET/CFG mitigation
+/// opt-outs the CLI would apply to its own relaunched child, while capturing
+/// stdout/stderr through pipes. The CLI's internal relaunch is suppressed via
+/// SHARPEMU_DISABLE_MITIGATION_RELAUNCH so output is not lost to a detached
+/// console. A kill-on-close job object ties the emulator's lifetime to the GUI.
+/// </summary>
+internal sealed class EmulatorProcess : IDisposable
+{
+    private const uint EXTENDED_STARTUPINFO_PRESENT = 0x00080000;
+    private const uint CREATE_NO_WINDOW = 0x08000000;
+    private const int STARTF_USESTDHANDLES = 0x00000100;
+    private const uint HANDLE_FLAG_INHERIT = 0x00000001;
+    private const uint INFINITE = 0xFFFFFFFF;
+    private const int PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY = 0x00020007;
+    private const uint JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE = 0x00002000;
+    private const int JobObjectExtendedLimitInformation = 9;
+    private const ulong PROCESS_CREATION_MITIGATION_POLICY_CONTROL_FLOW_GUARD_ALWAYS_OFF = 0x00000002UL << 40;
+    private const ulong PROCESS_CREATION_MITIGATION_POLICY2_CET_USER_SHADOW_STACKS_ALWAYS_OFF = 0x00000002UL << 28;
+    private const ulong PROCESS_CREATION_MITIGATION_POLICY2_USER_CET_SET_CONTEXT_IP_VALIDATION_ALWAYS_OFF = 0x00000002UL << 32;
+    private const ulong PROCESS_CREATION_MITIGATION_POLICY2_XTENDED_CONTROL_FLOW_GUARD_ALWAYS_OFF = 0x00000002UL << 40;
+
+    private readonly object _sync = new();
+    private nint _processHandle;
+    private nint _jobHandle;
+    private Process? _fallbackProcess;
+    private bool _running;
+    private bool _disposed;
+
+    public event Action<string, bool>? OutputReceived;
+
+    public event Action<int>? Exited;
+
+    public bool IsRunning
+    {
+        get
+        {
+            lock (_sync)
+            {
+                return _running;
+            }
+        }
+    }
+
+    public void Start(string exePath, IReadOnlyList<string> arguments, string? workingDirectory)
+    {
+        lock (_sync)
+        {
+            ObjectDisposedException.ThrowIf(_disposed, this);
+            if (_running)
+            {
+                throw new InvalidOperationException("The emulator process is already running.");
+            }
+
+            if (OperatingSystem.IsWindows())
+            {
+                StartWindows(exePath, arguments, workingDirectory);
+            }
+            else
+            {
+                StartFallback(exePath, arguments, workingDirectory);
+            }
+
+            _running = true;
+        }
+    }
+
+    public void Stop()
+    {
+        lock (_sync)
+        {
+            if (!_running)
+            {
+                return;
+            }
+
+            // Prefer terminating the job: it kills the whole tree, including
+            // any children the emulator spawned, even when the main process
+            // is wedged in a GPU driver call.
+            if (_jobHandle != 0)
+            {
+                _ = TerminateJobObject(_jobHandle, 1);
+            }
+
+            if (_processHandle != 0)
+            {
+                _ = TerminateProcess(_processHandle, 1);
+            }
+
+            try
+            {
+                _fallbackProcess?.Kill(entireProcessTree: true);
+            }
+            catch (InvalidOperationException)
+            {
+                // Already exited.
+            }
+        }
+    }
+
+    public void Dispose()
+    {
+        lock (_sync)
+        {
+            if (_disposed)
+            {
+                return;
+            }
+
+            _disposed = true;
+        }
+
+        Stop();
+    }
+
+    private void StartWindows(string exePath, IReadOnlyList<string> arguments, string? workingDirectory)
+    {
+        // The CLI would otherwise relaunch itself into a mitigated child whose
+        // console output cannot flow through our pipes.
+        Environment.SetEnvironmentVariable("SHARPEMU_DISABLE_MITIGATION_RELAUNCH", "1");
+
+        var securityAttributes = new SECURITY_ATTRIBUTES
+        {
+            nLength = Marshal.SizeOf<SECURITY_ATTRIBUTES>(),
+            bInheritHandle = 1,
+        };
+
+        if (!CreatePipe(out var stdoutRead, out var stdoutWrite, ref securityAttributes, 0) ||
+            !CreatePipe(out var stderrRead, out var stderrWrite, ref securityAttributes, 0))
+        {
+            throw new Win32Exception(Marshal.GetLastWin32Error(), "Failed to create output pipes.");
+        }
+
+        _ = SetHandleInformation(stdoutRead, HANDLE_FLAG_INHERIT, 0);
+        _ = SetHandleInformation(stderrRead, HANDLE_FLAG_INHERIT, 0);
+
+        var startupInfoEx = new STARTUPINFOEX();
+        startupInfoEx.StartupInfo.cb = Marshal.SizeOf<STARTUPINFOEX>();
+        startupInfoEx.StartupInfo.dwFlags = STARTF_USESTDHANDLES;
+        startupInfoEx.StartupInfo.hStdOutput = stdoutWrite;
+        startupInfoEx.StartupInfo.hStdError = stderrWrite;
+
+        nint attributeList = 0;
+        nint mitigationPolicies = 0;
+        try
+        {
+            nuint attributeListSize = 0;
+            _ = InitializeProcThreadAttributeList(0, 1, 0, ref attributeListSize);
+            attributeList = Marshal.AllocHGlobal((nint)attributeListSize);
+            if (!InitializeProcThreadAttributeList(attributeList, 1, 0, ref attributeListSize))
+            {
+                throw new Win32Exception(Marshal.GetLastWin32Error(), "Failed to initialize the process attribute list.");
+            }
+
+            startupInfoEx.lpAttributeList = attributeList;
+
+            var policy1 = PROCESS_CREATION_MITIGATION_POLICY_CONTROL_FLOW_GUARD_ALWAYS_OFF;
+            var policy2 =
+                PROCESS_CREATION_MITIGATION_POLICY2_CET_USER_SHADOW_STACKS_ALWAYS_OFF |
+                PROCESS_CREATION_MITIGATION_POLICY2_USER_CET_SET_CONTEXT_IP_VALIDATION_ALWAYS_OFF |
+                PROCESS_CREATION_MITIGATION_POLICY2_XTENDED_CONTROL_FLOW_GUARD_ALWAYS_OFF;
+
+            mitigationPolicies = Marshal.AllocHGlobal(sizeof(ulong) * 2);
+            Marshal.WriteInt64(mitigationPolicies, unchecked((long)policy1));
+            Marshal.WriteInt64(nint.Add(mitigationPolicies, sizeof(long)), unchecked((long)policy2));
+
+            if (!UpdateProcThreadAttribute(
+                attributeList,
+                0,
+                PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY,
+                mitigationPolicies,
+                (nuint)(sizeof(ulong) * 2),
+                0,
+                0))
+            {
+                throw new Win32Exception(Marshal.GetLastWin32Error(), "Failed to apply the mitigation policy.");
+            }
+
+            var currentDirectory = workingDirectory ?? Environment.CurrentDirectory;
+            var created = CreateProcessW(
+                exePath,
+                new StringBuilder(BuildCommandLine(exePath, arguments)),
+                0,
+                0,
+                true,
+                EXTENDED_STARTUPINFO_PRESENT | CREATE_NO_WINDOW,
+                0,
+                currentDirectory,
+                ref startupInfoEx,
+                out var processInfo);
+
+            if (!created)
+            {
+                // Some mitigation policy bits (e.g. XFG) are not supported on
+                // older Windows builds. Mirror the CLI's behavior and fall back
+                // to launching without the mitigation attribute list.
+                startupInfoEx.lpAttributeList = 0;
+                created = CreateProcessW(
+                    exePath,
+                    new StringBuilder(BuildCommandLine(exePath, arguments)),
+                    0,
+                    0,
+                    true,
+                    CREATE_NO_WINDOW,
+                    0,
+                    currentDirectory,
+                    ref startupInfoEx,
+                    out processInfo);
+            }
+
+            if (!created)
+            {
+                var error = Marshal.GetLastWin32Error();
+                throw new Win32Exception(error, $"Failed to start '{exePath}' (Win32 error {error}: {new Win32Exception(error).Message}).");
+            }
+
+            CloseHandle(processInfo.hThread);
+            _processHandle = processInfo.hProcess;
+
+            _jobHandle = CreateJobObjectW(0, null);
+            if (_jobHandle != 0 &&
+                (!TryEnableKillOnJobClose(_jobHandle) || !AssignProcessToJobObject(_jobHandle, processInfo.hProcess)))
+            {
+                CloseHandle(_jobHandle);
+                _jobHandle = 0;
+            }
+
+            StartReaderThread(stdoutRead, isError: false);
+            StartReaderThread(stderrRead, isError: true);
+            StartExitWatcherThread();
+        }
+        catch
+        {
+            CloseHandle(stdoutRead);
+            CloseHandle(stderrRead);
+            throw;
+        }
+        finally
+        {
+            // The child owns duplicated pipe write ends; closing ours lets the
+            // readers observe EOF when the child exits.
+            CloseHandle(stdoutWrite);
+            CloseHandle(stderrWrite);
+
+            if (attributeList != 0)
+            {
+                DeleteProcThreadAttributeList(attributeList);
+                Marshal.FreeHGlobal(attributeList);
+            }
+
+            if (mitigationPolicies != 0)
+            {
+                Marshal.FreeHGlobal(mitigationPolicies);
+            }
+        }
+    }
+
+    private void StartFallback(string exePath, IReadOnlyList<string> arguments, string? workingDirectory)
+    {
+        var startInfo = new ProcessStartInfo
+        {
+            FileName = exePath,
+            WorkingDirectory = workingDirectory ?? Environment.CurrentDirectory,
+            UseShellExecute = false,
+            CreateNoWindow = true,
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+        };
+        foreach (var argument in arguments)
+        {
+            startInfo.ArgumentList.Add(argument);
+        }
+
+        var process = new Process { StartInfo = startInfo, EnableRaisingEvents = true };
+        process.OutputDataReceived += (_, e) =>
+        {
+            if (e.Data is not null)
+            {
+                OutputReceived?.Invoke(e.Data, false);
+            }
+        };
+        process.ErrorDataReceived += (_, e) =>
+        {
+            if (e.Data is not null)
+            {
+                OutputReceived?.Invoke(e.Data, true);
+            }
+        };
+        process.Exited += (_, _) =>
+        {
+            int exitCode;
+            try
+            {
+                exitCode = process.ExitCode;
+            }
+            catch (InvalidOperationException)
+            {
+                exitCode = -1;
+            }
+
+            OnExited(exitCode);
+        };
+
+        process.Start();
+        process.BeginOutputReadLine();
+        process.BeginErrorReadLine();
+        _fallbackProcess = process;
+    }
+
+    private void StartReaderThread(nint readHandle, bool isError)
+    {
+        var thread = new Thread(() =>
+        {
+            using var stream = new FileStream(new SafeFileHandle(readHandle, ownsHandle: true), FileAccess.Read);
+            using var reader = new StreamReader(stream, Encoding.UTF8);
+            try
+            {
+                while (reader.ReadLine() is { } line)
+                {
+                    OutputReceived?.Invoke(line, isError);
+                }
+            }
+            catch (IOException)
+            {
+                // Pipe broken on process teardown.
+            }
+        })
+        {
+            IsBackground = true,
+            Name = isError ? "SharpEmu stderr reader" : "SharpEmu stdout reader",
+        };
+        thread.Start();
+    }
+
+    private void StartExitWatcherThread()
+    {
+        var processHandle = _processHandle;
+        var thread = new Thread(() =>
+        {
+            _ = WaitForSingleObject(processHandle, INFINITE);
+            var exitCode = GetExitCodeProcess(processHandle, out var rawExitCode)
+                ? unchecked((int)rawExitCode)
+                : -1;
+            OnExited(exitCode);
+        })
+        {
+            IsBackground = true,
+            Name = "SharpEmu exit watcher",
+        };
+        thread.Start();
+    }
+
+    private void OnExited(int exitCode)
+    {
+        lock (_sync)
+        {
+            if (!_running)
+            {
+                return;
+            }
+
+            _running = false;
+            if (_processHandle != 0)
+            {
+                CloseHandle(_processHandle);
+                _processHandle = 0;
+            }
+
+            if (_jobHandle != 0)
+            {
+                CloseHandle(_jobHandle);
+                _jobHandle = 0;
+            }
+
+            _fallbackProcess?.Dispose();
+            _fallbackProcess = null;
+        }
+
+        Exited?.Invoke(exitCode);
+    }
+
+    private static bool TryEnableKillOnJobClose(nint jobHandle)
+    {
+        var extendedLimitInfo = new JOBOBJECT_EXTENDED_LIMIT_INFORMATION
+        {
+            BasicLimitInformation = new JOBOBJECT_BASIC_LIMIT_INFORMATION
+            {
+                LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE,
+            },
+        };
+
+        var size = Marshal.SizeOf<JOBOBJECT_EXTENDED_LIMIT_INFORMATION>();
+        var memory = Marshal.AllocHGlobal(size);
+        try
+        {
+            Marshal.StructureToPtr(extendedLimitInfo, memory, false);
+            return SetInformationJobObject(
+                jobHandle,
+                JobObjectExtendedLimitInformation,
+                memory,
+                unchecked((uint)size));
+        }
+        finally
+        {
+            Marshal.FreeHGlobal(memory);
+        }
+    }
+
+    private static string BuildCommandLine(string processPath, IReadOnlyList<string> args)
+    {
+        var builder = new StringBuilder();
+        builder.Append(QuoteArgument(processPath));
+        for (var i = 0; i < args.Count; i++)
+        {
+            builder.Append(' ');
+            builder.Append(QuoteArgument(args[i]));
+        }
+
+        return builder.ToString();
+    }
+
+    private static string QuoteArgument(string argument)
+    {
+        if (argument.Length == 0)
+        {
+            return "\"\"";
+        }
+
+        var needsQuotes = false;
+        foreach (var c in argument)
+        {
+            if (char.IsWhiteSpace(c) || c == '"')
+            {
+                needsQuotes = true;
+                break;
+            }
+        }
+
+        if (!needsQuotes)
+        {
+            return argument;
+        }
+
+        var builder = new StringBuilder(argument.Length + 2);
+        builder.Append('"');
+
+        var backslashCount = 0;
+        foreach (var c in argument)
+        {
+            if (c == '\\')
+            {
+                backslashCount++;
+                continue;
+            }
+
+            if (c == '"')
+            {
+                builder.Append('\\', (backslashCount * 2) + 1);
+                builder.Append('"');
+                backslashCount = 0;
+                continue;
+            }
+
+            if (backslashCount > 0)
+            {
+                builder.Append('\\', backslashCount);
+                backslashCount = 0;
+            }
+
+            builder.Append(c);
+        }
+
+        if (backslashCount > 0)
+        {
+            builder.Append('\\', backslashCount * 2);
+        }
+
+        builder.Append('"');
+        return builder.ToString();
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct SECURITY_ATTRIBUTES
+    {
+        public int nLength;
+        public nint lpSecurityDescriptor;
+        public int bInheritHandle;
+    }
+
+    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
+    private struct STARTUPINFO
+    {
+        public int cb;
+        public nint lpReserved;
+        public nint lpDesktop;
+        public nint lpTitle;
+        public int dwX;
+        public int dwY;
+        public int dwXSize;
+        public int dwYSize;
+        public int dwXCountChars;
+        public int dwYCountChars;
+        public int dwFillAttribute;
+        public int dwFlags;
+        public short wShowWindow;
+        public short cbReserved2;
+        public nint lpReserved2;
+        public nint hStdInput;
+        public nint hStdOutput;
+        public nint hStdError;
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct STARTUPINFOEX
+    {
+        public STARTUPINFO StartupInfo;
+        public nint lpAttributeList;
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct PROCESS_INFORMATION
+    {
+        public nint hProcess;
+        public nint hThread;
+        public int dwProcessId;
+        public int dwThreadId;
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct JOBOBJECT_BASIC_LIMIT_INFORMATION
+    {
+        public long PerProcessUserTimeLimit;
+        public long PerJobUserTimeLimit;
+        public uint LimitFlags;
+        public nuint MinimumWorkingSetSize;
+        public nuint MaximumWorkingSetSize;
+        public uint ActiveProcessLimit;
+        public nint Affinity;
+        public uint PriorityClass;
+        public uint SchedulingClass;
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct IO_COUNTERS
+    {
+        public ulong ReadOperationCount;
+        public ulong WriteOperationCount;
+        public ulong OtherOperationCount;
+        public ulong ReadTransferCount;
+        public ulong WriteTransferCount;
+        public ulong OtherTransferCount;
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct JOBOBJECT_EXTENDED_LIMIT_INFORMATION
+    {
+        public JOBOBJECT_BASIC_LIMIT_INFORMATION BasicLimitInformation;
+        public IO_COUNTERS IoInfo;
+        public nuint ProcessMemoryLimit;
+        public nuint JobMemoryLimit;
+        public nuint PeakProcessMemoryUsed;
+        public nuint PeakJobMemoryUsed;
+    }
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool CreatePipe(
+        out nint hReadPipe,
+        out nint hWritePipe,
+        ref SECURITY_ATTRIBUTES lpPipeAttributes,
+        uint nSize);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool SetHandleInformation(nint hObject, uint dwMask, uint dwFlags);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool InitializeProcThreadAttributeList(
+        nint lpAttributeList,
+        int dwAttributeCount,
+        int dwFlags,
+        ref nuint lpSize);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool UpdateProcThreadAttribute(
+        nint lpAttributeList,
+        uint dwFlags,
+        nint attribute,
+        nint lpValue,
+        nuint cbSize,
+        nint lpPreviousValue,
+        nint lpReturnSize);
+
+    [DllImport("kernel32.dll")]
+    private static extern void DeleteProcThreadAttributeList(nint lpAttributeList);
+
+    [DllImport("kernel32.dll", EntryPoint = "CreateJobObjectW", SetLastError = true, CharSet = CharSet.Unicode)]
+    private static extern nint CreateJobObjectW(nint lpJobAttributes, string? lpName);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool SetInformationJobObject(
+        nint hJob,
+        int jobObjectInfoClass,
+        nint lpJobObjectInfo,
+        uint cbJobObjectInfoLength);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool AssignProcessToJobObject(nint hJob, nint hProcess);
+
+    [DllImport("kernel32.dll", EntryPoint = "CreateProcessW", SetLastError = true, CharSet = CharSet.Unicode)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool CreateProcessW(
+        string applicationName,
+        StringBuilder commandLine,
+        nint processAttributes,
+        nint threadAttributes,
+        [MarshalAs(UnmanagedType.Bool)] bool inheritHandles,
+        uint creationFlags,
+        nint environment,
+        string currentDirectory,
+        ref STARTUPINFOEX startupInfo,
+        out PROCESS_INFORMATION processInformation);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    private static extern uint WaitForSingleObject(nint handle, uint milliseconds);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool GetExitCodeProcess(nint process, out uint exitCode);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool TerminateProcess(nint process, uint exitCode);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool TerminateJobObject(nint job, uint exitCode);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool CloseHandle(nint handle);
+}

src/SharpEmu.GUI/GameEntry.cs

@@ -0,0 +1,156 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.ComponentModel;
+using Avalonia;
+using Avalonia.Media;
+using Avalonia.Media.Imaging;
+
+namespace SharpEmu.GUI;
+
+public sealed class GameEntry : INotifyPropertyChanged
+{
+    // Placeholder gradients for games without cover art, picked
+    // deterministically from the game name so a game keeps its color.
+    private static readonly (Color Start, Color End)[] PlaceholderPalette =
+    {
+        (Color.Parse("#5B4B8A"), Color.Parse("#2C2A4A")),
+        (Color.Parse("#1F6E8C"), Color.Parse("#173B45")),
+        (Color.Parse("#7A4069"), Color.Parse("#3B1C32")),
+        (Color.Parse("#2D6A4F"), Color.Parse("#1B3A2B")),
+        (Color.Parse("#8C5425"), Color.Parse("#4A2B12")),
+        (Color.Parse("#4F6D9E"), Color.Parse("#263349")),
+        (Color.Parse("#8A4B4B"), Color.Parse("#3F2222")),
+        (Color.Parse("#3E7C7B"), Color.Parse("#1E3D3C")),
+    };
+
+    private Bitmap? _cover;
+    private IBrush? _placeholderBrush;
+    private long _sizeBytes;
+
+    public GameEntry(
+        string name, string? titleId, string path, long sizeBytes, string? coverPath, string? backgroundPath)
+    {
+        Name = name;
+        TitleId = titleId;
+        Path = path;
+        _sizeBytes = sizeBytes;
+        CoverPath = coverPath;
+        BackgroundPath = backgroundPath;
+        Initials = ComputeInitials(name);
+    }
+
+    public event PropertyChangedEventHandler? PropertyChanged;
+
+    public string Name { get; }
+
+    public string? TitleId { get; }
+
+    public string Path { get; }
+
+    /// <summary>
+    /// Total size of the game. Initially the eboot's own size from the scan;
+    /// replaced with the full install folder size once computed in the
+    /// background.
+    /// </summary>
+    public long SizeBytes
+    {
+        get => _sizeBytes;
+        set
+        {
+            if (_sizeBytes == value)
+            {
+                return;
+            }
+
+            _sizeBytes = value;
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(SizeBytes)));
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Detail)));
+        }
+    }
+
+    /// <summary>Path to the cover art image shipped with the game, if found.</summary>
+    public string? CoverPath { get; }
+
+    /// <summary>Path to the key art (pic0/pic1) shipped with the game, if found.</summary>
+    public string? BackgroundPath { get; }
+
+    /// <summary>
+    /// Decoded key art used as the window backdrop while this game is
+    /// selected. Loaded on demand and cached; not exposed via binding.
+    /// </summary>
+    public Bitmap? Background { get; set; }
+
+    public string Initials { get; }
+
+    // Built lazily: brushes are AvaloniaObjects that must be created on the
+    // UI thread, while GameEntry itself is constructed on the scan thread.
+    public IBrush PlaceholderBrush => _placeholderBrush ??= BuildPlaceholderBrush(Name);
+
+    /// <summary>Decoded cover art; loaded asynchronously after the library scan.</summary>
+    public Bitmap? Cover
+    {
+        get => _cover;
+        set
+        {
+            if (ReferenceEquals(_cover, value))
+            {
+                return;
+            }
+
+            _cover = value;
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Cover)));
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(HasCover)));
+        }
+    }
+
+    public bool HasCover => _cover is not null;
+
+    public string Detail => TitleId is not null
+        ? $"{TitleId}  •  {FormatSize(SizeBytes)}"
+        : FormatSize(SizeBytes);
+
+    private static string ComputeInitials(string name)
+    {
+        var initials = name
+            .Split(' ', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
+            .Where(word => char.IsLetterOrDigit(word[0]))
+            .Select(word => char.ToUpperInvariant(word[0]))
+            .Take(2)
+            .ToArray();
+
+        return initials.Length > 0 ? new string(initials) : "?";
+    }
+
+    private static IBrush BuildPlaceholderBrush(string name)
+    {
+        var hash = 0;
+        foreach (var ch in name)
+        {
+            hash = unchecked(hash * 31 + ch);
+        }
+
+        var (start, end) = PlaceholderPalette[(int)((uint)hash % PlaceholderPalette.Length)];
+        return new LinearGradientBrush
+        {
+            StartPoint = new RelativePoint(0, 0, RelativeUnit.Relative),
+            EndPoint = new RelativePoint(1, 1, RelativeUnit.Relative),
+            GradientStops =
+            {
+                new GradientStop(start, 0),
+                new GradientStop(end, 1),
+            },
+        };
+    }
+
+    private static string FormatSize(long bytes)
+    {
+        return bytes switch
+        {
+            >= 1L << 30 => $"{bytes / (double)(1L << 30):0.0} GiB",
+            >= 1L << 20 => $"{bytes / (double)(1L << 20):0.0} MiB",
+            >= 1L << 10 => $"{bytes / (double)(1L << 10):0.0} KiB",
+            _ => $"{bytes} B",
+        };
+    }
+}

src/SharpEmu.GUI/GuiLauncher.cs

@@ -0,0 +1,47 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using Avalonia;
+
+namespace SharpEmu.GUI;
+
+/// <summary>
+/// Entry point for the desktop frontend, hosted by the SharpEmu executable
+/// when it is started without command-line arguments.
+/// </summary>
+public static class GuiLauncher
+{
+    public static int Run()
+    {
+        try
+        {
+            BuildAvaloniaApp().StartWithClassicDesktopLifetime(Array.Empty<string>());
+            return 0;
+        }
+        catch (Exception ex)
+        {
+            WriteCrashLog(ex);
+            throw;
+        }
+    }
+
+    public static AppBuilder BuildAvaloniaApp()
+        => AppBuilder.Configure<App>()
+            .UsePlatformDetect()
+            .WithInterFont()
+            .LogToTrace();
+
+    private static void WriteCrashLog(Exception ex)
+    {
+        try
+        {
+            File.AppendAllText(
+                Path.Combine(AppContext.BaseDirectory, "gui-crash.log"),
+                $"[{DateTime.Now:yyyy-MM-dd HH:mm:ss}] {ex}{Environment.NewLine}{Environment.NewLine}");
+        }
+        catch (Exception)
+        {
+            // Crash logging is best-effort.
+        }
+    }
+}

src/SharpEmu.GUI/GuiSettings.cs

@@ -0,0 +1,94 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.Text.Json;
+
+namespace SharpEmu.GUI;
+
+public sealed class GuiSettings
+{
+    private static readonly JsonSerializerOptions SerializerOptions = new()
+    {
+        WriteIndented = true,
+    };
+
+    public List<string> GameFolders { get; set; } = new();
+
+    /// <summary>Eboot paths hidden from the library via "Remove from library".</summary>
+    public List<string> ExcludedGames { get; set; } = new();
+
+    public string LogLevel { get; set; } = "Info";
+
+    public int ImportTraceLimit { get; set; }
+
+    public bool StrictDynlibResolution { get; set; }
+
+    /// <summary>
+    /// Mirror emulator output to user/logs/&lt;titleId&gt;-&lt;timestamp&gt;.log, if <see cref="LogFilePath"/> is null.
+    /// </summary>
+    public bool LogToFile { get; set; }
+
+    /// <summary>If <see cref="LogToFile"/> is true it logs to this file path.</summary>
+    public string? LogFilePath { get; set; }
+
+    /// <summary> 
+    /// If <see cref="OverrideLogFile"/> is false it appends &lt;titleId&gt;-&lt;timestamp&gt; to the filename specified by 
+    /// <see cref="LogFilePath"/>. Otherwise it uses the exact filename from <see cref="LogFilePath"/>
+    /// </summary>
+    public bool OverrideLogFile { get; set; }
+
+    /// <summary>Loop the selected game's sce_sys/snd0.at9 preview music.</summary>
+    public bool PlayTitleMusic { get; set; } = true;
+
+    public string? EmulatorPath { get; set; }
+
+    /// <summary>Publish launcher/game status to Discord Rich Presence.</summary>
+    public bool DiscordRichPresence { get; set; } = true;
+
+    /// <summary>
+    /// Discord application ID used for Rich Presence; the default is the
+    /// SharpEmu application. Override to rebrand what Discord shows as
+    /// "Playing …" (register at discord.com/developers/applications).
+    /// </summary>
+    public string DiscordClientId { get; set; } = "1525606762248540221";
+
+    // The emulator is portable and keeps its data next to the executable;
+    // the GUI follows the same convention.
+    public static string SettingsPath => Path.Combine(AppContext.BaseDirectory, "gui-settings.json");
+
+    public static GuiSettings Load()
+    {
+        try
+        {
+            if (File.Exists(SettingsPath))
+            {
+                var json = File.ReadAllText(SettingsPath);
+                return JsonSerializer.Deserialize<GuiSettings>(json, SerializerOptions) ?? new GuiSettings();
+            }
+        }
+        catch (Exception)
+        {
+            // Corrupt or unreadable settings fall back to defaults.
+        }
+
+        return new GuiSettings();
+    }
+
+    public void Save()
+    {
+        try
+        {
+            var directory = Path.GetDirectoryName(SettingsPath);
+            if (!string.IsNullOrEmpty(directory))
+            {
+                Directory.CreateDirectory(directory);
+            }
+
+            File.WriteAllText(SettingsPath, JsonSerializer.Serialize(this, SerializerOptions));
+        }
+        catch (Exception)
+        {
+            // Settings persistence is best-effort.
+        }
+    }
+}

src/SharpEmu.GUI/LogLine.cs

@@ -0,0 +1,8 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using Avalonia.Media;
+
+namespace SharpEmu.GUI;
+
+public sealed record LogLine(string Text, IBrush Brush);

src/SharpEmu.GUI/MainWindow.axaml

@@ -0,0 +1,291 @@
+<!--
+Copyright (C) 2026 SharpEmu Emulator Project
+SPDX-License-Identifier: GPL-2.0-or-later
+-->
+
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        x:Class="SharpEmu.GUI.MainWindow"
+        Title="SharpEmu"
+        Width="1280" Height="820"
+        MinWidth="980" MinHeight="640"
+        WindowStartupLocation="CenterScreen"
+        Background="{StaticResource BgBrush}"
+        ExtendClientAreaToDecorationsHint="True"
+        ExtendClientAreaChromeHints="PreferSystemChrome"
+        ExtendClientAreaTitleBarHeightHint="44"
+        Icon="avares://SharpEmu.GUI/Assets/SharpEmu.ico"
+        KeyDown="OnKeyDown">
+
+  <Grid RowDefinitions="44,*,32">
+
+    <!-- Selected-game backdrop: key art behind the main content, dimmed by
+         a scrim so tiles and text stay readable. Fades on selection. -->
+    <Panel Grid.Row="1" ClipToBounds="True">
+      <Image x:Name="BackdropImage" Stretch="UniformToFill" Opacity="0"
+             HorizontalAlignment="Center" VerticalAlignment="Center">
+        <Image.Transitions>
+          <Transitions>
+            <DoubleTransition Property="Opacity" Duration="0:0:0.35" />
+          </Transitions>
+        </Image.Transitions>
+      </Image>
+      <Border>
+        <Border.Background>
+          <LinearGradientBrush StartPoint="0%,0%" EndPoint="0%,100%">
+            <GradientStop Offset="0" Color="#730D1017" />
+            <GradientStop Offset="0.55" Color="#BF0D1017" />
+            <GradientStop Offset="1" Color="#EB0D1017" />
+          </LinearGradientBrush>
+        </Border.Background>
+      </Border>
+    </Panel>
+
+    <!-- Title bar -->
+    <Grid x:Name="TitleBar" Grid.Row="0" Background="{StaticResource ChromeBrush}">
+      <StackPanel Orientation="Horizontal" Spacing="10" Margin="16,0" VerticalAlignment="Center">
+        <Image Source="avares://SharpEmu.GUI/Assets/SharpEmu.ico" Width="20" Height="20"
+               RenderOptions.BitmapInterpolationMode="HighQuality" />
+        <TextBlock Text="SharpEmu" FontSize="14" FontWeight="SemiBold" VerticalAlignment="Center" />
+        <Border Classes="pill">
+          <TextBlock x:Name="VersionText" Text="v0.0.1" FontSize="11" Foreground="{StaticResource MutedBrush}" />
+        </Border>
+      </StackPanel>
+    </Grid>
+
+    <!-- Main content -->
+    <Grid Grid.Row="1" Margin="18,14,18,14" RowDefinitions="Auto,*,Auto,Auto">
+
+      <!-- Library toolbar -->
+      <Grid Grid.Row="0" ColumnDefinitions="Auto,Auto,*,Auto,Auto,Auto,Auto" Margin="6,0,6,12">
+        <TextBlock Grid.Column="0" Text="Library" FontSize="22" FontWeight="Bold" VerticalAlignment="Center" />
+        <Border Grid.Column="1" Classes="pill" Margin="12,2,0,0" VerticalAlignment="Center">
+          <TextBlock x:Name="GameCountText" Text="0 games" FontSize="11" Foreground="{StaticResource MutedBrush}" />
+        </Border>
+        <TextBox Grid.Column="3" x:Name="SearchBox" Watermark="Search library…" Width="280"
+                 VerticalAlignment="Center" Margin="0,0,12,0" />
+        <Button Grid.Column="4" x:Name="AddFolderButton" Classes="ghost" Content="＋ Add folder"
+                VerticalAlignment="Center" Margin="0,0,8,0" />
+        <Button Grid.Column="5" x:Name="RescanButton" Classes="ghost" Content="⟳ Rescan"
+                VerticalAlignment="Center" Margin="0,0,8,0" />
+        <Button Grid.Column="6" x:Name="OpenFileButton" Classes="ghost" Content="Open file…"
+                VerticalAlignment="Center" />
+      </Grid>
+
+      <!-- Cover-art grid -->
+      <Panel Grid.Row="1">
+        <ListBox x:Name="GameList" Classes="tileGrid" Background="Transparent"
+                 SelectionMode="Single" Padding="0">
+          <ListBox.ContextMenu>
+            <ContextMenu x:Name="GameContextMenu" Placement="Pointer">
+              <MenuItem x:Name="CtxLaunch" Header="Launch" FontWeight="SemiBold">
+                <MenuItem.Icon>
+                  <TextBlock Text="▶" FontSize="11" Foreground="{StaticResource AccentHoverBrush}"
+                             HorizontalAlignment="Center" VerticalAlignment="Center" />
+                </MenuItem.Icon>
+              </MenuItem>
+              <MenuItem x:Name="CtxOpenFolder" Header="Open game folder">
+                <MenuItem.Icon>
+                  <TextBlock Text="📂" FontSize="12" HorizontalAlignment="Center" VerticalAlignment="Center" />
+                </MenuItem.Icon>
+              </MenuItem>
+              <Separator />
+              <MenuItem x:Name="CtxCopyPath" Header="Copy path">
+                <MenuItem.Icon>
+                  <TextBlock Text="⧉" FontSize="13" Foreground="{StaticResource MutedBrush}"
+                             HorizontalAlignment="Center" VerticalAlignment="Center" />
+                </MenuItem.Icon>
+              </MenuItem>
+              <MenuItem x:Name="CtxCopyTitleId" Header="Copy title ID">
+                <MenuItem.Icon>
+                  <TextBlock Text="⧉" FontSize="13" Foreground="{StaticResource MutedBrush}"
+                             HorizontalAlignment="Center" VerticalAlignment="Center" />
+                </MenuItem.Icon>
+              </MenuItem>
+              <Separator />
+              <MenuItem x:Name="CtxRemove" Header="Remove from library"
+                        Foreground="{StaticResource DangerHoverBrush}">
+                <MenuItem.Icon>
+                  <TextBlock Text="✕" FontSize="12" Foreground="{StaticResource DangerHoverBrush}"
+                             HorizontalAlignment="Center" VerticalAlignment="Center" />
+                </MenuItem.Icon>
+              </MenuItem>
+            </ContextMenu>
+          </ListBox.ContextMenu>
+          <ListBox.ItemsPanel>
+            <ItemsPanelTemplate>
+              <WrapPanel />
+            </ItemsPanelTemplate>
+          </ListBox.ItemsPanel>
+          <ListBox.ItemTemplate>
+            <DataTemplate>
+              <StackPanel Width="128" Height="186" Spacing="7">
+                <Border Classes="coverShadow" Width="128" Height="128">
+                  <Border Classes="coverClip">
+                    <Panel>
+                      <Border Background="{Binding PlaceholderBrush}" IsVisible="{Binding !HasCover}">
+                        <TextBlock Text="{Binding Initials}" FontSize="36" FontWeight="Bold"
+                                   Foreground="#E8ECF4" Opacity="0.85"
+                                   HorizontalAlignment="Center" VerticalAlignment="Center" />
+                      </Border>
+                      <Image Source="{Binding Cover}" Stretch="UniformToFill" IsVisible="{Binding HasCover}" />
+                    </Panel>
+                  </Border>
+                </Border>
+                <StackPanel Spacing="2">
+                  <TextBlock Text="{Binding Name}" FontSize="13" FontWeight="SemiBold"
+                             TextWrapping="Wrap" MaxLines="2" TextTrimming="CharacterEllipsis" />
+                  <TextBlock Text="{Binding Detail}" FontSize="11" Foreground="{StaticResource MutedBrush}"
+                             TextTrimming="CharacterEllipsis" />
+                </StackPanel>
+              </StackPanel>
+            </DataTemplate>
+          </ListBox.ItemTemplate>
+        </ListBox>
+
+        <!-- Empty state -->
+        <StackPanel x:Name="EmptyState" Spacing="10" HorizontalAlignment="Center" VerticalAlignment="Center"
+                    IsVisible="False">
+          <TextBlock Text="🎮" FontSize="44" HorizontalAlignment="Center" Opacity="0.7" />
+          <TextBlock x:Name="EmptyStateTitle" Text="Your library is empty" FontSize="18" FontWeight="SemiBold"
+                     HorizontalAlignment="Center" />
+          <TextBlock x:Name="EmptyStateHint" Text="Add a folder containing your games to get started."
+                     FontSize="13" Foreground="{StaticResource MutedBrush}" HorizontalAlignment="Center" />
+          <Button x:Name="EmptyAddFolderButton" Classes="accent" Content="＋ Add game folder"
+                  HorizontalAlignment="Center" Margin="0,8,0,0" />
+        </StackPanel>
+      </Panel>
+
+      <!-- Console (collapsible) -->
+      <Border Grid.Row="2" x:Name="ConsolePanel" Classes="card" Padding="0" Height="240"
+              Margin="0,12,0,0" IsVisible="False">
+        <Grid RowDefinitions="Auto,*">
+          <Grid Grid.Row="0" ColumnDefinitions="*,Auto,Auto,Auto,Auto,Auto" Margin="16,12,16,8">
+            <TextBlock Classes="sectionTitle" Text="CONSOLE" VerticalAlignment="Center" />
+            <TextBox Grid.Column="1" FontSize="12" Margin="0,0,12,0" x:Name="ConsoleSearchBox"
+                    Watermark="Search..." Width="320" />
+            <CheckBox Grid.Column="2" x:Name="AutoScrollCheck" Content="Auto-scroll" IsChecked="True"
+                    FontSize="12" Margin="0,0,12,0" />
+            <Button Grid.Column="3" x:Name="DetachConsoleButton" Classes="ghost" Content="Split" FontSize="12"
+                    Padding="10,4" Margin="0,0,8,0" />
+            <Button Grid.Column="4" x:Name="CopyLogButton" Classes="ghost" Content="Copy" FontSize="12"
+                    Padding="10,4" Margin="0,0,8,0" />
+            <Button Grid.Column="5" x:Name="ClearLogButton" Classes="ghost" Content="Clear" FontSize="12"
+                    Padding="10,4" />
+          </Grid>
+          <ListBox Grid.Row="1" x:Name="ConsoleList" Classes="console" BorderThickness="0,1,0,0"
+                   BorderBrush="{StaticResource CardBorderBrush}" CornerRadius="0,0,12,12">
+            <ListBox.ItemTemplate>
+              <DataTemplate>
+                <TextBlock Text="{Binding Text}" Foreground="{Binding Brush}" TextWrapping="NoWrap" />
+              </DataTemplate>
+            </ListBox.ItemTemplate>
+          </ListBox>
+        </Grid>
+      </Border>
+
+      <!-- Launch bar -->
+      <Border Grid.Row="3" Classes="card" Margin="0,12,0,0" Padding="14">
+        <StackPanel Spacing="14">
+          <Grid ColumnDefinitions="Auto,*,Auto">
+
+            <!-- Selected game cover thumbnail -->
+            <Border Grid.Column="0" Classes="coverClip" Width="56" Height="56" CornerRadius="8"
+                    VerticalAlignment="Center">
+              <Panel x:Name="SelectedCoverPanel">
+                <Border Background="{Binding PlaceholderBrush, FallbackValue={x:Null}}"
+                        IsVisible="{Binding !HasCover, FallbackValue=False}">
+                  <TextBlock Text="{Binding Initials}" FontSize="20" FontWeight="Bold"
+                             Foreground="#E8ECF4" Opacity="0.85"
+                             HorizontalAlignment="Center" VerticalAlignment="Center" />
+                </Border>
+                <Image Source="{Binding Cover}" Stretch="UniformToFill"
+                       IsVisible="{Binding HasCover, FallbackValue=False}" />
+              </Panel>
+            </Border>
+
+            <StackPanel Grid.Column="1" Spacing="3" VerticalAlignment="Center" Margin="14,0,14,0">
+              <TextBlock x:Name="SelectedGameTitle" Text="No game selected" FontSize="16" FontWeight="Bold"
+                         TextTrimming="CharacterEllipsis" />
+              <TextBlock x:Name="SelectedGamePath" Text="Pick a game from the library, or open an eboot.bin directly."
+                         FontSize="11" Foreground="{StaticResource MutedBrush}" TextTrimming="CharacterEllipsis" />
+              <StackPanel Orientation="Horizontal" Spacing="7">
+                <Ellipse x:Name="StatusDot" Width="8" Height="8" Fill="{StaticResource FaintBrush}"
+                         VerticalAlignment="Center" />
+                <TextBlock x:Name="StatusText" Text="Idle" FontSize="11" Foreground="{StaticResource MutedBrush}"
+                           VerticalAlignment="Center" />
+              </StackPanel>
+            </StackPanel>
+
+            <StackPanel Grid.Column="2" Orientation="Horizontal" Spacing="8" VerticalAlignment="Center">
+              <ToggleButton x:Name="OptionsToggle" Classes="ghost" Content="⚙ Options" />
+              <ToggleButton x:Name="ConsoleToggle" Classes="ghost" Content="≡ Console" />
+              <Button x:Name="LaunchButton" Classes="accent" Content="▶  Launch" IsEnabled="False" />
+              <Button x:Name="StopButton" Classes="danger" Content="■  Stop" IsEnabled="False" />
+            </StackPanel>
+          </Grid>
+
+          <!-- Launch options (collapsible) -->
+          <WrapPanel x:Name="OptionsPanel" IsVisible="False">
+            <StackPanel Margin="0,0,24,0">
+              <TextBlock Classes="fieldLabel" Text="CPU engine" />
+              <ComboBox x:Name="CpuEngineBox" Width="150" SelectedIndex="0" CornerRadius="8">
+                <ComboBoxItem Content="Native" />
+              </ComboBox>
+            </StackPanel>
+            <StackPanel Margin="0,0,24,0">
+              <TextBlock Classes="fieldLabel" Text="Log level" />
+              <ComboBox x:Name="LogLevelBox" Width="150" SelectedIndex="2" CornerRadius="8">
+                <ComboBoxItem Content="Trace" />
+                <ComboBoxItem Content="Debug" />
+                <ComboBoxItem Content="Info" />
+                <ComboBoxItem Content="Warning" />
+                <ComboBoxItem Content="Error" />
+                <ComboBoxItem Content="Critical" />
+              </ComboBox>
+            </StackPanel>
+            <StackPanel Margin="0,0,24,0">
+              <TextBlock Classes="fieldLabel" Text="Import trace limit (0 = off)" />
+              <NumericUpDown x:Name="TraceImportsBox" Width="170" Minimum="0" Maximum="4096" Increment="16"
+                             Value="0" FormatString="0" CornerRadius="8" />
+            </StackPanel>
+            <StackPanel Margin="0,0,24,0">
+              <TextBlock Classes="fieldLabel" Text="Strict dynlib resolution" />
+              <ToggleSwitch x:Name="StrictToggle" OnContent="On" OffContent="Off" />
+            </StackPanel>
+            <StackPanel Margin="0,0,24,0">
+              <TextBlock Classes="fieldLabel" Text="Log to file" />
+              <ToggleSwitch x:Name="LogToFileToggle" OnContent="On" OffContent="Off" />
+            </StackPanel>
+            <StackPanel Margin="0,0,24,0">
+              <TextBlock Classes="fieldLabel" Text="Log file path" />
+              <Button x:Name="SelectLogFilePathButton" Classes="ghost" Content="Select…"
+                VerticalAlignment="Center" />
+            </StackPanel>
+            <StackPanel Margin="0,0,24,0">
+              <TextBlock Classes="fieldLabel" Text="Override log file" />
+              <ToggleSwitch x:Name="OverrideLogFileToggle" OnContent="On" OffContent="Off" />
+            </StackPanel>
+            <StackPanel Margin="0,0,24,0">
+              <TextBlock Classes="fieldLabel" Text="Title music" />
+              <ToggleSwitch x:Name="TitleMusicToggle" OnContent="On" OffContent="Off" IsChecked="True" />
+            </StackPanel>
+            <StackPanel>
+              <TextBlock Classes="fieldLabel" Text="Discord presence" />
+              <ToggleSwitch x:Name="DiscordToggle" OnContent="On" OffContent="Off" />
+            </StackPanel>
+          </WrapPanel>
+        </StackPanel>
+      </Border>
+    </Grid>
+
+    <!-- Status bar -->
+    <Grid Grid.Row="2" Background="{StaticResource ChromeBrush}" ColumnDefinitions="*,Auto">
+      <TextBlock x:Name="EmulatorPathText" Grid.Column="0" Text="Emulator: locating…" FontSize="11"
+                 Foreground="{StaticResource FaintBrush}" VerticalAlignment="Center" Margin="16,0"
+                 TextTrimming="CharacterEllipsis" />
+      <TextBlock x:Name="StatusBarRight" Grid.Column="1" Text="" FontSize="11"
+                 Foreground="{StaticResource FaintBrush}" VerticalAlignment="Center" Margin="16,0" />
+    </Grid>
+  </Grid>
+</Window>

src/SharpEmu.GUI/SharpEmu.GUI.csproj

@@ -0,0 +1,44 @@
+<!--
+Copyright (C) 2026 SharpEmu Emulator Project
+SPDX-License-Identifier: GPL-2.0-or-later
+-->
+
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <!-- Class library: the GUI is hosted by SharpEmu.CLI, which opens it when
+       the executable is started without arguments. -->
+  <PropertyGroup>
+    <GenerateDocumentationFile>false</GenerateDocumentationFile>
+    <Version>0.0.1</Version>
+  </PropertyGroup>
+
+  <!-- Dependency-free; provides the BuildInfo provenance shown in the
+       title bar. -->
+  <ItemGroup>
+    <ProjectReference Include="..\SharpEmu.Logging\SharpEmu.Logging.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Avalonia" />
+    <PackageReference Include="Avalonia.Desktop" />
+    <PackageReference Include="Avalonia.Fonts.Inter" />
+    <PackageReference Include="Avalonia.Themes.Fluent" />
+    <PackageReference Include="Tmds.DBus.Protocol" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <AvaloniaResource Include="..\..\assets\images\SharpEmu.ico" Link="Assets/SharpEmu.ico" />
+  </ItemGroup>
+
+  <!-- The controller readers (DualSense raw HID + Xbox XInput) are shared
+       with the emulator's pad HLE. They are dependency-free, so they are
+       compiled in directly rather than pulling a reference to all of
+       SharpEmu.Libs into the launcher. -->
+  <ItemGroup>
+    <Compile Include="..\SharpEmu.Libs\Pad\PadState.cs" Link="Input/PadState.cs" />
+    <Compile Include="..\SharpEmu.Libs\Pad\HidNative.cs" Link="Input/HidNative.cs" />
+    <Compile Include="..\SharpEmu.Libs\Pad\DualSenseReader.cs" Link="Input/DualSenseReader.cs" />
+    <Compile Include="..\SharpEmu.Libs\Pad\XInputReader.cs" Link="Input/XInputReader.cs" />
+  </ItemGroup>
+
+</Project>

src/SharpEmu.GUI/SndPreviewPlayer.cs

@@ -0,0 +1,301 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.Buffers.Binary;
+using System.Runtime.InteropServices;
+using System.Text;
+using LibAtrac9;
+
+namespace SharpEmu.GUI;
+
+/// <summary>
+/// Loops a game's sce_sys/snd0.at9 preview music while the game is selected
+/// in the library, like the console home screen. The ATRAC9 stream is decoded
+/// to WAV on a background task (vendored LibAtrac9); playback uses winmm's
+/// PlaySound, so this is Windows-only and a no-op elsewhere.
+/// </summary>
+internal sealed class SndPreviewPlayer
+{
+    private const uint SND_ASYNC = 0x0001;
+    private const uint SND_NODEFAULT = 0x0002;
+    private const uint SND_MEMORY = 0x0004;
+    private const uint SND_LOOP = 0x0008;
+
+    private readonly object _sync = new();
+    private int _generation;
+    private GCHandle _pinnedWav;
+    private bool _playing;
+    private bool _paused;
+    private string? _cachedPath;
+    private byte[]? _cachedWav;
+
+    /// <summary>Starts looping the given snd0.at9 after a short debounce.</summary>
+    public void Play(string at9Path)
+    {
+        if (!OperatingSystem.IsWindows())
+        {
+            return;
+        }
+
+        int generation;
+        lock (_sync)
+        {
+            generation = ++_generation;
+        }
+
+        _ = Task.Run(async () =>
+        {
+            // Debounce so skimming through the library does not decode (or
+            // start) a preview per tile.
+            await Task.Delay(300).ConfigureAwait(false);
+
+            byte[]? wav;
+            lock (_sync)
+            {
+                if (generation != _generation)
+                {
+                    return;
+                }
+
+                wav = string.Equals(_cachedPath, at9Path, StringComparison.OrdinalIgnoreCase)
+                    ? _cachedWav
+                    : null;
+            }
+
+            if (wav is null)
+            {
+                try
+                {
+                    wav = DecodeAt9ToWav(File.ReadAllBytes(at9Path));
+                }
+                catch (Exception)
+                {
+                    return; // corrupt or unsupported preview: stay silent
+                }
+            }
+
+            lock (_sync)
+            {
+                if (generation != _generation)
+                {
+                    return;
+                }
+
+                _cachedPath = at9Path;
+                _cachedWav = wav;
+                StopLocked();
+
+                // The WAV image must stay pinned while winmm plays from it.
+                _pinnedWav = GCHandle.Alloc(wav, GCHandleType.Pinned);
+                _playing = PlaySound(_pinnedWav.AddrOfPinnedObject(), 0, SND_MEMORY | SND_ASYNC | SND_LOOP | SND_NODEFAULT);
+                if (!_playing)
+                {
+                    _pinnedWav.Free();
+                }
+            }
+        });
+    }
+
+    public void Stop()
+    {
+        if (!OperatingSystem.IsWindows())
+        {
+            return;
+        }
+
+        lock (_sync)
+        {
+            _generation++;
+            StopLocked();
+        }
+    }
+
+    /// <summary>
+    /// Silences playback but keeps the decoded track ready, so
+    /// <see cref="Resume"/> can restart it (winmm cannot truly pause).
+    /// </summary>
+    public void Pause()
+    {
+        if (!OperatingSystem.IsWindows())
+        {
+            return;
+        }
+
+        lock (_sync)
+        {
+            if (!_playing)
+            {
+                return;
+            }
+
+            _ = PlaySound(0, 0, 0);
+            _playing = false;
+            _paused = true;
+        }
+    }
+
+    /// <summary>Restarts the track silenced by <see cref="Pause"/>.</summary>
+    public void Resume()
+    {
+        if (!OperatingSystem.IsWindows())
+        {
+            return;
+        }
+
+        lock (_sync)
+        {
+            if (!_paused || !_pinnedWav.IsAllocated)
+            {
+                return;
+            }
+
+            _paused = false;
+            _playing = PlaySound(_pinnedWav.AddrOfPinnedObject(), 0, SND_MEMORY | SND_ASYNC | SND_LOOP | SND_NODEFAULT);
+        }
+    }
+
+    private void StopLocked()
+    {
+        _ = PlaySound(0, 0, 0);
+        _playing = false;
+        _paused = false;
+        if (_pinnedWav.IsAllocated)
+        {
+            _pinnedWav.Free();
+        }
+    }
+
+    private static readonly Guid Atrac9SubFormat = new("47E142D2-36BA-4D8D-88FC-61654F8C836C");
+
+    /// <summary>
+    /// Decodes a Sony AT9 (RIFF-wrapped ATRAC9) file to a PCM16 WAV image.
+    /// Layout per Sony's container: an extensible fmt chunk whose extension
+    /// carries the 4-byte codec config, a fact chunk with the sample count
+    /// and encoder delay, and superframes in the data chunk.
+    /// </summary>
+    private static byte[] DecodeAt9ToWav(byte[] file)
+    {
+        using var reader = new BinaryReader(new MemoryStream(file), Encoding.ASCII);
+        if (Encoding.ASCII.GetString(reader.ReadBytes(4)) != "RIFF")
+        {
+            throw new InvalidDataException("Not a RIFF file.");
+        }
+
+        reader.BaseStream.Position += 4; // riff size
+        if (Encoding.ASCII.GetString(reader.ReadBytes(4)) != "WAVE")
+        {
+            throw new InvalidDataException("Not a WAVE file.");
+        }
+
+        byte[]? configData = null;
+        var sampleCount = 0;
+        var encoderDelay = 0;
+        var dataOffset = -1;
+        var dataSize = 0;
+
+        while (reader.BaseStream.Position + 8 <= reader.BaseStream.Length)
+        {
+            var chunkId = Encoding.ASCII.GetString(reader.ReadBytes(4));
+            var chunkSize = reader.ReadInt32();
+            var chunkStart = reader.BaseStream.Position;
+            switch (chunkId)
+            {
+                case "fmt ":
+                    var formatTag = reader.ReadUInt16();
+                    reader.BaseStream.Position = chunkStart + 24; // to SubFormat GUID
+                    var subFormat = new Guid(reader.ReadBytes(16));
+                    if (formatTag != 0xFFFE || subFormat != Atrac9SubFormat)
+                    {
+                        throw new InvalidDataException("Not an ATRAC9 stream.");
+                    }
+
+                    reader.BaseStream.Position += 4; // version info
+                    configData = reader.ReadBytes(4);
+                    break;
+                case "fact":
+                    sampleCount = reader.ReadInt32();
+                    reader.BaseStream.Position += 4; // input overlap delay
+                    encoderDelay = reader.ReadInt32();
+                    break;
+                case "data":
+                    dataOffset = (int)chunkStart;
+                    dataSize = chunkSize;
+                    break;
+            }
+
+            reader.BaseStream.Position = chunkStart + chunkSize + (chunkSize & 1);
+        }
+
+        if (configData is null || sampleCount <= 0 || dataOffset < 0)
+        {
+            throw new InvalidDataException("Missing fmt, fact, or data chunk.");
+        }
+
+        var decoder = new Atrac9Decoder();
+        decoder.Initialize(configData);
+        var config = decoder.Config;
+
+        var superframeCount = (sampleCount + encoderDelay + config.SuperframeSamples - 1) / config.SuperframeSamples;
+        superframeCount = Math.Min(superframeCount, dataSize / config.SuperframeBytes);
+
+        var channels = config.ChannelCount;
+        var pcmBuffer = new short[channels][];
+        for (var i = 0; i < channels; i++)
+        {
+            pcmBuffer[i] = new short[config.SuperframeSamples];
+        }
+
+        var wav = new byte[44 + (sampleCount * channels * 2)];
+        WriteWavHeader(wav, channels, config.SampleRate, sampleCount);
+
+        var superframe = new byte[config.SuperframeBytes];
+        var decodedIndex = 0L; // per-channel, includes the encoder delay
+        var written = 0;
+        for (var f = 0; f < superframeCount && written < sampleCount; f++)
+        {
+            Buffer.BlockCopy(file, dataOffset + (f * config.SuperframeBytes), superframe, 0, config.SuperframeBytes);
+            decoder.Decode(superframe, pcmBuffer);
+            for (var s = 0; s < config.SuperframeSamples && written < sampleCount; s++)
+            {
+                if (decodedIndex++ < encoderDelay)
+                {
+                    continue;
+                }
+
+                var sampleOffset = 44 + ((long)written * channels * 2);
+                for (var ch = 0; ch < channels; ch++)
+                {
+                    BinaryPrimitives.WriteInt16LittleEndian(
+                        wav.AsSpan((int)(sampleOffset + (ch * 2))),
+                        pcmBuffer[ch][s]);
+                }
+
+                written++;
+            }
+        }
+
+        return wav;
+    }
+
+    private static void WriteWavHeader(byte[] wav, int channels, int sampleRate, int sampleCount)
+    {
+        var span = wav.AsSpan();
+        Encoding.ASCII.GetBytes("RIFF").CopyTo(span);
+        BinaryPrimitives.WriteInt32LittleEndian(span[4..], wav.Length - 8);
+        Encoding.ASCII.GetBytes("WAVE").CopyTo(span[8..]);
+        Encoding.ASCII.GetBytes("fmt ").CopyTo(span[12..]);
+        BinaryPrimitives.WriteInt32LittleEndian(span[16..], 16);
+        BinaryPrimitives.WriteInt16LittleEndian(span[20..], 1); // PCM
+        BinaryPrimitives.WriteInt16LittleEndian(span[22..], (short)channels);
+        BinaryPrimitives.WriteInt32LittleEndian(span[24..], sampleRate);
+        BinaryPrimitives.WriteInt32LittleEndian(span[28..], sampleRate * channels * 2);
+        BinaryPrimitives.WriteInt16LittleEndian(span[32..], (short)(channels * 2));
+        BinaryPrimitives.WriteInt16LittleEndian(span[34..], 16); // bits per sample
+        Encoding.ASCII.GetBytes("data").CopyTo(span[36..]);
+        BinaryPrimitives.WriteInt32LittleEndian(span[40..], sampleCount * channels * 2);
+    }
+
+    [DllImport("winmm.dll")]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool PlaySound(nint sound, nint module, uint flags);
+}

src/SharpEmu.GUI/packages.lock.json

@@ -0,0 +1,189 @@
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+        }
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+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "3EZ1mpIiKWRLL5hUYA82ZHteeDIVaEA/Z0rA/wU6tjx6crcAkJnBPwDXZugBSfo8+J3EznvRJf49uMsqYfKrHg=="
+      },
+      "HarfBuzzSharp.NativeAssets.macOS": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "jbtCsgftcaFLCA13tVKo5iWdElJScrulLTKJre36O4YQTIlwDtPPqhRZNk+Y0vv4D1gxbscasGRucUDfS44ofQ=="
+      },
+      "HarfBuzzSharp.NativeAssets.WebAssembly": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "loJweK2u/mH/3C2zBa0ggJlITIszOkK64HLAZB7FUT670dTg965whLFYHDQo69NmC4+d9UN0icLC9VHidXaVCA=="
+      },
+      "HarfBuzzSharp.NativeAssets.Win32": {
+        "type": "Transitive",
+        "resolved": "8.3.1.1",
+        "contentHash": "UsJtQsfAJoFDZrXc4hCUfRPMqccfKZ0iumJ/upcUjz/cmsTgVFGNEL5yaJWmkqsuFYdMWbj/En5/kS4PFl9hBA=="
+      },
+      "MicroCom.Runtime": {
+        "type": "Transitive",
+        "resolved": "0.11.0",
+        "contentHash": "MEnrZ3UIiH40hjzMDsxrTyi8dtqB5ziv3iBeeU4bXsL/7NLSal9F1lZKpK+tfBRnUoDSdtcW3KufE4yhATOMCA=="
+      },
+      "SkiaSharp": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "3MD5VHjXXieSHCleRLuaTXmL2pD0mB7CcOB1x2kA1I4bhptf4e3R27iM93264ZYuAq6mkUyX5XbcxnZvMJYc1Q==",
+        "dependencies": {
+          "SkiaSharp.NativeAssets.Win32": "2.88.9",
+          "SkiaSharp.NativeAssets.macOS": "2.88.9"
+        }
+      },
+      "SkiaSharp.NativeAssets.Linux": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "cWSaJKVPWAaT/WIn9c8T5uT/l4ETwHxNJTkEOtNKjphNo8AW6TF9O32aRkxqw3l8GUdUo66Bu7EiqtFh/XG0Zg==",
+        "dependencies": {
+          "SkiaSharp": "2.88.9"
+        }
+      },
+      "SkiaSharp.NativeAssets.macOS": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "Nv5spmKc4505Ep7oUoJ5vp3KweFpeNqxpyGDWyeEPTX2uR6S6syXIm3gj75dM0YJz7NPvcix48mR5laqs8dPuA=="
+      },
+      "SkiaSharp.NativeAssets.WebAssembly": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "kt06RccBHSnAs2wDYdBSfsjIDbY3EpsOVqnlDgKdgvyuRA8ZFDaHRdWNx1VHjGgYzmnFCGiTJBnXFl5BqGwGnA=="
+      },
+      "SkiaSharp.NativeAssets.Win32": {
+        "type": "Transitive",
+        "resolved": "2.88.9",
+        "contentHash": "wb2kYgU7iy84nQLYZwMeJXixvK++GoIuECjU4ECaUKNuflyRlJKyiRhN1MAHswvlvzuvkrjRWlK0Za6+kYQK7w=="
+      },
+      "sharpemu.logging": {
+        "type": "Project"
+      }
+    }
+  }
+}

src/SharpEmu.HLE/CpuContext.cs

@@ -2,25 +2,20 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 using System.Buffers.Binary;
+using System.Text;
 
 namespace SharpEmu.HLE;
 
-public sealed class CpuContext
+public sealed class CpuContext(ICpuMemory memory, Generation generation)
 {
     private readonly ulong[] _registers = new ulong[16];
     private readonly ulong[] _xmmRegisters = new ulong[32];
     private readonly ulong[] _ymmUpperRegisters = new ulong[32];
     private bool _raxWritten;
 
-    public CpuContext(ICpuMemory memory, Generation generation)
+    public ICpuMemory Memory { get; } = memory ?? throw new ArgumentNullException(nameof(memory));
-    {
-        Memory = memory ?? throw new ArgumentNullException(nameof(memory));
-        TargetGeneration = generation;
-    }
 
-    public ICpuMemory Memory { get; }
+    public Generation TargetGeneration { get; } = generation;
-
-    public Generation TargetGeneration { get; }
 
     public ulong Rip { get; set; }
 
@@ -130,6 +125,91 @@ public sealed class CpuContext
         SetYmmUpper(registerIndex, highLow, highHigh);
     }
 
+    public bool TryReadByte(ulong address, out byte value)
+    {
+        Span<byte> buffer = stackalloc byte[1];
+        if (!Memory.TryRead(address, buffer))
+        {
+            value = 0;
+            return false;
+        }
+
+        value = buffer[0];
+        return true;
+    }
+
+    public bool TryReadUInt16(ulong address, out ushort value)
+    {
+        Span<byte> bytes = stackalloc byte[sizeof(ushort)];
+        if (!Memory.TryRead(address, bytes))
+        {
+            value = 0;
+            return false;
+        }
+
+        value = BinaryPrimitives.ReadUInt16LittleEndian(bytes);
+        return true;
+    }
+
+    public bool TryWriteUInt16(ulong address, ushort value)
+    {
+        Span<byte> buffer = stackalloc byte[sizeof(ushort)];
+        BinaryPrimitives.WriteUInt16LittleEndian(buffer, value);
+        return Memory.TryWrite(address, buffer);
+    }
+
+    public bool TryReadInt32(ulong address, out int value)
+    {
+        Span<byte> bytes = stackalloc byte[sizeof(int)];
+        if (!Memory.TryRead(address, bytes))
+        {
+            value = 0;
+            return false;
+        }
+
+        value = BinaryPrimitives.ReadInt32LittleEndian(bytes);
+        return true;
+    }
+
+    public bool TryWriteInt32(ulong address, int value, bool checkNil = false)
+    {
+        if (checkNil && address == 0)
+        {
+            return false;
+        }
+
+        Span<byte> bytes = stackalloc byte[sizeof(int)];
+        BinaryPrimitives.WriteInt32LittleEndian(bytes, value);
+        return Memory.TryWrite(address, bytes);
+    }
+
+    public bool TryReadUInt32(ulong address, out uint value)
+    {
+        Span<byte> buffer = stackalloc byte[sizeof(uint)];
+        if (!Memory.TryRead(address, buffer))
+        {
+            value = 0;
+            return false;
+        }
+
+        value = BinaryPrimitives.ReadUInt32LittleEndian(buffer);
+        return true;
+    }
+
+    public bool TryWriteUInt32(ulong address, uint value)
+    {
+        Span<byte> buffer = stackalloc byte[sizeof(uint)];
+        BinaryPrimitives.WriteUInt32LittleEndian(buffer, value);
+        return Memory.TryWrite(address, buffer);
+    }
+
+    public bool TryWriteInt64(ulong address, long value)
+    {
+        Span<byte> buffer = stackalloc byte[sizeof(long)];
+        BinaryPrimitives.WriteInt64LittleEndian(buffer, value);
+        return Memory.TryWrite(address, buffer);
+    }
+
     public bool TryReadUInt64(ulong address, out ulong value)
     {
         Span<byte> buffer = stackalloc byte[sizeof(ulong)];
@@ -150,6 +230,33 @@ public sealed class CpuContext
         return Memory.TryWrite(address, buffer);
     }
 
+    public bool TryReadNullTerminatedUtf8(ulong address, int capacity, out string value)
+    {
+        value = string.Empty;
+        if (address == 0 || capacity <= 0)
+        {
+            return false;
+        }
+
+        var bytes = new byte[capacity];
+        for (var index = 0; index < bytes.Length; index++)
+        {
+            if (!Memory.TryRead(address + (ulong)index, bytes.AsSpan(index, 1)))
+            {
+                return false;
+            }
+
+            if (bytes[index] == 0)
+            {
+                value = Encoding.UTF8.GetString(bytes, 0, index);
+                return true;
+            }
+        }
+
+        value = Encoding.UTF8.GetString(bytes);
+        return true;
+    }
+
     public bool PushUInt64(ulong value)
     {
         var rsp = this[CpuRegister.Rsp];
@@ -169,4 +276,23 @@ public sealed class CpuContext
         this[CpuRegister.Rsp] = rsp + sizeof(ulong);
         return true;
     }
+
+    public int SetReturn(int result, Type? cast = null)
+    {
+        var value = cast switch
+        {
+            null => (ulong)result,
+            _ when cast == typeof(long) => (ulong)(long)result,
+            _ => throw new NotSupportedException(),
+        };
+
+        this[CpuRegister.Rax] = unchecked(value);
+        return result;
+    }
+
+    public int SetReturn(OrbisGen2Result result)
+    {
+        this[CpuRegister.Rax] = unchecked((ulong)(int)result);
+        return (int)result;
+    }
 }

src/SharpEmu.HLE/GuestThreadExecution.cs

@@ -1,6 +1,8 @@
 // Copyright (C) 2026 SharpEmu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+using System.Diagnostics;
+
 namespace SharpEmu.HLE;
 
 public readonly record struct GuestThreadStartRequest(
@@ -8,14 +10,37 @@ public readonly record struct GuestThreadStartRequest(
     ulong EntryPoint,
     ulong Argument,
     ulong AttributeAddress,
-    string Name);
+    string Name,
+    int Priority,
+    ulong AffinityMask);
+
+public readonly record struct GuestThreadSnapshot(
+    ulong ThreadHandle,
+    string Name,
+    string State,
+    long ImportCount,
+    string? LastImportNid,
+    ulong LastReturnRip,
+    string? BlockReason);
 
 public interface IGuestThreadScheduler
 {
+    bool SupportsGuestContextTransfer { get; }
+
     bool TryStartThread(CpuContext creatorContext, GuestThreadStartRequest request, out string? error);
 
+    bool TryJoinThread(
+        CpuContext callerContext,
+        ulong threadHandle,
+        out ulong returnValue,
+        out string? error);
+
     void Pump(CpuContext callerContext, string reason);
 
+    int WakeBlockedThreads(string wakeKey, int maxCount = int.MaxValue);
+
+    IReadOnlyList<GuestThreadSnapshot> SnapshotThreads();
+
     bool TryCallGuestFunction(
         CpuContext callerContext,
         ulong entryPoint,
@@ -71,15 +96,39 @@ public static class GuestThreadExecution
     [ThreadStatic]
     private static string? _pendingBlockReason;
 
+    [ThreadStatic]
+    private static bool _pendingBlockContinuationValid;
+
+    [ThreadStatic]
+    private static GuestCpuContinuation _pendingBlockContinuation;
+
+    [ThreadStatic]
+    private static string? _pendingBlockWakeKey;
+
+    [ThreadStatic]
+    private static Func<int>? _pendingBlockResumeHandler;
+
+    [ThreadStatic]
+    private static Func<bool>? _pendingBlockWakeHandler;
+
+    [ThreadStatic]
+    private static long _pendingBlockDeadlineTimestamp;
+
     [ThreadStatic]
     private static bool _pendingEntryExit;
 
     [ThreadStatic]
-    private static int _pendingEntryExitStatus;
+    private static ulong _pendingEntryExitValue;
 
     [ThreadStatic]
     private static string? _pendingEntryExitReason;
 
+    [ThreadStatic]
+    private static bool _pendingContextTransfer;
+
+    [ThreadStatic]
+    private static GuestCpuContinuation _pendingContextTransferTarget;
+
     [ThreadStatic]
     private static bool _hasCurrentImportCallFrame;
 
@@ -105,9 +154,17 @@ public static class GuestThreadExecution
         var previous = _currentGuestThreadHandle;
         _currentGuestThreadHandle = threadHandle;
         _pendingBlockReason = null;
+        _pendingBlockContinuationValid = false;
+        _pendingBlockContinuation = default;
+        _pendingBlockWakeKey = null;
+        _pendingBlockResumeHandler = null;
+        _pendingBlockWakeHandler = null;
+        _pendingBlockDeadlineTimestamp = 0;
         _pendingEntryExit = false;
-        _pendingEntryExitStatus = 0;
+        _pendingEntryExitValue = 0;
         _pendingEntryExitReason = null;
+        _pendingContextTransfer = false;
+        _pendingContextTransferTarget = default;
         _hasCurrentImportCallFrame = false;
         _currentImportReturnRip = 0;
         _currentImportResumeRsp = 0;
@@ -119,9 +176,17 @@ public static class GuestThreadExecution
     {
         _currentGuestThreadHandle = previousThreadHandle;
         _pendingBlockReason = null;
+        _pendingBlockContinuationValid = false;
+        _pendingBlockContinuation = default;
+        _pendingBlockWakeKey = null;
+        _pendingBlockResumeHandler = null;
+        _pendingBlockWakeHandler = null;
+        _pendingBlockDeadlineTimestamp = 0;
         _pendingEntryExit = false;
-        _pendingEntryExitStatus = 0;
+        _pendingEntryExitValue = 0;
         _pendingEntryExitReason = null;
+        _pendingContextTransfer = false;
+        _pendingContextTransferTarget = default;
         _hasCurrentImportCallFrame = false;
         _currentImportReturnRip = 0;
         _currentImportResumeRsp = 0;
@@ -140,7 +205,15 @@ public static class GuestThreadExecution
         _currentFiberAddress = previousFiberAddress;
     }
 
-    public static bool RequestCurrentThreadBlock(string reason)
+    public static bool RequestCurrentThreadBlock(string reason) => RequestCurrentThreadBlock(null, reason);
+
+    public static bool RequestCurrentThreadBlock(
+        CpuContext? context,
+        string reason,
+        string? wakeKey = null,
+        Func<int>? resumeHandler = null,
+        Func<bool>? wakeHandler = null,
+        long blockDeadlineTimestamp = 0)
     {
         if (!IsGuestThread)
         {
@@ -148,31 +221,167 @@ public static class GuestThreadExecution
         }
 
         _pendingBlockReason = string.IsNullOrWhiteSpace(reason) ? "guest_thread_blocked" : reason;
+        _pendingBlockWakeKey = string.IsNullOrWhiteSpace(wakeKey) ? _pendingBlockReason : wakeKey;
+        _pendingBlockResumeHandler = resumeHandler;
+        _pendingBlockWakeHandler = wakeHandler;
+        _pendingBlockDeadlineTimestamp = blockDeadlineTimestamp;
+        if (context is not null && TryCaptureCurrentBlockContinuation(context, out var continuation))
+        {
+            _pendingBlockContinuation = continuation;
+            _pendingBlockContinuationValid = true;
+        }
+        else
+        {
+            _pendingBlockContinuation = default;
+            _pendingBlockContinuationValid = false;
+        }
+
         return true;
     }
 
     public static bool TryConsumeCurrentThreadBlock(out string reason)
+    {
+        return TryConsumeCurrentThreadBlock(out reason, out _, out _);
+    }
+
+    public static bool TryConsumeCurrentThreadBlock(
+        out string reason,
+        out GuestCpuContinuation continuation,
+        out bool hasContinuation)
+    {
+        return TryConsumeCurrentThreadBlock(
+            out reason,
+            out continuation,
+            out hasContinuation,
+            out _,
+            out _,
+            out _,
+            out _);
+    }
+
+    public static bool TryConsumeCurrentThreadBlock(
+        out string reason,
+        out GuestCpuContinuation continuation,
+        out bool hasContinuation,
+        out string wakeKey,
+        out Func<int>? resumeHandler,
+        out Func<bool>? wakeHandler)
+    {
+        return TryConsumeCurrentThreadBlock(
+            out reason,
+            out continuation,
+            out hasContinuation,
+            out wakeKey,
+            out resumeHandler,
+            out wakeHandler,
+            out _);
+    }
+
+    public static bool TryConsumeCurrentThreadBlock(
+        out string reason,
+        out GuestCpuContinuation continuation,
+        out bool hasContinuation,
+        out string wakeKey,
+        out Func<int>? resumeHandler,
+        out Func<bool>? wakeHandler,
+        out long blockDeadlineTimestamp)
     {
         reason = _pendingBlockReason ?? string.Empty;
         if (string.IsNullOrEmpty(reason))
         {
+            continuation = default;
+            hasContinuation = false;
+            wakeKey = string.Empty;
+            resumeHandler = null;
+            wakeHandler = null;
+            blockDeadlineTimestamp = 0;
             return false;
         }
 
+        continuation = _pendingBlockContinuation;
+        hasContinuation = _pendingBlockContinuationValid;
+        wakeKey = _pendingBlockWakeKey ?? reason;
+        resumeHandler = _pendingBlockResumeHandler;
+        wakeHandler = _pendingBlockWakeHandler;
+        blockDeadlineTimestamp = _pendingBlockDeadlineTimestamp;
         _pendingBlockReason = null;
+        _pendingBlockContinuation = default;
+        _pendingBlockContinuationValid = false;
+        _pendingBlockWakeKey = null;
+        _pendingBlockResumeHandler = null;
+        _pendingBlockWakeHandler = null;
+        _pendingBlockDeadlineTimestamp = 0;
+        return true;
+    }
+
+    public static long ComputeDeadlineTimestamp(TimeSpan timeout)
+    {
+        if (timeout <= TimeSpan.Zero)
+        {
+            return Stopwatch.GetTimestamp();
+        }
+
+        var ticks = timeout.TotalSeconds >= long.MaxValue / (double)Stopwatch.Frequency
+            ? long.MaxValue
+            : (long)Math.Ceiling(timeout.TotalSeconds * Stopwatch.Frequency);
+        var now = Stopwatch.GetTimestamp();
+        if (long.MaxValue - now <= ticks)
+        {
+            return long.MaxValue;
+        }
+
+        return now + Math.Max(1, ticks);
+    }
+
+    private static bool TryCaptureCurrentBlockContinuation(CpuContext context, out GuestCpuContinuation continuation)
+    {
+        if (!TryGetCurrentImportCallFrame(out var frame) ||
+            frame.ReturnRip < 65536 ||
+            frame.ResumeRsp == 0 ||
+            frame.ReturnSlotAddress == 0)
+        {
+            continuation = default;
+            return false;
+        }
+
+        continuation = new GuestCpuContinuation(
+            frame.ReturnRip,
+            frame.ResumeRsp,
+            frame.ReturnSlotAddress,
+            context.Rflags,
+            context.FsBase,
+            context.GsBase,
+            0,
+            context[CpuRegister.Rcx],
+            context[CpuRegister.Rdx],
+            context[CpuRegister.Rbx],
+            context[CpuRegister.Rbp],
+            context[CpuRegister.Rsi],
+            context[CpuRegister.Rdi],
+            context[CpuRegister.R8],
+            context[CpuRegister.R9],
+            context[CpuRegister.R12],
+            context[CpuRegister.R13],
+            context[CpuRegister.R14],
+            context[CpuRegister.R15]);
         return true;
     }
 
     public static void RequestCurrentEntryExit(string reason, int status)
+    {
+        RequestCurrentEntryExit(reason, unchecked((ulong)(long)status));
+    }
+
+    public static void RequestCurrentEntryExit(string reason, ulong value)
     {
         _pendingEntryExit = true;
-        _pendingEntryExitStatus = status;
+        _pendingEntryExitValue = value;
         _pendingEntryExitReason = string.IsNullOrWhiteSpace(reason) ? "guest_entry_exit" : reason;
     }
 
-    public static bool TryConsumeCurrentEntryExit(out int status, out string reason)
+    public static bool TryConsumeCurrentEntryExit(out ulong value, out string reason)
     {
-        status = _pendingEntryExitStatus;
+        value = _pendingEntryExitValue;
         reason = _pendingEntryExitReason ?? string.Empty;
         if (!_pendingEntryExit)
         {
@@ -180,11 +389,30 @@ public static class GuestThreadExecution
         }
 
         _pendingEntryExit = false;
-        _pendingEntryExitStatus = 0;
+        _pendingEntryExitValue = 0;
         _pendingEntryExitReason = null;
         return true;
     }
 
+    public static void RequestCurrentContextTransfer(GuestCpuContinuation target)
+    {
+        _pendingContextTransferTarget = target;
+        _pendingContextTransfer = true;
+    }
+
+    public static bool TryConsumeCurrentContextTransfer(out GuestCpuContinuation target)
+    {
+        target = _pendingContextTransferTarget;
+        if (!_pendingContextTransfer)
+        {
+            return false;
+        }
+
+        _pendingContextTransfer = false;
+        _pendingContextTransferTarget = default;
+        return true;
+    }
+
     public static GuestImportCallFrame EnterImportCallFrame(
         ulong returnRip,
         ulong resumeRsp,

src/SharpEmu.HLE/ModuleManager.cs

@@ -47,6 +47,7 @@ public sealed class ModuleManager : IModuleManager
                     var handler = CreateHandler(type, method, instances);
                     if (!_dispatchTable.TryAdd(exportInfo.Value.Nid, handler))
                     {
+                        Console.Error.WriteLine($"[HLE] Duplicate NID '{exportInfo.Value.Nid}' ({exportInfo.Value.ExportName}) — already registered, skipping.");
                         continue;
                     }
 
@@ -105,6 +106,7 @@ public sealed class ModuleManager : IModuleManager
 
         if (!_dispatchTable.TryGetValue(nid, out var function) || !_exportTable.TryGetValue(nid, out var export))
         {
+            Console.Error.WriteLine($"[HLE] NID '{nid}' not found in dispatch table.");
             context[CpuRegister.Rax] = unchecked((ulong)(int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
             result = OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
             return false;
@@ -112,11 +114,13 @@ public sealed class ModuleManager : IModuleManager
 
         if ((export.Target & context.TargetGeneration) == 0)
         {
-            context[CpuRegister.Rax] = unchecked((ulong)(int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+            Console.Error.WriteLine($"[HLE] NID '{nid}' ({export.Name}) found but not implemented for generation {context.TargetGeneration} (targets: {export.Target}).");
-            result = OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+            context[CpuRegister.Rax] = unchecked((ulong)(int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_IMPLEMENTED);
+            result = OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_IMPLEMENTED;
             return false;
         }
 
+
         context.ClearRaxWriteFlag();
         int ret = ((SysAbiFunction)function).Invoke(context);
 

src/SharpEmu.HLE/OrbisGen2Result.cs

@@ -40,6 +40,13 @@ public enum OrbisGen2Result : int
     /// </summary>
     ORBIS_GEN2_ERROR_DEADLOCK = unchecked((int)0x8002000B),
 
+    /// <summary>
+    /// Indicates that the waited-on object was deleted while the caller was
+    /// blocked on it. Matches the SCE kernel EACCES code that waiters of a
+    /// deleted semaphore observe.
+    /// </summary>
+    ORBIS_GEN2_ERROR_DELETED = unchecked((int)0x8002000D),
+
     /// <summary>
     /// Indicates that the target resource is busy.
     /// </summary>
@@ -50,6 +57,13 @@ public enum OrbisGen2Result : int
     /// </summary>
     ORBIS_GEN2_ERROR_TRY_AGAIN = unchecked((int)0x80020023),
 
+    /// <summary>
+    /// Indicates that a blocked wait was canceled (e.g. sceKernelCancelSema).
+    /// Matches the SCE kernel ECANCELED code that canceled semaphore waiters
+    /// observe.
+    /// </summary>
+    ORBIS_GEN2_ERROR_CANCELED = unchecked((int)0x80020055),
+
     /// <summary>
     /// Indicates that behavior is recognized but not implemented yet.
     /// </summary>

src/SharpEmu.HLE/SharpEmu.HLE.csproj

@@ -8,6 +8,10 @@ SPDX-License-Identifier: GPL-2.0-or-later
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <NoWarn>$(NoWarn);1591</NoWarn>
+  </PropertyGroup>
+
   <ItemGroup>
     <EmbeddedResource Include="Aerolib\aerolib.bin" />
   </ItemGroup>

src/SharpEmu.Libs/Agc/Gen5ShaderIr.cs

@@ -0,0 +1,313 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+namespace SharpEmu.Libs.Agc;
+
+internal enum Gen5ShaderEncoding
+{
+    Sop1,
+    Sop2,
+    Sopc,
+    Sopp,
+    Sopk,
+    Smrd,
+    Smem,
+    Mubuf,
+    Mtbuf,
+    Vop1,
+    Vop2,
+    Vopc,
+    Vop3,
+    Vintrp,
+    Ds,
+    Flat,
+    Vop3p,
+    Mimg,
+    Exp,
+}
+
+internal enum Gen5OperandKind
+{
+    ScalarRegister,
+    VectorRegister,
+    EncodedConstant,
+    LiteralConstant,
+}
+
+internal enum Gen5ShaderResourceKind
+{
+    ReadOnlyTexture,
+    ReadWriteTexture,
+    Sampler,
+    ConstantBuffer,
+}
+
+internal enum Gen5PixelOutputKind
+{
+    Float,
+    Uint,
+    Sint,
+}
+
+internal enum Gen5SpirvStage
+{
+    Vertex,
+    Pixel,
+    Compute,
+}
+
+internal sealed record Gen5SpirvShader(
+    byte[] Spirv,
+    IReadOnlyList<Gen5GlobalMemoryBinding> GlobalMemoryBindings,
+    IReadOnlyList<Gen5ImageBinding> ImageBindings,
+    uint AttributeCount,
+    IReadOnlyList<Gen5VertexInputBinding> VertexInputs);
+
+internal readonly record struct Gen5ShaderResourceMapping(
+    Gen5ShaderResourceKind Kind,
+    uint Slot,
+    uint OffsetDwords,
+    bool SizeFlag);
+
+internal sealed record Gen5ShaderMetadata(
+    uint ExtendedUserDataSizeDwords,
+    uint ShaderResourceTableSizeDwords,
+    IReadOnlyDictionary<uint, uint> DirectResources,
+    IReadOnlyList<Gen5ShaderResourceMapping> Resources);
+
+internal readonly record struct Gen5ComputeSystemRegisters(
+    uint? WorkGroupXRegister,
+    uint? WorkGroupYRegister,
+    uint? WorkGroupZRegister,
+    uint? ThreadGroupSizeRegister)
+{
+    public bool TryGetExpression(uint scalarRegister, out string expression)
+    {
+        if (WorkGroupXRegister == scalarRegister)
+        {
+            expression = "gl_WorkGroupID.x";
+            return true;
+        }
+
+        if (WorkGroupYRegister == scalarRegister)
+        {
+            expression = "gl_WorkGroupID.y";
+            return true;
+        }
+
+        if (WorkGroupZRegister == scalarRegister)
+        {
+            expression = "gl_WorkGroupID.z";
+            return true;
+        }
+
+        if (ThreadGroupSizeRegister == scalarRegister)
+        {
+            expression = "(gl_WorkGroupSize.x * gl_WorkGroupSize.y * gl_WorkGroupSize.z)";
+            return true;
+        }
+
+        expression = string.Empty;
+        return false;
+    }
+
+    public void ClearStaticValues(Span<uint> scalarRegisters)
+    {
+        ClearStaticValue(scalarRegisters, WorkGroupXRegister);
+        ClearStaticValue(scalarRegisters, WorkGroupYRegister);
+        ClearStaticValue(scalarRegisters, WorkGroupZRegister);
+        ClearStaticValue(scalarRegisters, ThreadGroupSizeRegister);
+    }
+
+    private static void ClearStaticValue(Span<uint> scalarRegisters, uint? scalarRegister)
+    {
+        if (scalarRegister is { } register && register < scalarRegisters.Length)
+        {
+            scalarRegisters[(int)register] = 0;
+        }
+    }
+}
+
+internal sealed record Gen5ShaderState(
+    Gen5ShaderProgram Program,
+    IReadOnlyList<uint> UserData,
+    Gen5ShaderMetadata? Metadata,
+    Gen5ComputeSystemRegisters? ComputeSystemRegisters = null,
+    uint UserDataScalarRegisterBase = 0);
+
+internal readonly record struct Gen5Operand(Gen5OperandKind Kind, uint Value)
+{
+    public static Gen5Operand Scalar(uint index) =>
+        new(Gen5OperandKind.ScalarRegister, index);
+
+    public static Gen5Operand Vector(uint index) =>
+        new(Gen5OperandKind.VectorRegister, index);
+
+    public static Gen5Operand Source(uint encoded, uint? literal = null)
+    {
+        if (encoded >= 256)
+        {
+            return Vector(encoded - 256);
+        }
+
+        if (encoded is 249 or 255 && literal.HasValue)
+        {
+            return new(Gen5OperandKind.LiteralConstant, literal.Value);
+        }
+
+        if (encoded <= 105 || encoded is 106 or 107 or 124 or 126 or 127)
+        {
+            return Scalar(encoded);
+        }
+
+        return new(Gen5OperandKind.EncodedConstant, encoded);
+    }
+
+    public override string ToString() => Kind switch
+    {
+        Gen5OperandKind.ScalarRegister => $"s{Value}",
+        Gen5OperandKind.VectorRegister => $"v{Value}",
+        Gen5OperandKind.LiteralConstant => $"0x{Value:X8}",
+        _ => $"src[{Value}]",
+    };
+}
+
+internal abstract record Gen5InstructionControl;
+
+internal sealed record Gen5ImageControl(
+    uint Dmask,
+    uint VectorAddress,
+    IReadOnlyList<uint> AddressRegisters,
+    uint VectorData,
+    uint ScalarResource,
+    uint ScalarSampler,
+    uint Dimension,
+    bool IsArray,
+    bool Glc,
+    bool Slc) : Gen5InstructionControl
+{
+    public uint GetAddressRegister(int component) =>
+        component < AddressRegisters.Count
+            ? AddressRegisters[component]
+            : VectorAddress + (uint)component;
+}
+
+internal sealed record Gen5GlobalMemoryControl(
+    uint DwordCount,
+    uint VectorAddress,
+    uint VectorData,
+    uint ScalarAddress,
+    int OffsetBytes,
+    bool Glc,
+    bool Slc) : Gen5InstructionControl;
+
+internal sealed record Gen5BufferMemoryControl(
+    uint DwordCount,
+    uint VectorAddress,
+    uint VectorData,
+    uint ScalarResource,
+    int OffsetBytes,
+    bool IndexEnabled,
+    bool OffsetEnabled,
+    bool Glc,
+    bool Slc) : Gen5InstructionControl;
+
+internal sealed record Gen5ExportControl(
+    uint Target,
+    uint EnableMask,
+    bool Compressed,
+    bool Done,
+    bool ValidMask) : Gen5InstructionControl;
+
+internal sealed record Gen5InterpolationControl(
+    uint Attribute,
+    uint Channel) : Gen5InstructionControl;
+
+internal sealed record Gen5Vop3Control(
+    uint AbsoluteMask,
+    uint NegateMask,
+    uint OutputModifier,
+    bool Clamp,
+    uint? ScalarDestination) : Gen5InstructionControl;
+
+internal sealed record Gen5SdwaControl(
+    uint DestinationSelect,
+    uint Source0Select,
+    uint Source1Select,
+    uint AbsoluteMask,
+    uint NegateMask,
+    uint OutputModifier,
+    bool Clamp) : Gen5InstructionControl;
+
+internal sealed record Gen5DppControl(
+    uint Control,
+    bool FetchInactive,
+    bool BoundControl,
+    uint AbsoluteMask,
+    uint NegateMask,
+    uint BankMask,
+    uint RowMask) : Gen5InstructionControl;
+
+internal sealed record Gen5ScalarMemoryControl(
+    uint DestinationCount,
+    int ImmediateOffsetBytes,
+    uint? DynamicOffsetRegister) : Gen5InstructionControl;
+
+internal sealed record Gen5DataShareControl(
+    uint Offset0,
+    uint Offset1,
+    bool Gds) : Gen5InstructionControl;
+
+internal sealed record Gen5ImageBinding(
+    uint Pc,
+    string Opcode,
+    Gen5ImageControl Control,
+    IReadOnlyList<uint> ResourceDescriptor,
+    IReadOnlyList<uint> SamplerDescriptor,
+    uint? MipLevel);
+
+internal sealed record Gen5GlobalMemoryBinding(
+    uint ScalarAddress,
+    ulong BaseAddress,
+    IReadOnlyList<uint> InstructionPcs,
+    byte[] Data);
+
+internal sealed record Gen5VertexInputBinding(
+    uint Pc,
+    uint Location,
+    uint ComponentCount,
+    uint DataFormat,
+    uint NumberFormat,
+    ulong BaseAddress,
+    uint Stride,
+    uint OffsetBytes,
+    byte[] Data);
+
+internal sealed record Gen5ShaderEvaluation(
+    IReadOnlyList<uint> InitialScalarRegisters,
+    IReadOnlyList<uint> ScalarRegisters,
+    IReadOnlyDictionary<uint, IReadOnlyList<uint>> ScalarRegistersByPc,
+    IReadOnlyList<Gen5ImageBinding> ImageBindings,
+    IReadOnlyList<Gen5GlobalMemoryBinding> GlobalMemoryBindings,
+    Gen5ComputeSystemRegisters? ComputeSystemRegisters = null,
+    IReadOnlySet<uint>? RuntimeScalarRegisters = null,
+    IReadOnlyList<Gen5VertexInputBinding>? VertexInputs = null);
+
+internal sealed record Gen5ShaderInstruction(
+    uint Pc,
+    Gen5ShaderEncoding Encoding,
+    string Opcode,
+    IReadOnlyList<uint> Words,
+    IReadOnlyList<Gen5Operand> Sources,
+    IReadOnlyList<Gen5Operand> Destinations,
+    Gen5InstructionControl? Control);
+
+internal sealed record Gen5ShaderProgram(
+    ulong Address,
+    IReadOnlyList<Gen5ShaderInstruction> Instructions)
+{
+    public IEnumerable<Gen5ImageControl> ImageResources =>
+        Instructions
+            .Select(instruction => instruction.Control)
+            .OfType<Gen5ImageControl>();
+}

src/SharpEmu.Libs/Agc/Gen5ShaderMetadataReader.cs

@@ -0,0 +1,124 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.HLE;
+
+namespace SharpEmu.Libs.Agc;
+
+internal static class Gen5ShaderMetadataReader
+{
+    private const ulong ShaderUserDataOffset = 0x08;
+    private const int ResourceClassCount = 4;
+    private const int MaxMetadataEntries = 4096;
+
+    public static bool TryRead(
+        CpuContext ctx,
+        ulong shaderHeaderAddress,
+        out Gen5ShaderMetadata metadata)
+    {
+        metadata = default!;
+        if (!ctx.TryReadUInt64(shaderHeaderAddress + ShaderUserDataOffset, out var userDataAddress) ||
+            userDataAddress == 0 ||
+            !ctx.TryReadUInt64(userDataAddress, out var directResourceOffsetsAddress))
+        {
+            return false;
+        }
+
+        var resourceOffsets = new ulong[ResourceClassCount];
+        for (var resourceClass = 0; resourceClass < ResourceClassCount; resourceClass++)
+        {
+            if (!ctx.TryReadUInt64(
+                    userDataAddress + 0x08 + (ulong)(resourceClass * sizeof(ulong)),
+                    out resourceOffsets[resourceClass]))
+            {
+                return false;
+            }
+        }
+
+        if (!ctx.TryReadUInt16(userDataAddress + 0x28, out var extendedUserDataSize) ||
+            !ctx.TryReadUInt16(userDataAddress + 0x2A, out var shaderResourceTableSize) ||
+            !ctx.TryReadUInt16(userDataAddress + 0x2C, out var directResourceCount) ||
+            directResourceCount > MaxMetadataEntries)
+        {
+            return false;
+        }
+
+        var resourceCounts = new ushort[ResourceClassCount];
+        for (var resourceClass = 0; resourceClass < ResourceClassCount; resourceClass++)
+        {
+            if (!ctx.TryReadUInt16(
+                    userDataAddress + 0x2E + (ulong)(resourceClass * sizeof(ushort)),
+                    out resourceCounts[resourceClass]) ||
+                resourceCounts[resourceClass] > MaxMetadataEntries)
+            {
+                return false;
+            }
+        }
+
+        var directResources = new Dictionary<uint, uint>();
+        if (directResourceCount != 0)
+        {
+            if (directResourceOffsetsAddress == 0)
+            {
+                return false;
+            }
+
+            for (uint type = 0; type < directResourceCount; type++)
+            {
+                if (!ctx.TryReadUInt16(directResourceOffsetsAddress + type * sizeof(ushort), out var offset))
+                {
+                    return false;
+                }
+
+                if (offset != ushort.MaxValue)
+                {
+                    directResources[type] = offset;
+                }
+            }
+        }
+
+        var resources = new List<Gen5ShaderResourceMapping>();
+        for (var resourceClass = 0; resourceClass < ResourceClassCount; resourceClass++)
+        {
+            var count = resourceCounts[resourceClass];
+            if (count == 0)
+            {
+                continue;
+            }
+
+            if (resourceOffsets[resourceClass] == 0)
+            {
+                return false;
+            }
+
+            for (uint slot = 0; slot < count; slot++)
+            {
+                if (!ctx.TryReadUInt16(
+                        resourceOffsets[resourceClass] + slot * sizeof(ushort),
+                        out var sharp))
+                {
+                    return false;
+                }
+
+                var offset = (uint)(sharp & 0x7FFF);
+                if (offset == 0x7FFF)
+                {
+                    continue;
+                }
+
+                resources.Add(new Gen5ShaderResourceMapping(
+                    (Gen5ShaderResourceKind)resourceClass,
+                    slot,
+                    offset,
+                    (sharp & 0x8000) != 0));
+            }
+        }
+
+        metadata = new Gen5ShaderMetadata(
+            extendedUserDataSize,
+            shaderResourceTableSize,
+            directResources,
+            resources);
+        return true;
+    }
+}

src/SharpEmu.Libs/Agc/GpuWaitRegistry.cs

@@ -0,0 +1,102 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+namespace SharpEmu.Libs.Agc;
+
+// Holds DCBs whose parsing was suspended on an unsatisfied WAIT_REG_MEM condition.
+// AgcExports re-checks every waiter against guest memory on each submit and resumes
+// the ones whose condition became true (labels are advanced by ReleaseMem/WriteData/
+// DmaData packets or by direct CPU writes).
+internal static class GpuWaitRegistry
+{
+    public struct WaitingDcb
+    {
+        public ulong CommandBufferAddress;
+        public ulong ResumeAddress;
+        public uint TotalDwords;
+        public uint ResumeOffset;
+        public ulong WaitAddress;
+        public ulong ReferenceValue;
+        public ulong Mask;
+        public uint CompareFunction;
+        public bool Is64Bit;
+        public object? State;
+    }
+
+    private static readonly object _gate = new();
+    private static readonly Dictionary<ulong, List<WaitingDcb>> _waiters = new();
+
+    public static void Register(ulong address, WaitingDcb waiter)
+    {
+        waiter.WaitAddress = address;
+        lock (_gate)
+        {
+            if (!_waiters.TryGetValue(address, out var list))
+            {
+                list = new List<WaitingDcb>();
+                _waiters.Add(address, list);
+            }
+
+            list.Add(waiter);
+        }
+    }
+
+    // Re-evaluates every registered waiter. readValue receives (address, is64Bit) and
+    // returns null when the memory is unreadable; such waiters are kept registered.
+    public static List<WaitingDcb>? CollectSatisfied(Func<ulong, bool, ulong?> readValue)
+    {
+        List<WaitingDcb>? woken = null;
+        lock (_gate)
+        {
+            List<ulong>? emptied = null;
+            foreach (var (address, list) in _waiters)
+            {
+                for (var i = list.Count - 1; i >= 0; i--)
+                {
+                    var value = readValue(address, list[i].Is64Bit);
+                    if (value is null || !Compare(list[i], value.Value))
+                    {
+                        continue;
+                    }
+
+                    woken ??= new List<WaitingDcb>();
+                    woken.Add(list[i]);
+                    list.RemoveAt(i);
+                }
+
+                if (list.Count == 0)
+                {
+                    emptied ??= new List<ulong>();
+                    emptied.Add(address);
+                }
+            }
+
+            if (emptied != null)
+            {
+                foreach (var address in emptied)
+                {
+                    _waiters.Remove(address);
+                }
+            }
+        }
+
+        return woken;
+    }
+
+    public static bool Compare(in WaitingDcb waiter, ulong value)
+    {
+        var masked = value & waiter.Mask;
+        return waiter.CompareFunction switch
+        {
+            1 => masked < waiter.ReferenceValue,
+            2 => masked <= waiter.ReferenceValue,
+            3 => masked == waiter.ReferenceValue,
+            4 => masked != waiter.ReferenceValue,
+            5 => masked >= waiter.ReferenceValue,
+            6 => masked > waiter.ReferenceValue,
+            // 0 is "always" in the PM4 encoding and 7 is reserved; treating both as
+            // satisfied keeps a malformed packet from suspending its DCB forever.
+            _ => true,
+        };
+    }
+}

src/SharpEmu.Libs/Agc/SpirvFixedShaders.cs

@@ -0,0 +1,167 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+namespace SharpEmu.Libs.Agc;
+
+internal static class SpirvFixedShaders
+{
+    public static byte[] CreateFullscreenVertex(uint attributeCount)
+    {
+        var module = new SpirvModuleBuilder();
+        module.AddCapability(SpirvCapability.Shader);
+
+        var voidType = module.TypeVoid();
+        var boolType = module.TypeBool();
+        var uintType = module.TypeInt(32, signed: false);
+        var floatType = module.TypeFloat(32);
+        var vec4Type = module.TypeVector(floatType, 4);
+        var inputUintPointer = module.TypePointer(SpirvStorageClass.Input, uintType);
+        var outputVec4Pointer = module.TypePointer(SpirvStorageClass.Output, vec4Type);
+
+        var vertexIndex = module.AddGlobalVariable(inputUintPointer, SpirvStorageClass.Input);
+        module.AddName(vertexIndex, "vertexIndex");
+        module.AddDecoration(
+            vertexIndex,
+            SpirvDecoration.BuiltIn,
+            (uint)SpirvBuiltIn.VertexIndex);
+
+        var position = module.AddGlobalVariable(outputVec4Pointer, SpirvStorageClass.Output);
+        module.AddName(position, "position");
+        module.AddDecoration(position, SpirvDecoration.BuiltIn, (uint)SpirvBuiltIn.Position);
+
+        var attributes = new uint[attributeCount];
+        for (uint index = 0; index < attributeCount; index++)
+        {
+            attributes[index] =
+                module.AddGlobalVariable(outputVec4Pointer, SpirvStorageClass.Output);
+            module.AddName(attributes[index], $"attr{index}");
+            module.AddDecoration(attributes[index], SpirvDecoration.Location, index);
+            module.AddDecoration(attributes[index], SpirvDecoration.NoPerspective);
+        }
+
+        var functionType = module.TypeFunction(voidType);
+        var main = module.BeginFunction(voidType, functionType);
+        module.AddName(main, "main");
+        module.AddLabel();
+
+        var indexValue = module.AddInstruction(SpirvOp.Load, uintType, vertexIndex);
+        var one = module.Constant(uintType, 1);
+        var two = module.Constant(uintType, 2);
+        var shifted = module.AddInstruction(SpirvOp.ShiftLeftLogical, uintType, indexValue, one);
+        var xBits = module.AddInstruction(SpirvOp.BitwiseAnd, uintType, shifted, two);
+        var yBits = module.AddInstruction(SpirvOp.BitwiseAnd, uintType, indexValue, two);
+        var x = module.AddInstruction(SpirvOp.ConvertUToF, floatType, xBits);
+        var y = module.AddInstruction(SpirvOp.ConvertUToF, floatType, yBits);
+        var zero = module.ConstantFloat(floatType, 0f);
+        var oneFloat = module.ConstantFloat(floatType, 1f);
+        var twoFloat = module.ConstantFloat(floatType, 2f);
+        var xPosition = module.AddInstruction(SpirvOp.FMul, floatType, x, twoFloat);
+        xPosition = module.AddInstruction(SpirvOp.FSub, floatType, xPosition, oneFloat);
+        var yPosition = module.AddInstruction(SpirvOp.FMul, floatType, y, twoFloat);
+        yPosition = module.AddInstruction(SpirvOp.FSub, floatType, yPosition, oneFloat);
+        var positionValue = module.AddInstruction(
+            SpirvOp.CompositeConstruct,
+            vec4Type,
+            xPosition,
+            yPosition,
+            zero,
+            oneFloat);
+        module.AddStatement(SpirvOp.Store, position, positionValue);
+
+        var attributeValue = module.AddInstruction(
+            SpirvOp.CompositeConstruct,
+            vec4Type,
+            x,
+            y,
+            zero,
+            oneFloat);
+        foreach (var attribute in attributes)
+        {
+            module.AddStatement(SpirvOp.Store, attribute, attributeValue);
+        }
+
+        module.AddStatement(SpirvOp.Return);
+        module.EndFunction();
+
+        var interfaces = new uint[2 + attributes.Length];
+        interfaces[0] = vertexIndex;
+        interfaces[1] = position;
+        attributes.CopyTo(interfaces, 2);
+        module.AddEntryPoint(SpirvExecutionModel.Vertex, main, "main", interfaces);
+        _ = boolType;
+        return module.Build();
+    }
+
+    public static byte[] CreateCopyFragment()
+    {
+        var module = new SpirvModuleBuilder();
+        module.AddCapability(SpirvCapability.Shader);
+
+        var voidType = module.TypeVoid();
+        var floatType = module.TypeFloat(32);
+        var vec2Type = module.TypeVector(floatType, 2);
+        var vec4Type = module.TypeVector(floatType, 4);
+        var inputVec4Pointer = module.TypePointer(SpirvStorageClass.Input, vec4Type);
+        var outputVec4Pointer = module.TypePointer(SpirvStorageClass.Output, vec4Type);
+        var imageType = module.TypeImage(
+            floatType,
+            SpirvImageDim.Dim2D,
+            depth: false,
+            arrayed: false,
+            multisampled: false,
+            sampled: 1,
+            SpirvImageFormat.Unknown);
+        var sampledImageType = module.TypeSampledImage(imageType);
+        var sampledImagePointer =
+            module.TypePointer(SpirvStorageClass.UniformConstant, sampledImageType);
+
+        var attribute = module.AddGlobalVariable(inputVec4Pointer, SpirvStorageClass.Input);
+        module.AddName(attribute, "attr0");
+        module.AddDecoration(attribute, SpirvDecoration.Location, 0);
+
+        var texture = module.AddGlobalVariable(
+            sampledImagePointer,
+            SpirvStorageClass.UniformConstant);
+        module.AddName(texture, "tex0");
+        module.AddDecoration(texture, SpirvDecoration.DescriptorSet, 0);
+        module.AddDecoration(texture, SpirvDecoration.Binding, 1);
+
+        var output = module.AddGlobalVariable(outputVec4Pointer, SpirvStorageClass.Output);
+        module.AddName(output, "outColor");
+        module.AddDecoration(output, SpirvDecoration.Location, 0);
+
+        var functionType = module.TypeFunction(voidType);
+        var main = module.BeginFunction(voidType, functionType);
+        module.AddName(main, "main");
+        module.AddLabel();
+
+        var attributeValue = module.AddInstruction(SpirvOp.Load, vec4Type, attribute);
+        var coordinates = module.AddInstruction(
+            SpirvOp.VectorShuffle,
+            vec2Type,
+            attributeValue,
+            attributeValue,
+            0,
+            1);
+        var sampledImage = module.AddInstruction(SpirvOp.Load, sampledImageType, texture);
+        var lod = module.ConstantFloat(floatType, 0f);
+        var color = module.AddInstruction(
+            SpirvOp.ImageSampleExplicitLod,
+            vec4Type,
+            sampledImage,
+            coordinates,
+            2,
+            lod);
+        module.AddStatement(SpirvOp.Store, output, color);
+        module.AddStatement(SpirvOp.Return);
+        module.EndFunction();
+
+        module.AddEntryPoint(
+            SpirvExecutionModel.Fragment,
+            main,
+            "main",
+            [attribute, texture, output]);
+        module.AddExecutionMode(main, SpirvExecutionMode.OriginUpperLeft);
+        return module.Build();
+    }
+}

src/SharpEmu.Libs/Agc/SpirvModuleBuilder.cs

@@ -0,0 +1,885 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.Buffers.Binary;
+using System.Text;
+
+namespace SharpEmu.Libs.Agc;
+
+internal enum SpirvOp : ushort
+{
+    Nop = 0,
+    Name = 5,
+    Extension = 10,
+    ExtInstImport = 11,
+    ExtInst = 12,
+    MemoryModel = 14,
+    EntryPoint = 15,
+    ExecutionMode = 16,
+    Capability = 17,
+    TypeVoid = 19,
+    TypeBool = 20,
+    TypeInt = 21,
+    TypeFloat = 22,
+    TypeVector = 23,
+    TypeImage = 25,
+    TypeSampler = 26,
+    TypeSampledImage = 27,
+    TypeArray = 28,
+    TypeRuntimeArray = 29,
+    TypeStruct = 30,
+    TypePointer = 32,
+    TypeFunction = 33,
+    ConstantTrue = 41,
+    ConstantFalse = 42,
+    Constant = 43,
+    ConstantComposite = 44,
+    ConstantNull = 46,
+    Function = 54,
+    FunctionParameter = 55,
+    FunctionEnd = 56,
+    FunctionCall = 57,
+    Variable = 59,
+    Load = 61,
+    Store = 62,
+    AccessChain = 65,
+    ArrayLength = 68,
+    Decorate = 71,
+    VectorExtractDynamic = 77,
+    VectorInsertDynamic = 78,
+    VectorShuffle = 79,
+    CompositeConstruct = 80,
+    CompositeExtract = 81,
+    CompositeInsert = 82,
+    CopyObject = 83,
+    SampledImage = 86,
+    ImageSampleImplicitLod = 87,
+    ImageSampleExplicitLod = 88,
+    ImageSampleDrefImplicitLod = 89,
+    ImageSampleDrefExplicitLod = 90,
+    ImageFetch = 95,
+    ImageGather = 96,
+    ImageDrefGather = 97,
+    ImageRead = 98,
+    ImageWrite = 99,
+    Image = 100,
+    ImageQuerySizeLod = 103,
+    ImageQuerySize = 104,
+    ImageQueryLod = 105,
+    ImageQueryLevels = 106,
+    ImageQuerySamples = 107,
+    ConvertFToU = 109,
+    ConvertFToS = 110,
+    ConvertSToF = 111,
+    ConvertUToF = 112,
+    UConvert = 113,
+    SConvert = 114,
+    FConvert = 115,
+    Bitcast = 124,
+    SNegate = 126,
+    FNegate = 127,
+    IAdd = 128,
+    FAdd = 129,
+    ISub = 130,
+    FSub = 131,
+    IMul = 132,
+    FMul = 133,
+    UDiv = 134,
+    SDiv = 135,
+    FDiv = 136,
+    UMod = 137,
+    SRem = 138,
+    SMod = 139,
+    FRem = 140,
+    FMod = 141,
+    IAddCarry = 149,
+    ISubBorrow = 150,
+    UMulExtended = 151,
+    SMulExtended = 152,
+    Any = 154,
+    All = 155,
+    IsNan = 156,
+    IsInf = 157,
+    LogicalEqual = 164,
+    LogicalNotEqual = 165,
+    LogicalOr = 166,
+    LogicalAnd = 167,
+    LogicalNot = 168,
+    Select = 169,
+    IEqual = 170,
+    INotEqual = 171,
+    UGreaterThan = 172,
+    SGreaterThan = 173,
+    UGreaterThanEqual = 174,
+    SGreaterThanEqual = 175,
+    ULessThan = 176,
+    SLessThan = 177,
+    ULessThanEqual = 178,
+    SLessThanEqual = 179,
+    FOrdEqual = 180,
+    FUnordEqual = 181,
+    FOrdNotEqual = 182,
+    FUnordNotEqual = 183,
+    FOrdLessThan = 184,
+    FUnordLessThan = 185,
+    FOrdGreaterThan = 186,
+    FUnordGreaterThan = 187,
+    FOrdLessThanEqual = 188,
+    FUnordLessThanEqual = 189,
+    FOrdGreaterThanEqual = 190,
+    FUnordGreaterThanEqual = 191,
+    ShiftRightLogical = 194,
+    ShiftRightArithmetic = 195,
+    ShiftLeftLogical = 196,
+    BitwiseOr = 197,
+    BitwiseXor = 198,
+    BitwiseAnd = 199,
+    Not = 200,
+    BitFieldInsert = 201,
+    BitFieldSExtract = 202,
+    BitFieldUExtract = 203,
+    BitReverse = 204,
+    BitCount = 205,
+    ControlBarrier = 224,
+    MemoryBarrier = 225,
+    AtomicIAdd = 234,
+    Phi = 245,
+    LoopMerge = 246,
+    SelectionMerge = 247,
+    Label = 248,
+    Branch = 249,
+    BranchConditional = 250,
+    Switch = 251,
+    Kill = 252,
+    Return = 253,
+    ReturnValue = 254,
+    Unreachable = 255,
+    GroupNonUniformElect = 333,
+    GroupNonUniformAll = 334,
+    GroupNonUniformAny = 335,
+    GroupNonUniformAllEqual = 336,
+    GroupNonUniformBroadcast = 337,
+    GroupNonUniformBroadcastFirst = 338,
+    GroupNonUniformBallot = 339,
+    GroupNonUniformShuffle = 345,
+    GroupNonUniformShuffleXor = 346,
+    GroupNonUniformShuffleUp = 347,
+    GroupNonUniformShuffleDown = 348,
+}
+
+internal enum SpirvCapability : uint
+{
+    Shader = 1,
+    Float16 = 9,
+    Float64 = 10,
+    Int64 = 11,
+    Int16 = 22,
+    ImageGatherExtended = 25,
+    StorageImageExtendedFormats = 49,
+    ImageQuery = 50,
+    StorageImageReadWithoutFormat = 55,
+    StorageImageWriteWithoutFormat = 56,
+    GroupNonUniform = 61,
+    GroupNonUniformVote = 62,
+    GroupNonUniformBallot = 64,
+    GroupNonUniformShuffle = 65,
+    RuntimeDescriptorArray = 5302,
+}
+
+internal enum SpirvStorageClass : uint
+{
+    UniformConstant = 0,
+    Input = 1,
+    Uniform = 2,
+    Output = 3,
+    Workgroup = 4,
+    Private = 6,
+    Function = 7,
+    PushConstant = 9,
+    Image = 11,
+    StorageBuffer = 12,
+}
+
+internal enum SpirvExecutionModel : uint
+{
+    Vertex = 0,
+    Fragment = 4,
+    GLCompute = 5,
+}
+
+internal enum SpirvExecutionMode : uint
+{
+    OriginUpperLeft = 7,
+    DepthReplacing = 12,
+    LocalSize = 17,
+}
+
+internal enum SpirvDecoration : uint
+{
+    Block = 2,
+    ArrayStride = 6,
+    BuiltIn = 11,
+    NoPerspective = 13,
+    Flat = 14,
+    Location = 30,
+    Binding = 33,
+    DescriptorSet = 34,
+    Offset = 35,
+}
+
+internal enum SpirvBuiltIn : uint
+{
+    Position = 0,
+    VertexIndex = 42,
+    InstanceIndex = 43,
+    FragCoord = 15,
+    FrontFacing = 17,
+    WorkgroupId = 26,
+    LocalInvocationId = 27,
+    GlobalInvocationId = 28,
+    LocalInvocationIndex = 29,
+    SubgroupLocalInvocationId = 41,
+}
+
+internal enum SpirvImageDim : uint
+{
+    Dim1D = 0,
+    Dim2D = 1,
+    Dim3D = 2,
+    Cube = 3,
+    Buffer = 5,
+}
+
+internal enum SpirvImageFormat : uint
+{
+    Unknown = 0,
+    Rgba32f = 1,
+    Rgba16f = 2,
+    R32f = 3,
+    Rgba8 = 4,
+    Rgba8Snorm = 5,
+    Rg32f = 6,
+    Rg16f = 7,
+    R11fG11fB10f = 8,
+    R16f = 9,
+    Rgba16 = 10,
+    Rgb10A2 = 11,
+    Rg16 = 12,
+    Rg8 = 13,
+    R16 = 14,
+    R8 = 15,
+    Rgba16Snorm = 16,
+    Rg16Snorm = 17,
+    Rg8Snorm = 18,
+    R16Snorm = 19,
+    R8Snorm = 20,
+    Rgba32i = 21,
+    Rgba16i = 22,
+    Rgba8i = 23,
+    R32i = 24,
+    Rg32i = 25,
+    Rg16i = 26,
+    Rg8i = 27,
+    R16i = 28,
+    R8i = 29,
+    Rgba32ui = 30,
+    Rgba16ui = 31,
+    Rgba8ui = 32,
+    R32ui = 33,
+    Rgb10A2ui = 34,
+    Rg32ui = 35,
+    Rg16ui = 36,
+    Rg8ui = 37,
+    R16ui = 38,
+    R8ui = 39,
+}
+
+internal sealed class SpirvModuleBuilder
+{
+    private const uint Magic = 0x07230203;
+    private const uint Version15 = 0x00010500;
+    private const uint Generator = 0x53504500; // "SPE"
+
+    private readonly List<uint> _capabilities = [];
+    private readonly List<uint> _extensions = [];
+    private readonly List<uint> _imports = [];
+    private readonly List<uint> _memoryModel = [];
+    private readonly List<uint> _entryPoints = [];
+    private readonly List<uint> _executionModes = [];
+    private readonly List<uint> _debug = [];
+    private readonly List<uint> _annotations = [];
+    private readonly List<uint> _typesConstantsGlobals = [];
+    private readonly List<uint> _functions = [];
+    private readonly Dictionary<(uint Width, bool Signed), uint> _integerTypes = [];
+    private readonly Dictionary<uint, uint> _floatTypes = [];
+    private readonly Dictionary<(uint Component, uint Count), uint> _vectorTypes = [];
+    private readonly Dictionary<
+        (
+            uint SampledType,
+            SpirvImageDim Dimension,
+            bool Depth,
+            bool Arrayed,
+            bool Multisampled,
+            uint Sampled,
+            SpirvImageFormat Format
+        ),
+        uint> _imageTypes = [];
+    private readonly Dictionary<uint, uint> _sampledImageTypes = [];
+    private readonly Dictionary<(SpirvStorageClass Storage, uint Type), uint> _pointerTypes = [];
+    private readonly Dictionary<(uint Element, uint Count), uint> _arrayTypes = [];
+    private readonly Dictionary<uint, uint> _runtimeArrayTypes = [];
+    private readonly Dictionary<string, uint> _functionTypes = [];
+    private readonly Dictionary<(uint Type, ulong Value), uint> _constants = [];
+    private readonly HashSet<SpirvCapability> _declaredCapabilities = [];
+    private readonly Dictionary<string, uint> _extInstImports = [];
+    private uint _nextId = 1;
+    private uint? _voidType;
+    private uint? _boolType;
+
+    public uint AllocateId() => _nextId++;
+
+    public void AddCapability(SpirvCapability capability)
+    {
+        if (_declaredCapabilities.Add(capability))
+        {
+            Emit(_capabilities, SpirvOp.Capability, (uint)capability);
+        }
+    }
+
+    public void AddExtension(string extension) =>
+        EmitWithString(_extensions, SpirvOp.Extension, [], extension);
+
+    public uint ImportExtInst(string name)
+    {
+        if (_extInstImports.TryGetValue(name, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        EmitWithString(_imports, SpirvOp.ExtInstImport, [id], name);
+        _extInstImports.Add(name, id);
+        return id;
+    }
+
+    public void SetLogicalGlsl450MemoryModel() =>
+        Emit(_memoryModel, SpirvOp.MemoryModel, 0, 1);
+
+    public void AddEntryPoint(
+        SpirvExecutionModel model,
+        uint function,
+        string name,
+        IReadOnlyList<uint> interfaces)
+    {
+        var prefix = new uint[2 + interfaces.Count];
+        prefix[0] = (uint)model;
+        prefix[1] = function;
+        for (var index = 0; index < interfaces.Count; index++)
+        {
+            prefix[index + 2] = interfaces[index];
+        }
+
+        EmitWithString(_entryPoints, SpirvOp.EntryPoint, prefix, name, stringBeforeTailCount: 2);
+    }
+
+    public void AddExecutionMode(uint function, SpirvExecutionMode mode, params uint[] operands)
+    {
+        var values = new uint[2 + operands.Length];
+        values[0] = function;
+        values[1] = (uint)mode;
+        operands.CopyTo(values, 2);
+        Emit(_executionModes, SpirvOp.ExecutionMode, values);
+    }
+
+    public void AddName(uint target, string name) =>
+        EmitWithString(_debug, SpirvOp.Name, [target], name);
+
+    public void AddDecoration(uint target, SpirvDecoration decoration, params uint[] operands)
+    {
+        var values = new uint[2 + operands.Length];
+        values[0] = target;
+        values[1] = (uint)decoration;
+        operands.CopyTo(values, 2);
+        Emit(_annotations, SpirvOp.Decorate, values);
+    }
+
+    public void AddMemberDecoration(
+        uint target,
+        uint member,
+        SpirvDecoration decoration,
+        params uint[] operands)
+    {
+        var values = new uint[3 + operands.Length];
+        values[0] = target;
+        values[1] = member;
+        values[2] = (uint)decoration;
+        operands.CopyTo(values, 3);
+        EmitRaw(_annotations, 72, values);
+    }
+
+    public uint TypeVoid()
+    {
+        if (_voidType is { } existing)
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(_typesConstantsGlobals, SpirvOp.TypeVoid, id);
+        _voidType = id;
+        return id;
+    }
+
+    public uint TypeBool()
+    {
+        if (_boolType is { } existing)
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(_typesConstantsGlobals, SpirvOp.TypeBool, id);
+        _boolType = id;
+        return id;
+    }
+
+    public uint TypeInt(uint width, bool signed)
+    {
+        var key = (width, signed);
+        if (_integerTypes.TryGetValue(key, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(_typesConstantsGlobals, SpirvOp.TypeInt, id, width, signed ? 1u : 0u);
+        _integerTypes.Add(key, id);
+        return id;
+    }
+
+    public uint TypeFloat(uint width)
+    {
+        if (_floatTypes.TryGetValue(width, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(_typesConstantsGlobals, SpirvOp.TypeFloat, id, width);
+        _floatTypes.Add(width, id);
+        return id;
+    }
+
+    public uint TypeVector(uint componentType, uint count)
+    {
+        var key = (componentType, count);
+        if (_vectorTypes.TryGetValue(key, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(_typesConstantsGlobals, SpirvOp.TypeVector, id, componentType, count);
+        _vectorTypes.Add(key, id);
+        return id;
+    }
+
+    public uint TypeImage(
+        uint sampledType,
+        SpirvImageDim dimension,
+        bool depth,
+        bool arrayed,
+        bool multisampled,
+        uint sampled,
+        SpirvImageFormat format)
+    {
+        var key = (
+            sampledType,
+            dimension,
+            depth,
+            arrayed,
+            multisampled,
+            sampled,
+            format);
+        if (_imageTypes.TryGetValue(key, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(
+            _typesConstantsGlobals,
+            SpirvOp.TypeImage,
+            id,
+            sampledType,
+            (uint)dimension,
+            depth ? 1u : 0u,
+            arrayed ? 1u : 0u,
+            multisampled ? 1u : 0u,
+            sampled,
+            (uint)format);
+        _imageTypes.Add(key, id);
+        return id;
+    }
+
+    public uint TypeSampledImage(uint imageType)
+    {
+        if (_sampledImageTypes.TryGetValue(imageType, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(_typesConstantsGlobals, SpirvOp.TypeSampledImage, id, imageType);
+        _sampledImageTypes.Add(imageType, id);
+        return id;
+    }
+
+    public uint TypeArray(uint elementType, uint count)
+    {
+        var key = (elementType, count);
+        if (_arrayTypes.TryGetValue(key, out var existing))
+        {
+            return existing;
+        }
+
+        var length = Constant(TypeInt(32, false), count);
+        var id = AllocateId();
+        Emit(_typesConstantsGlobals, SpirvOp.TypeArray, id, elementType, length);
+        _arrayTypes.Add(key, id);
+        return id;
+    }
+
+    public uint TypeRuntimeArray(uint elementType)
+    {
+        if (_runtimeArrayTypes.TryGetValue(elementType, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(_typesConstantsGlobals, SpirvOp.TypeRuntimeArray, id, elementType);
+        _runtimeArrayTypes.Add(elementType, id);
+        return id;
+    }
+
+    public uint TypeStruct(params uint[] memberTypes)
+    {
+        var id = AllocateId();
+        var operands = new uint[memberTypes.Length + 1];
+        operands[0] = id;
+        memberTypes.CopyTo(operands, 1);
+        Emit(_typesConstantsGlobals, SpirvOp.TypeStruct, operands);
+        return id;
+    }
+
+    public uint TypePointer(SpirvStorageClass storageClass, uint type)
+    {
+        var key = (storageClass, type);
+        if (_pointerTypes.TryGetValue(key, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(_typesConstantsGlobals, SpirvOp.TypePointer, id, (uint)storageClass, type);
+        _pointerTypes.Add(key, id);
+        return id;
+    }
+
+    public uint TypeFunction(uint returnType, params uint[] parameterTypes)
+    {
+        var key = returnType + ":" + string.Join(',', parameterTypes);
+        if (_functionTypes.TryGetValue(key, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        var operands = new uint[parameterTypes.Length + 2];
+        operands[0] = id;
+        operands[1] = returnType;
+        parameterTypes.CopyTo(operands, 2);
+        Emit(_typesConstantsGlobals, SpirvOp.TypeFunction, operands);
+        _functionTypes.Add(key, id);
+        return id;
+    }
+
+    public uint ConstantBool(bool value)
+    {
+        var type = TypeBool();
+        var key = (type, value ? 1UL : 0UL);
+        if (_constants.TryGetValue(key, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(
+            _typesConstantsGlobals,
+            value ? SpirvOp.ConstantTrue : SpirvOp.ConstantFalse,
+            type,
+            id);
+        _constants.Add(key, id);
+        return id;
+    }
+
+    public uint Constant(uint type, uint value)
+    {
+        var key = (type, (ulong)value);
+        if (_constants.TryGetValue(key, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(_typesConstantsGlobals, SpirvOp.Constant, type, id, value);
+        _constants.Add(key, id);
+        return id;
+    }
+
+    public uint Constant64(uint type, ulong value)
+    {
+        var key = (type, value);
+        if (_constants.TryGetValue(key, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(
+            _typesConstantsGlobals,
+            SpirvOp.Constant,
+            type,
+            id,
+            (uint)value,
+            (uint)(value >> 32));
+        _constants.Add(key, id);
+        return id;
+    }
+
+    public uint ConstantFloat(uint type, float value) =>
+        Constant(type, BitConverter.SingleToUInt32Bits(value));
+
+    public uint ConstantComposite(uint type, params uint[] constituents)
+    {
+        var id = AllocateId();
+        var operands = new uint[constituents.Length + 2];
+        operands[0] = type;
+        operands[1] = id;
+        constituents.CopyTo(operands, 2);
+        Emit(_typesConstantsGlobals, SpirvOp.ConstantComposite, operands);
+        return id;
+    }
+
+    public uint ConstantNull(uint type)
+    {
+        var key = (type, ulong.MaxValue);
+        if (_constants.TryGetValue(key, out var existing))
+        {
+            return existing;
+        }
+
+        var id = AllocateId();
+        Emit(_typesConstantsGlobals, SpirvOp.ConstantNull, type, id);
+        _constants.Add(key, id);
+        return id;
+    }
+
+    public uint AddGlobalVariable(
+        uint pointerType,
+        SpirvStorageClass storageClass,
+        uint? initializer = null)
+    {
+        var id = AllocateId();
+        if (initializer.HasValue)
+        {
+            Emit(
+                _typesConstantsGlobals,
+                SpirvOp.Variable,
+                pointerType,
+                id,
+                (uint)storageClass,
+                initializer.Value);
+        }
+        else
+        {
+            Emit(_typesConstantsGlobals, SpirvOp.Variable, pointerType, id, (uint)storageClass);
+        }
+
+        return id;
+    }
+
+    public uint BeginFunction(uint returnType, uint functionType)
+    {
+        var id = AllocateId();
+        Emit(_functions, SpirvOp.Function, returnType, id, 0, functionType);
+        return id;
+    }
+
+    public uint AddFunctionParameter(uint type) =>
+        EmitResult(_functions, SpirvOp.FunctionParameter, type);
+
+    public uint AddLabel(uint? id = null)
+    {
+        var result = id ?? AllocateId();
+        Emit(_functions, SpirvOp.Label, result);
+        return result;
+    }
+
+    public uint AddFunctionVariable(uint pointerType, uint? initializer = null)
+    {
+        var id = AllocateId();
+        if (initializer.HasValue)
+        {
+            Emit(
+                _functions,
+                SpirvOp.Variable,
+                pointerType,
+                id,
+                (uint)SpirvStorageClass.Function,
+                initializer.Value);
+        }
+        else
+        {
+            Emit(
+                _functions,
+                SpirvOp.Variable,
+                pointerType,
+                id,
+                (uint)SpirvStorageClass.Function);
+        }
+
+        return id;
+    }
+
+    public uint AddInstruction(SpirvOp opcode, uint resultType, params uint[] operands) =>
+        EmitResult(_functions, opcode, resultType, operands);
+
+    public void AddStatement(SpirvOp opcode, params uint[] operands) =>
+        Emit(_functions, opcode, operands);
+
+    public void EndFunction() => Emit(_functions, SpirvOp.FunctionEnd);
+
+    public byte[] Build()
+    {
+        if (_memoryModel.Count == 0)
+        {
+            SetLogicalGlsl450MemoryModel();
+        }
+
+        var wordCount =
+            5 +
+            _capabilities.Count +
+            _extensions.Count +
+            _imports.Count +
+            _memoryModel.Count +
+            _entryPoints.Count +
+            _executionModes.Count +
+            _debug.Count +
+            _annotations.Count +
+            _typesConstantsGlobals.Count +
+            _functions.Count;
+        var words = new uint[wordCount];
+        var offset = 0;
+        WriteWord(Magic);
+        WriteWord(Version15);
+        WriteWord(Generator);
+        WriteWord(_nextId);
+        WriteWord(0);
+        WriteSection(_capabilities);
+        WriteSection(_extensions);
+        WriteSection(_imports);
+        WriteSection(_memoryModel);
+        WriteSection(_entryPoints);
+        WriteSection(_executionModes);
+        WriteSection(_debug);
+        WriteSection(_annotations);
+        WriteSection(_typesConstantsGlobals);
+        WriteSection(_functions);
+        var bytes = new byte[wordCount * sizeof(uint)];
+        Buffer.BlockCopy(words, 0, bytes, 0, bytes.Length);
+        return bytes;
+
+        void WriteWord(uint value)
+        {
+            words[offset++] = value;
+        }
+
+        void WriteSection(List<uint> section)
+        {
+            foreach (var value in section)
+            {
+                WriteWord(value);
+            }
+        }
+    }
+
+    private uint EmitResult(
+        List<uint> section,
+        SpirvOp opcode,
+        uint resultType,
+        params uint[] operands)
+    {
+        var result = AllocateId();
+        var values = new uint[operands.Length + 2];
+        values[0] = resultType;
+        values[1] = result;
+        operands.CopyTo(values, 2);
+        Emit(section, opcode, values);
+        return result;
+    }
+
+    private static void Emit(List<uint> section, SpirvOp opcode, params uint[] operands) =>
+        EmitRaw(section, (ushort)opcode, operands);
+
+    private static void EmitRaw(List<uint> section, ushort opcode, params uint[] operands)
+    {
+        section.Add(((uint)(operands.Length + 1) << 16) | opcode);
+        section.AddRange(operands);
+    }
+
+    private static void EmitWithString(
+        List<uint> section,
+        SpirvOp opcode,
+        IReadOnlyList<uint> prefix,
+        string value,
+        int stringBeforeTailCount = -1)
+    {
+        var encoded = EncodeString(value);
+        if (stringBeforeTailCount < 0)
+        {
+            var operands = new uint[prefix.Count + encoded.Length];
+            for (var index = 0; index < prefix.Count; index++)
+            {
+                operands[index] = prefix[index];
+            }
+
+            encoded.CopyTo(operands, prefix.Count);
+            Emit(section, opcode, operands);
+            return;
+        }
+
+        var result = new uint[prefix.Count + encoded.Length];
+        for (var index = 0; index < stringBeforeTailCount; index++)
+        {
+            result[index] = prefix[index];
+        }
+
+        encoded.CopyTo(result, stringBeforeTailCount);
+        for (var index = stringBeforeTailCount; index < prefix.Count; index++)
+        {
+            result[index + encoded.Length] = prefix[index];
+        }
+
+        Emit(section, opcode, result);
+    }
+
+    private static uint[] EncodeString(string value)
+    {
+        var byteCount = Encoding.UTF8.GetByteCount(value) + 1;
+        var words = new uint[(byteCount + 3) / 4];
+        Encoding.UTF8.GetBytes(value, System.Runtime.InteropServices.MemoryMarshal.AsBytes(words.AsSpan()));
+        return words;
+    }
+}

src/SharpEmu.Libs/Ampr/AmprExports.cs

@@ -3,6 +3,7 @@
 
 using SharpEmu.HLE;
 using SharpEmu.Libs.Kernel;
+using System.Buffers;
 using System.Buffers.Binary;
 using System.Collections.Concurrent;
 
@@ -23,6 +24,12 @@ public static class AmprExports
     private const uint KernelEventQueueRecordType = 2;
     private const uint WriteAddressRecordType = 3;
     private static readonly ConcurrentDictionary<ulong, CommandBufferState> _commandBuffers = new();
+    private static readonly ConcurrentDictionary<string, Lazy<CachedHostFile>> _hostFileCache = new(StringComparer.OrdinalIgnoreCase);
+    private static readonly bool _traceAmpr =
+        string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_AMPR"), "1", StringComparison.Ordinal);
+    private static readonly bool _traceAmprReads =
+        _traceAmpr ||
+        string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_AMPR_READS"), "1", StringComparison.Ordinal);
 
     private sealed class CommandBufferState
     {
@@ -31,6 +38,23 @@ public static class AmprExports
         public ulong WriteOffset;
     }
 
+    private sealed class CachedHostFile
+    {
+        public CachedHostFile(string path)
+        {
+            Stream = new FileStream(
+                path,
+                FileMode.Open,
+                FileAccess.Read,
+                FileShare.ReadWrite | FileShare.Delete,
+                bufferSize: 1024 * 1024,
+                FileOptions.RandomAccess);
+        }
+
+        public object Gate { get; } = new();
+        public FileStream Stream { get; }
+    }
+
     [SysAbiExport(
         Nid = "8aI7R7WaOlc",
         ExportName = "sceAmprCommandBufferConstructor",
@@ -75,12 +99,7 @@ public static class AmprExports
             return (int)OrbisGen2Result.ORBIS_GEN2_OK;
         }
 
-        var buffer = 0UL;
+        if (!InitializeCommandBuffer(ctx, commandBuffer, buffer: 0, size: 0, aux0, aux1, clear: false))
-        var size = 0UL;
-        _ = ctx.TryReadUInt64(commandBuffer + CommandBufferDataOffset, out buffer);
-        _ = ctx.TryReadUInt64(commandBuffer + CommandBufferSizeOffset, out size);
-
-        if (!InitializeCommandBuffer(ctx, commandBuffer, buffer, size, aux0, aux1, clear: false))
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
         }
@@ -104,8 +123,9 @@ public static class AmprExports
             return (int)OrbisGen2Result.ORBIS_GEN2_OK;
         }
 
-        if (!ctx.TryWriteUInt64(commandBuffer + CommandBufferAux0Offset, 0) ||
+        Span<byte> auxiliaryPointers = stackalloc byte[sizeof(ulong) * 2];
-            !ctx.TryWriteUInt64(commandBuffer + CommandBufferAux1Offset, 0))
+        auxiliaryPointers.Clear();
+        if (!ctx.Memory.TryWrite(commandBuffer + CommandBufferAux0Offset, auxiliaryPointers))
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
         }
@@ -179,8 +199,15 @@ public static class AmprExports
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
         }
 
-        if (!ctx.TryReadUInt64(commandBuffer + CommandBufferDataOffset, out var buffer) ||
+        Span<byte> bufferPointers = stackalloc byte[sizeof(ulong) * 2];
-            !ctx.TryReadUInt64(commandBuffer + CommandBufferSizeOffset, out var size) ||
+        if (!ctx.Memory.TryRead(commandBuffer + CommandBufferDataOffset, bufferPointers))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+        }
+
+        var buffer = BinaryPrimitives.ReadUInt64LittleEndian(bufferPointers);
+        var size = BinaryPrimitives.ReadUInt64LittleEndian(bufferPointers[sizeof(ulong)..]);
+        if (
             !WriteCommandBufferPointers(ctx, commandBuffer, buffer, size, writeOffset: 0))
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
@@ -240,19 +267,53 @@ public static class AmprExports
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
         }
 
+        ulong bytesRead = 0;
+
+        // Unregistered/missing files are zero-filled instead of failing: games queue
+        // speculative reads and only consume the bytes on success paths.
         if (!AmprFileRegistry.TryGetHostPath(fileId, out var hostPath) || !File.Exists(hostPath))
         {
-            TraceAmprRead(ctx, commandBuffer, fileId, destination, size, fileOffset, bytesRead: 0, hostPath, (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+            if (destination != 0 && size > 0)
-            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+            {
+                int chunkSize = (int)Math.Min(size, 4096);
+                Span<byte> zeros = stackalloc byte[chunkSize];
+                zeros.Clear();
+                while (bytesRead < size)
+                {
+                    int currentChunk = (int)Math.Min((ulong)chunkSize, size - bytesRead);
+                    if (!ctx.Memory.TryWrite(destination + bytesRead, zeros[..currentChunk]))
+                    {
+                        break;
+                    }
+
+                    bytesRead += (ulong)currentChunk;
+                }
+            }
+
+            TraceAmprRead(ctx, commandBuffer, fileId, destination, size, fileOffset, bytesRead, "(missing)", (int)OrbisGen2Result.ORBIS_GEN2_OK);
+            ctx[CpuRegister.Rax] = 0;
+            return (int)OrbisGen2Result.ORBIS_GEN2_OK;
         }
 
-        var result = TryReadFileToGuestMemory(ctx, hostPath, fileOffset, destination, size, out var bytesRead);
+        // Offset -1 means "continue after the previous read of this file id".
+        if (fileOffset == unchecked((ulong)(long)-1))
+        {
+            fileOffset = PakDirectoryTracker.ResolveSequentialOffset(fileId, size);
+        }
+        else if (fileOffset > long.MaxValue)
+        {
+            fileOffset = 0;
+        }
+
+        var result = TryReadFileToGuestMemory(ctx, hostPath, fileOffset, destination, size, out bytesRead);
         if (result != (int)OrbisGen2Result.ORBIS_GEN2_OK)
         {
             TraceAmprRead(ctx, commandBuffer, fileId, destination, size, fileOffset, bytesRead, hostPath, result);
             return result;
         }
 
+        PakDirectoryTracker.OnReadCompleted(ctx, fileId, destination, fileOffset, bytesRead);
+
         if (!AppendReadFileRecord(ctx, commandBuffer, fileId, destination, size, fileOffset, bytesRead))
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
@@ -355,24 +416,26 @@ public static class AmprExports
         var commandBuffer = ctx[CpuRegister.Rdi];
         var equeue = ctx[CpuRegister.Rsi];
         var ident = ctx[CpuRegister.Rdx];
-        var filter = ctx[CpuRegister.Rcx];
+        var completionToken = ctx[CpuRegister.Rcx];
         var userData = ctx[CpuRegister.R8];
-        var data = ctx[CpuRegister.R9];
 
         if (commandBuffer == 0)
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
         }
 
-        var extra = 0UL;
+        if (!AppendKernelEventQueueRecord(
-        _ = ctx.TryReadUInt64(ctx[CpuRegister.Rsp] + sizeof(ulong), out extra);
+                ctx,
-
+                commandBuffer,
-        if (!AppendKernelEventQueueRecord(ctx, commandBuffer, equeue, ident, filter, userData, data, extra))
+                equeue,
+                ident,
+                completionToken,
+                userData))
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
         }
 
-        TraceAmpr(ctx, "write_equeue", commandBuffer, equeue, ident);
+        TraceAmpr(ctx, "write_equeue", commandBuffer, ident, completionToken);
         ctx[CpuRegister.Rax] = 0;
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
@@ -424,7 +487,7 @@ public static class AmprExports
         var offset = 0UL;
         while (offset < writeOffset)
         {
-            if (!TryReadUInt32(ctx, buffer + offset, out var recordType))
+            if (!ctx.TryReadUInt32(buffer + offset, out var recordType))
             {
                 return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
             }
@@ -472,20 +535,34 @@ public static class AmprExports
         ulong aux1,
         bool clear)
     {
+        Span<byte> header = stackalloc byte[CommandBufferHeaderSize];
         if (clear)
         {
-            Span<byte> header = stackalloc byte[CommandBufferHeaderSize];
             header.Clear();
-            if (!ctx.Memory.TryWrite(commandBuffer, header))
+        }
+        else
+        {
+            if (!ctx.Memory.TryRead(commandBuffer, header))
             {
                 return false;
             }
+
+            buffer = BinaryPrimitives.ReadUInt64LittleEndian(header[(int)CommandBufferDataOffset..]);
+            size = BinaryPrimitives.ReadUInt64LittleEndian(header[(int)CommandBufferSizeOffset..]);
         }
 
-        return ctx.TryWriteUInt64(commandBuffer + CommandBufferSelfOffset, commandBuffer) &&
+        BinaryPrimitives.WriteUInt64LittleEndian(header[(int)CommandBufferSelfOffset..], commandBuffer);
-               ctx.TryWriteUInt64(commandBuffer + CommandBufferAux0Offset, aux0) &&
+        BinaryPrimitives.WriteUInt64LittleEndian(header[(int)CommandBufferDataOffset..], buffer);
-               ctx.TryWriteUInt64(commandBuffer + CommandBufferAux1Offset, aux1) &&
+        BinaryPrimitives.WriteUInt64LittleEndian(header[(int)CommandBufferSizeOffset..], size);
-               WriteCommandBufferPointers(ctx, commandBuffer, buffer, size, writeOffset: 0);
+        BinaryPrimitives.WriteUInt64LittleEndian(header[(int)CommandBufferAux0Offset..], aux0);
+        BinaryPrimitives.WriteUInt64LittleEndian(header[(int)CommandBufferAux1Offset..], aux1);
+        if (!ctx.Memory.TryWrite(commandBuffer, header))
+        {
+            return false;
+        }
+
+        UpdateCommandBufferState(commandBuffer, buffer, size, writeOffset: 0);
+        return true;
     }
 
     private static bool WriteCommandBufferPointers(CpuContext ctx, ulong commandBuffer, ulong buffer, ulong size)
@@ -500,6 +577,26 @@ public static class AmprExports
             return false;
         }
 
+        UpdateCommandBufferState(commandBuffer, buffer, size, writeOffset);
+
+        return true;
+    }
+
+    private static bool WriteVisibleCommandBufferPointers(CpuContext ctx, ulong commandBuffer, ulong buffer, ulong size)
+    {
+        Span<byte> pointers = stackalloc byte[sizeof(ulong) * 3];
+        BinaryPrimitives.WriteUInt64LittleEndian(pointers, commandBuffer);
+        BinaryPrimitives.WriteUInt64LittleEndian(pointers[sizeof(ulong)..], buffer);
+        BinaryPrimitives.WriteUInt64LittleEndian(pointers[(sizeof(ulong) * 2)..], size);
+        return ctx.Memory.TryWrite(commandBuffer + CommandBufferSelfOffset, pointers);
+    }
+
+    private static void UpdateCommandBufferState(
+        ulong commandBuffer,
+        ulong buffer,
+        ulong size,
+        ulong writeOffset)
+    {
         var state = _commandBuffers.GetOrAdd(commandBuffer, static _ => new CommandBufferState());
         lock (state)
         {
@@ -507,15 +604,6 @@ public static class AmprExports
             state.Size = size;
             state.WriteOffset = writeOffset;
         }
-
-        return true;
-    }
-
-    private static bool WriteVisibleCommandBufferPointers(CpuContext ctx, ulong commandBuffer, ulong buffer, ulong size)
-    {
-        return ctx.TryWriteUInt64(commandBuffer + CommandBufferSelfOffset, commandBuffer) &&
-               ctx.TryWriteUInt64(commandBuffer + CommandBufferDataOffset, buffer) &&
-               ctx.TryWriteUInt64(commandBuffer + CommandBufferSizeOffset, size);
     }
 
     private static bool TryGetCommandBufferState(
@@ -536,9 +624,11 @@ public static class AmprExports
             return true;
         }
 
-        if (ctx.TryReadUInt64(commandBuffer + CommandBufferDataOffset, out buffer) &&
+        Span<byte> pointers = stackalloc byte[sizeof(ulong) * 2];
-            ctx.TryReadUInt64(commandBuffer + CommandBufferSizeOffset, out size))
+        if (ctx.Memory.TryRead(commandBuffer + CommandBufferDataOffset, pointers))
         {
+            buffer = BinaryPrimitives.ReadUInt64LittleEndian(pointers);
+            size = BinaryPrimitives.ReadUInt64LittleEndian(pointers[sizeof(ulong)..]);
             state = _commandBuffers.GetOrAdd(commandBuffer, static _ => new CommandBufferState());
             lock (state)
             {
@@ -591,23 +681,48 @@ public static class AmprExports
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
         }
 
-        const int ChunkSize = 64 * 1024;
+        const int ChunkSize = 1024 * 1024;
-        var buffer = new byte[(int)Math.Min((ulong)ChunkSize, size)];
+        var buffer = ArrayPool<byte>.Shared.Rent((int)Math.Min((ulong)ChunkSize, size));
 
         try
         {
-            using var stream = new FileStream(hostPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite | FileShare.Delete);
+            if (!TryGetCachedHostFile(hostPath, out var cachedFile, out var openResult))
-            if (fileOffset >= (ulong)stream.Length)
+            {
+                return openResult;
+            }
+
+            long fileLength;
+            lock (cachedFile.Gate)
+            {
+                fileLength = cachedFile.Stream.Length;
+            }
+
+            if (fileOffset >= (ulong)fileLength)
             {
                 return (int)OrbisGen2Result.ORBIS_GEN2_OK;
             }
 
-            stream.Position = unchecked((long)fileOffset);
-
             while (bytesRead < size)
             {
+                if (bytesRead > ulong.MaxValue - fileOffset)
+                {
+                    return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+                }
+
+                var absoluteOffset = fileOffset + bytesRead;
+                if (absoluteOffset > long.MaxValue)
+                {
+                    return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+                }
+
                 var request = (int)Math.Min((ulong)buffer.Length, size - bytesRead);
-                var read = stream.Read(buffer, 0, request);
+                int read;
+                lock (cachedFile.Gate)
+                {
+                    cachedFile.Stream.Position = unchecked((long)absoluteOffset);
+                    read = cachedFile.Stream.Read(buffer, 0, request);
+                }
+
                 if (read <= 0)
                 {
                     break;
@@ -629,10 +744,52 @@ public static class AmprExports
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
         }
+        finally
+        {
+            ArrayPool<byte>.Shared.Return(buffer);
+        }
 
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
+    private static bool TryGetCachedHostFile(string hostPath, out CachedHostFile file, out int result)
+    {
+        file = null!;
+        result = (int)OrbisGen2Result.ORBIS_GEN2_OK;
+
+        string cachePath;
+        try
+        {
+            cachePath = Path.GetFullPath(hostPath);
+        }
+        catch
+        {
+            cachePath = hostPath;
+        }
+
+        var lazy = _hostFileCache.GetOrAdd(
+            cachePath,
+            static path => new Lazy<CachedHostFile>(() => new CachedHostFile(path), isThreadSafe: true));
+
+        try
+        {
+            file = lazy.Value;
+            return true;
+        }
+        catch (UnauthorizedAccessException)
+        {
+            _hostFileCache.TryRemove(cachePath, out _);
+            result = (int)OrbisGen2Result.ORBIS_GEN2_ERROR_PERMISSION_DENIED;
+            return false;
+        }
+        catch (IOException)
+        {
+            _hostFileCache.TryRemove(cachePath, out _);
+            result = (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+            return false;
+        }
+    }
+
     private static bool AppendReadFileRecord(
         CpuContext ctx,
         ulong commandBuffer,
@@ -659,20 +816,17 @@ public static class AmprExports
         ulong commandBuffer,
         ulong equeue,
         ulong ident,
-        ulong filter,
+        ulong completionToken,
-        ulong userData,
+        ulong userData)
-        ulong data,
-        ulong extra)
     {
         Span<byte> record = stackalloc byte[(int)KernelEventQueueRecordSize];
         record.Clear();
         BinaryPrimitives.WriteUInt32LittleEndian(record[0x00..], KernelEventQueueRecordType);
-        BinaryPrimitives.WriteUInt32LittleEndian(record[0x04..], unchecked((uint)filter));
+        BinaryPrimitives.WriteInt16LittleEndian(record[0x04..], KernelEventQueueCompatExports.KernelEventFilterAmpr);
         BinaryPrimitives.WriteUInt64LittleEndian(record[0x08..], equeue);
         BinaryPrimitives.WriteUInt64LittleEndian(record[0x10..], ident);
         BinaryPrimitives.WriteUInt64LittleEndian(record[0x18..], userData);
-        BinaryPrimitives.WriteUInt64LittleEndian(record[0x20..], data);
+        BinaryPrimitives.WriteUInt64LittleEndian(record[0x20..], completionToken);
-        BinaryPrimitives.WriteUInt64LittleEndian(record[0x28..], extra);
 
         return AppendCommandBufferRecord(ctx, commandBuffer, record);
     }
@@ -763,22 +917,9 @@ public static class AmprExports
         return true;
     }
 
-    private static bool TryReadUInt32(CpuContext ctx, ulong address, out uint value)
-    {
-        Span<byte> buffer = stackalloc byte[sizeof(uint)];
-        if (!ctx.Memory.TryRead(address, buffer))
-        {
-            value = 0;
-            return false;
-        }
-
-        value = BinaryPrimitives.ReadUInt32LittleEndian(buffer);
-        return true;
-    }
-
     private static void TraceAmpr(CpuContext ctx, string operation, ulong commandBuffer, ulong arg0, ulong arg1)
     {
-        if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_AMPR"), "1", StringComparison.Ordinal))
+        if (!_traceAmpr)
         {
             return;
         }
@@ -800,7 +941,7 @@ public static class AmprExports
         string? hostPath,
         int result)
     {
-        if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_AMPR"), "1", StringComparison.Ordinal))
+        if (!_traceAmprReads)
         {
             return;
         }

src/SharpEmu.Libs/Ampr/PakDirectoryTracker.cs

@@ -0,0 +1,156 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.Buffers.Binary;
+using System.Collections.Concurrent;
+using System.Text;
+using SharpEmu.HLE;
+
+namespace SharpEmu.Libs.Ampr;
+
+/// <summary>
+/// sceAmprAprCommandBufferReadFile carries -1 instead of an absolute offset whenever the guest
+/// wants "the next sequential chunk" of a file. For an id Software PACK archive that sequence is
+/// always header -> directory table -> individual archived files, and the guest never tells us
+/// which archived file it wants next - only the byte count it expects, taken from the very
+/// directory entry it already parsed on its side. This tracks a per-fileId read cursor, and once
+/// the directory table has streamed past, parses it so later reads can be matched back to their
+/// real absolute offset by the size the guest asks for.
+/// </summary>
+internal static class PakDirectoryTracker
+{
+    private const int DirectoryEntrySize = 64;
+    private const int DirectoryEntryNameLength = 56;
+
+    private static readonly bool _trace =
+        string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_AMPR"), "1", StringComparison.Ordinal) ||
+        string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_AMPR_READS"), "1", StringComparison.Ordinal);
+
+    private sealed class DirectoryEntry(string name, uint filePos, uint fileLen)
+    {
+        public string Name { get; } = name;
+        public uint FilePos { get; } = filePos;
+        public uint FileLen { get; } = fileLen;
+        public bool Consumed { get; set; }
+    }
+
+    private sealed class FileState
+    {
+        public ulong NextOffset;
+        public bool ExpectingDirectory;
+        public List<DirectoryEntry>? Directory;
+    }
+
+    private static readonly ConcurrentDictionary<uint, FileState> _state = new();
+
+    /// <summary>
+    /// Resolves what "read the next sequential chunk of size <paramref name="requestedSize"/>"
+    /// really means for this fileId: an unconsumed directory entry whose length matches, if the
+    /// directory has already been parsed, otherwise the tracked linear cursor.
+    /// </summary>
+    public static ulong ResolveSequentialOffset(uint fileId, ulong requestedSize)
+    {
+        var state = _state.GetOrAdd(fileId, static _ => new FileState());
+
+        if (state.Directory is { } entries)
+        {
+            foreach (var entry in entries)
+            {
+                if (!entry.Consumed && entry.FileLen == requestedSize)
+                {
+                    entry.Consumed = true;
+                    if (_trace)
+                    {
+                        Console.Error.WriteLine(
+                            $"[LOADER][TRACE] pak.directory_match: id=0x{fileId:X8} name='{entry.Name}' " +
+                            $"filepos=0x{entry.FilePos:X8} filelen=0x{entry.FileLen:X8}");
+                    }
+
+                    return entry.FilePos;
+                }
+            }
+        }
+
+        return state.NextOffset;
+    }
+
+    /// <summary>
+    /// Feeds back a completed read so the tracker can advance its cursor, recognize a PACK
+    /// header and jump straight to its directory table, or parse the directory table itself
+    /// once it streams past.
+    /// </summary>
+    public static void OnReadCompleted(CpuContext ctx, uint fileId, ulong destination, ulong fileOffset, ulong bytesRead)
+    {
+        if (bytesRead == 0)
+        {
+            return;
+        }
+
+        var state = _state.GetOrAdd(fileId, static _ => new FileState());
+
+        if (state.ExpectingDirectory && fileOffset == state.NextOffset)
+        {
+            state.Directory = TryParseDirectory(ctx, destination, bytesRead);
+            state.ExpectingDirectory = false;
+            state.NextOffset = fileOffset + bytesRead;
+            if (_trace)
+            {
+                Console.Error.WriteLine(
+                    $"[LOADER][TRACE] pak.directory_parsed: id=0x{fileId:X8} entries={state.Directory?.Count ?? 0}");
+            }
+
+            return;
+        }
+
+        if (fileOffset == 0 && bytesRead >= 12 && TryReadPackHeader(ctx, destination, out var dirOffset))
+        {
+            state.NextOffset = dirOffset;
+            state.ExpectingDirectory = true;
+            return;
+        }
+
+        state.NextOffset = fileOffset + bytesRead;
+    }
+
+    private static bool TryReadPackHeader(CpuContext ctx, ulong destination, out ulong dirOffset)
+    {
+        dirOffset = 0;
+        Span<byte> header = stackalloc byte[12];
+        if (!ctx.Memory.TryRead(destination, header) ||
+            header[0] != (byte)'P' || header[1] != (byte)'A' || header[2] != (byte)'C' || header[3] != (byte)'K')
+        {
+            return false;
+        }
+
+        dirOffset = BinaryPrimitives.ReadUInt32LittleEndian(header[4..8]);
+        return true;
+    }
+
+    private static List<DirectoryEntry>? TryParseDirectory(CpuContext ctx, ulong destination, ulong length)
+    {
+        var count = (int)(length / DirectoryEntrySize);
+        if (count <= 0)
+        {
+            return null;
+        }
+
+        var entries = new List<DirectoryEntry>(count);
+        Span<byte> record = stackalloc byte[DirectoryEntrySize];
+        for (var i = 0; i < count; i++)
+        {
+            if (!ctx.Memory.TryRead(destination + (ulong)(i * DirectoryEntrySize), record))
+            {
+                break;
+            }
+
+            var nameBytes = record[..DirectoryEntryNameLength];
+            var nullIndex = nameBytes.IndexOf((byte)0);
+            var name = Encoding.ASCII.GetString(nullIndex >= 0 ? nameBytes[..nullIndex] : nameBytes);
+            var filePos = BinaryPrimitives.ReadUInt32LittleEndian(record.Slice(56, 4));
+            var fileLen = BinaryPrimitives.ReadUInt32LittleEndian(record.Slice(60, 4));
+            entries.Add(new DirectoryEntry(name, filePos, fileLen));
+        }
+
+        return entries;
+    }
+}

src/SharpEmu.Libs/AppContent/AppContentExports.cs

@@ -73,7 +73,7 @@ public static class AppContentExports
         var valueAddress = ctx[CpuRegister.Rsi];
         if (valueAddress == 0)
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
         }
 
         int value;
@@ -83,18 +83,18 @@ public static class AppContentExports
         }
         else if (!TryReadUserDefinedParam(paramId, out value))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
         }
 
         Span<byte> valueBytes = stackalloc byte[sizeof(int)];
         BinaryPrimitives.WriteInt32LittleEndian(valueBytes, value);
         if (!ctx.Memory.TryWrite(valueAddress, valueBytes))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
         }
 
         TraceAppContent($"app_param_get_int id={paramId} value={value}");
-        return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+        return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_OK);
     }
 
     [SysAbiExport(
@@ -168,12 +168,6 @@ public static class AppContentExports
         }
     }
 
-    private static int SetReturn(CpuContext ctx, OrbisGen2Result result)
-    {
-        ctx[CpuRegister.Rax] = unchecked((ulong)(int)result);
-        return (int)result;
-    }
-
     private static void TraceAppContent(string message)
     {
         if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_APP_CONTENT"), "1", StringComparison.Ordinal))

src/SharpEmu.Libs/Audio/AudioOut2Exports.cs

@@ -0,0 +1,215 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.HLE;
+using System.Buffers.Binary;
+
+namespace SharpEmu.Libs.Audio;
+
+public static class AudioOut2Exports
+{
+    // Sized from guest evidence, not SDK headers: Quake keeps its
+    // SceAudioOut2ContextParam on the stack with the frame canary at param+0x60,
+    // and an earlier 0x80-byte ResetParam write zeroed that canary
+    // (__stack_chk_fail right after sceAudioOut2UserCreate, which silently killed
+    // the whole audio init). Stay well below 0x60 and only write the prefix we
+    // populate.
+    private const int AudioOut2ContextParamSize = 0x30;
+    private const int AudioOut2ContextMemorySize = 0x10000;
+    private static long _nextContextHandle = 1;
+    private static long _nextUserHandle = 1;
+    private static int _nextPortId;
+
+    [SysAbiExport(
+        Nid = "g2tViFIohHE",
+        ExportName = "sceAudioOut2Initialize",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut2")]
+    public static int AudioOut2Initialize(CpuContext ctx)
+    {
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "t5YrizufpQc",
+        ExportName = "sceAudioOut2ContextResetParam",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut2")]
+    public static int AudioOut2ContextResetParam(CpuContext ctx)
+    {
+        var paramAddress = ctx[CpuRegister.Rdi];
+        if (paramAddress == 0)
+        {
+            return ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        Span<byte> param = stackalloc byte[AudioOut2ContextParamSize];
+        param.Clear();
+        BinaryPrimitives.WriteUInt32LittleEndian(param[0x00..], AudioOut2ContextParamSize);
+        BinaryPrimitives.WriteUInt32LittleEndian(param[0x04..], 2);
+        BinaryPrimitives.WriteUInt32LittleEndian(param[0x08..], 48000);
+        BinaryPrimitives.WriteUInt32LittleEndian(param[0x0C..], 0x400);
+
+        return ctx.Memory.TryWrite(paramAddress, param)
+            ? ctx.SetReturn(0)
+            : ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+    }
+
+    [SysAbiExport(
+        Nid = "pDmme7Bgm6E",
+        ExportName = "sceAudioOut2ContextQueryMemory",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut2")]
+    public static int AudioOut2ContextQueryMemory(CpuContext ctx)
+    {
+        var paramAddress = ctx[CpuRegister.Rdi];
+        var outMemorySizeAddress = ctx[CpuRegister.Rsi];
+        if (paramAddress == 0 || outMemorySizeAddress == 0)
+        {
+            return ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+        
+        return ctx.TryWriteUInt64(outMemorySizeAddress, AudioOut2ContextMemorySize)
+            ? ctx.SetReturn(0)
+            : ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+    }
+
+    [SysAbiExport(
+        Nid = "0x6o1VVAYSY",
+        ExportName = "sceAudioOut2ContextCreate",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut2")]
+    public static int AudioOut2ContextCreate(CpuContext ctx)
+    {
+        var paramAddress = ctx[CpuRegister.Rdi];
+        var memoryAddress = ctx[CpuRegister.Rsi];
+        var memorySize = ctx[CpuRegister.Rdx];
+        var outContextAddress = ctx[CpuRegister.Rcx];
+        if (paramAddress == 0 || memoryAddress == 0 || memorySize == 0 || outContextAddress == 0)
+        {
+            return ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        var handle = (ulong)Interlocked.Increment(ref _nextContextHandle);
+        return ctx.TryWriteUInt64(outContextAddress, handle)
+            ? ctx.SetReturn(0)
+            : ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+    }
+
+    [SysAbiExport(
+        Nid = "on6ZH7Abo10",
+        ExportName = "sceAudioOut2ContextDestroy",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut2")]
+    public static int AudioOut2ContextDestroy(CpuContext ctx) => ctx.SetReturn(0);
+
+    [SysAbiExport(
+        Nid = "JK2wamZPzwM",
+        ExportName = "sceAudioOut2PortCreate",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut2")]
+    public static int AudioOut2PortCreate(CpuContext ctx)
+    {
+        var type = unchecked((int)ctx[CpuRegister.Rdi]);
+        var paramAddress = ctx[CpuRegister.Rsi];
+        var outPortAddress = ctx[CpuRegister.Rdx];
+        var contextAddress = ctx[CpuRegister.Rcx];
+        if (type < 0 || type > 255 || paramAddress == 0 || outPortAddress == 0 || contextAddress == 0)
+        {
+            return ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        var portId = unchecked((uint)Interlocked.Increment(ref _nextPortId)) & 0xFF;
+        var handle = 0x2000_0000UL | ((ulong)(uint)type << 16) | portId;
+        return ctx.TryWriteUInt64(outPortAddress, handle)
+            ? ctx.SetReturn(0)
+            : ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+    }
+
+    [SysAbiExport(
+        Nid = "gatEUKG+Ea4",
+        ExportName = "sceAudioOut2PortGetState",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut2")]
+    public static int AudioOut2PortGetState(CpuContext ctx)
+    {
+        var handle = ctx[CpuRegister.Rdi];
+        var stateAddress = ctx[CpuRegister.Rsi];
+        if (handle == 0 || stateAddress == 0)
+        {
+            return ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        var type = (int)((handle >> 16) & 0xFF);
+        Span<byte> state = stackalloc byte[0x20];
+        state.Clear();
+        var output = type == 2 ? 0x40 : 0x01;
+        var channels = type == 2 ? 1 : 2;
+        BinaryPrimitives.WriteUInt16LittleEndian(state[0x00..], unchecked((ushort)output));
+        state[0x02] = unchecked((byte)channels);
+        BinaryPrimitives.WriteInt16LittleEndian(state[0x04..], -1);
+
+        return ctx.Memory.TryWrite(stateAddress, state)
+            ? ctx.SetReturn(0)
+            : ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+    }
+
+    [SysAbiExport(
+        Nid = "DImz2Ft9E2g",
+        ExportName = "sceAudioOut2GetSpeakerInfo",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut2")]
+    public static int AudioOut2GetSpeakerInfo(CpuContext ctx)
+    {
+        var infoAddress = ctx[CpuRegister.Rdi];
+        if (infoAddress == 0)
+        {
+            return ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        Span<byte> info = stackalloc byte[0x40];
+        info.Clear();
+        BinaryPrimitives.WriteUInt32LittleEndian(info[0x00..], 1);
+        BinaryPrimitives.WriteUInt32LittleEndian(info[0x04..], 2);
+        BinaryPrimitives.WriteUInt32LittleEndian(info[0x08..], 48000);
+
+        return ctx.Memory.TryWrite(infoAddress, info)
+            ? ctx.SetReturn(0)
+            : ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+    }
+
+    [SysAbiExport(
+        Nid = "cd+Rtw+D1x8",
+        ExportName = "sceAudioOut2PortDestroy",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut2")]
+    public static int AudioOut2PortDestroy(CpuContext ctx) => ctx.SetReturn(0);
+
+    [SysAbiExport(
+        Nid = "IaZXJ9M79uo",
+        ExportName = "sceAudioOut2UserDestroy",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut2")]
+    public static int AudioOut2UserDestroy(CpuContext ctx) => ctx.SetReturn(0);
+
+    [SysAbiExport(
+        Nid = "xywYcRB7nbQ",
+        ExportName = "sceAudioOut2UserCreate",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut2")]
+    public static int AudioOut2UserCreate(CpuContext ctx)
+    {
+        var userId = unchecked((int)ctx[CpuRegister.Rdi]);
+        var outUserAddress = ctx[CpuRegister.Rsi];
+        if ((userId != 0 && userId != 1 && userId != 255) || outUserAddress == 0)
+        {
+            return ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        var handle = (ulong)Interlocked.Increment(ref _nextUserHandle);
+        return ctx.TryWriteUInt64(outUserAddress, handle)
+            ? ctx.SetReturn(0)
+            : ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+    }
+}

src/SharpEmu.Libs/Audio/AudioOutExports.cs

@@ -0,0 +1,234 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.HLE;
+using System.Buffers;
+using System.Collections.Concurrent;
+using System.Diagnostics;
+
+namespace SharpEmu.Libs.Audio;
+
+public static class AudioOutExports
+{
+    private static readonly ConcurrentDictionary<int, PortState> Ports = new();
+    private static int _nextPortHandle;
+
+    private sealed class PortState : IDisposable
+    {
+        private readonly object _paceGate = new();
+        private long _nextSilentOutput;
+
+        public PortState(
+            int userId,
+            int type,
+            uint bufferLength,
+            uint frequency,
+            int format,
+            int channels,
+            int bytesPerSample,
+            bool isFloat,
+            WinMmAudioPort? backend)
+        {
+            UserId = userId;
+            Type = type;
+            BufferLength = bufferLength;
+            Frequency = frequency;
+            Format = format;
+            Channels = channels;
+            BytesPerSample = bytesPerSample;
+            IsFloat = isFloat;
+            Backend = backend;
+        }
+
+        public int UserId { get; }
+        public int Type { get; }
+        public uint BufferLength { get; }
+        public uint Frequency { get; }
+        public int Format { get; }
+        public int Channels { get; }
+        public int BytesPerSample { get; }
+        public bool IsFloat { get; }
+        public WinMmAudioPort? Backend { get; }
+        public int BufferByteLength =>
+            checked((int)BufferLength * Channels * BytesPerSample);
+
+        public void PaceSilence()
+        {
+            long delay;
+            lock (_paceGate)
+            {
+                var now = Stopwatch.GetTimestamp();
+                if (_nextSilentOutput < now)
+                {
+                    _nextSilentOutput = now;
+                }
+
+                delay = _nextSilentOutput - now;
+                _nextSilentOutput += checked(
+                    (long)Math.Ceiling(
+                        Stopwatch.Frequency * (double)BufferLength / Frequency));
+            }
+
+            if (delay > 0)
+            {
+                Thread.Sleep(TimeSpan.FromSeconds((double)delay / Stopwatch.Frequency));
+            }
+        }
+
+        public void Dispose() => Backend?.Dispose();
+    }
+
+    [SysAbiExport(
+        Nid = "JfEPXVxhFqA",
+        ExportName = "sceAudioOutInit",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceAudioOut")]
+    public static int AudioOutInit(CpuContext ctx) => ctx.SetReturn(0);
+
+    [SysAbiExport(
+        Nid = "ekNvsT22rsY",
+        ExportName = "sceAudioOutOpen",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceAudioOut")]
+    public static int AudioOutOpen(CpuContext ctx)
+    {
+        var userId = unchecked((int)ctx[CpuRegister.Rdi]);
+        var type = unchecked((int)ctx[CpuRegister.Rsi]);
+        var bufferLength = unchecked((uint)ctx[CpuRegister.Rcx]);
+        var frequency = unchecked((uint)ctx[CpuRegister.R8]);
+        var format = unchecked((int)ctx[CpuRegister.R9]);
+        if (bufferLength == 0 || frequency == 0 ||
+            !TryGetFormat(format, out var channels, out var bytesPerSample, out var isFloat))
+        {
+            return ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        WinMmAudioPort? backend = null;
+        string backendName;
+        try
+        {
+            backend = new WinMmAudioPort(frequency);
+            backendName = "winmm";
+        }
+        catch (Exception exception)
+        {
+            backendName = "silent";
+            Console.Error.WriteLine(
+                $"[LOADER][WARN] AudioOut host backend unavailable: {exception.Message}");
+        }
+
+        var handle = Interlocked.Increment(ref _nextPortHandle);
+        Ports[handle] = new PortState(
+            userId,
+            type,
+            bufferLength,
+            frequency,
+            format,
+            channels,
+            bytesPerSample,
+            isFloat,
+            backend);
+        Console.Error.WriteLine(
+            $"[LOADER][INFO] AudioOut port {handle}: {frequency} Hz, " +
+            $"{channels} ch, {(isFloat ? "float32" : "s16")}, " +
+            $"{bufferLength} frames, backend={backendName}");
+        return ctx.SetReturn(handle);
+    }
+
+    [SysAbiExport(
+        Nid = "s1--uE9mBFw",
+        ExportName = "sceAudioOutClose",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceAudioOut")]
+    public static int AudioOutClose(CpuContext ctx)
+    {
+        var handle = unchecked((int)ctx[CpuRegister.Rdi]);
+        if (!Ports.TryRemove(handle, out var port))
+        {
+            return ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        port.Dispose();
+        return ctx.SetReturn(0);
+    }
+
+    [SysAbiExport(
+        Nid = "QOQtbeDqsT4",
+        ExportName = "sceAudioOutOutput",
+        Target = Generation.Gen5,
+        LibraryName = "libSceAudioOut")]
+    public static int AudioOutOutput(CpuContext ctx)
+    {
+        var handle = unchecked((int)ctx[CpuRegister.Rdi]);
+        var sourceAddress = ctx[CpuRegister.Rsi];
+        if (!Ports.TryGetValue(handle, out var port))
+        {
+            return ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        if (sourceAddress == 0)
+        {
+            return ctx.SetReturn(0);
+        }
+
+        var buffer = ArrayPool<byte>.Shared.Rent(port.BufferByteLength);
+        try
+        {
+            var source = buffer.AsSpan(0, port.BufferByteLength);
+            if (!ctx.Memory.TryRead(sourceAddress, source))
+            {
+                return ctx.SetReturn((int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+            }
+
+            if (port.Backend is null ||
+                !port.Backend.Submit(
+                    source,
+                    port.BufferLength,
+                    port.Channels,
+                    port.BytesPerSample,
+                    port.IsFloat))
+            {
+                port.PaceSilence();
+            }
+
+            return ctx.SetReturn(0);
+        }
+        finally
+        {
+            ArrayPool<byte>.Shared.Return(buffer);
+        }
+    }
+
+    [SysAbiExport(
+        Nid = "b+uAV89IlxE",
+        ExportName = "sceAudioOutSetVolume",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceAudioOut")]
+    public static int AudioOutSetVolume(CpuContext ctx)
+    {
+        var handle = unchecked((int)ctx[CpuRegister.Rdi]);
+        return ctx.SetReturn(
+            Ports.ContainsKey(handle)
+                ? 0
+                : (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+    }
+
+    private static bool TryGetFormat(
+        int rawFormat,
+        out int channels,
+        out int bytesPerSample,
+        out bool isFloat)
+    {
+        var format = rawFormat & 0xFF;
+        channels = format switch
+        {
+            0 or 3 => 1,
+            1 or 4 => 2,
+            2 or 5 or 6 or 7 => 8,
+            _ => 0,
+        };
+        bytesPerSample = format is >= 3 and <= 5 or 7 ? 4 : 2;
+        isFloat = bytesPerSample == 4;
+        return channels != 0;
+    }
+}

src/SharpEmu.Libs/Audio/WinMmAudioPort.cs

@@ -0,0 +1,302 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.Buffers;
+using System.Buffers.Binary;
+using System.Runtime.InteropServices;
+
+namespace SharpEmu.Libs.Audio;
+
+internal sealed class WinMmAudioPort : IDisposable
+{
+    private const uint WaveMapper = uint.MaxValue;
+    private const uint CallbackEvent = 0x0005_0000;
+    private const ushort WaveFormatPcm = 1;
+    private const uint WaveHeaderDone = 0x0000_0001;
+    private const int MaximumQueuedPcmBytes = 32 * 1024;
+
+    private readonly object _gate = new();
+    private readonly AutoResetEvent _completion = new(false);
+    private readonly Queue<NativeBuffer> _buffers = new();
+    private IntPtr _device;
+    private int _queuedPcmBytes;
+    private bool _disposed;
+
+    public WinMmAudioPort(uint sampleRate)
+    {
+        if (!OperatingSystem.IsWindows())
+        {
+            throw new PlatformNotSupportedException("WinMM audio is only available on Windows.");
+        }
+
+        var format = new WaveFormat
+        {
+            FormatTag = WaveFormatPcm,
+            Channels = 2,
+            SamplesPerSecond = sampleRate,
+            AverageBytesPerSecond = checked(sampleRate * 4),
+            BlockAlign = 4,
+            BitsPerSample = 16,
+            ExtraSize = 0,
+        };
+        var result = WaveOutOpen(
+            out _device,
+            WaveMapper,
+            ref format,
+            _completion.SafeWaitHandle.DangerousGetHandle(),
+            IntPtr.Zero,
+            CallbackEvent);
+        if (result != 0)
+        {
+            throw new InvalidOperationException($"waveOutOpen failed with MMRESULT {result}.");
+        }
+    }
+
+    public bool Submit(
+        ReadOnlySpan<byte> source,
+        uint frames,
+        int channels,
+        int bytesPerSample,
+        bool isFloat)
+    {
+        lock (_gate)
+        {
+            if (_disposed)
+            {
+                return false;
+            }
+
+            var outputLength = checked((int)frames * 4);
+            ReapCompletedBuffers();
+            while (_queuedPcmBytes != 0 &&
+                   _queuedPcmBytes + outputLength > MaximumQueuedPcmBytes)
+            {
+                if (!_completion.WaitOne(TimeSpan.FromSeconds(1)))
+                {
+                    return false;
+                }
+
+                ReapCompletedBuffers();
+            }
+
+            var output = ArrayPool<byte>.Shared.Rent(outputLength);
+            try
+            {
+                ConvertToStereoPcm16(
+                    source,
+                    output.AsSpan(0, outputLength),
+                    checked((int)frames),
+                    channels,
+                    bytesPerSample,
+                    isFloat);
+                return QueueBuffer(output.AsSpan(0, outputLength));
+            }
+            finally
+            {
+                ArrayPool<byte>.Shared.Return(output);
+            }
+        }
+    }
+
+    public void Dispose()
+    {
+        lock (_gate)
+        {
+            if (_disposed)
+            {
+                return;
+            }
+
+            _disposed = true;
+            if (_device != IntPtr.Zero)
+            {
+                WaveOutReset(_device);
+                while (_buffers.TryDequeue(out var buffer))
+                {
+                    ReleaseBuffer(buffer);
+                }
+
+                WaveOutClose(_device);
+                _device = IntPtr.Zero;
+            }
+
+            _completion.Dispose();
+        }
+    }
+
+    private bool QueueBuffer(ReadOnlySpan<byte> data)
+    {
+        var dataAddress = Marshal.AllocHGlobal(data.Length);
+        var headerAddress = IntPtr.Zero;
+        try
+        {
+            unsafe
+            {
+                data.CopyTo(new Span<byte>((void*)dataAddress, data.Length));
+            }
+
+            var header = new WaveHeader
+            {
+                Data = dataAddress,
+                BufferLength = checked((uint)data.Length),
+            };
+            headerAddress = Marshal.AllocHGlobal(Marshal.SizeOf<WaveHeader>());
+            Marshal.StructureToPtr(header, headerAddress, false);
+
+            var result = WaveOutPrepareHeader(
+                _device,
+                headerAddress,
+                checked((uint)Marshal.SizeOf<WaveHeader>()));
+            if (result != 0)
+            {
+                return false;
+            }
+
+            result = WaveOutWrite(
+                _device,
+                headerAddress,
+                checked((uint)Marshal.SizeOf<WaveHeader>()));
+            if (result != 0)
+            {
+                WaveOutUnprepareHeader(
+                    _device,
+                    headerAddress,
+                    checked((uint)Marshal.SizeOf<WaveHeader>()));
+                return false;
+            }
+
+            _buffers.Enqueue(new NativeBuffer(dataAddress, headerAddress, data.Length));
+            _queuedPcmBytes += data.Length;
+            dataAddress = IntPtr.Zero;
+            headerAddress = IntPtr.Zero;
+            return true;
+        }
+        finally
+        {
+            if (headerAddress != IntPtr.Zero)
+            {
+                Marshal.FreeHGlobal(headerAddress);
+            }
+
+            if (dataAddress != IntPtr.Zero)
+            {
+                Marshal.FreeHGlobal(dataAddress);
+            }
+        }
+    }
+
+    private void ReapCompletedBuffers()
+    {
+        while (_buffers.TryPeek(out var buffer))
+        {
+            var header = Marshal.PtrToStructure<WaveHeader>(buffer.Header);
+            if ((header.Flags & WaveHeaderDone) == 0)
+            {
+                return;
+            }
+
+            _buffers.Dequeue();
+            ReleaseBuffer(buffer);
+        }
+    }
+
+    private void ReleaseBuffer(NativeBuffer buffer)
+    {
+        WaveOutUnprepareHeader(
+            _device,
+            buffer.Header,
+            checked((uint)Marshal.SizeOf<WaveHeader>()));
+        _queuedPcmBytes -= buffer.Length;
+        Marshal.FreeHGlobal(buffer.Header);
+        Marshal.FreeHGlobal(buffer.Data);
+    }
+
+    private static void ConvertToStereoPcm16(
+        ReadOnlySpan<byte> source,
+        Span<byte> destination,
+        int frames,
+        int channels,
+        int bytesPerSample,
+        bool isFloat)
+    {
+        var sourceFrameSize = checked(channels * bytesPerSample);
+        for (var frame = 0; frame < frames; frame++)
+        {
+            var sourceFrame = source.Slice(frame * sourceFrameSize, sourceFrameSize);
+            var left = ReadSample(sourceFrame, 0, bytesPerSample, isFloat);
+            var right = channels == 1
+                ? left
+                : ReadSample(sourceFrame, 1, bytesPerSample, isFloat);
+            BinaryPrimitives.WriteInt16LittleEndian(destination[(frame * 4)..], left);
+            BinaryPrimitives.WriteInt16LittleEndian(destination[((frame * 4) + 2)..], right);
+        }
+    }
+
+    private static short ReadSample(
+        ReadOnlySpan<byte> frame,
+        int channel,
+        int bytesPerSample,
+        bool isFloat)
+    {
+        var sample = frame.Slice(channel * bytesPerSample, bytesPerSample);
+        if (!isFloat)
+        {
+            return BinaryPrimitives.ReadInt16LittleEndian(sample);
+        }
+
+        var bits = BinaryPrimitives.ReadInt32LittleEndian(sample);
+        var value = Math.Clamp(BitConverter.Int32BitsToSingle(bits), -1.0f, 1.0f);
+        return checked((short)MathF.Round(value * short.MaxValue));
+    }
+
+    private readonly record struct NativeBuffer(IntPtr Data, IntPtr Header, int Length);
+
+    [StructLayout(LayoutKind.Sequential, Pack = 2)]
+    private struct WaveFormat
+    {
+        public ushort FormatTag;
+        public ushort Channels;
+        public uint SamplesPerSecond;
+        public uint AverageBytesPerSecond;
+        public ushort BlockAlign;
+        public ushort BitsPerSample;
+        public ushort ExtraSize;
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct WaveHeader
+    {
+        public IntPtr Data;
+        public uint BufferLength;
+        public uint BytesRecorded;
+        public nuint User;
+        public uint Flags;
+        public uint Loops;
+        public IntPtr Next;
+        public nuint Reserved;
+    }
+
+    [DllImport("winmm.dll", EntryPoint = "waveOutOpen")]
+    private static extern uint WaveOutOpen(
+        out IntPtr device,
+        uint deviceId,
+        ref WaveFormat format,
+        IntPtr callback,
+        IntPtr instance,
+        uint flags);
+
+    [DllImport("winmm.dll", EntryPoint = "waveOutPrepareHeader")]
+    private static extern uint WaveOutPrepareHeader(IntPtr device, IntPtr header, uint headerSize);
+
+    [DllImport("winmm.dll", EntryPoint = "waveOutWrite")]
+    private static extern uint WaveOutWrite(IntPtr device, IntPtr header, uint headerSize);
+
+    [DllImport("winmm.dll", EntryPoint = "waveOutUnprepareHeader")]
+    private static extern uint WaveOutUnprepareHeader(IntPtr device, IntPtr header, uint headerSize);
+
+    [DllImport("winmm.dll", EntryPoint = "waveOutReset")]
+    private static extern uint WaveOutReset(IntPtr device);
+
+    [DllImport("winmm.dll", EntryPoint = "waveOutClose")]
+    private static extern uint WaveOutClose(IntPtr device);
+}

src/SharpEmu.Libs/AvPlayer/AvPlayerExports.cs

@@ -0,0 +1,104 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.HLE;
+using SharpEmu.Libs.Kernel;
+
+namespace SharpEmu.Libs.AvPlayer;
+
+public static class AvPlayerExports
+{
+    private const int InvalidParameters = unchecked((int)0x806A0001);
+    private static readonly object StateGate = new();
+    private static readonly HashSet<ulong> Players = new();
+
+    [SysAbiExport(
+        Nid = "aS66RI0gGgo",
+        ExportName = "sceAvPlayerInit",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceAvPlayer")]
+    public static int AvPlayerInit(CpuContext ctx)
+    {
+        if (ctx[CpuRegister.Rdi] == 0 ||
+            !KernelMemoryCompatExports.TryAllocateHleData(ctx, 0x40, 16, out var handle))
+        {
+            ctx[CpuRegister.Rax] = 0;
+            return 0;
+        }
+
+        lock (StateGate)
+        {
+            Players.Add(handle);
+        }
+
+        ctx[CpuRegister.Rax] = handle;
+        return unchecked((int)handle);
+    }
+
+    [SysAbiExport(
+        Nid = "JdksQu8pNdQ",
+        ExportName = "sceAvPlayerGetVideoDataEx",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceAvPlayer")]
+    public static int AvPlayerGetVideoDataEx(CpuContext ctx)
+    {
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    // "UbQoYawOsfY" is sceAvPlayerIsActive, not sceAvPlayerGetVideoDataEx (the previous NID here
+    // was wrong - verified by hashing both names against scripts/ps5_names.txt). No player is
+    // ever actually active in this HLE implementation, so report false/inactive.
+    [SysAbiExport(
+        Nid = "UbQoYawOsfY",
+        ExportName = "sceAvPlayerIsActive",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceAvPlayer")]
+    public static int AvPlayerIsActive(CpuContext ctx)
+    {
+        ctx[CpuRegister.Rax] = 0;
+        return 0;
+    }
+
+    [SysAbiExport(
+        Nid = "Wnp1OVcrZgk",
+        ExportName = "sceAvPlayerGetAudioData",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceAvPlayer")]
+    public static int AvPlayerGetAudioData(CpuContext ctx)
+    {
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "HD1YKVU26-M",
+        ExportName = "sceAvPlayerPostInit",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceAvPlayer")]
+    public static int AvPlayerPostInit(CpuContext ctx)
+    {
+        var handle = ctx[CpuRegister.Rdi];
+        var dataAddress = ctx[CpuRegister.Rsi];
+        lock (StateGate)
+        {
+            return ctx.SetReturn(
+                handle != 0 && dataAddress != 0 && Players.Contains(handle)
+                    ? 0
+                    : InvalidParameters);
+        }
+    }
+
+    [SysAbiExport(
+        Nid = "NkJwDzKmIlw",
+        ExportName = "sceAvPlayerClose",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceAvPlayer")]
+    public static int AvPlayerClose(CpuContext ctx)
+    {
+        lock (StateGate)
+        {
+            return ctx.SetReturn(Players.Remove(ctx[CpuRegister.Rdi]) ? 0 : InvalidParameters);
+        }
+    }
+}

src/SharpEmu.Libs/CommonDialog/CommonDialogExports.cs

@@ -8,7 +8,6 @@ namespace SharpEmu.Libs.CommonDialog;
 
 public static class CommonDialogExports
 {
-    private const int AlreadySystemInitialized = unchecked((int)0x80B80002);
     private static int _initialized;
 
     [SysAbiExport(
@@ -18,11 +17,12 @@ public static class CommonDialogExports
         LibraryName = "libSceCommonDialog")]
     public static int CommonDialogInitialize(CpuContext ctx)
     {
-        var result = Interlocked.Exchange(ref _initialized, 1) == 0
+        // Games can initialize the common-dialog service defensively from more than one
-            ? 0
+        // subsystem. Keeping this HLE initialization idempotent avoids turning an error
-            : AlreadySystemInitialized;
+        // reporting path into a second, unrelated failure.
-        ctx[CpuRegister.Rax] = unchecked((ulong)result);
+        Interlocked.Exchange(ref _initialized, 1);
-        return result;
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
     [SysAbiExport(

src/SharpEmu.Libs/CommonDialog/MsgDialogExports.cs

@@ -0,0 +1,185 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.HLE;
+using System.Threading;
+
+namespace SharpEmu.Libs.CommonDialog;
+
+public static class MsgDialogExports
+{
+    private const int StatusNone = 0;
+    private const int StatusInitialized = 1;
+    private const int StatusFinished = 3;
+    private const int ResultSize = 0x20;
+
+    private static int _initialized;
+    private static int _status;
+
+    [SysAbiExport(
+        Nid = "lDqxaY1UbEo",
+        ExportName = "sceMsgDialogInitialize",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceMsgDialog")]
+    public static int MsgDialogInitialize(CpuContext ctx)
+    {
+        // Treat repeated initialization as success. The dialog service is process-global in
+        // this HLE implementation and has no per-call resources to recreate.
+        Interlocked.Exchange(ref _initialized, 1);
+        Interlocked.Exchange(ref _status, StatusInitialized);
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "ePw-kqZmelo",
+        ExportName = "sceMsgDialogTerminate",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceMsgDialog")]
+    public static int MsgDialogTerminate(CpuContext ctx)
+    {
+        Interlocked.Exchange(ref _initialized, 0);
+        Interlocked.Exchange(ref _status, StatusNone);
+        return SetReturn(ctx, (int)OrbisGen2Result.ORBIS_GEN2_OK);
+    }
+
+    [SysAbiExport(
+        Nid = "b06Hh0DPEaE",
+        ExportName = "sceMsgDialogOpen",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceMsgDialog")]
+    public static int MsgDialogOpen(CpuContext ctx)
+    {
+        LogDialogMessage(ctx, ctx[CpuRegister.Rdi]);
+
+        // There is no host popup to actually show. Complete immediately with "finished" so a
+        // guest polling loop (GetStatus/UpdateStatus -> GetResult -> Close) sees a dismissed
+        // dialog on its very first poll instead of spinning forever waiting for user input.
+        Interlocked.Exchange(ref _status, StatusFinished);
+        return SetReturn(ctx, (int)OrbisGen2Result.ORBIS_GEN2_OK);
+    }
+
+    // Best-effort extraction of the dialog text so fatal-error popups are visible in the
+    // log even though no host dialog is shown. The PS5 SceMsgDialogParam layout is not
+    // fully known, so chase every qword in the struct that points at readable text - one
+    // level deep, then a second level for nested sub-param structs.
+    private static void LogDialogMessage(CpuContext ctx, ulong paramAddress)
+    {
+        if (paramAddress == 0)
+        {
+            Console.Error.WriteLine("[LOADER][INFO] sceMsgDialogOpen: param=NULL");
+            return;
+        }
+
+        Console.Error.WriteLine($"[LOADER][INFO] sceMsgDialogOpen: param=0x{paramAddress:X12}");
+
+        Span<byte> head = stackalloc byte[0xA0];
+        if (ctx.Memory.TryRead(paramAddress, head))
+        {
+            DumpPointerStrings(ctx, paramAddress, head, "param", chaseNested: true);
+        }
+    }
+
+    private static void DumpPointerStrings(CpuContext ctx, ulong baseAddress, ReadOnlySpan<byte> bytes, string label, bool chaseNested)
+    {
+        Span<byte> nested = stackalloc byte[0x40];
+        for (var offset = 0; offset + 8 <= bytes.Length; offset += 8)
+        {
+            var value = System.Buffers.Binary.BinaryPrimitives.ReadUInt64LittleEndian(bytes[offset..]);
+            if (value < 0x10000 || value == baseAddress)
+            {
+                continue;
+            }
+
+            var text = TryReadPrintableText(ctx, value);
+            if (text is not null)
+            {
+                Console.Error.WriteLine($"[LOADER][INFO]   {label}+0x{offset:X2} -> 0x{value:X12} text=\"{text}\"");
+            }
+            else if (chaseNested && ctx.Memory.TryRead(value, nested))
+            {
+                DumpPointerStrings(ctx, value, nested, $"{label}+0x{offset:X2}", chaseNested: false);
+            }
+        }
+    }
+
+    private static string? TryReadPrintableText(CpuContext ctx, ulong address)
+    {
+        Span<byte> bytes = stackalloc byte[256];
+        if (!ctx.Memory.TryRead(address, bytes))
+        {
+            return null;
+        }
+
+        var nullIndex = bytes.IndexOf((byte)0);
+        if (nullIndex < 2)
+        {
+            return null;
+        }
+
+        var candidate = bytes[..nullIndex];
+        foreach (var b in candidate)
+        {
+            if (b is < 0x20 or > 0x7E && b != (byte)'\n' && b != (byte)'\r' && b != (byte)'\t')
+            {
+                return null;
+            }
+        }
+
+        return System.Text.Encoding.ASCII.GetString(candidate).Replace("\n", "\\n").Replace("\r", "\\r");
+    }
+
+    [SysAbiExport(
+        Nid = "CWVW78Qc3fI",
+        ExportName = "sceMsgDialogGetStatus",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceMsgDialog")]
+    public static int MsgDialogGetStatus(CpuContext ctx) => SetReturn(ctx, Volatile.Read(ref _status));
+
+    [SysAbiExport(
+        Nid = "6fIC3XKt2k0",
+        ExportName = "sceMsgDialogUpdateStatus",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceMsgDialog")]
+    public static int MsgDialogUpdateStatus(CpuContext ctx) => SetReturn(ctx, Volatile.Read(ref _status));
+
+    [SysAbiExport(
+        Nid = "Lr8ovHH9l6A",
+        ExportName = "sceMsgDialogGetResult",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceMsgDialog")]
+    public static int MsgDialogGetResult(CpuContext ctx)
+    {
+        var resultAddress = ctx[CpuRegister.Rdi];
+        if (resultAddress == 0)
+        {
+            return SetReturn(ctx, (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        Span<byte> result = stackalloc byte[ResultSize];
+        result.Clear();
+        if (!ctx.Memory.TryWrite(resultAddress, result))
+        {
+            return SetReturn(ctx, (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+        }
+
+        return SetReturn(ctx, (int)OrbisGen2Result.ORBIS_GEN2_OK);
+    }
+
+    [SysAbiExport(
+        Nid = "HTrcDKlFKuM",
+        ExportName = "sceMsgDialogClose",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceMsgDialog")]
+    public static int MsgDialogClose(CpuContext ctx)
+    {
+        Interlocked.Exchange(ref _status, StatusFinished);
+        return SetReturn(ctx, (int)OrbisGen2Result.ORBIS_GEN2_OK);
+    }
+
+    private static int SetReturn(CpuContext ctx, int result)
+    {
+        ctx[CpuRegister.Rax] = unchecked((ulong)result);
+        return result;
+    }
+}

src/SharpEmu.Libs/CxxAbiExports.cs

@@ -93,7 +93,7 @@ public static class CxaGuardExports
     }
 
     [SysAbiExport(
-        Nid = "",
+        Nid = "9rAeANT2tyE",
         ExportName = "__cxa_guard_release",
         Target = Generation.Gen4 | Generation.Gen5,
         LibraryName = "libc")]
@@ -142,7 +142,7 @@ public static class CxaGuardExports
     }
 
     [SysAbiExport(
-        Nid = "",
+        Nid = "2emaaluWzUw",
         ExportName = "__cxa_guard_abort",
         Target = Generation.Gen4 | Generation.Gen5,
         LibraryName = "libc")]

src/SharpEmu.Libs/DiscMap/DiscMapExports.cs

@@ -0,0 +1,104 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.HLE;
+
+namespace SharpEmu.Libs.DiscMap;
+
+/// <summary>
+/// HLE implementation of libSceDiscMap, ported from Kyty's LibDiscMap.cpp
+/// (https://github.com/InoriRus/Kyty, MIT). Titles installed to internal
+/// storage query these entry points on nearly every file access to decide
+/// whether a read must be redirected to the Blu-ray drive. Reporting every
+/// request as already resident on HDD lets the regular file system path
+/// service the read.
+/// </summary>
+public static class DiscMapExports
+{
+    private const int DiscMapErrorInvalidArgument = unchecked((int)0x81100001);
+    private const int DiscMapErrorLocationNotMapped = unchecked((int)0x81100002);
+    private const int DiscMapErrorFileNotFound = unchecked((int)0x81100003);
+    private const int DiscMapErrorNoBitmapInfo = unchecked((int)0x81100004);
+
+    [SysAbiExport(
+        Nid = "lbQKqsERhtE",
+        ExportName = "sceDiscMapIsRequestOnHDD",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceDiscMap")]
+    public static int DiscMapIsRequestOnHDD(CpuContext ctx)
+    {
+        var pathAddress = ctx[CpuRegister.Rdi];
+        var offset = ctx[CpuRegister.Rsi];
+        var size = ctx[CpuRegister.Rdx];
+        var resultAddress = ctx[CpuRegister.Rcx];
+
+        if (pathAddress == 0 || resultAddress == 0)
+        {
+            return DiscMapErrorInvalidArgument;
+        }
+
+        if (!ctx.TryWriteInt32(resultAddress, 1))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+        }
+
+        TraceDiscMap(ctx, "sceDiscMapIsRequestOnHDD", pathAddress, offset, size);
+
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "fJgP+wqifno",
+        ExportName = "sceDiscMapUnknownFJgP",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceDiscMap")]
+    public static int DiscMapUnknownFJgP(CpuContext ctx) => WriteMappingTriple(ctx, "sceDiscMapUnknownFJgP");
+
+    [SysAbiExport(
+        Nid = "ioKMruft1ek",
+        ExportName = "sceDiscMapUnknownIoKM",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceDiscMap")]
+    public static int DiscMapUnknownIoKM(CpuContext ctx) => WriteMappingTriple(ctx, "sceDiscMapUnknownIoKM");
+
+    private static int WriteMappingTriple(CpuContext ctx, string exportName)
+    {
+        var pathAddress = ctx[CpuRegister.Rdi];
+        var offset = ctx[CpuRegister.Rsi];
+        var size = ctx[CpuRegister.Rdx];
+        var flagsAddress = ctx[CpuRegister.Rcx];
+        var outAddress1 = ctx[CpuRegister.R8];
+        var outAddress2 = ctx[CpuRegister.R9];
+
+        if (pathAddress == 0 || flagsAddress == 0 || outAddress1 == 0 || outAddress2 == 0)
+        {
+            return DiscMapErrorInvalidArgument;
+        }
+
+        if (!ctx.TryWriteUInt64(flagsAddress, 0) ||
+            !ctx.TryWriteUInt64(outAddress1, 0) ||
+            !ctx.TryWriteUInt64(outAddress2, 0))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+        }
+
+        TraceDiscMap(ctx, exportName, pathAddress, offset, size);
+
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    private static void TraceDiscMap(CpuContext ctx, string exportName, ulong pathAddress, ulong offset, ulong size)
+    {
+        if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_DISCMAP"), "1", StringComparison.Ordinal))
+        {
+            return;
+        }
+
+        var path = ctx.TryReadNullTerminatedUtf8(pathAddress, 1024, out var value)
+            ? value
+            : $"<unreadable 0x{pathAddress:X16}>";
+        Console.Error.WriteLine($"[HLE][DISCMAP] {exportName} path={path} offset=0x{offset:X} size=0x{size:X}");
+    }
+}

src/SharpEmu.Libs/Fiber/FiberExports.cs

@@ -48,15 +48,10 @@ public static class FiberExports
     [ThreadStatic]
     private static ulong _currentFiberAddress;
 
-    [ThreadStatic]
+    private static readonly object _fiberGate = new();
-    private static bool _fiberReturnRequested;
-
-    [ThreadStatic]
-    private static ulong _fiberReturnArgument;
-
     private static readonly ConcurrentDictionary<ulong, FiberContinuation> _continuations = new();
+    private static readonly ConcurrentDictionary<ulong, FiberReturnTarget> _returnTargets = new();
     private static readonly ConcurrentDictionary<ulong, FiberStackRange> _stackRanges = new();
-    private static readonly ConcurrentDictionary<ulong, FiberRunSession> _runSessions = new();
 
     [SysAbiExport(
         Nid = "hVYD7Ou2pCQ",
@@ -109,17 +104,17 @@ public static class FiberExports
         var optParam = ctx[CpuRegister.Rdi];
         if (optParam == 0)
         {
-            return SetReturn(ctx, FiberErrorNull);
+            return ctx.SetReturn(FiberErrorNull);
         }
 
         if ((optParam & 7) != 0)
         {
-            return SetReturn(ctx, FiberErrorAlignment);
+            return ctx.SetReturn(FiberErrorAlignment);
         }
 
-        return TryWriteUInt32(ctx, optParam, FiberOptSignature)
+        return ctx.TryWriteUInt32(optParam, FiberOptSignature)
-            ? SetReturn(ctx, 0)
+            ? ctx.SetReturn(0)
-            : SetReturn(ctx, FiberErrorInvalid);
+            : ctx.SetReturn(FiberErrorInvalid);
     }
 
     [SysAbiExport(
@@ -132,23 +127,24 @@ public static class FiberExports
         var fiber = ctx[CpuRegister.Rdi];
         if (!TryValidateFiber(ctx, fiber, out var error))
         {
-            return SetReturn(ctx, error);
+            return ctx.SetReturn(error);
         }
 
-        if (!TryReadUInt32(ctx, fiber + FiberStateOffset, out var state))
+        if (!ctx.TryReadUInt32(fiber + FiberStateOffset, out var state))
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
         if (state != FiberStateIdle)
         {
-            return SetReturn(ctx, FiberErrorState);
+            return ctx.SetReturn(FiberErrorState);
         }
 
         _continuations.TryRemove(fiber, out _);
+        _returnTargets.TryRemove(fiber, out _);
         _stackRanges.TryRemove(fiber, out _);
-        _ = TryWriteUInt32(ctx, fiber + FiberStateOffset, FiberStateTerminated);
+        _ = ctx.TryWriteUInt32(fiber + FiberStateOffset, FiberStateTerminated);
-        return SetReturn(ctx, 0);
+        return ctx.SetReturn(0);
     }
 
     [SysAbiExport(
@@ -231,44 +227,76 @@ public static class FiberExports
     public static int FiberReturnToThread(CpuContext ctx)
     {
         var fiberAddress = ResolveCurrentFiberAddress(ctx);
-        var inferredFiber = false;
-        if (_currentFiberAddress == 0 && fiberAddress != 0)
-        {
-            inferredFiber = true;
-        }
-
         if (fiberAddress == 0)
         {
-            return SetReturn(ctx, FiberErrorPermission);
+            return ctx.SetReturn(FiberErrorPermission);
         }
 
+        if (GuestThreadExecution.Scheduler is not { SupportsGuestContextTransfer: true } ||
+            !GuestThreadExecution.TryGetCurrentImportCallFrame(out var frame))
+        {
+            return ctx.SetReturn(FiberErrorPermission);
+        }
+
+        var returnArgument = ctx[CpuRegister.Rdi];
         var argOnRunAddress = ctx[CpuRegister.Rsi];
-        if (argOnRunAddress != 0 && !TryWriteUInt64(ctx, argOnRunAddress, 0))
+        if (argOnRunAddress != 0 && !ctx.TryWriteUInt64(argOnRunAddress, 0))
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
-        _fiberReturnRequested = true;
+        GuestCpuContinuation transferTarget;
-        _fiberReturnArgument = ctx[CpuRegister.Rdi];
+        ulong previousFiber;
-        if (_runSessions.TryGetValue(fiberAddress, out var session))
+        lock (_fiberGate)
-        {
-            session.SetReturn(ctx[CpuRegister.Rdi]);
-        }
-
-        if (GuestThreadExecution.TryGetCurrentImportCallFrame(out var frame))
         {
             _continuations[fiberAddress] = new FiberContinuation(
                 CaptureContinuation(ctx, frame.ReturnRip, frame.ResumeRsp, frame.ReturnSlotAddress),
                 argOnRunAddress);
-            TraceFiber($"yield{(inferredFiber ? "-inferred" : string.Empty)} fiber=0x{fiberAddress:X16} resume=0x{frame.ReturnRip:X16} rsp=0x{frame.ResumeRsp:X16} return_slot=0x{frame.ReturnSlotAddress:X16} arg_out=0x{argOnRunAddress:X16}");
+
-        }
+            if (!_returnTargets.TryRemove(fiberAddress, out var returnTarget))
-        else
+            {
-        {
+                _continuations.TryRemove(fiberAddress, out _);
-            TraceFiber($"yield-no-frame{(inferredFiber ? "-inferred" : string.Empty)} fiber=0x{fiberAddress:X16} arg_out=0x{argOnRunAddress:X16}");
+                return ctx.SetReturn(FiberErrorPermission);
+            }
+
+            previousFiber = returnTarget.PreviousFiber;
+            if (previousFiber != 0)
+            {
+                if (!_continuations.TryRemove(previousFiber, out var previousContinuation) ||
+                    !TryWriteResumeArgument(ctx, previousContinuation, returnArgument) ||
+                    !ctx.TryWriteUInt32(previousFiber + FiberStateOffset, FiberStateRun))
+                {
+                    _continuations.TryRemove(fiberAddress, out _);
+                    return ctx.SetReturn(FiberErrorState);
+                }
+
+                transferTarget = previousContinuation.Context with { Rax = 0 };
+            }
+            else
+            {
+                if (!returnTarget.ThreadContinuation.HasValue ||
+                    !TryWriteResumeArgument(ctx, returnTarget.ThreadContinuation.Value, returnArgument))
+                {
+                    _continuations.TryRemove(fiberAddress, out _);
+                    return ctx.SetReturn(FiberErrorState);
+                }
+
+                transferTarget = returnTarget.ThreadContinuation.Value.Context with { Rax = 0 };
+            }
+
+            if (!ctx.TryWriteUInt32(fiberAddress + FiberStateOffset, FiberStateIdle))
+            {
+                return ctx.SetReturn(FiberErrorInvalid);
+            }
         }
 
-        GuestThreadExecution.RequestCurrentEntryExit("sceFiberReturnToThread", 0);
+        _currentFiberAddress = previousFiber;
-        return SetReturn(ctx, 0);
+        _ = GuestThreadExecution.EnterFiber(previousFiber);
+        GuestThreadExecution.RequestCurrentContextTransfer(transferTarget);
+        TraceFiber(
+            $"return fiber=0x{fiberAddress:X16} to=0x{previousFiber:X16} " +
+            $"resume=0x{transferTarget.Rip:X16} rsp=0x{transferTarget.Rsp:X16} arg=0x{returnArgument:X16}");
+        return ctx.SetReturn(0);
     }
 
     [SysAbiExport(
@@ -281,18 +309,18 @@ public static class FiberExports
         var outAddress = ctx[CpuRegister.Rdi];
         if (outAddress == 0)
         {
-            return SetReturn(ctx, FiberErrorNull);
+            return ctx.SetReturn(FiberErrorNull);
         }
 
         var fiberAddress = ResolveCurrentFiberAddress(ctx);
         if (fiberAddress == 0)
         {
-            return SetReturn(ctx, FiberErrorPermission);
+            return ctx.SetReturn(FiberErrorPermission);
         }
 
-        return TryWriteUInt64(ctx, outAddress, fiberAddress)
+        return ctx.TryWriteUInt64(outAddress, fiberAddress)
-            ? SetReturn(ctx, 0)
+            ? ctx.SetReturn(0)
-            : SetReturn(ctx, FiberErrorInvalid);
+            : ctx.SetReturn(FiberErrorInvalid);
     }
 
     [SysAbiExport(
@@ -306,35 +334,35 @@ public static class FiberExports
         var info = ctx[CpuRegister.Rsi];
         if (info == 0)
         {
-            return SetReturn(ctx, FiberErrorNull);
+            return ctx.SetReturn(FiberErrorNull);
         }
 
         if (!TryValidateFiber(ctx, fiber, out var error))
         {
-            return SetReturn(ctx, error);
+            return ctx.SetReturn(error);
         }
 
-        if (!TryReadUInt64(ctx, info, out var size) || size != FiberInfoSize)
+        if (!ctx.TryReadUInt64(info, out var size) || size != FiberInfoSize)
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
         if (!TryReadFiberFields(ctx, fiber, out var fields))
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
-        if (!TryWriteUInt64(ctx, info + 8, fields.Entry) ||
+        if (!ctx.TryWriteUInt64(info + 8, fields.Entry) ||
-            !TryWriteUInt64(ctx, info + 16, fields.ArgOnInitialize) ||
+            !ctx.TryWriteUInt64(info + 16, fields.ArgOnInitialize) ||
-            !TryWriteUInt64(ctx, info + 24, fields.ContextAddress) ||
+            !ctx.TryWriteUInt64(info + 24, fields.ContextAddress) ||
-            !TryWriteUInt64(ctx, info + 32, fields.ContextSize) ||
+            !ctx.TryWriteUInt64(info + 32, fields.ContextSize) ||
             !TryWriteName(ctx, info + 40, fields.Name) ||
-            !TryWriteUInt64(ctx, info + 72, ulong.MaxValue))
+            !ctx.TryWriteUInt64(info + 72, ulong.MaxValue))
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
-        return SetReturn(ctx, 0);
+        return ctx.SetReturn(0);
     }
 
     [SysAbiExport(
@@ -348,22 +376,22 @@ public static class FiberExports
         var nameAddress = ctx[CpuRegister.Rsi];
         if (!TryValidateFiber(ctx, fiber, out var error))
         {
-            return SetReturn(ctx, error);
+            return ctx.SetReturn(error);
         }
 
         if (nameAddress == 0)
         {
-            return SetReturn(ctx, FiberErrorNull);
+            return ctx.SetReturn(FiberErrorNull);
         }
 
-        if (!TryReadNullTerminatedUtf8(ctx, nameAddress, MaxNameLength + 1, out var name))
+        if (!ctx.TryReadNullTerminatedUtf8(nameAddress, MaxNameLength + 1, out var name))
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
         return TryWriteName(ctx, fiber + FiberNameOffset, name)
-            ? SetReturn(ctx, 0)
+            ? ctx.SetReturn(0)
-            : SetReturn(ctx, FiberErrorInvalid);
+            : ctx.SetReturn(FiberErrorInvalid);
     }
 
     [SysAbiExport(
@@ -375,12 +403,12 @@ public static class FiberExports
     {
         if (ctx[CpuRegister.Rdi] != 0)
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
         return Interlocked.Exchange(ref _contextSizeCheck, 1) == 0
-            ? SetReturn(ctx, 0)
+            ? ctx.SetReturn(0)
-            : SetReturn(ctx, FiberErrorState);
+            : ctx.SetReturn(FiberErrorState);
     }
 
     [SysAbiExport(
@@ -391,8 +419,8 @@ public static class FiberExports
     public static int FiberStopContextSizeCheck(CpuContext ctx)
     {
         return Interlocked.Exchange(ref _contextSizeCheck, 0) == 1
-            ? SetReturn(ctx, 0)
+            ? ctx.SetReturn(0)
-            : SetReturn(ctx, FiberErrorState);
+            : ctx.SetReturn(FiberErrorState);
     }
 
     [SysAbiExport(
@@ -405,17 +433,17 @@ public static class FiberExports
         var outAddress = ctx[CpuRegister.Rdi];
         if (outAddress == 0)
         {
-            return SetReturn(ctx, FiberErrorNull);
+            return ctx.SetReturn(FiberErrorNull);
         }
 
         if (ResolveCurrentFiberAddress(ctx) == 0)
         {
-            return SetReturn(ctx, FiberErrorPermission);
+            return ctx.SetReturn(FiberErrorPermission);
         }
 
-        return TryWriteUInt64(ctx, outAddress, ctx[CpuRegister.Rbp])
+        return ctx.TryWriteUInt64(outAddress, ctx[CpuRegister.Rbp])
-            ? SetReturn(ctx, 0)
+            ? ctx.SetReturn(0)
-            : SetReturn(ctx, FiberErrorInvalid);
+            : ctx.SetReturn(FiberErrorInvalid);
     }
 
     private static int FiberInitializeCore(
@@ -431,37 +459,37 @@ public static class FiberExports
     {
         if (fiber == 0 || nameAddress == 0 || entry == 0)
         {
-            return SetReturn(ctx, FiberErrorNull);
+            return ctx.SetReturn(FiberErrorNull);
         }
 
         if ((fiber & 7) != 0 ||
             (contextAddress & 15) != 0 ||
             (optParam & 7) != 0)
         {
-            return SetReturn(ctx, FiberErrorAlignment);
+            return ctx.SetReturn(FiberErrorAlignment);
         }
 
         if (contextSize != 0 && contextSize < FiberContextMinimumSize)
         {
-            return SetReturn(ctx, FiberErrorRange);
+            return ctx.SetReturn(FiberErrorRange);
         }
 
         if ((contextSize & 15) != 0 ||
             (contextAddress == 0 && contextSize != 0) ||
             (contextAddress != 0 && contextSize == 0))
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
         if (optParam != 0 &&
-            (!TryReadUInt32(ctx, optParam, out var optMagic) || optMagic != FiberOptSignature))
+            (!ctx.TryReadUInt32(optParam, out var optMagic) || optMagic != FiberOptSignature))
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
-        if (!TryReadNullTerminatedUtf8(ctx, nameAddress, MaxNameLength + 1, out var name))
+        if (!ctx.TryReadNullTerminatedUtf8(nameAddress, MaxNameLength + 1, out var name))
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
         if (Volatile.Read(ref _contextSizeCheck) != 0)
@@ -469,27 +497,27 @@ public static class FiberExports
             flags |= FiberFlagContextSizeCheck;
         }
 
-        if (!TryWriteUInt32(ctx, fiber + FiberMagicStartOffset, FiberSignature0) ||
+        if (!ctx.TryWriteUInt32(fiber + FiberMagicStartOffset, FiberSignature0) ||
-            !TryWriteUInt32(ctx, fiber + FiberStateOffset, FiberStateIdle) ||
+            !ctx.TryWriteUInt32(fiber + FiberStateOffset, FiberStateIdle) ||
-            !TryWriteUInt64(ctx, fiber + FiberEntryOffset, entry) ||
+            !ctx.TryWriteUInt64(fiber + FiberEntryOffset, entry) ||
-            !TryWriteUInt64(ctx, fiber + FiberArgOnInitializeOffset, argOnInitialize) ||
+            !ctx.TryWriteUInt64(fiber + FiberArgOnInitializeOffset, argOnInitialize) ||
-            !TryWriteUInt64(ctx, fiber + FiberContextAddressOffset, contextAddress) ||
+            !ctx.TryWriteUInt64(fiber + FiberContextAddressOffset, contextAddress) ||
-            !TryWriteUInt64(ctx, fiber + FiberContextSizeOffset, contextSize) ||
+            !ctx.TryWriteUInt64(fiber + FiberContextSizeOffset, contextSize) ||
             !TryWriteName(ctx, fiber + FiberNameOffset, name) ||
-            !TryWriteUInt64(ctx, fiber + FiberContextPointerOffset, 0) ||
+            !ctx.TryWriteUInt64(fiber + FiberContextPointerOffset, 0) ||
-            !TryWriteUInt32(ctx, fiber + FiberFlagsOffset, flags) ||
+            !ctx.TryWriteUInt32(fiber + FiberFlagsOffset, flags) ||
-            !TryWriteUInt64(ctx, fiber + FiberContextStartOffset, contextAddress) ||
+            !ctx.TryWriteUInt64(fiber + FiberContextStartOffset, contextAddress) ||
-            !TryWriteUInt64(ctx, fiber + FiberContextEndOffset, contextAddress == 0 ? 0 : contextAddress + contextSize) ||
+            !ctx.TryWriteUInt64(fiber + FiberContextEndOffset, contextAddress == 0 ? 0 : contextAddress + contextSize) ||
-            !TryWriteUInt32(ctx, fiber + FiberMagicEndOffset, FiberSignature1))
+            !ctx.TryWriteUInt32(fiber + FiberMagicEndOffset, FiberSignature1))
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
         if (contextAddress != 0)
         {
-            if (!TryWriteUInt64(ctx, contextAddress, FiberStackSignature))
+            if (!ctx.TryWriteUInt64(contextAddress, FiberStackSignature))
             {
-                return SetReturn(ctx, FiberErrorInvalid);
+                return ctx.SetReturn(FiberErrorInvalid);
             }
 
             if ((flags & FiberFlagContextSizeCheck) != 0)
@@ -504,7 +532,7 @@ public static class FiberExports
         }
 
         TraceFiber($"init fiber=0x{fiber:X16} entry=0x{entry:X16} ctx=0x{contextAddress:X16} size=0x{contextSize:X} name='{name}'");
-        return SetReturn(ctx, 0);
+        return ctx.SetReturn(0);
     }
 
     private static int FiberRunCore(
@@ -519,12 +547,12 @@ public static class FiberExports
     {
         if (!TryValidateFiber(ctx, fiber, out var error))
         {
-            return SetReturn(ctx, error);
+            return ctx.SetReturn(error);
         }
 
         if (!TryReadFiberFields(ctx, fiber, out var fields))
         {
-            return SetReturn(ctx, FiberErrorInvalid);
+            return ctx.SetReturn(FiberErrorInvalid);
         }
 
         if (attachContextAddress != 0 || attachContextSize != 0)
@@ -532,174 +560,156 @@ public static class FiberExports
             var attachResult = AttachContext(ctx, fiber, attachContextAddress, attachContextSize, ref fields);
             if (attachResult != 0)
             {
-                return SetReturn(ctx, attachResult);
+                return ctx.SetReturn(attachResult);
             }
         }
 
-        if (fields.State != FiberStateIdle)
-        {
-            TraceFiber($"run-state-error reason={reason} fiber=0x{fiber:X16} state=0x{fields.State:X8}");
-            return SetReturn(ctx, FiberErrorState);
-        }
-
         var previousFiber = ResolveCurrentFiberAddress(ctx);
-        var switchingFromFiber = isSwitch && previousFiber != 0 && previousFiber != fiber;
+        if ((isSwitch && previousFiber == 0) ||
-        if (isSwitch && previousFiber == 0)
+            (!isSwitch && previousFiber != 0))
         {
-            return SetReturn(ctx, FiberErrorPermission);
+            return ctx.SetReturn(FiberErrorPermission);
+        }
+        if (previousFiber == fiber)
+        {
+            return ctx.SetReturn(FiberErrorState);
+        }
+        if (GuestThreadExecution.Scheduler is not { SupportsGuestContextTransfer: true } ||
+            !GuestThreadExecution.TryGetCurrentImportCallFrame(out var frame))
+        {
+            return ctx.SetReturn(FiberErrorPermission);
         }
 
-        var scheduler = GuestThreadExecution.Scheduler;
+        GuestCpuContinuation transferTarget;
-        if (scheduler is null)
+        var resumed = false;
+        lock (_fiberGate)
         {
-            return SetReturn(ctx, FiberErrorPermission);
+            if (!TryReadFiberFields(ctx, fiber, out fields))
-        }
-
-        var session = new FiberRunSession();
-        var ownsSession = _runSessions.TryAdd(fiber, session);
-        if (!ownsSession && !_runSessions.TryGetValue(fiber, out session))
-        {
-            return SetReturn(ctx, FiberErrorState);
-        }
-
-        FiberContinuation? previousContinuation = null;
-        GuestImportCallFrame switchFrame = default;
-        if (switchingFromFiber)
-        {
-            if (!GuestThreadExecution.TryGetCurrentImportCallFrame(out switchFrame))
             {
-                if (ownsSession)
+                return ctx.SetReturn(FiberErrorInvalid);
-                {
+            }
-                    _runSessions.TryRemove(fiber, out _);
+            if (fields.State != FiberStateIdle)
-                }
+            {
-                TraceFiber($"switch-no-frame from=0x{previousFiber:X16} to=0x{fiber:X16} arg_out=0x{outArgumentAddress:X16}");
+                TraceFiber($"run-state-error reason={reason} fiber=0x{fiber:X16} state=0x{fields.State:X8}");
-                return SetReturn(ctx, FiberErrorPermission);
+                return ctx.SetReturn(FiberErrorState);
             }
 
-            previousContinuation = new FiberContinuation(
+            FiberContinuation targetContinuation;
-                CaptureContinuation(ctx, switchFrame.ReturnRip, switchFrame.ResumeRsp, switchFrame.ReturnSlotAddress),
+            if (_continuations.TryGetValue(fiber, out var savedContinuation))
+            {
+                targetContinuation = savedContinuation;
+                resumed = true;
+            }
+            else if (!TryCreateInitialContinuation(ctx, fields, argOnRun, out targetContinuation))
+            {
+                return ctx.SetReturn(FiberErrorInvalid);
+            }
+
+            if (resumed && !TryWriteResumeArgument(ctx, targetContinuation, argOnRun))
+            {
+                return ctx.SetReturn(FiberErrorInvalid);
+            }
+
+            var callerContinuation = new FiberContinuation(
+                CaptureContinuation(ctx, frame.ReturnRip, frame.ResumeRsp, frame.ReturnSlotAddress),
                 outArgumentAddress);
-        }
 
-        if (!TryWriteUInt32(ctx, fiber + FiberStateOffset, FiberStateRun))
+            if (previousFiber != 0)
-        {
-            if (ownsSession)
             {
-                _runSessions.TryRemove(fiber, out _);
+                if (!ctx.TryReadUInt32(previousFiber + FiberStateOffset, out var previousState) ||
-            }
+                    previousState != FiberStateRun ||
-            return SetReturn(ctx, FiberErrorInvalid);
+                    !ctx.TryWriteUInt32(previousFiber + FiberStateOffset, FiberStateIdle))
-        }
-
-        if (switchingFromFiber && !TryWriteUInt32(ctx, previousFiber + FiberStateOffset, FiberStateIdle))
-        {
-            _ = TryWriteUInt32(ctx, fiber + FiberStateOffset, FiberStateIdle);
-            if (ownsSession)
-            {
-                _runSessions.TryRemove(fiber, out _);
-            }
-            return SetReturn(ctx, FiberErrorInvalid);
-        }
-
-        if (previousContinuation.HasValue)
-        {
-            _continuations[previousFiber] = previousContinuation.Value;
-            TraceFiber($"switch-save from=0x{previousFiber:X16} to=0x{fiber:X16} resume=0x{switchFrame.ReturnRip:X16} rsp=0x{switchFrame.ResumeRsp:X16} return_slot=0x{switchFrame.ReturnSlotAddress:X16} arg_out=0x{outArgumentAddress:X16}");
-        }
-
-        var previousReturnRequested = _fiberReturnRequested;
-        var previousReturnArgument = _fiberReturnArgument;
-        _currentFiberAddress = fiber;
-        _fiberReturnRequested = false;
-        _fiberReturnArgument = 0;
-        var previousExecutionFiber = GuestThreadExecution.EnterFiber(fiber);
-        TraceFiber($"run-enter reason={reason} fiber=0x{fiber:X16} prev=0x{previousFiber:X16} thread=0x{GuestThreadExecution.CurrentGuestThreadHandle:X16} managed={Environment.CurrentManagedThreadId} stack=0x{fields.ContextAddress:X16}");
-
-        var hasContinuation = _continuations.TryGetValue(fiber, out var continuation);
-        if (hasContinuation)
-        {
-            _continuations.TryRemove(fiber, out _);
-        }
-
-        TraceFiber(hasContinuation
-            ? $"run-dispatch reason={reason} fiber=0x{fiber:X16} resume=1 rip=0x{continuation.Context.Rip:X16} rsp=0x{continuation.Context.Rsp:X16} return_slot=0x{continuation.Context.ReturnSlotAddress:X16} arg_out=0x{continuation.ArgOnRunAddress:X16}"
-            : $"run-dispatch reason={reason} fiber=0x{fiber:X16} resume=0 rip=0x{fields.Entry:X16} rsp=0x{fields.ContextAddress + fields.ContextSize:X16} arg_out=0x{outArgumentAddress:X16}");
-        bool callbackOk;
-        string? callbackError;
-        try
-        {
-            if (hasContinuation)
-            {
-                if (continuation.ArgOnRunAddress != 0 &&
-                    !TryWriteUInt64(ctx, continuation.ArgOnRunAddress, argOnRun))
                 {
-                    callbackOk = false;
+                    return ctx.SetReturn(FiberErrorState);
-                    callbackError = $"failed to write resumed argOnRun to 0x{continuation.ArgOnRunAddress:X16}";
-                }
-                else
-                {
-                    callbackOk = scheduler.TryCallGuestContinuation(
-                        ctx,
-                        continuation.Context,
-                        reason,
-                        out callbackError);
                 }
+
+                _continuations[previousFiber] = callerContinuation;
+                _returnTargets[fiber] = new FiberReturnTarget(previousFiber, null);
             }
             else
             {
-                callbackOk = scheduler.TryCallGuestFunction(
+                _returnTargets[fiber] = new FiberReturnTarget(0, callerContinuation);
-                    ctx,
-                    fields.Entry,
-                    fields.ArgOnInitialize,
-                    argOnRun,
-                    fields.ContextAddress,
-                    fields.ContextSize,
-                    reason,
-                    out callbackError);
             }
-        }
+
-        finally
+            if (!ctx.TryWriteUInt32(fiber + FiberStateOffset, FiberStateRun))
-        {
+            {
-            GuestThreadExecution.RestoreFiber(previousExecutionFiber);
+                if (previousFiber != 0)
+                {
+                    _continuations.TryRemove(previousFiber, out _);
+                    _ = ctx.TryWriteUInt32(previousFiber + FiberStateOffset, FiberStateRun);
+                }
+                _returnTargets.TryRemove(fiber, out _);
+                return ctx.SetReturn(FiberErrorInvalid);
+            }
+
+            if (resumed)
+            {
+                _continuations.TryRemove(fiber, out _);
+            }
+
+            transferTarget = targetContinuation.Context with { Rax = 0 };
         }
 
-        var returnRequested = _fiberReturnRequested;
+        _currentFiberAddress = fiber;
-        var returnArgument = _fiberReturnArgument;
+        _ = GuestThreadExecution.EnterFiber(fiber);
-        if (!returnRequested && session.TryGetReturn(out var sessionReturnArgument))
+        GuestThreadExecution.RequestCurrentContextTransfer(transferTarget);
-        {
+        TraceFiber(
-            returnRequested = true;
+            $"transfer reason={reason} from=0x{previousFiber:X16} to=0x{fiber:X16} resume={resumed} " +
-            returnArgument = sessionReturnArgument;
+            $"rip=0x{transferTarget.Rip:X16} rsp=0x{transferTarget.Rsp:X16} arg=0x{argOnRun:X16}");
-        }
+        return ctx.SetReturn(0);
-
-        if (ownsSession)
-        {
-            _runSessions.TryRemove(fiber, out _);
-        }
-
-        _currentFiberAddress = previousFiber;
-        _fiberReturnRequested = previousReturnRequested;
-        _fiberReturnArgument = previousReturnArgument;
-
-        _ = TryWriteUInt32(ctx, fiber + FiberStateOffset, FiberStateIdle);
-        if (switchingFromFiber)
-        {
-            _ = TryWriteUInt32(ctx, previousFiber + FiberStateOffset, FiberStateRun);
-        }
-
-        if (!callbackOk)
-        {
-            TraceFiber($"run-failed fiber=0x{fiber:X16} entry=0x{fields.Entry:X16} error={callbackError}");
-            return SetReturn(ctx, (int)OrbisGen2Result.ORBIS_GEN2_ERROR_CPU_TRAP);
-        }
-
-        if (outArgumentAddress != 0 && !TryWriteUInt64(ctx, outArgumentAddress, returnArgument))
-        {
-            return SetReturn(ctx, FiberErrorInvalid);
-        }
-
-        TraceFiber($"run fiber=0x{fiber:X16} entry=0x{fields.Entry:X16} resume={hasContinuation} arg=0x{argOnRun:X16} ret=0x{returnArgument:X16}");
-        return SetReturn(ctx, 0);
     }
 
+    private static bool TryCreateInitialContinuation(
+        CpuContext ctx,
+        FiberFields fields,
+        ulong argOnRun,
+        out FiberContinuation continuation)
+    {
+        continuation = default;
+        if (fields.ContextAddress == 0 || fields.ContextSize < FiberContextMinimumSize)
+        {
+            return false;
+        }
+
+        var stackEnd = fields.ContextAddress + fields.ContextSize;
+        var entryRsp = (stackEnd & ~15UL) - sizeof(ulong);
+        if (!ctx.TryWriteUInt64(entryRsp, 0))
+        {
+            return false;
+        }
+
+        continuation = new FiberContinuation(
+            new GuestCpuContinuation(
+                fields.Entry,
+                entryRsp,
+                entryRsp,
+                ctx.Rflags == 0 ? 0x202UL : ctx.Rflags,
+                ctx.FsBase,
+                ctx.GsBase,
+                0,
+                0,
+                0,
+                0,
+                0,
+                argOnRun,
+                fields.ArgOnInitialize,
+                0,
+                0,
+                0,
+                0,
+                0,
+                0),
+            0);
+        return true;
+    }
+
+    private static bool TryWriteResumeArgument(
+        CpuContext ctx,
+        FiberContinuation continuation,
+        ulong argument) =>
+        continuation.ArgOnRunAddress == 0 ||
+        ctx.TryWriteUInt64(continuation.ArgOnRunAddress, argument);
+
     private static GuestCpuContinuation CaptureContinuation(
         CpuContext ctx,
         ulong resumeRip,
@@ -769,11 +779,11 @@ public static class FiberExports
             return FiberErrorInvalid;
         }
 
-        if (!TryWriteUInt64(ctx, fiber + FiberContextAddressOffset, contextAddress) ||
+        if (!ctx.TryWriteUInt64(fiber + FiberContextAddressOffset, contextAddress) ||
-            !TryWriteUInt64(ctx, fiber + FiberContextSizeOffset, contextSize) ||
+            !ctx.TryWriteUInt64(fiber + FiberContextSizeOffset, contextSize) ||
-            !TryWriteUInt64(ctx, fiber + FiberContextStartOffset, contextAddress) ||
+            !ctx.TryWriteUInt64(fiber + FiberContextStartOffset, contextAddress) ||
-            !TryWriteUInt64(ctx, fiber + FiberContextEndOffset, contextAddress + contextSize) ||
+            !ctx.TryWriteUInt64(fiber + FiberContextEndOffset, contextAddress + contextSize) ||
-            !TryWriteUInt64(ctx, contextAddress, FiberStackSignature))
+            !ctx.TryWriteUInt64(contextAddress, FiberStackSignature))
         {
             return FiberErrorInvalid;
         }
@@ -829,8 +839,8 @@ public static class FiberExports
             return false;
         }
 
-        if (!TryReadUInt32(ctx, fiber + FiberMagicStartOffset, out var magicStart) ||
+        if (!ctx.TryReadUInt32(fiber + FiberMagicStartOffset, out var magicStart) ||
-            !TryReadUInt32(ctx, fiber + FiberMagicEndOffset, out var magicEnd) ||
+            !ctx.TryReadUInt32(fiber + FiberMagicEndOffset, out var magicEnd) ||
             magicStart != FiberSignature0 ||
             magicEnd != FiberSignature1)
         {
@@ -845,12 +855,12 @@ public static class FiberExports
     private static bool TryReadFiberFields(CpuContext ctx, ulong fiber, out FiberFields fields)
     {
         fields = default;
-        if (!TryReadUInt32(ctx, fiber + FiberStateOffset, out var state) ||
+        if (!ctx.TryReadUInt32(fiber + FiberStateOffset, out var state) ||
-            !TryReadUInt64(ctx, fiber + FiberEntryOffset, out var entry) ||
+            !ctx.TryReadUInt64(fiber + FiberEntryOffset, out var entry) ||
-            !TryReadUInt64(ctx, fiber + FiberArgOnInitializeOffset, out var argOnInitialize) ||
+            !ctx.TryReadUInt64(fiber + FiberArgOnInitializeOffset, out var argOnInitialize) ||
-            !TryReadUInt64(ctx, fiber + FiberContextAddressOffset, out var contextAddress) ||
+            !ctx.TryReadUInt64(fiber + FiberContextAddressOffset, out var contextAddress) ||
-            !TryReadUInt64(ctx, fiber + FiberContextSizeOffset, out var contextSize) ||
+            !ctx.TryReadUInt64(fiber + FiberContextSizeOffset, out var contextSize) ||
-            !TryReadUInt32(ctx, fiber + FiberFlagsOffset, out var flags) ||
+            !ctx.TryReadUInt32(fiber + FiberFlagsOffset, out var flags) ||
             !TryReadInlineName(ctx, fiber + FiberNameOffset, out var name))
         {
             return false;
@@ -888,46 +898,6 @@ public static class FiberExports
         return 0;
     }
 
-    private static bool TryReadUInt32(CpuContext ctx, ulong address, out uint value)
-    {
-        Span<byte> buffer = stackalloc byte[sizeof(uint)];
-        if (!ctx.Memory.TryRead(address, buffer))
-        {
-            value = 0;
-            return false;
-        }
-
-        value = BinaryPrimitives.ReadUInt32LittleEndian(buffer);
-        return true;
-    }
-
-    private static bool TryWriteUInt32(CpuContext ctx, ulong address, uint value)
-    {
-        Span<byte> buffer = stackalloc byte[sizeof(uint)];
-        BinaryPrimitives.WriteUInt32LittleEndian(buffer, value);
-        return ctx.Memory.TryWrite(address, buffer);
-    }
-
-    private static bool TryReadUInt64(CpuContext ctx, ulong address, out ulong value)
-    {
-        Span<byte> buffer = stackalloc byte[sizeof(ulong)];
-        if (!ctx.Memory.TryRead(address, buffer))
-        {
-            value = 0;
-            return false;
-        }
-
-        value = BinaryPrimitives.ReadUInt64LittleEndian(buffer);
-        return true;
-    }
-
-    private static bool TryWriteUInt64(CpuContext ctx, ulong address, ulong value)
-    {
-        Span<byte> buffer = stackalloc byte[sizeof(ulong)];
-        BinaryPrimitives.WriteUInt64LittleEndian(buffer, value);
-        return ctx.Memory.TryWrite(address, buffer);
-    }
-
     private static bool TryWriteName(CpuContext ctx, ulong address, string name)
     {
         Span<byte> buffer = stackalloc byte[MaxNameLength + 1];
@@ -955,37 +925,6 @@ public static class FiberExports
         return true;
     }
 
-    private static bool TryReadNullTerminatedUtf8(CpuContext ctx, ulong address, int capacity, out string value)
-    {
-        var bytes = new byte[capacity];
-        for (var index = 0; index < bytes.Length; index++)
-        {
-            Span<byte> current = stackalloc byte[1];
-            if (!ctx.Memory.TryRead(address + (ulong)index, current))
-            {
-                value = string.Empty;
-                return false;
-            }
-
-            if (current[0] == 0)
-            {
-                value = Encoding.UTF8.GetString(bytes, 0, index);
-                return true;
-            }
-
-            bytes[index] = current[0];
-        }
-
-        value = Encoding.UTF8.GetString(bytes);
-        return true;
-    }
-
-    private static int SetReturn(CpuContext ctx, int result)
-    {
-        ctx[CpuRegister.Rax] = unchecked((ulong)result);
-        return result;
-    }
-
     private static void TraceFiber(string message)
     {
         if (string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_FIBER"), "1", StringComparison.Ordinal))
@@ -1007,30 +946,9 @@ public static class FiberExports
         GuestCpuContinuation Context,
         ulong ArgOnRunAddress);
 
-    private sealed class FiberRunSession
+    private readonly record struct FiberReturnTarget(
-    {
+        ulong PreviousFiber,
-        private int _returnRequested;
+        FiberContinuation? ThreadContinuation);
-
-        private ulong _returnArgument;
-
-        public void SetReturn(ulong argument)
-        {
-            _returnArgument = argument;
-            Volatile.Write(ref _returnRequested, 1);
-        }
-
-        public bool TryGetReturn(out ulong argument)
-        {
-            if (Volatile.Read(ref _returnRequested) == 0)
-            {
-                argument = 0;
-                return false;
-            }
-
-            argument = _returnArgument;
-            return true;
-        }
-    }
 
     private readonly record struct FiberStackRange(ulong Start, ulong Size)
     {

src/SharpEmu.Libs/Ime/ImeExports.cs

@@ -0,0 +1,46 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.HLE;
+
+namespace SharpEmu.Libs.Ime;
+
+public static class ImeExports
+{
+    // Quake (KEX) calls this from its main loop and from the audio bring-up path with
+    // an event-handler pointer. No IME session ever exists here, so report success
+    // without invoking the handler ("no pending IME events"). This NID was previously
+    // misbound as an sceNgs2VoiceControl alias, which fed the game NGS2 errors.
+    [SysAbiExport(
+        Nid = "-4GCfYdNF1s",
+        ExportName = "sceImeUpdate",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceIme")]
+    public static int ImeUpdate(CpuContext ctx)
+    {
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "eaFXjfJv3xs",
+        ExportName = "sceImeKeyboardOpen",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceIme")]
+    public static int ImeKeyboardOpen(CpuContext ctx)
+    {
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "dKadqZFgKKQ",
+        ExportName = "sceImeKeyboardGetResourceId",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceIme")]
+    public static int ImeKeyboardGetResourceId(CpuContext ctx)
+    {
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+}

src/SharpEmu.Libs/Kernel/KernelAprCompatExports.cs

@@ -3,7 +3,6 @@
 
 using SharpEmu.HLE;
 using SharpEmu.Libs.Ampr;
-using System.Buffers.Binary;
 using System.Collections.Concurrent;
 using System.Threading;
 
@@ -11,8 +10,13 @@ namespace SharpEmu.Libs.Kernel;
 
 public static class KernelAprCompatExports
 {
-    private static readonly ConcurrentDictionary<uint, ulong> _submittedCommandBuffers = new();
+    private static readonly ConcurrentDictionary<uint, AprSubmission> _submittedCommandBuffers = new();
     private static int _nextSubmissionId;
+    private static int _aprWaitTraceCount;
+    private static readonly bool _traceApr =
+        string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_AMPR"), "1", StringComparison.Ordinal);
+
+    private readonly record struct AprSubmission(ulong CommandBuffer, ulong Priority, ulong ResultAddress);
 
     [SysAbiExport(
         Nid = "ASoW5WE-UPo",
@@ -37,7 +41,7 @@ public static class KernelAprCompatExports
             submissionId = unchecked((uint)Interlocked.Increment(ref _nextSubmissionId));
         }
 
-        _submittedCommandBuffers[submissionId] = commandBuffer;
+        _submittedCommandBuffers[submissionId] = new AprSubmission(commandBuffer, priority, resultAddress);
 
         var completionResult = AmprExports.CompleteCommandBuffer(ctx, commandBuffer);
         if (completionResult != (int)OrbisGen2Result.ORBIS_GEN2_OK)
@@ -45,7 +49,7 @@ public static class KernelAprCompatExports
             return completionResult;
         }
 
-        if (outSubmissionId != 0 && !TryWriteUInt32(ctx, outSubmissionId, submissionId))
+        if (outSubmissionId != 0 && !ctx.TryWriteUInt32(outSubmissionId, submissionId))
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
         }
@@ -67,20 +71,23 @@ public static class KernelAprCompatExports
     public static int KernelAprWaitCommandBuffer(CpuContext ctx)
     {
         var submissionId = unchecked((uint)ctx[CpuRegister.Rdi]);
-        var priority = ctx[CpuRegister.Rsi];
+        var waitArg1 = ctx[CpuRegister.Rsi];
-        var resultAddress = ctx[CpuRegister.Rdx];
+        var waitArg2 = ctx[CpuRegister.Rdx];
 
-        if (!_submittedCommandBuffers.TryRemove(submissionId, out var commandBuffer))
+        if (!_submittedCommandBuffers.TryRemove(submissionId, out var submission))
         {
+            TraceAprWaitFailure(ctx, "wait_missing", submissionId, commandBuffer: 0, waitArg1, waitArg2);
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
         }
 
+        var resultAddress = ResolveWaitResultAddress(waitArg1, waitArg2, submission.ResultAddress);
         if (resultAddress != 0 && !TryWriteAprResult(ctx, resultAddress))
         {
+            TraceAprWaitFailure(ctx, "wait_result_fault", submissionId, submission.CommandBuffer, waitArg1, waitArg2);
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
         }
 
-        TraceApr(ctx, "wait", submissionId, commandBuffer, priority, resultAddress);
+        TraceApr(ctx, "wait", submissionId, submission.CommandBuffer, waitArg1, resultAddress);
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
@@ -98,7 +105,7 @@ public static class KernelAprCompatExports
         }
 
         var submissionId = unchecked((uint)Interlocked.Increment(ref _nextSubmissionId));
-        _submittedCommandBuffers[submissionId] = commandBuffer;
+        _submittedCommandBuffers[submissionId] = new AprSubmission(commandBuffer, ctx[CpuRegister.Rsi], ResultAddress: 0);
 
         var completionResult = AmprExports.CompleteCommandBuffer(ctx, commandBuffer);
         if (completionResult != (int)OrbisGen2Result.ORBIS_GEN2_OK)
@@ -125,7 +132,7 @@ public static class KernelAprCompatExports
         }
 
         var submissionId = unchecked((uint)Interlocked.Increment(ref _nextSubmissionId));
-        _submittedCommandBuffers[submissionId] = commandBuffer;
+        _submittedCommandBuffers[submissionId] = new AprSubmission(commandBuffer, ctx[CpuRegister.Rsi], ResultAddress: 0);
 
         var completionResult = AmprExports.CompleteCommandBuffer(ctx, commandBuffer);
         if (completionResult != (int)OrbisGen2Result.ORBIS_GEN2_OK)
@@ -133,7 +140,7 @@ public static class KernelAprCompatExports
             return completionResult;
         }
 
-        if (!TryWriteUInt32(ctx, outSubmissionId, submissionId))
+        if (!ctx.TryWriteUInt32(outSubmissionId, submissionId))
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
         }
@@ -142,6 +149,19 @@ public static class KernelAprCompatExports
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
+    // Success stub: the argument layout is unknown and callers tolerate the
+    // empty answer (Quake streams fine), so no output payload is written until
+    // the real signature is reversed.
+    [SysAbiExport(
+        Nid = "WvEu7yl3Ivg",
+        ExportName = "sceKernelAprGetFileSize",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelAprGetFileSize(CpuContext ctx)
+    {
+        return ctx.SetReturn(0);
+    }
+
     private static bool TryWriteAprResult(CpuContext ctx, ulong resultAddress)
     {
         Span<byte> result = stackalloc byte[sizeof(ulong)];
@@ -149,11 +169,25 @@ public static class KernelAprCompatExports
         return ctx.Memory.TryWrite(resultAddress, result);
     }
 
-    private static bool TryWriteUInt32(CpuContext ctx, ulong address, uint value)
+    private static ulong ResolveWaitResultAddress(ulong waitArg1, ulong waitArg2, ulong submittedResultAddress)
     {
-        Span<byte> buffer = stackalloc byte[sizeof(uint)];
+        if (waitArg2 == 0)
-        BinaryPrimitives.WriteUInt32LittleEndian(buffer, value);
+        {
-        return ctx.Memory.TryWrite(address, buffer);
+            return submittedResultAddress;
+        }
+
+        if (IsAmprCompletionToken(waitArg1) && waitArg2 <= 0xFFFF)
+        {
+            return submittedResultAddress;
+        }
+
+        return waitArg2;
+    }
+
+    private static bool IsAmprCompletionToken(ulong value)
+    {
+        var tag = value >> 56;
+        return tag is 0x0C or 0x10;
     }
 
     private static void TraceApr(
@@ -164,7 +198,7 @@ public static class KernelAprCompatExports
         ulong priority,
         ulong aux)
     {
-        if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_AMPR"), "1", StringComparison.Ordinal))
+        if (!_traceApr)
         {
             return;
         }
@@ -181,4 +215,46 @@ public static class KernelAprCompatExports
                 $"[LOADER][TRACE] apr.{operation}.result: addr=0x{aux:X16} q0=0x{result0:X16} q1=0x{result1:X16}");
         }
     }
+
+    private static void TraceAprWaitFailure(
+        CpuContext ctx,
+        string operation,
+        uint submissionId,
+        ulong commandBuffer,
+        ulong priority,
+        ulong resultAddress)
+    {
+        if (!_traceApr)
+        {
+            return;
+        }
+
+        var traceCount = Interlocked.Increment(ref _aprWaitTraceCount);
+        if (traceCount > 32 && (traceCount & 0x3FF) != 0)
+        {
+            return;
+        }
+
+        var returnRip = 0UL;
+        _ = ctx.TryReadUInt64(ctx[CpuRegister.Rsp], out returnRip);
+        Console.Error.WriteLine(
+            $"[LOADER][TRACE] apr.{operation}: id=0x{submissionId:X8} cmd=0x{commandBuffer:X16} " +
+            $"rsi=0x{priority:X16} rdx=0x{resultAddress:X16} rcx=0x{ctx[CpuRegister.Rcx]:X16} " +
+            $"r8=0x{ctx[CpuRegister.R8]:X16} r9=0x{ctx[CpuRegister.R9]:X16} ret=0x{returnRip:X16}");
+        TraceReadableQword(ctx, operation, "rsi", priority);
+        TraceReadableQword(ctx, operation, "rdx", resultAddress);
+        TraceReadableQword(ctx, operation, "rcx", ctx[CpuRegister.Rcx]);
+        TraceReadableQword(ctx, operation, "r8", ctx[CpuRegister.R8]);
+    }
+
+    private static void TraceReadableQword(CpuContext ctx, string operation, string name, ulong address)
+    {
+        if (address == 0 || !ctx.TryReadUInt64(address, out var value))
+        {
+            return;
+        }
+
+        Console.Error.WriteLine(
+            $"[LOADER][TRACE] apr.{operation}.{name}: addr=0x{address:X16} q0=0x{value:X16}");
+    }
 }

src/SharpEmu.Libs/Kernel/KernelEventFlagCompatExports.cs

@@ -1,7 +1,6 @@
 // Copyright (C) 2026 SharpEmu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-using System.Buffers.Binary;
 using System.Collections.Concurrent;
 using System.Text;
 using SharpEmu.HLE;
@@ -52,17 +51,17 @@ public static class KernelEventFlagCompatExports
             optionAddress != 0 ||
             !IsValidAttributes(attributes))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
         }
 
-        if (!TryReadNullTerminatedUtf8(ctx, nameAddress, MaxEventFlagNameLength + 1, out var name))
+        if (!ctx.TryReadNullTerminatedUtf8(nameAddress, MaxEventFlagNameLength + 1, out var name))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
         }
 
         if (Encoding.UTF8.GetByteCount(name) > MaxEventFlagNameLength)
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
         }
 
         var handle = unchecked((ulong)Interlocked.Increment(ref _nextEventFlagHandle));
@@ -76,11 +75,11 @@ public static class KernelEventFlagCompatExports
         if (!ctx.TryWriteUInt64(outAddress, handle))
         {
             _eventFlags.TryRemove(handle, out _);
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
         }
 
         TraceEventFlag($"create handle=0x{handle:X16} name='{name}' attr=0x{attributes:X2} bits=0x{initialPattern:X16}");
-        return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+        return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_OK);
     }
 
     [SysAbiExport(
@@ -93,7 +92,7 @@ public static class KernelEventFlagCompatExports
         var handle = ctx[CpuRegister.Rdi];
         if (!_eventFlags.TryRemove(handle, out var state))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
         }
 
         lock (state.Gate)
@@ -102,7 +101,7 @@ public static class KernelEventFlagCompatExports
         }
 
         TraceEventFlag($"delete handle=0x{handle:X16} name='{state.Name}'");
-        return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+        return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_OK);
     }
 
     [SysAbiExport(
@@ -117,7 +116,7 @@ public static class KernelEventFlagCompatExports
         var returnRip = GetCurrentReturnRip();
         if (!_eventFlags.TryGetValue(handle, out var state))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
         }
 
         lock (state.Gate)
@@ -127,7 +126,8 @@ public static class KernelEventFlagCompatExports
             TraceEventFlag($"set handle=0x{handle:X16} pattern=0x{pattern:X16} bits=0x{state.Bits:X16} ret=0x{returnRip:X16}");
         }
 
-        return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+        _ = GuestThreadExecution.Scheduler?.WakeBlockedThreads(GetEventFlagWakeKey(handle));
+        return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_OK);
     }
 
     [SysAbiExport(
@@ -141,7 +141,7 @@ public static class KernelEventFlagCompatExports
         var pattern = ctx[CpuRegister.Rsi];
         if (!_eventFlags.TryGetValue(handle, out var state))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
         }
 
         lock (state.Gate)
@@ -150,7 +150,7 @@ public static class KernelEventFlagCompatExports
             TraceEventFlag($"clear handle=0x{handle:X16} mask=0x{pattern:X16} bits=0x{state.Bits:X16}");
         }
 
-        return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+        return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_OK);
     }
 
     [SysAbiExport(
@@ -167,29 +167,29 @@ public static class KernelEventFlagCompatExports
 
         if (!_eventFlags.TryGetValue(handle, out var state))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
         }
 
         if (pattern == 0 || !IsValidWaitMode(waitMode))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
         }
 
         lock (state.Gate)
         {
             if (!TryWriteResultPattern(ctx, resultAddress, state.Bits))
             {
-                return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+                return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
             }
 
             if (!IsSatisfied(state.Bits, pattern, waitMode))
             {
-                return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_BUSY);
+                return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_BUSY);
             }
 
             ApplyClearMode(state, pattern, waitMode);
             TraceEventFlag($"poll handle=0x{handle:X16} pattern=0x{pattern:X16} mode=0x{waitMode:X2} bits=0x{state.Bits:X16}");
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_OK);
         }
     }
 
@@ -209,40 +209,61 @@ public static class KernelEventFlagCompatExports
 
         if (!_eventFlags.TryGetValue(handle, out var state))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
         }
 
         if (pattern == 0 || !IsValidWaitMode(waitMode))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
         }
 
         uint timeoutUsec = 0;
-        if (timeoutAddress != 0 && !TryReadUInt32(ctx, timeoutAddress, out timeoutUsec))
+        if (timeoutAddress != 0 && !ctx.TryReadUInt32(timeoutAddress, out timeoutUsec))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
         }
 
         Monitor.Enter(state.Gate);
         try
         {
-            if (TryCompleteSatisfiedWait(ctx, state, pattern, waitMode, out var immediateWaitResult))
+            if (TryCompleteSatisfiedWait(ctx, state, pattern, waitMode, resultAddress, out var immediateWaitResult))
             {
-                return SetReturn(ctx, immediateWaitResult);
+                return ctx.SetReturn(immediateWaitResult);
             }
 
             if (timeoutAddress != 0)
             {
-                _ = TryWriteUInt32(ctx, timeoutAddress, 0);
+                _ = ctx.TryWriteUInt32(timeoutAddress, 0);
                 _ = TryWriteResultPattern(ctx, resultAddress, state.Bits);
                 TraceEventFlag($"wait-timeout handle=0x{handle:X16} pattern=0x{pattern:X16} timeout={timeoutUsec} ret=0x{returnRip:X16}");
-                return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_TIMED_OUT);
+                return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_TIMED_OUT);
             }
 
             var currentGuestThread = GuestThreadExecution.CurrentGuestThreadHandle;
             var currentFiber = FiberExports.GetCurrentFiberAddressForDiagnostics(ctx);
             var managedThread = Environment.CurrentManagedThreadId;
-            var requestedBlock = GuestThreadExecution.RequestCurrentThreadBlock("sceKernelWaitEventFlag");
+            var blockedWaitResult = OrbisGen2Result.ORBIS_GEN2_OK;
+            var requestedBlock = GuestThreadExecution.RequestCurrentThreadBlock(
+                ctx,
+                "sceKernelWaitEventFlag",
+                GetEventFlagWakeKey(handle),
+                () => (int)blockedWaitResult,
+                () =>
+                {
+                    if (!TryPrepareBlockedWait(
+                            ctx,
+                            state,
+                            pattern,
+                            waitMode,
+                            resultAddress,
+                            out var preparedResult))
+                    {
+                        return false;
+                    }
+
+                    blockedWaitResult = preparedResult;
+                    return true;
+                });
             TraceEventFlag($"wait-unsatisfied handle=0x{handle:X16} pattern=0x{pattern:X16} bits=0x{state.Bits:X16} guest_thread=0x{currentGuestThread:X16} fiber=0x{currentFiber:X16} managed={managedThread} block={requestedBlock} ret=0x{returnRip:X16} frames={FormatFrameChain(ctx)}");
             TraceEventFlag($"wait-object handle=0x{handle:X16} name='{state.Name}' {FormatGuestWaitObject(ctx)}");
             if (!requestedBlock)
@@ -250,7 +271,7 @@ public static class KernelEventFlagCompatExports
                 var scheduler = GuestThreadExecution.Scheduler;
                 if (scheduler is null)
                 {
-                    return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_TRY_AGAIN);
+                    return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_TRY_AGAIN);
                 }
 
                 state.WaitingThreads++;
@@ -270,12 +291,12 @@ public static class KernelEventFlagCompatExports
                             Monitor.Enter(state.Gate);
                         }
 
-                        if (TryCompleteSatisfiedWait(ctx, state, pattern, waitMode, out var pumpedWaitResult))
+                        if (TryCompleteSatisfiedWait(ctx, state, pattern, waitMode, resultAddress, out var pumpedWaitResult))
                         {
                             state.WaitingThreads = Math.Max(0, state.WaitingThreads - 1);
                             releaseWaiter = false;
                             TraceEventFlag($"wait-wake handle=0x{handle:X16} pattern=0x{pattern:X16} bits=0x{state.Bits:X16} waiters={state.WaitingThreads} ret=0x{returnRip:X16}");
-                            return SetReturn(ctx, pumpedWaitResult);
+                            return ctx.SetReturn(pumpedWaitResult);
                         }
 
                         Monitor.Wait(state.Gate, HostWaitPumpMilliseconds);
@@ -292,7 +313,7 @@ public static class KernelEventFlagCompatExports
 
             state.WaitingThreads++;
             TraceEventFlag($"wait-block handle=0x{handle:X16} pattern=0x{pattern:X16} waiters={state.WaitingThreads} guest_thread=0x{currentGuestThread:X16} fiber=0x{currentFiber:X16} managed={managedThread} ret=0x{returnRip:X16}");
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_OK);
         }
         finally
         {
@@ -312,15 +333,15 @@ public static class KernelEventFlagCompatExports
         var waiterCountAddress = ctx[CpuRegister.Rdx];
         if (!_eventFlags.TryGetValue(handle, out var state))
         {
-            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+            return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
         }
 
         lock (state.Gate)
         {
             if (waiterCountAddress != 0 &&
-                !TryWriteUInt32(ctx, waiterCountAddress, unchecked((uint)state.WaitingThreads)))
+                !ctx.TryWriteUInt32(waiterCountAddress, unchecked((uint)state.WaitingThreads)))
             {
-                return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+                return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
             }
 
             state.Bits = setPattern;
@@ -329,7 +350,7 @@ public static class KernelEventFlagCompatExports
             TraceEventFlag($"cancel handle=0x{handle:X16} bits=0x{setPattern:X16}");
         }
 
-        return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+        return ctx.SetReturn(OrbisGen2Result.ORBIS_GEN2_OK);
     }
 
     private static bool IsValidAttributes(uint attributes)
@@ -369,19 +390,21 @@ public static class KernelEventFlagCompatExports
     }
 
     private static bool TryCompleteSatisfiedWait(
-        CpuContext ctx,
+    CpuContext ctx,
-        EventFlagState state,
+    EventFlagState state,
-        ulong pattern,
+    ulong pattern,
-        uint waitMode,
+    uint waitMode,
-        out OrbisGen2Result result)
+    ulong resultAddress,
+    out OrbisGen2Result result)
     {
         result = OrbisGen2Result.ORBIS_GEN2_OK;
+
         if (!IsSatisfied(state.Bits, pattern, waitMode))
         {
             return false;
         }
 
-        if (!TryWriteResultPattern(ctx, ctx[CpuRegister.Rcx], state.Bits))
+        if (!TryWriteResultPattern(ctx, resultAddress, state.Bits))
         {
             result = OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
             return true;
@@ -391,86 +414,43 @@ public static class KernelEventFlagCompatExports
         return true;
     }
 
-    private static bool TryWriteResultPattern(CpuContext ctx, ulong address, ulong bits) =>
+    private static bool TryPrepareBlockedWait(
-        address == 0 || ctx.TryWriteUInt64(address, bits);
+        CpuContext ctx,
-
+        EventFlagState state,
-    private static bool TryReadUInt32(CpuContext ctx, ulong address, out uint value)
+        ulong pattern,
+        uint waitMode,
+        ulong resultAddress,
+        out OrbisGen2Result result)
     {
-        Span<byte> buffer = stackalloc byte[sizeof(uint)];
+        lock (state.Gate)
-        if (!ctx.Memory.TryRead(address, buffer))
         {
-            value = 0;
+            result = OrbisGen2Result.ORBIS_GEN2_OK;
-            return false;
+            if (!IsSatisfied(state.Bits, pattern, waitMode))
-        }
-
-        value = BinaryPrimitives.ReadUInt32LittleEndian(buffer);
-        return true;
-    }
-
-    private static bool TryReadUInt64(CpuContext ctx, ulong address, out ulong value)
-    {
-        Span<byte> buffer = stackalloc byte[sizeof(ulong)];
-        if (!ctx.Memory.TryRead(address, buffer))
-        {
-            value = 0;
-            return false;
-        }
-
-        value = BinaryPrimitives.ReadUInt64LittleEndian(buffer);
-        return true;
-    }
-
-    private static bool TryReadByte(CpuContext ctx, ulong address, out byte value)
-    {
-        Span<byte> buffer = stackalloc byte[1];
-        if (!ctx.Memory.TryRead(address, buffer))
-        {
-            value = 0;
-            return false;
-        }
-
-        value = buffer[0];
-        return true;
-    }
-
-    private static bool TryWriteUInt32(CpuContext ctx, ulong address, uint value)
-    {
-        Span<byte> buffer = stackalloc byte[sizeof(uint)];
-        BinaryPrimitives.WriteUInt32LittleEndian(buffer, value);
-        return ctx.Memory.TryWrite(address, buffer);
-    }
-
-    private static bool TryReadNullTerminatedUtf8(CpuContext ctx, ulong address, int capacity, out string value)
-    {
-        var bytes = new byte[capacity];
-        for (var index = 0; index < bytes.Length; index++)
-        {
-            Span<byte> current = stackalloc byte[1];
-            if (!ctx.Memory.TryRead(address + (ulong)index, current))
             {
-                value = string.Empty;
                 return false;
             }
 
-            if (current[0] == 0)
+            if (!TryWriteResultPattern(ctx, resultAddress, state.Bits))
             {
-                value = Encoding.UTF8.GetString(bytes, 0, index);
+                result = OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
-                return true;
+            }
+            else
+            {
+                ApplyClearMode(state, pattern, waitMode);
             }
 
-            bytes[index] = current[0];
+            state.WaitingThreads = Math.Max(0, state.WaitingThreads - 1);
+            TraceEventFlag(
+                $"wait-wake pattern=0x{pattern:X16} mode=0x{waitMode:X2} bits=0x{state.Bits:X16} waiters={state.WaitingThreads}");
+            return true;
         }
-
-        value = Encoding.UTF8.GetString(bytes);
-        return true;
     }
 
-    private static int SetReturn(CpuContext ctx, OrbisGen2Result result)
+    private static string GetEventFlagWakeKey(ulong handle) =>
-    {
+        $"event_flag:0x{handle:X16}";
-        var value = (int)result;
+
-        ctx[CpuRegister.Rax] = unchecked((ulong)value);
+    private static bool TryWriteResultPattern(CpuContext ctx, ulong address, ulong bits) =>
-        return value;
+        address == 0 || ctx.TryWriteUInt64(address, bits);
-    }
 
     private static void TraceEventFlag(string message)
     {
@@ -555,7 +535,7 @@ public static class KernelEventFlagCompatExports
 
     private static void AppendByte(StringBuilder builder, CpuContext ctx, ulong address, string name)
     {
-        if (TryReadByte(ctx, address, out var value))
+        if (ctx.TryReadByte(address, out var value))
         {
             builder.Append($" {name}=0x{value:X2}");
         }
@@ -563,7 +543,7 @@ public static class KernelEventFlagCompatExports
 
     private static void AppendUInt32(StringBuilder builder, CpuContext ctx, ulong address, string name)
     {
-        if (TryReadUInt32(ctx, address, out var value))
+        if (ctx.TryReadUInt32(address, out var value))
         {
             builder.Append($" {name}=0x{value:X8}");
         }
@@ -571,7 +551,7 @@ public static class KernelEventFlagCompatExports
 
     private static void AppendUInt64(StringBuilder builder, CpuContext ctx, ulong address, string name)
     {
-        if (TryReadUInt64(ctx, address, out var value))
+        if (ctx.TryReadUInt64(address, out var value))
         {
             builder.Append($" {name}=0x{value:X16}");
         }

src/SharpEmu.Libs/Kernel/KernelEventQueueCompatExports.cs

@@ -10,10 +10,14 @@ namespace SharpEmu.Libs.Kernel;
 public static class KernelEventQueueCompatExports
 {
     private const int KernelEventSize = 0x20;
+    public const short KernelEventFilterGraphics = -14;
+    public const short KernelEventFilterAmpr = -16;
+    public const short KernelEventFilterAmprSystem = -17;
 
     private static readonly object _eventQueueGate = new();
     private static readonly HashSet<ulong> _eventQueues = new();
     private static readonly Dictionary<ulong, LinkedList<KernelQueuedEvent>> _pendingEvents = new();
+    private static readonly Dictionary<ulong, Dictionary<(ulong Ident, short Filter), KernelEventRegistration>> _registeredEvents = new();
     private static long _nextEventQueueHandle = 1;
 
     public readonly record struct KernelQueuedEvent(
@@ -24,6 +28,11 @@ public static class KernelEventQueueCompatExports
         ulong Data,
         ulong UserData);
 
+    private readonly record struct KernelEventRegistration(
+        ulong Ident,
+        short Filter,
+        ulong UserData);
+
     [SysAbiExport(
         Nid = "D0OdFMjp46I",
         ExportName = "sceKernelCreateEqueue",
@@ -42,6 +51,7 @@ public static class KernelEventQueueCompatExports
         {
             _eventQueues.Add(handle);
             _pendingEvents[handle] = new LinkedList<KernelQueuedEvent>();
+            _registeredEvents[handle] = new Dictionary<(ulong Ident, short Filter), KernelEventRegistration>();
         }
 
         if (!ctx.TryWriteUInt64(outAddress, handle))
@@ -65,6 +75,7 @@ public static class KernelEventQueueCompatExports
         {
             _eventQueues.Remove(handle);
             _pendingEvents.Remove(handle);
+            _registeredEvents.Remove(handle);
         }
 
         TraceEventQueue(ctx, "delete", handle);
@@ -122,8 +133,16 @@ public static class KernelEventQueueCompatExports
         LibraryName = "libKernel")]
     public static int KernelAddAmprEvent(CpuContext ctx)
     {
-        TraceEventQueue(ctx, "add_ampr", ctx[CpuRegister.Rdi]);
+        var handle = ctx[CpuRegister.Rdi];
-        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        var registered = RegisterEvent(
+            handle,
+            unchecked((uint)ctx[CpuRegister.Rsi]),
+            KernelEventFilterAmpr,
+            ctx[CpuRegister.Rdx]);
+        TraceEventQueue(ctx, "add_ampr", handle);
+        return registered
+            ? (int)OrbisGen2Result.ORBIS_GEN2_OK
+            : (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
     }
 
     [SysAbiExport(
@@ -133,8 +152,16 @@ public static class KernelEventQueueCompatExports
         LibraryName = "libKernel")]
     public static int KernelAddAmprSystemEvent(CpuContext ctx)
     {
-        TraceEventQueue(ctx, "add_ampr_system", ctx[CpuRegister.Rdi]);
+        var handle = ctx[CpuRegister.Rdi];
-        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        var registered = RegisterEvent(
+            handle,
+            unchecked((uint)ctx[CpuRegister.Rsi]),
+            KernelEventFilterAmprSystem,
+            ctx[CpuRegister.Rdx]);
+        TraceEventQueue(ctx, "add_ampr_system", handle);
+        return registered
+            ? (int)OrbisGen2Result.ORBIS_GEN2_OK
+            : (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
     }
 
     [SysAbiExport(
@@ -144,8 +171,15 @@ public static class KernelEventQueueCompatExports
         LibraryName = "libKernel")]
     public static int KernelDeleteAmprEvent(CpuContext ctx)
     {
-        TraceEventQueue(ctx, "delete_ampr", ctx[CpuRegister.Rdi]);
+        var handle = ctx[CpuRegister.Rdi];
-        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        var deleted = DeleteRegisteredEvent(
+            handle,
+            unchecked((uint)ctx[CpuRegister.Rsi]),
+            KernelEventFilterAmpr);
+        TraceEventQueue(ctx, "delete_ampr", handle);
+        return deleted
+            ? (int)OrbisGen2Result.ORBIS_GEN2_OK
+            : (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
     }
 
     [SysAbiExport(
@@ -155,8 +189,15 @@ public static class KernelEventQueueCompatExports
         LibraryName = "libKernel")]
     public static int KernelDeleteAmprSystemEvent(CpuContext ctx)
     {
-        TraceEventQueue(ctx, "delete_ampr_system", ctx[CpuRegister.Rdi]);
+        var handle = ctx[CpuRegister.Rdi];
-        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        var deleted = DeleteRegisteredEvent(
+            handle,
+            unchecked((uint)ctx[CpuRegister.Rsi]),
+            KernelEventFilterAmprSystem);
+        TraceEventQueue(ctx, "delete_ampr_system", handle);
+        return deleted
+            ? (int)OrbisGen2Result.ORBIS_GEN2_OK
+            : (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
     }
 
     [SysAbiExport(
@@ -171,6 +212,57 @@ public static class KernelEventQueueCompatExports
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
+    [SysAbiExport(
+        Nid = "vz+pg2zdopI",
+        ExportName = "sceKernelGetEventUserData",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelGetEventUserData(CpuContext ctx)
+    {
+        _ = ctx.TryReadUInt64(ctx[CpuRegister.Rdi] + 0x18, out var userData);
+        ctx[CpuRegister.Rax] = userData;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "mJ7aghmgvfc",
+        ExportName = "sceKernelGetEventId",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelGetEventId(CpuContext ctx)
+    {
+        _ = ctx.TryReadUInt64(ctx[CpuRegister.Rdi], out var ident);
+        ctx[CpuRegister.Rax] = ident;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "23CPPI1tyBY",
+        ExportName = "sceKernelGetEventFilter",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelGetEventFilter(CpuContext ctx)
+    {
+        Span<byte> filterBytes = stackalloc byte[sizeof(short)];
+        var filter = ctx.Memory.TryRead(ctx[CpuRegister.Rdi] + 0x08, filterBytes)
+            ? BinaryPrimitives.ReadInt16LittleEndian(filterBytes)
+            : (short)0;
+        ctx[CpuRegister.Rax] = unchecked((uint)filter);
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "kwGyyjohI50",
+        ExportName = "sceKernelGetEventData",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelGetEventData(CpuContext ctx)
+    {
+        _ = ctx.TryReadUInt64(ctx[CpuRegister.Rdi] + 0x10, out var data);
+        ctx[CpuRegister.Rax] = data;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
     [SysAbiExport(
         Nid = "fzyMKs9kim0",
         ExportName = "sceKernelWaitEqueue",
@@ -184,8 +276,24 @@ public static class KernelEventQueueCompatExports
         var outCountAddress = ctx[CpuRegister.Rcx];
         var timeoutAddress = ctx[CpuRegister.R8];
 
+        if (!IsValidEqueue(handle))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+        }
+
+        if (eventsAddress == 0 || eventCapacity < 1)
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+        }
+
+        uint timeoutUsec = 0;
+        if (timeoutAddress != 0 && !ctx.TryReadUInt32(timeoutAddress, out timeoutUsec))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+        }
+
         var deliveredCount = DequeueEvents(ctx, handle, eventsAddress, eventCapacity);
-        if (outCountAddress != 0 && !TryWriteUInt32(ctx, outCountAddress, (uint)deliveredCount))
+        if (outCountAddress != 0 && !ctx.TryWriteUInt32(outCountAddress, (uint)deliveredCount))
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
         }
@@ -196,12 +304,53 @@ public static class KernelEventQueueCompatExports
             return (int)OrbisGen2Result.ORBIS_GEN2_OK;
         }
 
-        if (timeoutAddress == 0 && GuestThreadExecution.RequestCurrentThreadBlock("sceKernelWaitEqueue"))
+        if (timeoutAddress == 0 &&
+            GuestThreadExecution.RequestCurrentThreadBlock(
+                ctx,
+                "sceKernelWaitEqueue",
+                GetEventQueueWakeKey(handle),
+                () => ResumeWaitEqueue(ctx, handle, eventsAddress, eventCapacity, outCountAddress),
+                () => HasPendingEvents(handle)))
         {
             TraceEventQueue(ctx, "wait-block", handle);
             return (int)OrbisGen2Result.ORBIS_GEN2_OK;
         }
 
+        if (timeoutAddress != 0 && ctx.TryReadUInt64(timeoutAddress, out var timeoutRaw))
+        {
+            var timeoutMicros = timeoutRaw & 0xFFFF_FFFFUL;
+            var deadline = Environment.TickCount64 +
+                Math.Max(1L, (long)Math.Min(timeoutMicros / 1000, int.MaxValue));
+            lock (_eventQueueGate)
+            {
+                while (!HasPendingEvents(handle))
+                {
+                    var remaining = deadline - Environment.TickCount64;
+                    if (remaining <= 0)
+                    {
+                        break;
+                    }
+
+                    Monitor.Wait(_eventQueueGate, (int)Math.Min(remaining, 100));
+                }
+            }
+
+            deliveredCount = DequeueEvents(ctx, handle, eventsAddress, eventCapacity);
+            if (outCountAddress != 0 && !ctx.TryWriteUInt32(outCountAddress, (uint)deliveredCount))
+            {
+                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+            }
+
+            if (deliveredCount > 0)
+            {
+                TraceEventQueue(ctx, "wait-timed-deliver", handle);
+                return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+            }
+
+            TraceEventQueue(ctx, "wait-timeout", handle);
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_TIMED_OUT;
+        }
+
         TraceEventQueue(ctx, "wait", handle);
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
@@ -216,6 +365,7 @@ public static class KernelEventQueueCompatExports
 
     public static bool EnqueueEvent(ulong handle, KernelQueuedEvent queuedEvent)
     {
+        var queued = false;
         lock (_eventQueueGate)
         {
             if (!_eventQueues.Contains(handle))
@@ -230,10 +380,101 @@ public static class KernelEventQueueCompatExports
             }
 
             queue.AddLast(queuedEvent);
+            queued = true;
+            Monitor.PulseAll(_eventQueueGate);
+        }
+
+        if (queued)
+        {
+            WakeEventQueue(handle);
+        }
+
+        return queued;
+    }
+
+    public static bool RegisterEvent(
+        ulong handle,
+        ulong ident,
+        short filter,
+        ulong userData)
+    {
+        lock (_eventQueueGate)
+        {
+            if (!_eventQueues.Contains(handle))
+            {
+                return false;
+            }
+
+            if (!_registeredEvents.TryGetValue(handle, out var events))
+            {
+                events = new Dictionary<(ulong Ident, short Filter), KernelEventRegistration>();
+                _registeredEvents[handle] = events;
+            }
+
+            events[(ident, filter)] = new KernelEventRegistration(ident, filter, userData);
             return true;
         }
     }
 
+    public static bool DeleteRegisteredEvent(
+        ulong handle,
+        ulong ident,
+        short filter)
+    {
+        lock (_eventQueueGate)
+        {
+            return _registeredEvents.TryGetValue(handle, out var events) &&
+                   events.Remove((ident, filter));
+        }
+    }
+
+    public static int TriggerRegisteredEvents(
+        ulong ident,
+        short filter,
+        ulong data)
+    {
+        List<ulong>? wakeHandles = null;
+        var triggeredCount = 0;
+        lock (_eventQueueGate)
+        {
+            foreach (var (handle, registrations) in _registeredEvents)
+            {
+                if (!registrations.TryGetValue((ident, filter), out var registration))
+                {
+                    continue;
+                }
+
+                if (!_pendingEvents.TryGetValue(handle, out var queue))
+                {
+                    queue = new LinkedList<KernelQueuedEvent>();
+                    _pendingEvents[handle] = queue;
+                }
+
+                QueueOrUpdateEvent(
+                    queue,
+                    new KernelQueuedEvent(
+                        registration.Ident,
+                        registration.Filter,
+                        0,
+                        1,
+                        data,
+                        registration.UserData));
+                (wakeHandles ??= new List<ulong>()).Add(handle);
+                triggeredCount++;
+            }
+        }
+
+        if (wakeHandles is not null)
+        {
+            foreach (var handle in wakeHandles)
+            {
+                WakeEventQueue(handle);
+            }
+        }
+
+        return triggeredCount;
+    }
+
     public static bool TriggerDisplayEvent(
         ulong handle,
         ulong ident,
@@ -241,6 +482,7 @@ public static class KernelEventQueueCompatExports
         ulong eventHint,
         ulong userData)
     {
+        var triggered = false;
         lock (_eventQueueGate)
         {
             if (!_eventQueues.Contains(handle))
@@ -254,17 +496,8 @@ public static class KernelEventQueueCompatExports
                 _pendingEvents[handle] = events;
             }
 
-            LinkedListNode<KernelQueuedEvent>? pendingNode = null;
-            for (var node = events.First; node is not null; node = node.Next)
-            {
-                if (node.Value.Ident == ident && node.Value.Filter == filter)
-                {
-                    pendingNode = node;
-                    break;
-                }
-            }
-
             var count = 1UL;
+            var pendingNode = FindPendingEvent(events, ident, filter);
             if (pendingNode is not null)
             {
                 count = Math.Min(((pendingNode.Value.Data >> 12) & 0xFUL) + 1, 0xFUL);
@@ -289,8 +522,82 @@ public static class KernelEventQueueCompatExports
                 events.AddLast(triggeredEvent);
             }
 
-            return true;
+            triggered = true;
         }
+
+        if (triggered)
+        {
+            WakeEventQueue(handle);
+        }
+
+        return triggered;
+    }
+
+    private static int ResumeWaitEqueue(
+        CpuContext ctx,
+        ulong handle,
+        ulong eventsAddress,
+        int eventCapacity,
+        ulong outCountAddress)
+    {
+        var deliveredCount = DequeueEvents(ctx, handle, eventsAddress, eventCapacity);
+        if (outCountAddress != 0 && !ctx.TryWriteUInt32(outCountAddress, (uint)deliveredCount))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+        }
+
+        return deliveredCount > 0
+            ? (int)OrbisGen2Result.ORBIS_GEN2_OK
+            : (int)OrbisGen2Result.ORBIS_GEN2_ERROR_TIMED_OUT;
+    }
+
+    private static bool HasPendingEvents(ulong handle)
+    {
+        lock (_eventQueueGate)
+        {
+            return _pendingEvents.TryGetValue(handle, out var events) && events.Count != 0;
+        }
+    }
+
+    private static void QueueOrUpdateEvent(
+        LinkedList<KernelQueuedEvent> queue,
+        KernelQueuedEvent queuedEvent)
+    {
+        var pendingNode = FindPendingEvent(queue, queuedEvent.Ident, queuedEvent.Filter);
+        if (pendingNode is null)
+        {
+            queue.AddLast(queuedEvent);
+            return;
+        }
+
+        pendingNode.Value = queuedEvent with
+        {
+            Fflags = Math.Max(pendingNode.Value.Fflags + 1, queuedEvent.Fflags),
+        };
+    }
+
+    private static LinkedListNode<KernelQueuedEvent>? FindPendingEvent(
+        LinkedList<KernelQueuedEvent> queue,
+        ulong ident,
+        short filter)
+    {
+        for (var node = queue.First; node is not null; node = node.Next)
+        {
+            if (node.Value.Ident == ident && node.Value.Filter == filter)
+            {
+                return node;
+            }
+        }
+
+        return null;
+    }
+
+    private static string GetEventQueueWakeKey(ulong handle) =>
+        $"sceKernelWaitEqueue:{handle:X16}";
+
+    private static void WakeEventQueue(ulong handle)
+    {
+        _ = GuestThreadExecution.Scheduler?.WakeBlockedThreads(GetEventQueueWakeKey(handle));
     }
 
     private static int DequeueEvents(CpuContext ctx, ulong handle, ulong eventsAddress, int eventCapacity)
@@ -347,16 +654,8 @@ public static class KernelEventQueueCompatExports
             return;
         }
 
-        var returnRip = 0UL;
+        _ = ctx.TryReadUInt64(ctx[CpuRegister.Rsp], out ulong returnRip);
-        _ = ctx.TryReadUInt64(ctx[CpuRegister.Rsp], out returnRip);
         Console.Error.WriteLine(
             $"[LOADER][TRACE] equeue.{operation}: handle=0x{handle:X16} rsi=0x{ctx[CpuRegister.Rsi]:X16} rdx=0x{ctx[CpuRegister.Rdx]:X16} ret=0x{returnRip:X16}");
     }
-
-    private static bool TryWriteUInt32(CpuContext ctx, ulong address, uint value)
-    {
-        Span<byte> buffer = stackalloc byte[sizeof(uint)];
-        BinaryPrimitives.WriteUInt32LittleEndian(buffer, value);
-        return ctx.Memory.TryWrite(address, buffer);
-    }
 }

src/SharpEmu.Libs/Kernel/KernelExceptionCompatExports.cs

@@ -0,0 +1,65 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.HLE;
+
+namespace SharpEmu.Libs.Kernel;
+
+public static class KernelExceptionCompatExports
+{
+    private static readonly HashSet<int> AllowedSignals = new() { 1, 4, 8, 10, 11, 30 };
+    private static readonly Dictionary<int, ulong> _installedHandlers = new();
+    private static readonly object _gate = new();
+
+    [SysAbiExport(
+        Nid = "WkwEd3N7w0Y",
+        ExportName = "sceKernelInstallExceptionHandler",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int InstallExceptionHandler(CpuContext ctx)
+    {
+        var signum = unchecked((int)ctx[CpuRegister.Rdi]);
+        var handler = ctx[CpuRegister.Rsi];
+
+        if (!AllowedSignals.Contains(signum))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+        }
+
+        lock (_gate)
+        {
+            if (_installedHandlers.ContainsKey(signum))
+            {
+                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_ALREADY_EXISTS;
+            }
+
+            _installedHandlers[signum] = handler;
+        }
+
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "Qhv5ARAoOEc",
+        ExportName = "sceKernelRemoveExceptionHandler",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int RemoveExceptionHandler(CpuContext ctx)
+    {
+        var signum = unchecked((int)ctx[CpuRegister.Rdi]);
+
+        if (!AllowedSignals.Contains(signum))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+        }
+
+        lock (_gate)
+        {
+            _installedHandlers.Remove(signum);
+        }
+
+        ctx[CpuRegister.Rax] = 0;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+}

src/SharpEmu.Libs/Kernel/KernelExports.cs

@@ -8,12 +8,13 @@ namespace SharpEmu.Libs.Kernel;
 
 public static class KernelExports
 {
-    private static int _nextFileDescriptor = 2;
     private static readonly object _cxaGate = new();
     private static readonly List<CxaDestructorEntry> _cxaDestructors = new();
     private static readonly object _coredumpGate = new();
     private static ulong _coredumpHandler;
     private static ulong _coredumpHandlerContext;
+    private const uint Gen4CompiledSdkVersion = 0x05000000;
+    private const uint Gen5CompiledSdkVersion = 0x09000000;
 
     private readonly record struct CxaDestructorEntry(
         ulong Function,
@@ -27,7 +28,24 @@ public static class KernelExports
         LibraryName = "libKernel")]
     public static int KernelGetCompiledSdkVersion(CpuContext ctx)
     {
-        _ = ctx;
+        var versionAddress = ctx[CpuRegister.Rdi];
+        if (versionAddress == 0)
+        {
+            ctx[CpuRegister.Rax] = unchecked((ulong)(int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+        }
+
+        var sdkVersion = ctx.TargetGeneration == Generation.Gen5
+            ? Gen5CompiledSdkVersion
+            : Gen4CompiledSdkVersion;
+
+        if (!ctx.TryWriteUInt32(versionAddress, sdkVersion))
+        {
+            ctx[CpuRegister.Rax] = unchecked((ulong)(int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+        }
+
+        ctx[CpuRegister.Rax] = 0;
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
@@ -53,12 +71,20 @@ public static class KernelExports
         ExportName = "exit",
         Target = Generation.Gen4 | Generation.Gen5,
         LibraryName = "libKernel")]
-    public static int Exit(CpuContext ctx)
+    public static int Exit(CpuContext ctx) => RequestProcessExit(ctx, "exit");
+
+    [SysAbiExport(
+        Nid = "L1SBTkC+Cvw",
+        ExportName = "abort",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libc")]
+    public static int Abort(CpuContext ctx)
     {
-        var status = unchecked((int)ctx[CpuRegister.Rdi]);
+        // Route through the same graceful guest-entry-exit path as exit(): letting the call
-        Console.Error.WriteLine($"[LOADER][INFO] exit(status={status})");
+        // fall through to the host's native abort() does not unwind the guest thread cleanly.
-        GuestThreadExecution.RequestCurrentEntryExit("exit", status);
+        Console.Error.WriteLine("[LOADER][INFO] abort() called by guest - terminating");
-        ctx[CpuRegister.Rax] = unchecked((ulong)status);
+        GuestThreadExecution.RequestCurrentEntryExit("abort", -1);
+        ctx[CpuRegister.Rax] = unchecked((ulong)(-1L));
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
@@ -173,11 +199,7 @@ public static class KernelExports
         ExportName = "_exit",
         Target = Generation.Gen4 | Generation.Gen5,
         LibraryName = "libKernel")]
-    public static int UnderscoreExit(CpuContext ctx)
+    public static int UnderscoreExit(CpuContext ctx) => RequestProcessExit(ctx, "_exit");
-    {
-        _ = ctx;
-        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
-    }
 
     [SysAbiExport(
         Nid = "Ac86z8q7T8A",
@@ -204,6 +226,16 @@ public static class KernelExports
         var nameAddress = ctx[CpuRegister.R8];
         var name = nameAddress == 0 ? string.Empty : ReadCString(ctx, nameAddress, 256);
         var threadHandle = KernelPthreadState.CreateThreadHandle(name);
+        KernelPthreadExtendedCompatExports.GetThreadStartScheduling(
+            ctx,
+            attrAddress,
+            out var priority,
+            out var affinityMask);
+        KernelPthreadExtendedCompatExports.RegisterThreadStart(
+            threadHandle,
+            name,
+            priority,
+            affinityMask);
         if (threadIdAddress != 0 && !ctx.TryWriteUInt64(threadIdAddress, threadHandle))
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
@@ -212,13 +244,22 @@ public static class KernelExports
         if (ShouldTracePthread())
         {
             Console.Error.WriteLine(
-                $"[LOADER][TRACE] pthread_create: out=0x{threadIdAddress:X16} attr=0x{attrAddress:X16} entry=0x{entryAddress:X16} arg=0x{argument:X16} name_ptr=0x{nameAddress:X16} name='{name}' -> thread=0x{threadHandle:X16}");
+                $"[LOADER][TRACE] pthread_create: out=0x{threadIdAddress:X16} attr=0x{attrAddress:X16} " +
+                $"entry=0x{entryAddress:X16} arg=0x{argument:X16} name_ptr=0x{nameAddress:X16} " +
+                $"name='{name}' priority={priority} affinity=0x{affinityMask:X} -> thread=0x{threadHandle:X16}");
         }
 
         var scheduler = GuestThreadExecution.Scheduler;
         if (scheduler is not null && entryAddress != 0)
         {
-            var request = new GuestThreadStartRequest(threadHandle, entryAddress, argument, attrAddress, name);
+            var request = new GuestThreadStartRequest(
+                threadHandle,
+                entryAddress,
+                argument,
+                attrAddress,
+                name,
+                priority,
+                affinityMask);
             if (!scheduler.TryStartThread(ctx, request, out var error))
             {
                 Console.Error.WriteLine(
@@ -237,19 +278,39 @@ public static class KernelExports
         ExportName = "pthread_create",
         Target = Generation.Gen4 | Generation.Gen5,
         LibraryName = "libKernel")]
-    public static int PosixPthreadCreate(CpuContext ctx)
+    public static int PosixPthreadCreate(CpuContext ctx) => PthreadCreate(ctx);
-    {
-        return PthreadCreate(ctx);
-    }
 
     [SysAbiExport(
         Nid = "Jmi+9w9u0E4",
         ExportName = "pthread_create_name_np",
         Target = Generation.Gen4 | Generation.Gen5,
         LibraryName = "libKernel")]
-    public static int PosixPthreadCreateNameNp(CpuContext ctx)
+    public static int PosixPthreadCreateNameNp(CpuContext ctx) => PthreadCreate(ctx);
+
+    [SysAbiExport(
+        Nid = "3kg7rT0NQIs",
+        ExportName = "scePthreadExit",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int PthreadExit(CpuContext ctx)
     {
-        return PthreadCreate(ctx);
+        var value = ctx[CpuRegister.Rdi];
+        GuestThreadExecution.RequestCurrentEntryExit("scePthreadExit", value);
+        ctx[CpuRegister.Rax] = value;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "FJrT5LuUBAU",
+        ExportName = "pthread_exit",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libScePosix")]
+    public static int PosixPthreadExit(CpuContext ctx)
+    {
+        var value = ctx[CpuRegister.Rdi];
+        GuestThreadExecution.RequestCurrentEntryExit("pthread_exit", value);
+        ctx[CpuRegister.Rax] = value;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
     [SysAbiExport(
@@ -261,10 +322,6 @@ public static class KernelExports
     {
         var threadId = ctx[CpuRegister.Rdi];
         var returnValueAddress = ctx[CpuRegister.Rsi];
-        if (returnValueAddress != 0 && !ctx.TryWriteUInt64(returnValueAddress, 0))
-        {
-            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
-        }
 
         if (ShouldTracePthread())
         {
@@ -272,6 +329,30 @@ public static class KernelExports
                 $"[LOADER][TRACE] pthread_join: thread=0x{threadId:X16} retval_out=0x{returnValueAddress:X16}");
         }
 
+        var returnValue = 0UL;
+        if (GuestThreadExecution.Scheduler is { } scheduler &&
+            !scheduler.TryJoinThread(ctx, threadId, out returnValue, out var error))
+        {
+            Console.Error.WriteLine(
+                $"[LOADER][ERROR] pthread_join: thread=0x{threadId:X16}: {error}");
+            var result = string.Equals(
+                error,
+                "thread cannot join itself",
+                StringComparison.Ordinal)
+                ? OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT
+                : OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+            ctx[CpuRegister.Rax] = unchecked((ulong)(int)result);
+            return (int)result;
+        }
+
+        if (returnValueAddress != 0 &&
+            !ctx.TryWriteUInt64(returnValueAddress, returnValue))
+        {
+            ctx[CpuRegister.Rax] =
+                unchecked((ulong)(int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+        }
+
         ctx[CpuRegister.Rax] = 0;
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
@@ -281,10 +362,7 @@ public static class KernelExports
         ExportName = "pthread_join",
         Target = Generation.Gen4 | Generation.Gen5,
         LibraryName = "libKernel")]
-    public static int PosixPthreadJoin(CpuContext ctx)
+    public static int PosixPthreadJoin(CpuContext ctx) => PthreadJoin(ctx);
-    {
-        return PthreadJoin(ctx);
-    }
 
     [SysAbiExport(
         Nid = "wuCroIGjt2g",
@@ -300,6 +378,13 @@ public static class KernelExports
         LibraryName = "libKernel")]
     public static int KernelOpen(CpuContext ctx) => KernelMemoryCompatExports.KernelOpenUnderscore(ctx);
 
+    [SysAbiExport(
+        Nid = "mqQMh1zPPT8",
+        ExportName = "fstat",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libc")]
+    public static int Fstat(CpuContext ctx) => KernelMemoryCompatExports.KernelFstat(ctx);
+
     [SysAbiExport(
         Nid = "hcuQgD53UxM",
         ExportName = "printf",
@@ -366,4 +451,76 @@ public static class KernelExports
     {
         return string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_PTHREADS"), "1", StringComparison.Ordinal);
     }
+
+    private static int RequestProcessExit(CpuContext ctx, string syscallName)
+    {
+        var status = unchecked((int)ctx[CpuRegister.Rdi]);
+        Console.Error.WriteLine($"[LOADER][INFO] {syscallName}(status={status})");
+        GuestThreadExecution.RequestCurrentEntryExit(syscallName, status);
+        ctx[CpuRegister.Rax] = unchecked((ulong)status);
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    // Unidentified kernel NIDs observed at runtime; stubbed to return 0 until they are
+    // resolved against scripts/ps5_names.txt.
+    [SysAbiExport(
+        Nid = "9T2pDF2Ryqg",
+        ExportName = "sceKernelUnknown9T2p",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelUnknown9T2p(CpuContext ctx) => SetZeroReturn(ctx);
+
+    [SysAbiExport(
+        Nid = "TU-d9PfIHPM",
+        ExportName = "sceKernelUnknownTU",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelUnknownTU(CpuContext ctx) => SetZeroReturn(ctx);
+
+    [SysAbiExport(
+        Nid = "iWQWrwiSt8A",
+        ExportName = "sceKernelUnknowniWQW",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelUnknowniWQW(CpuContext ctx) => SetZeroReturn(ctx);
+
+    [SysAbiExport(
+        Nid = "KuOmgKoqCdY",
+        ExportName = "sceKernelUnknownKuOmg",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelUnknownKuOmg(CpuContext ctx) => SetZeroReturn(ctx);
+
+    [SysAbiExport(
+        Nid = "RenI1lL1WFk",
+        ExportName = "sceKernelUnknownRenI",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelUnknownRenI(CpuContext ctx) => SetZeroReturn(ctx);
+
+    [SysAbiExport(
+        Nid = "pQGpHYopAIY",
+        ExportName = "sceKernelUnknownpQGp",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelUnknownpQGp(CpuContext ctx) => SetZeroReturn(ctx);
+
+    [SysAbiExport(
+        Nid = "Rbvt+5Y2iEw",
+        ExportName = "sceKernelUnknownRbvt",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelUnknownRbvt(CpuContext ctx) => SetZeroReturn(ctx);
+
+    // NOTE: "SHtAad20YYM"/"DIxvoy7Ngvk" are sce::Json::Value::getType/getInteger, and
+    // "3GPpjQdAMTw"/"9rAeANT2tyE"/"tsvEmnenz48" are __cxa_guard_acquire/__cxa_guard_release/
+    // __cxa_atexit (verified by hashing against scripts/ps5_names.txt). Do not register them
+    // here as kernel mutex functions: the cxa guards are implemented in CxxAbiExports.cs and
+    // shadowing them breaks every C++ static-init guard in the game.
+
+    private static int SetZeroReturn(CpuContext ctx)
+    {
+        ctx[CpuRegister.Rax] = 0;
+        return 0;
+    }
 }