[1lawl]

What this fixes

Independent fixes found while bringing up FIFA Street 2 (SLES-53797, PAL) on Linux, from boot to in-game matches. Each commit carries its own test, so they can be reviewed or cherry-picked one by one. Sections 6 to 17 were added after the first review round.

1. fix(recomp): align LQ/SQ/LQC2/SQC2 addresses to 16 bytes

The R5900 ignores the low four bits of the effective address for quadword loads/stores, but the translator passed the raw address through. Unaligned memcpy routines depend on that implicit alignment: they LQ from an unaligned source pointer and splice the quadwords with QFSRV. In FIFA Street 2 the memcpy at 0x3cbdd8 copied a config struct from an 8-byte-aligned source, zeroed its size field, and left a later allocator callback NULL (JALR to 0x0 during boot).

The mask is applied in both the expression path and the constant-address (memory hint) path. Rebuilding with it changed 16k generated functions in this game.

2. fix(runtime): match cdrom0: paths case-insensitively

ISO9660 names are case-insensitive and games spell them freely (this game opens anims.big, the disc has ANIMS.BIG). The sceCd* layer already falls back to a case-insensitive lookup, but fio/VFS opens resolved cdrom0: paths verbatim, so they failed on case-sensitive hosts. When the exact path is missing, cdrom0: paths are now matched one component at a time, ignoring ASCII case. host0: and mc0: keep exact matching.

3. feat(runtime): take the CD image path from PS2X_CD_IMAGE

IoPaths::cdImage exists and readCdSectors falls back to it, but nothing on desktop sets it. Games with their own ISO9660 reader (EA's ASYNCFILE reads sector 16, then raw file extents) could never read anything. configureIoPathsFromElf now sets cdImage from the PS2X_CD_IMAGE environment variable.

4. fix(kernel): use 50 Hz VBlanks when SetGsCrt selects PAL

The VBlank period was fixed at 16.667 ms, so PAL games ran their VSync-paced logic 20% fast. SetGsCrt now selects 20 ms for mode 3 (PAL), effective from the next scheduled VBlank. Every other mode keeps exactly the previous 16.667 ms, so NTSC titles are unaffected. A small EeScheduler::vblankPeriod() getter was added for the test.

5. fix(iop): load sceSifLoadModuleBuffer images from IOP RAM

sceSifLoadModuleBuffer takes an IOP address. The EE first copies the IRX into IOP memory (sceSifAllocIopHeap + sceSifSetDma), then asks the IOP to load it from there. The emulator read the image from EE RAM at that address instead, found no ELF header, and failed silently. FIFA Street 2 loads SIO2MAN, MTAPMAN, PADMAN, LIBSD, SNDDRV, MCMAN and MCSERV this way from DATA/IOP.BIG, so none of them started and sceMtapInit spun forever binding SID 0x80000900. The loader now reads IOP RAM first and falls back to EE RAM, so callers that pass an EE address keep working.

6. fix(recomp): compare sign-testing branches on the full 64-bit register

BLEZ, BGTZ, BLTZ and BGEZ (and their likely and linking forms) test bit 63, but the generated conditions used GPR_S32. A value like 0x0000000080000000 (from DSUBU, LD or a 64-bit shift) branched as negative. In FIFA Street 2 this broke the comparator of EA's file-system hash table and its movies failed to open.

7. fix(recomp): read the SQRT.S operand from ft

SQRT.S fd, ft encodes its source in ft (fs is 0); the translator used fs, so every SQRT.S returned sqrt(f0).

8. fix(runtime): truncate CVT.W.S toward zero and saturate

The EE's CVT.W.S always rounds toward zero and saturates from 2^31 up; FPU_CVT_W_S used nearbyintf. (int)(log(112) / log(2)) came out as 7 instead of 6, so FIFA Street 2 sized its text textures twice too wide and its menu text was cut in half.

9. fix(runtime): advance COP0 Count with the EE cycle counter

MFC0 Count read a field nothing updated. Count is now derived from the scheduler's EE cycle counter; MTC0 rebases it. Adds EeScheduler::eeCycle().

10. fix(recomp): keep resume entries from taking other functions' addresses

Resume points are registered after the normal functions but before stubs and library functions. A resume point on a stub's first instruction (a final branch whose delay slot is the next function's entry) sent calls to that stub into the middle of the previous function. Such resume points are now skipped.

11. fix(runtime): keep unwinding nested calls after a scheduler checkpoint

When a checkpoint or jump unwinds to the scheduler, a dispatchGuestBranch call whose callee came back with ctx->pc equal to the callee's entry took that for "returned without setting pc" and continued at its fallthrough. With recursion and an inner loop on the function's first instruction, the outer frame ran on with the inner frame's registers (FIFA Street 2 crashed with a jalr to 0). An unwind flag, set on every unwinding path and cleared by the scheduler before each dispatch, keeps all frames returning.

12. fix(pad): report the DualShock 2 pressure mode ID 0x79

In pressure mode the pad data's second byte is 0x79 (9 halfwords), not 0x73. EA's pad library re-runs its setup forever while it still sees 0x73.

13. fix(iop): complete SPU2 auto-DMA transfers at playback speed

With ADMAS set the SPU2 takes PCM only as fast as it plays it (192 IOP cycles per byte at 48 kHz stereo 16-bit). Completing those transfers at bus speed made sceSdBlockTrans mixers such as EA's snddrv refill back-to-back and kept the IOP 100% busy. Adds a ps2_iop_memory_tests executable.

14. fix(vif): stall VIF1 after a VIFcode with the interrupt bit

An I-bit VIFcode raises the INTC VIF1 interrupt and stops VIF1 until VIF1_FBRST.STC (unless ERR.MII masks it); VIF1 only set STAT.INT and went on. EA's renderer syncs PATH3 uploads with VIF1 this way and waited forever on its first loading screen. The remaining DMA data waits for STC, the VIF1 channel completes after it, and INTC causes queued by PS2Memory reach the scheduler's INTC dispatch (also from the sceDmaSend HLE path, through the new PS2Runtime::dispatchCompletedDmacCause).

15. fix(gif): let PATH2 data resumed after a VIF1 stall beat PATH3

The interrupt handlers restart GIF before VIF1, and the game relies on the PATH2 draws behind the stall winning the arbitration: the PATH3 uploads are for the next batch and may reuse VRAM those draws still read. The runtime ran the whole GIF chain at the CHCR write, so a UI texture overwrote a flag's shading data before the flag was drawn. A GIF chain started while VIF1 is stalled with data left now waits for the next I/O write. If that write is FBRST.STC, the resumed VIF1 data goes first. Any other write, a read of GIF_STAT/GIF_CHCR/D_STAT, or FLUSHA runs it at once, so code waiting for the transfer cannot hang.

16. fix(kernel): set the VBlank rate in sceGsResetGraph too

The libgraph sceGsResetGraph ends with SetGsCrt, so it now selects the PAL/NTSC VBlank rate like the syscall in section 4.

17. feat(runtime): interpret EE code that has no recompiled function

FIFA Street 2's sound engine ships MIPS code modules inside its .ABK banks, links them into the heap and calls them every frame, which a static recompilation cannot see. User RAM (1 MB and up) outside the recompiled code regions now runs in an EE interpreter that follows the recompiler's semantics. It hands control back as soon as it reaches recompiled code or leaves that RAM, and takes a scheduler checkpoint every 32 instructions. hasFunction() keeps meaning "has a recompiled function" (HLE code probes optional helpers with it); the new canRunGuestCode() gates dispatch. PS2X_NO_INTERPRETER=1 turns it off.

Related

This game also needs #354 (sceCdCallback). That PR found the same callback dependency in the NTSC release, so it isn't duplicated here.

Verification

• Linux (Fedora 44, GCC 16.2), Release, Ninja, -msse4.1 as in CI. Configured with -DPS2X_ENABLE_FFMPEG=OFF -DPLATFORM=SDL because those development packages aren't installed locally.
• ps2x_tests: 459/459 pass (446 existing + 13 new; sections 9 and 12 extend existing tests). ps2xIOP tests: all five executables pass, including the new ps2_iop_memory_tests.
• The new tests for sections 10, 11, 13 and 15 were run against the code without their fix and fail there. The others check the exact generated code or value that their fix changes.
• In-game: with these fixes (plus performance work that is still in my own patches) FIFA Street 2 runs from boot through its menus and loading screens into matches.

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