Sinan KARAKAYA
6bf1feff8b
dispatchSyscallOverride returns bool, and its caller uses that to decide whether the built-in handler still needs to run. The success path -- the one that actually queues the guest's handler as an invocation -- fell off the end of the function without returning. That is undefined behaviour, and the practical failure mode is bad: whatever happened to be in the return register decided whether the built-in syscall ran in addition to the guest's override, so a game that overrides a syscall could get the effect applied twice, or not at all, depending on the build. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Runtime Library
The runtime library provides the execution environment for recompiled code, including:
- Memory management (32MB main RAM, scratchpad, etc.)
- Register context (128-bit GPRs, VU0 registers, etc.)
- Function table for dynamic linking
- Basic PS2 system call stubs
How to use:
Take your decompiled code and place the cpp files on ps2xRuntime/src/runner and header files on ps2xRuntime/include and compile/be happy.
Vita Build Notes
The Vita runtime uses Quenom/raylib-5.5-vita for vita build. I recommend build runtime only.
Expected environment:
VITASDKpoints to your VitaSDK root.Quenom/raylib-5.5-vitahas already been built and installed into$VITASDK/arm-vita-eabi.- SDL2 with the PVR backend required by that raylib fork is also installed into the same VitaSDK prefix.
PS2X_DEFAULT_BOOT_ELFis mandatory, you need to define where your game is like "ux0:data/RANJ00001/game/SLUS_201.84".
The CMake for ps2xRuntime consumes those preinstalled headers and libraries from VitaSDK. It does not fetch or install the Vita raylib fork for you.
Adding Custom Function Implementations
You can add custom implementations for PS2 system calls or game functions by:
- Creating function implementations that match the signature:
void function_name(uint8_t* rdram, R5900Context* ctx, PS2Runtime *runtime);
- Registering them with the runtime:
runtime.registerFunction(address, function_name);
Advanced Features
Memory Translation The runtime handles PS2's memory addressing, including:
- KSEG0/KSEG1 direct mapping
- TLB lookups for user memory
- Special memory areas (scratchpad, I/O registers)
Vector Unit Support
PS2-specific 128-bit MMI instructions and VU0 macro mode instructions are supported via SSE/AVX intrinsics.
Instruction Patching
You can patch specific instructions in the recompiled code to fix game issues or implement custom behavior.
Limitations
- Graphics and sound output require external implementations
- Some PS2-specific hardware features may not be fully supported
- Performance may vary based on the complexity of the game