VITASDK points to your VitaSDK root.
Quenom/raylib-5.5-vita has 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_ELF is 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