PS2Recomp/ps2xIOP

ps2xIOP

ps2xIOP runs original IRX modules on an R3000A interpreter, with a virtual IOP kernel providing imports without a PS2 BIOS. The C++20 static library ps2_iop / ps2x::iop is linked into ps2xRuntime.

Execution policy

Game-specific IOP code executes from IRX modules. There is no game-profile selection or native profile-plugin loader. A physical IRX RPC server is authoritative for its SID.

Generic HLE services remain available when no loaded IRX provides an endpoint:

Service	SID	Activation
MCSERV	0x80000400, 0x80000480	Recognized module load
LIBSD	0x80000701	Recognized module load
DBCMAN	0x80001300	Recognized module load

These services are dormant before module load and after reset or the final module stop. Unknown modules fail to load; unknown RPC SIDs remain unhandled. Games previously using TSNDDRV, CRI DTX, CLFILE, SOUND or SDRDRV profiles now require their IRX modules and support for the imports and hardware they use.

Lifecycle and transport

• reset() clears loaded modules, HLE service state and emulator state.
• loadModule(...) / loadModuleBuffer(...) load and start an IRX.
• stopModule(...) releases a module and its owned state.
• runEeCycles(...) advances the IOP from EE cycle accounting.
• selectRpcAbi(...), handleRpc(...) and onSifTransfer(...) connect SIF transport.

IOP RAM is separate from EE RAM. The transport copies data through the IOP memory accessors; SIF notifications do not mirror bytes into equal-numbered EE addresses. RpcResult describes completion and dispatch actions for the runtime.

Link with target_link_libraries(my_runtime PRIVATE ps2x::iop). The public API is iop_subsystem.h; PS2Runtime owns its subsystem and host adapter.

Diagnostics and tests

debugSnapshot() exposes emulator cycle/instruction counts, loaded module, thread and RPC-server counts, generic service metrics and load diagnostics. The runtime debugger renders these in the IOP/SIF tab.

Build standalone tests with:

cmake -S ps2xIOP -B out/build/iop-tests -DPS2X_IOP_BUILD_TESTS=ON
cmake --build out/build/iop-tests
ctest --test-dir out/build/iop-tests --output-on-failure

The suites cover IRX execution, RPC, imports, version resolution and generic HLE compatibility. ps2x_tests also covers runtime SIF RPC/DMA integration.