jpolo1224
4d8701a49d
Ported from EmuCoreX with sashkinbro's approval. The GPU family alone was never enough to decide behaviour: the same Mali part behaves differently under ARM's proprietary driver than under Mesa PanVK, a lesson this tree learned twice the expensive way - the r44p1 DEVICE_LOST fix had to be gated on driverID rather than vendorID, and the 8 Elite push-descriptor disable likewise. Driver identity, version and a bug set are now recorded in a table, so the next device quirk is an entry rather than another bespoke branch. Twenty-five rules, with match confidence so a vendor-wide rule never overrides a driver-version-specific one. The shaders gain gpu_bitwise_and / gpu_bitwise_not / gpu_boolean_not, whose bodies the device emits: plain a & b normally, scalarized where the database says the driver miscompiles vector bitwise ops. A device matching no rule renders exactly as before. opengl/tfx_fs.glsl already carried this fix as IAND3/UAND2/UAND4 macros gated on GPU_PROFILE_MALI. Those are replaced by the shared helpers, but the GL macro is deliberately (workaround || IsMaliGPUProfile()): Mali reached through ANGLE or Panfrost resolves a non-ARM driver and matches no rule, so a database-only gate would have silently removed a fix those users have today. Widening only. SHADER_CACHE_VERSION 108 -> 109. Every TFX and convert shader's source text changed, so a blob cached from 108 no longer matches the source that produced it; without the bump users would get stale binaries and garbage rendering after updating. RewriteConstantLoads is deliberately absent - the database records BrokenConstantLoad with no workaround bits, so the macro would be permanently zero and the shader code dead. Shaders validated offline with glslc across 136 Vulkan and 296 GL/GLES permutations, every macro on and off; the failure set is byte-identical to the pre-change baseline.
ARMSX2 — Native ARM64 JIT Fork of PCSX2
ARMSX2 is a free and open-source PlayStation 2 (PS2) emulator based on PCSX2. Its purpose is to emulate the PS2's hardware, using a combination of MIPS CPU Interpreters, Recompilers and a Virtual Machine which manages hardware states and PS2 system memory. This allows you to play PS2 games on your phone, PC, or gaming handheld, with many additional features and benefits.
Thank You
The ARMSX2 team is eternally indebted to the PCSX2 project it is based on. We are so fortunate to build on their 20 years of hardcore development.
About This Fork
The upstream PCSX2 project ships an ARM64 interpreter build for ARM, but its high-performance JIT recompilers (EE, IOP, VU0, VU1, and vtlb fast memory) are x86-64 only.
This fork exists to close that gap. The goal is to preserve the correctness features of 20 years of PCSX2 development, while generating the fastest native ARM performance possible.
Current status:
- ✅ EE (Emotion Engine) recompiler — integer, float, MMI, COP0/COP1/COP2, branches, load/store
- ✅ IOP (I/O Processor / R3000A) recompiler — full integer, load/store, branches, coprocessors
- ✅ VU (Vector Unit) recompiler — microVU skeleton + Upper FMAC vector ISA complete; Lower ISA and runtime complete
- ✅ vtlb fast memory
- ✅ Native ARM64 binary builds and boots the PS2 BIOS
- ✅ 2D games are already playable
- ✅ 3D games run
Why LLMs / AI Were Used
A word on methodology:
The x86-64 JIT code in upstream ARMSX2 is already proven correct — it has run thousands of PS2 titles for years. The challenge in this port is not emulator design or JIT theory; it is mechanical translation of a large, well-understood x86-64 assembly codebase into equivalent ARM64 assembly (via VIXL) while preserving the exact same register-allocation contracts, block lifecycle, and recompiler semantics.
Large language models (LLMs) were used as an accelerant for this translation work — pattern-matching x86 JIT boilerplate to ARM64 equivalents, scaffolding emit routines, and keeping the porting velocity high. The JIT logic (block compiler, dispatcher, analysis passes, flag pipelines, clamping rules, Tri-Ace hacks, etc.) is taken directly from the upstream x86 implementation and validated against it. Nothing was hallucinated from scratch.
In other words: the hard engineering was done by the PCSX2 team over two decades. The hard typing — translating ~50k lines of x86 emitter code into ARM64 — is what AI helped compress.
System Requirements
ARMSX2 targets ARM64 across desktop (macOS, Windows, Linux) and mobile (Android, iOS/iPadOS), all from the single shared core. Our setup documentation page contains additional details on software and hardware requirements.
Please note that a BIOS dump from a legitimately-owned PS2 console is required to use the emulator. For more information, visit this page.
Building
Check out our github actions for the latest build recipe