Astro Bot shader type 4, pthread_cond_timedwait, and HLE/memory/cpu bug fixes (#40)

* [agc] Add shader type 4 (GS) and register defaults v13 support

Astro Bot (#11) crashes on boot due to two missing GPU features:

1. Shader type 4 (Geometry Shader) — SPI_SHADER_PGM_LO/HI register
   offsets 0x8A/0x8B were missing. Added constants and switch cases
   for shader type 4 in GetExpectedSpiShaderPgmLo/Hi. Also added
   type 4 to IsEsGeometryShaderType (2 or 4 or 6).

2. Register defaults version 13 — was not recognized as supported.
   Added RegisterDefaultsVersion13 constant and included it in
   IsSupportedRegisterDefaultsVersion.

* [kernel] Add POSIX pthread_cond_timedwait export

SILENT HILL (#4) and Poppy Playtime (#3) crash on boot due to
missing POSIX pthread_cond_timedwait (NID 27bAgiJmOh0).

The Sony wrapper scePthreadCondTimedwait (NID BmMjYxmew1w) was
already implemented, but the raw POSIX symbol was not exported.
Added [SysAbiExport] for pthread_cond_timedwait delegating to
existing PthreadCondWaitCore with timed: true.

* [memory] Fix FlushInstructionCache null process handle

PhysicalVirtualMemory.cs called FlushInstructionCache with null as the
process handle in two places (SetProtection and TryWriteExclusive).
On Windows, a null handle does not reliably resolve to the current
process — the correct call is GetCurrentProcess() (pseudo-handle -1).

Also corrected the P/Invoke signature:
- Changed return type from void to bool with [return: MarshalAs(Bool)]
- Added SetLastError = true
- Added GetCurrentProcess() P/Invoke import

This matches the pattern already used in DirectExecutionBackend.cs
which correctly passes GetCurrentProcess() to all FlushInstructionCache
calls.

* [hle] Distinguish NOT_FOUND from NOT_IMPLEMENTED and log duplicate NIDs

Three diagnostic improvements to the HLE dispatch path:

1. ModuleManager.RegisterFromAssembly — duplicate NID registration was
   silently skipped (dispatchTable first-wins, exportTable last-wins,
   causing metadata divergence). Now logs a warning with the NID and
   export name so conflicts are visible.

2. ModuleManager.TryDispatch — generation mismatch returned
   ORBIS_GEN2_ERROR_NOT_FOUND, conflating 'function does not exist'
   with 'function exists but not for this generation'. Now returns
   ORBIS_GEN2_ERROR_NOT_IMPLEMENTED for generation mismatch, matching
   the existing convention in CpuDispatcher. Also adds debug logging
   for both NOT_FOUND and NOT_IMPLEMENTED paths.

3. DirectExecutionBackend.Imports.cs — the import dispatch else-branch
   (the actual hot path that bypasses ModuleManager.TyDispatch via
   cached export) had the same conflation. Split into:
   - else if (export exists but generation mismatch) → NOT_IMPLEMENTED
   - else (no export at all) → NOT_FOUND
   This makes runtime diagnostics correctly distinguish missing exports
   from generation-unsupported exports.

* [cpu] Check VirtualProtect return values in all stub creation paths

9 VirtualProtect calls in DirectExecutionBackend.cs had unchecked
return values. If VirtualProtect silently fails, memory protection
remains incorrect — stubs allocated with PAGE_EXECUTE_READWRITE (0x40)
never get downgraded to PAGE_EXECUTE_READ (0x20), or guest thread
entry stubs never get upgraded to writable. This causes access
violations on next execution or silent data corruption.

Fixed all 9 sites with proper error handling:
- 6 stub creation methods (return 0 on failure + log error)
- 2 guest thread entry methods (set reason + return Exception)
- 1 guest entry method (set LastError + return MEMORY_FAULT)

Stub creation sites fixed:
- CreateImportDispatchStub (line ~1683)
- EnsureTlsHandler (void, log + return)
- CreateUnresolvedReturnStub (return 0)
- CreateGuestReturnStub (return 0)
- CreateExceptionHandlerTrampoline (return 0)
- CreateTlsStoreHelperStub (return 0)

Guest thread entry sites fixed:
- StartGuestThreadNativeCall (return Exception)
- StartGuestContinuationNativeCall (return Exception)
- RunGuestEntryPoint (return MEMORY_FAULT)

* [kernel] Remove unused duplicate _nextFileDescriptor field

KernelExports.cs declared _nextFileDescriptor but never used it.
The actual field used for file descriptor allocation lives in
KernelMemoryCompatExports.cs (lines 1314, 1337). This was a dead
duplicate causing CS0414 warning.

Build is now 0 errors, 0 warnings.

---------

Co-authored-by: Hermes Atlas <hermesatlas@example.com>

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

@@ -358,12 +358,21 @@ public sealed partial class DirectExecutionBackend
 					}
 					orbisGen2Result = (OrbisGen2Result)returnValue;
 				}
-				else
+                else if (importStubEntry.Export is { } mismatchedExport)
-				{
+                {
-					dispatchResolved = false;
+                    dispatchResolved = true;
-					orbisGen2Result = OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+                    orbisGen2Result = OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_IMPLEMENTED;
-					cpuContext[CpuRegister.Rax] = unchecked((ulong)(int)orbisGen2Result);
+                    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
 			{

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

@@ -1679,10 +1679,14 @@ public sealed unsafe partial class DirectExecutionBackend : INativeCpuBackend, I
 			ptr2[num++] = 65;
 			ptr2[num++] = 95;
 			ptr2[num++] = 195;
-			uint num2 = default(uint);
+		uint num2 = default(uint);
-			VirtualProtect(ptr, 192u, 32u, &num2);
+		if (!VirtualProtect(ptr, 192u, 32u, &num2))
-			FlushInstructionCache(GetCurrentProcess(), ptr, 192u);
+		{
-			return (nint)ptr;
+			Console.Error.WriteLine($"[LOADER][ERROR] VirtualProtect failed for import dispatch stub at 0x{(nint)ptr:X16}");
+			return 0;
+		}
+		FlushInstructionCache(GetCurrentProcess(), ptr, 192u);
+		return (nint)ptr;
 		}
 		catch
 		{
@@ -1763,7 +1767,11 @@ public sealed unsafe partial class DirectExecutionBackend : INativeCpuBackend, I
 		tlsHandlerAddress[num++] = 195;
 		_tlsPatchStubOffset = (num + 15) & ~15;
 		uint num2 = default(uint);
-		VirtualProtect((void*)_tlsHandlerAddress, TlsHandlerRegionSize, 32u, &num2);
+		if (!VirtualProtect((void*)_tlsHandlerAddress, TlsHandlerRegionSize, 32u, &num2))
+		{
+			Console.Error.WriteLine($"[LOADER][ERROR] VirtualProtect failed for TLS handler at 0x{_tlsHandlerAddress:X16}");
+			return;
+		}
 		FlushInstructionCache(GetCurrentProcess(), (void*)_tlsHandlerAddress, TlsHandlerRegionSize);
 		Console.Error.WriteLine($"[LOADER][INFO] TLS handler at 0x{_tlsHandlerAddress:X16}");
 	}
@@ -1784,7 +1792,11 @@ public sealed unsafe partial class DirectExecutionBackend : INativeCpuBackend, I
 			ptr2[i] = 144;
 		}
 		uint num = default(uint);
-		VirtualProtect(ptr, 4096u, 32u, &num);
+		if (!VirtualProtect(ptr, 4096u, 32u, &num))
+		{
+			Console.Error.WriteLine($"[LOADER][ERROR] VirtualProtect failed for unresolved return stub at 0x{(nint)ptr:X16}");
+			return 0;
+		}
 		FlushInstructionCache(GetCurrentProcess(), ptr, 16u);
 		return (nint)ptr;
 	}
@@ -1831,7 +1843,11 @@ public sealed unsafe partial class DirectExecutionBackend : INativeCpuBackend, I
 		EmitByte(code, ref offset, 0xC3);
 
 		uint oldProtect = default;
-		VirtualProtect(ptr, stubSize, 32u, &oldProtect);
+		if (!VirtualProtect(ptr, stubSize, 32u, &oldProtect))
+		{
+			Console.Error.WriteLine($"[LOADER][ERROR] VirtualProtect failed for guest return stub at 0x{(nint)ptr:X16}");
+			return 0;
+		}
 		FlushInstructionCache(GetCurrentProcess(), ptr, (nuint)offset);
 		return (nint)ptr;
 	}
@@ -1923,7 +1939,11 @@ public sealed unsafe partial class DirectExecutionBackend : INativeCpuBackend, I
 		*(int*)(code + guestRestoreJump) = restoreOffset - (guestRestoreJump + sizeof(int));
 
 		uint oldProtect = default;
-		VirtualProtect(ptr, stubSize, 32u, &oldProtect);
+		if (!VirtualProtect(ptr, stubSize, 32u, &oldProtect))
+		{
+			Console.Error.WriteLine($"[LOADER][ERROR] VirtualProtect failed for exception handler trampoline at 0x{(nint)ptr:X16}");
+			return 0;
+		}
 		FlushInstructionCache(GetCurrentProcess(), ptr, (nuint)offset);
 		return (nint)ptr;
 	}
@@ -2254,7 +2274,11 @@ public sealed unsafe partial class DirectExecutionBackend : INativeCpuBackend, I
 			ptr[num2++] = 144;
 		}
 		uint flNewProtect = default(uint);
-		VirtualProtect((void*)num, 32u, 32u, &flNewProtect);
+		if (!VirtualProtect((void*)num, 32u, 32u, &flNewProtect))
+		{
+			Console.Error.WriteLine($"[LOADER][ERROR] VirtualProtect failed for TLS store helper at 0x{num:X16}");
+			return 0;
+		}
 		FlushInstructionCache(GetCurrentProcess(), (void*)num, 32u);
 		return num;
 	}
@@ -3591,7 +3615,11 @@ public sealed unsafe partial class DirectExecutionBackend : INativeCpuBackend, I
 				return GuestNativeCallExitReason.Exception;
 			}
 			uint oldProtect = default(uint);
-			VirtualProtect(ptr, stubSize, 64u, &oldProtect);
+			if (!VirtualProtect(ptr, stubSize, 64u, &oldProtect))
+			{
+				reason = $"VirtualProtect failed for guest thread entry stub at 0x{(nint)ptr:X16}";
+				return GuestNativeCallExitReason.Exception;
+			}
 			FlushInstructionCache(GetCurrentProcess(), ptr, stubSize);
 			TlsSetValue(_hostRspSlotTlsIndex, (nint)hostRspSlot);
 			ActiveGuestThreadYieldRequested = false;
@@ -3728,7 +3756,11 @@ public sealed unsafe partial class DirectExecutionBackend : INativeCpuBackend, I
 				return GuestNativeCallExitReason.Exception;
 			}
 			uint oldProtect = default(uint);
-			VirtualProtect(ptr, stubSize, 64u, &oldProtect);
+			if (!VirtualProtect(ptr, stubSize, 64u, &oldProtect))
+			{
+				reason = $"VirtualProtect failed for guest continuation stub at 0x{(nint)ptr:X16}";
+				return GuestNativeCallExitReason.Exception;
+			}
 			FlushInstructionCache(GetCurrentProcess(), ptr, stubSize);
 			TlsSetValue(_hostRspSlotTlsIndex, (nint)hostRspSlot);
 			ActiveGuestThreadYieldRequested = false;
@@ -3988,7 +4020,12 @@ public sealed unsafe partial class DirectExecutionBackend : INativeCpuBackend, I
 				return false;
 			}
 			uint num5 = default(uint);
-			VirtualProtect(ptr, stubSize, 64u, &num5);
+			if (!VirtualProtect(ptr, stubSize, 64u, &num5))
+			{
+				LastError = $"VirtualProtect failed for guest entry stub at 0x{(nint)ptr:X16}";
+				result = OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+				return false;
+			}
 			FlushInstructionCache(GetCurrentProcess(), ptr, stubSize);
 			if (_hostRspSlotStorage != 0)
 			{

src/SharpEmu.Core/Memory/PhysicalVirtualMemory.cs

@@ -55,7 +55,11 @@ 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)
     {
@@ -451,7 +455,7 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
 
         if ((flags & ProgramHeaderFlags.Execute) != 0)
         {
-            FlushInstructionCache(null, (void*)address, (nuint)size);
+            FlushInstructionCache(GetCurrentProcess(), (void*)address, (nuint)size);
         }
     }
 
@@ -699,7 +703,7 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
                 VirtualProtect(destPtr, (nuint)source.Length, oldProtect, out _);
                 if (IsExecutableProtection(oldProtect))
                 {
-                    FlushInstructionCache(null, destPtr, (nuint)source.Length);
+                    FlushInstructionCache(GetCurrentProcess(), destPtr, (nuint)source.Length);
                 }
             }
 

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.Libs/Agc/AgcExports.cs

@@ -58,6 +58,8 @@ public static class AgcExports
     private const uint SpiShaderPgmHiEs = 0xC9;
     private const uint SpiShaderPgmLoLs = 0x148;
     private const uint SpiShaderPgmHiLs = 0x149;
+    private const uint SpiShaderPgmLoGs = 0x8A;
+    private const uint SpiShaderPgmHiGs = 0x8B;
     private const uint SpiPsInputEna = 0x1B3;
     private const uint SpiPsInputAddr = 0x1B4;
     private const uint ComputePgmLo = 0x20C;
@@ -115,6 +117,7 @@ public static class AgcExports
     private const uint RegisterDefaultsVersion7 = 7;
     private const uint RegisterDefaultsVersion8 = 8;
     private const uint RegisterDefaultsVersion10 = 10;
+    private const uint RegisterDefaultsVersion13 = 13;
     private const int RegisterDefaultsSize = 0x40;
     private const int RegisterDefaultBlockSize = 16 * 8;
 
@@ -5081,6 +5084,7 @@ public static class AgcExports
             0 => ComputePgmLo,
             1 => SpiShaderPgmLoPs,
             2 or 6 => SpiShaderPgmLoEs,
+            4 => SpiShaderPgmLoGs,
             7 => SpiShaderPgmLoLs,
             _ => 0u,
         };
@@ -5089,6 +5093,7 @@ public static class AgcExports
             0 => ComputePgmHi,
             1 => SpiShaderPgmHiPs,
             2 or 6 => SpiShaderPgmHiEs,
+            4 => SpiShaderPgmHiGs,
             7 => SpiShaderPgmHiLs,
             _ => 0u,
         };
@@ -5105,7 +5110,7 @@ public static class AgcExports
     }
 
     private static bool IsEsGeometryShaderType(byte shaderType) =>
-        shaderType is 2 or 6;
+        shaderType is 2 or 4 or 6;
 
     private static int SetIndirectPatchAddress(CpuContext ctx, string registerSpace)
     {
@@ -5252,7 +5257,8 @@ public static class AgcExports
         return version is
             RegisterDefaultsVersion7 or
             RegisterDefaultsVersion8 or
-            RegisterDefaultsVersion10;
+            RegisterDefaultsVersion10 or
+            RegisterDefaultsVersion13;
     }
 
     private static bool TryGetRegisterDefaultsAllocation(

src/SharpEmu.Libs/Kernel/KernelExports.cs

@@ -8,7 +8,6 @@ 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();

src/SharpEmu.Libs/Kernel/KernelPthreadCompatExports.cs

@@ -329,6 +329,12 @@ public static class KernelPthreadCompatExports
         Target = Generation.Gen4 | Generation.Gen5,
         LibraryName = "libKernel")]
     public static int PosixPthreadCondSignal(CpuContext ctx) => PthreadCondSignalCore(ctx, ctx[CpuRegister.Rdi], broadcast: false);
+    [SysAbiExport(
+        Nid = "27bAgiJmOh0",
+        ExportName = "pthread_cond_timedwait",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int PosixPthreadCondTimedwait(CpuContext ctx) => PthreadCondWaitCore(ctx, ctx[CpuRegister.Rdi], ctx[CpuRegister.Rsi], timed: true, timeoutUsec: unchecked((uint)ctx[CpuRegister.Rdx]));
 
     [SysAbiExport(
         Nid = "m5-2bsNfv7s",