mirror of
https://github.com/RetroPortingToolKit/psxrecomp
synced 2026-10-26 10:19:47 -04:00
Matthew Stanley
b3833aa253
Root cause: the recompiler split the kernel exception handler at the jalr $s1 (chain handler dispatch) into func_00000C80 and func_00000E10. The chain-walker continuation at BFC10910 never executed — only the first handler in chain 0 was ever called. I_STAT bits 0 (VBlank) and 2 (CDROM) were never acknowledged, causing an interrupt livelock. Fixes: - Emitter jalr/jal safety-net: when the return address falls outside the current function, emit a continuation psx_dispatch call after the jalr dispatch. This bridges split functions at indirect calls. - Merged exception handler: removed BFC10910 seed so the chain walker continuation is part of func_00000C80 (C fall-through after jalr). - 0xBFC10910 dispatch special case in psx_unknown_dispatch: chain handlers return to $ra=BFC10910 via jr $ra (compiled as `return;`); the dispatch loop picks up the $ra value — handled as a no-op since the continuation already ran via C fall-through. - Post-exception adaptive cooldown: if the handler didn't clear any I_STAT bits, give main code 500 blocks before re-firing. Prevents VBlank livelock when no handler claims the interrupt. - SIO byte write handler in mmio_write8 (was missing, caused crash). - GPU→RAM DMA ch2 stub: fills target with zeros, completes transfer. - Dispatch trace (debug_server_trace_dispatch) added to emitter template so it survives regeneration. Result: shell device detection completes, StartPad dispatched, chain E014 populated, GPU actively rendering the Memory Card / CD-ROM screen. VSync counter still 0 (handler installed but not yet incrementing — next investigation). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>