[kernel/videoOut] extend memory managements and videoOut (this is not a swapchain)

src/SharpEmu.Libs/Kernel/KernelEventQueueCompatExports.cs

@@ -9,10 +9,21 @@ namespace SharpEmu.Libs.Kernel;
 
 public static class KernelEventQueueCompatExports
 {
+    private const int KernelEventSize = 0x20;
+
     private static readonly object _eventQueueGate = new();
     private static readonly HashSet<ulong> _eventQueues = new();
+    private static readonly Dictionary<ulong, Queue<KernelQueuedEvent>> _pendingEvents = new();
     private static long _nextEventQueueHandle = 1;
 
+    public readonly record struct KernelQueuedEvent(
+        ulong Ident,
+        short Filter,
+        ushort Flags,
+        uint Fflags,
+        ulong Data,
+        ulong UserData);
+
     [SysAbiExport(
         Nid = "D0OdFMjp46I",
         ExportName = "sceKernelCreateEqueue",
@@ -30,6 +41,7 @@ public static class KernelEventQueueCompatExports
         lock (_eventQueueGate)
         {
             _eventQueues.Add(handle);
+            _pendingEvents[handle] = new Queue<KernelQueuedEvent>();
         }
 
         if (!ctx.TryWriteUInt64(outAddress, handle))
@@ -52,6 +64,7 @@ public static class KernelEventQueueCompatExports
         lock (_eventQueueGate)
         {
             _eventQueues.Remove(handle);
+            _pendingEvents.Remove(handle);
         }
 
         TraceEventQueue(ctx, "delete", handle);
@@ -165,23 +178,108 @@ public static class KernelEventQueueCompatExports
         LibraryName = "libKernel")]
     public static int KernelWaitEqueue(CpuContext ctx)
     {
+        var handle = ctx[CpuRegister.Rdi];
+        var eventsAddress = ctx[CpuRegister.Rsi];
+        var eventCapacity = (int)Math.Min(ctx[CpuRegister.Rdx], int.MaxValue);
         var outCountAddress = ctx[CpuRegister.Rcx];
         var timeoutAddress = ctx[CpuRegister.R8];
-        if (outCountAddress != 0 && !TryWriteUInt32(ctx, outCountAddress, 0))
+
+        var deliveredCount = DequeueEvents(ctx, handle, eventsAddress, eventCapacity);
+        if (outCountAddress != 0 && !TryWriteUInt32(ctx, outCountAddress, (uint)deliveredCount))
         {
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
         }
 
-        if (timeoutAddress == 0 && GuestThreadExecution.RequestCurrentThreadBlock("sceKernelWaitEqueue"))
+        if (deliveredCount > 0)
         {
-            TraceEventQueue(ctx, "wait-block", ctx[CpuRegister.Rdi]);
+            TraceEventQueue(ctx, "wait-deliver", handle);
             return (int)OrbisGen2Result.ORBIS_GEN2_OK;
         }
 
-        TraceEventQueue(ctx, "wait", ctx[CpuRegister.Rdi]);
+        if (timeoutAddress == 0 && GuestThreadExecution.RequestCurrentThreadBlock("sceKernelWaitEqueue"))
+        {
+            TraceEventQueue(ctx, "wait-block", handle);
+            return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        }
+
+        TraceEventQueue(ctx, "wait", handle);
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
+    public static bool IsValidEqueue(ulong handle)
+    {
+        lock (_eventQueueGate)
+        {
+            return _eventQueues.Contains(handle);
+        }
+    }
+
+    public static bool EnqueueEvent(ulong handle, KernelQueuedEvent queuedEvent)
+    {
+        lock (_eventQueueGate)
+        {
+            if (!_eventQueues.Contains(handle))
+            {
+                return false;
+            }
+
+            if (!_pendingEvents.TryGetValue(handle, out var queue))
+            {
+                queue = new Queue<KernelQueuedEvent>();
+                _pendingEvents[handle] = queue;
+            }
+
+            queue.Enqueue(queuedEvent);
+            return true;
+        }
+    }
+
+    private static int DequeueEvents(CpuContext ctx, ulong handle, ulong eventsAddress, int eventCapacity)
+    {
+        if (eventsAddress == 0 || eventCapacity <= 0)
+        {
+            return 0;
+        }
+
+        KernelQueuedEvent[] events;
+        lock (_eventQueueGate)
+        {
+            if (!_pendingEvents.TryGetValue(handle, out var queue) || queue.Count == 0)
+            {
+                return 0;
+            }
+
+            var count = Math.Min(eventCapacity, queue.Count);
+            events = new KernelQueuedEvent[count];
+            for (var i = 0; i < count; i++)
+            {
+                events[i] = queue.Dequeue();
+            }
+        }
+
+        for (var i = 0; i < events.Length; i++)
+        {
+            if (!WriteKernelEvent(ctx, eventsAddress + ((ulong)i * KernelEventSize), events[i]))
+            {
+                return i;
+            }
+        }
+
+        return events.Length;
+    }
+
+    private static bool WriteKernelEvent(CpuContext ctx, ulong address, KernelQueuedEvent queuedEvent)
+    {
+        Span<byte> eventBytes = stackalloc byte[KernelEventSize];
+        BinaryPrimitives.WriteUInt64LittleEndian(eventBytes[0x00..], queuedEvent.Ident);
+        BinaryPrimitives.WriteInt16LittleEndian(eventBytes[0x08..], queuedEvent.Filter);
+        BinaryPrimitives.WriteUInt16LittleEndian(eventBytes[0x0A..], queuedEvent.Flags);
+        BinaryPrimitives.WriteUInt32LittleEndian(eventBytes[0x0C..], queuedEvent.Fflags);
+        BinaryPrimitives.WriteUInt64LittleEndian(eventBytes[0x10..], queuedEvent.Data);
+        BinaryPrimitives.WriteUInt64LittleEndian(eventBytes[0x18..], queuedEvent.UserData);
+        return ctx.Memory.TryWrite(address, eventBytes);
+    }
+
     private static void TraceEventQueue(CpuContext ctx, string operation, ulong handle)
     {
         if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_EQUEUE"), "1", StringComparison.Ordinal))

src/SharpEmu.Libs/Kernel/KernelMemoryCompatExports.cs

@@ -1444,6 +1444,51 @@ public static class KernelMemoryCompatExports
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
+    [SysAbiExport(
+        Nid = "Oy6IpwgtYOk",
+        ExportName = "lseek",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int PosixLseek(CpuContext ctx)
+    {
+        var result = KernelLseekCore(
+            unchecked((int)ctx[CpuRegister.Rdi]),
+            unchecked((long)ctx[CpuRegister.Rsi]),
+            unchecked((int)ctx[CpuRegister.Rdx]),
+            out var position);
+
+        if (result != OrbisGen2Result.ORBIS_GEN2_OK)
+        {
+            ctx[CpuRegister.Rax] = ulong.MaxValue;
+            return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        }
+
+        ctx[CpuRegister.Rax] = unchecked((ulong)position);
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "oib76F-12fk",
+        ExportName = "sceKernelLseek",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelLseek(CpuContext ctx)
+    {
+        var result = KernelLseekCore(
+            unchecked((int)ctx[CpuRegister.Rdi]),
+            unchecked((long)ctx[CpuRegister.Rsi]),
+            unchecked((int)ctx[CpuRegister.Rdx]),
+            out var position);
+
+        if (result != OrbisGen2Result.ORBIS_GEN2_OK)
+        {
+            return (int)result;
+        }
+
+        ctx[CpuRegister.Rax] = unchecked((ulong)position);
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
     [SysAbiExport(
         Nid = "taRWhTJFTgE",
         ExportName = "sceKernelGetdirentries",
@@ -1474,6 +1519,58 @@ public static class KernelMemoryCompatExports
             0);
     }
 
+    private static OrbisGen2Result KernelLseekCore(int fd, long offset, int whence, out long position)
+    {
+        position = -1;
+
+        FileStream? stream;
+        lock (_fdGate)
+        {
+            _openFiles.TryGetValue(fd, out stream);
+        }
+
+        if (stream is null)
+        {
+            LogIoTrace("lseek", $"fd:{fd}", $"offset={offset} whence={whence} result=badfd");
+            return OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+        }
+
+        SeekOrigin origin;
+        switch (whence)
+        {
+            case SeekSet:
+                origin = SeekOrigin.Begin;
+                break;
+            case SeekCur:
+                origin = SeekOrigin.Current;
+                break;
+            case SeekEnd:
+                origin = SeekOrigin.End;
+                break;
+            default:
+                LogIoTrace("lseek", stream.Name, $"fd={fd} offset={offset} whence={whence} result=invalid_whence");
+                return OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+        }
+
+        try
+        {
+            position = stream.Seek(offset, origin);
+        }
+        catch (IOException ex)
+        {
+            LogIoTrace("lseek", stream.Name, $"fd={fd} offset={offset} whence={whence} result=io_error ex={ex.Message}");
+            return OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+        }
+        catch (ArgumentException ex)
+        {
+            LogIoTrace("lseek", stream.Name, $"fd={fd} offset={offset} whence={whence} result=invalid ex={ex.Message}");
+            return OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+        }
+
+        LogIoTrace("lseek", stream.Name, $"fd={fd} offset={offset} whence={whence} pos={position}");
+        return OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
     [SysAbiExport(
         Nid = "FxVZqBAA7ks",
         ExportName = "_write",
@@ -3567,13 +3664,13 @@ public static class KernelMemoryCompatExports
         var devlogAppRoot = ResolveDevlogAppRoot();
         if (guestPath.StartsWith("/devlog/app/", StringComparison.OrdinalIgnoreCase))
         {
-            var relative = guestPath["/devlog/app/".Length..].Replace('/', Path.DirectorySeparatorChar);
+            var relative = NormalizeMountRelativePath(guestPath["/devlog/app/".Length..]);
             return Path.Combine(devlogAppRoot, relative);
         }
 
         if (guestPath.StartsWith("devlog/app/", StringComparison.OrdinalIgnoreCase))
         {
-            var relative = guestPath["devlog/app/".Length..].Replace('/', Path.DirectorySeparatorChar);
+            var relative = NormalizeMountRelativePath(guestPath["devlog/app/".Length..]);
             return Path.Combine(devlogAppRoot, relative);
         }
 
@@ -3586,7 +3683,7 @@ public static class KernelMemoryCompatExports
         var temp0Root = ResolveTemp0Root();
         if (guestPath.StartsWith("/temp0/", StringComparison.OrdinalIgnoreCase))
         {
-            var relative = guestPath["/temp0/".Length..].Replace('/', Path.DirectorySeparatorChar);
+            var relative = NormalizeMountRelativePath(guestPath["/temp0/".Length..]);
             return Path.Combine(temp0Root, relative);
         }
 
@@ -3606,13 +3703,13 @@ public static class KernelMemoryCompatExports
 
             if (guestPath.StartsWith("/app0/", StringComparison.OrdinalIgnoreCase))
             {
-                var relative = guestPath["/app0/".Length..].Replace('/', Path.DirectorySeparatorChar);
+                var relative = NormalizeMountRelativePath(guestPath["/app0/".Length..]);
                 return Path.Combine(app0Root, relative);
             }
 
             if (guestPath.StartsWith("app0/", StringComparison.OrdinalIgnoreCase))
             {
-                var relative = guestPath["app0/".Length..].Replace('/', Path.DirectorySeparatorChar);
+                var relative = NormalizeMountRelativePath(guestPath["app0/".Length..]);
                 return Path.Combine(app0Root, relative);
             }
 
@@ -3628,6 +3725,14 @@ public static class KernelMemoryCompatExports
         return guestPath;
     }
 
+    private static string NormalizeMountRelativePath(string relativePath)
+    {
+        return relativePath
+            .TrimStart('/', '\\')
+            .Replace('/', Path.DirectorySeparatorChar)
+            .Replace('\\', Path.DirectorySeparatorChar);
+    }
+
     private static string ResolveDevlogAppRoot()
     {
         var configuredRoot = Environment.GetEnvironmentVariable("SHARPEMU_DEVLOG_APP_DIR");

src/SharpEmu.Libs/Kernel/KernelSemaphoreCompatExports.cs

@@ -0,0 +1,318 @@
+// 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.Kernel;
+
+public static class KernelSemaphoreCompatExports
+{
+    private const int MaxSemaphoreNameLength = 128;
+    private static readonly ConcurrentDictionary<uint, KernelSemaphoreState> _semaphores = new();
+    private static int _nextSemaphoreHandle = 1;
+
+    private sealed class KernelSemaphoreState
+    {
+        public required string Name { get; init; }
+        public required int InitialCount { get; init; }
+        public required int MaxCount { get; init; }
+        public int Count { get; set; }
+        public int WaitingThreads { get; set; }
+        public object Gate { get; } = new();
+    }
+
+    [SysAbiExport(
+        Nid = "188x57JYp0g",
+        ExportName = "sceKernelCreateSema",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelCreateSema(CpuContext ctx)
+    {
+        var semaphoreAddress = ctx[CpuRegister.Rdi];
+        var nameAddress = ctx[CpuRegister.Rsi];
+        var attr = unchecked((uint)ctx[CpuRegister.Rdx]);
+        var initialCount = unchecked((int)ctx[CpuRegister.Rcx]);
+        var maxCount = unchecked((int)ctx[CpuRegister.R8]);
+        var optionAddress = ctx[CpuRegister.R9];
+
+        if (semaphoreAddress == 0 ||
+            nameAddress == 0 ||
+            attr > 2 ||
+            initialCount < 0 ||
+            maxCount <= 0 ||
+            initialCount > maxCount ||
+            optionAddress != 0)
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        if (!TryReadNullTerminatedUtf8(ctx, nameAddress, MaxSemaphoreNameLength, out var name))
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+        }
+
+        var handle = unchecked((uint)Interlocked.Increment(ref _nextSemaphoreHandle));
+        if (handle == 0)
+        {
+            handle = unchecked((uint)Interlocked.Increment(ref _nextSemaphoreHandle));
+        }
+
+        _semaphores[handle] = new KernelSemaphoreState
+        {
+            Name = name,
+            InitialCount = initialCount,
+            MaxCount = maxCount,
+            Count = initialCount,
+        };
+
+        if (!TryWriteUInt32(ctx, semaphoreAddress, handle))
+        {
+            _semaphores.TryRemove(handle, out _);
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+        }
+
+        TraceSemaphore($"create handle=0x{handle:X8} name='{name}' attr=0x{attr:X} init={initialCount} max={maxCount}");
+        return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+    }
+
+    [SysAbiExport(
+        Nid = "Zxa0VhQVTsk",
+        ExportName = "sceKernelWaitSema",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelWaitSema(CpuContext ctx)
+    {
+        var handle = unchecked((uint)ctx[CpuRegister.Rdi]);
+        var needCount = unchecked((int)ctx[CpuRegister.Rsi]);
+        var timeoutAddress = ctx[CpuRegister.Rdx];
+
+        if (!_semaphores.TryGetValue(handle, out var semaphore))
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+        }
+
+        if (needCount < 1 || needCount > semaphore.MaxCount)
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        lock (semaphore.Gate)
+        {
+            if (semaphore.Count >= needCount)
+            {
+                semaphore.Count -= needCount;
+                TraceSemaphore($"wait handle=0x{handle:X8} name='{semaphore.Name}' need={needCount} count={semaphore.Count}");
+                return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+            }
+
+            if (timeoutAddress != 0)
+            {
+                if (!TryReadUInt32(ctx, timeoutAddress, out _))
+                {
+                    return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+                }
+
+                _ = TryWriteUInt32(ctx, timeoutAddress, 0);
+                TraceSemaphore($"wait-timeout handle=0x{handle:X8} name='{semaphore.Name}' need={needCount} count={semaphore.Count}");
+                return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_TIMED_OUT);
+            }
+
+            if (!GuestThreadExecution.RequestCurrentThreadBlock("sceKernelWaitSema"))
+            {
+                TraceSemaphore($"wait-would-block handle=0x{handle:X8} name='{semaphore.Name}' need={needCount} count={semaphore.Count}");
+                return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_TRY_AGAIN);
+            }
+
+            semaphore.WaitingThreads++;
+            TraceSemaphore($"wait-block handle=0x{handle:X8} name='{semaphore.Name}' need={needCount} count={semaphore.Count} waiters={semaphore.WaitingThreads}");
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+        }
+    }
+
+    [SysAbiExport(
+        Nid = "12wOHk8ywb0",
+        ExportName = "sceKernelPollSema",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelPollSema(CpuContext ctx)
+    {
+        var handle = unchecked((uint)ctx[CpuRegister.Rdi]);
+        var needCount = unchecked((int)ctx[CpuRegister.Rsi]);
+
+        if (!_semaphores.TryGetValue(handle, out var semaphore))
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+        }
+
+        if (needCount < 1 || needCount > semaphore.MaxCount)
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        lock (semaphore.Gate)
+        {
+            if (semaphore.Count < needCount)
+            {
+                TraceSemaphore($"poll-busy handle=0x{handle:X8} name='{semaphore.Name}' need={needCount} count={semaphore.Count}");
+                return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_BUSY);
+            }
+
+            semaphore.Count -= needCount;
+            TraceSemaphore($"poll handle=0x{handle:X8} name='{semaphore.Name}' need={needCount} count={semaphore.Count}");
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+        }
+    }
+
+    [SysAbiExport(
+        Nid = "4czppHBiriw",
+        ExportName = "sceKernelSignalSema",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelSignalSema(CpuContext ctx)
+    {
+        var handle = unchecked((uint)ctx[CpuRegister.Rdi]);
+        var signalCount = unchecked((int)ctx[CpuRegister.Rsi]);
+
+        if (!_semaphores.TryGetValue(handle, out var semaphore))
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+        }
+
+        if (signalCount <= 0)
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        lock (semaphore.Gate)
+        {
+            if (semaphore.Count > semaphore.MaxCount - signalCount)
+            {
+                return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+            }
+
+            semaphore.Count += signalCount;
+            TraceSemaphore($"signal handle=0x{handle:X8} name='{semaphore.Name}' signal={signalCount} count={semaphore.Count} waiters={semaphore.WaitingThreads}");
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+        }
+    }
+
+    [SysAbiExport(
+        Nid = "4DM06U2BNEY",
+        ExportName = "sceKernelCancelSema",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelCancelSema(CpuContext ctx)
+    {
+        var handle = unchecked((uint)ctx[CpuRegister.Rdi]);
+        var setCount = unchecked((int)ctx[CpuRegister.Rsi]);
+        var waitingThreadsAddress = ctx[CpuRegister.Rdx];
+
+        if (!_semaphores.TryGetValue(handle, out var semaphore))
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+        }
+
+        if (setCount > semaphore.MaxCount)
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        lock (semaphore.Gate)
+        {
+            if (waitingThreadsAddress != 0 && !TryWriteUInt32(ctx, waitingThreadsAddress, unchecked((uint)semaphore.WaitingThreads)))
+            {
+                return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+            }
+
+            semaphore.Count = setCount < 0 ? semaphore.InitialCount : setCount;
+            semaphore.WaitingThreads = 0;
+            TraceSemaphore($"cancel handle=0x{handle:X8} name='{semaphore.Name}' set={setCount} count={semaphore.Count}");
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+        }
+    }
+
+    [SysAbiExport(
+        Nid = "R1Jvn8bSCW8",
+        ExportName = "sceKernelDeleteSema",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelDeleteSema(CpuContext ctx)
+    {
+        var handle = unchecked((uint)ctx[CpuRegister.Rdi]);
+        if (!_semaphores.TryRemove(handle, out var semaphore))
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND);
+        }
+
+        TraceSemaphore($"delete handle=0x{handle:X8} name='{semaphore.Name}'");
+        return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
+    }
+
+    private static int SetReturn(CpuContext ctx, OrbisGen2Result result)
+    {
+        var value = (int)result;
+        ctx[CpuRegister.Rax] = unchecked((ulong)value);
+        return value;
+    }
+
+    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 TryReadNullTerminatedUtf8(CpuContext ctx, ulong address, int maxLength, out string value)
+    {
+        value = string.Empty;
+        if (address == 0 || maxLength <= 0)
+        {
+            return false;
+        }
+
+        var bytes = new byte[Math.Min(maxLength, 4096)];
+        for (var i = 0; i < bytes.Length; i++)
+        {
+            Span<byte> current = stackalloc byte[1];
+            if (!ctx.Memory.TryRead(address + (ulong)i, current))
+            {
+                return false;
+            }
+
+            if (current[0] == 0)
+            {
+                value = Encoding.UTF8.GetString(bytes, 0, i);
+                return true;
+            }
+
+            bytes[i] = current[0];
+        }
+
+        value = Encoding.UTF8.GetString(bytes);
+        return true;
+    }
+
+    private static void TraceSemaphore(string message)
+    {
+        if (string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_SEMA"), "1", StringComparison.Ordinal))
+        {
+            Console.Error.WriteLine($"[LOADER][TRACE] sema.{message}");
+        }
+    }
+}