mirror of
https://github.com/RetroPortingToolKit/psxrecomp
synced 2026-10-26 18:25:35 -04:00
Matthew Stanley
fba58d76b3
Three interrupt delivery bugs fixed that were blocking shell progression: 1. RFE after handler exit: The exception handler's normal exit path (jmpbuf longjmp at 0xBFC10944) does not execute RFE. In our model the handler returns to psx_check_interrupts, not to the WaitEvent caller. Without RFE, IEc stays 0 forever after the first interrupt. Fix: apply RFE in psx_check_interrupts if IEc is still 0 after the handler returns. 2. GPR save/restore around handler dispatch: The handler's jmpbuf exit restores callee-saved registers from the kernel jmpbuf (intended for a non-local jump to WaitEvent's caller). In our model this corrupts the interrupted code's registers. Fix: save all GPRs before handler dispatch and restore them after, matching real hardware where the interrupted code's registers are preserved via TCB save/restore. 3. VBlank tick gated on !in_exception: The handler runs thousands of block leaders, each calling psx_check_interrupts. Without gating, dispatch_count advances inside the handler, firing new VBlanks that stack up and starve the main code. Fix: only increment dispatch_count and fire VBlank/timer ticks when not in exception handling. 4. DMA IRQ edge-triggered: update_master_irq() was level-triggered, re-asserting i_stat bit 3 on every call while master_flag=1. Combined with no BIOS callback to acknowledge DMA IRQs, this caused an interrupt storm. Fix: edge-detect master_flag 0->1 transition, and suppress DMA completion IRQs entirely since transfers are synchronous. Also adds GPU debug diagnostics: GP0 command counters (nop/fill/draw/ env/copy), draw area/offset in gpu_state, vram_peek debug command. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
52 lines
1.6 KiB
C
52 lines
1.6 KiB
C
/* gpu.h — PS1 GPU hardware simulation (Phase 3).
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*
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* Implements GPUSTAT, GP0, GP1, and 1024x512 16-bit VRAM.
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* No rendering to screen — just correct hardware state transitions.
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*/
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#ifndef PSXRECOMP_V4_GPU_H
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#define PSXRECOMP_V4_GPU_H
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#include <stdint.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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void gpu_init(void);
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uint32_t gpu_read_gpustat(void); /* 0x1F801814 read */
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uint32_t gpu_read_gpuread(void); /* 0x1F801810 read */
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void gpu_write_gp0(uint32_t val); /* 0x1F801810 write */
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void gpu_write_gp1(uint32_t val); /* 0x1F801814 write */
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void gpu_vblank_tick(void); /* Toggle LCF, called at each simulated vblank */
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/* Display presentation accessors (Phase 3). */
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const uint16_t* gpu_get_vram(void); /* Pointer to 1024x512 16-bit VRAM */
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typedef struct {
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uint32_t display_x, display_y; /* VRAM start of display area (GP1(05h)) */
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uint32_t width, height; /* Derived from display mode + ranges */
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int disabled; /* GP1(03h) display disable flag */
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} GpuDisplayInfo;
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void gpu_get_display_info(GpuDisplayInfo* out);
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uint64_t gpu_get_gp0_count(void); /* Total GP0 writes since init */
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void gpu_get_gp0_stats(uint64_t* nop, uint64_t* fill, uint64_t* draw, uint64_t* env, uint64_t* copy);
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typedef struct {
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uint32_t left, top, right, bottom;
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int32_t offset_x, offset_y;
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} GpuDrawArea;
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void gpu_get_draw_area(GpuDrawArea* out);
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uint16_t gpu_vram_peek(int x, int y);
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/* Vblank presentation callback — called from gpu_vblank_tick(). */
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typedef void (*gpu_vblank_cb)(void);
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void gpu_set_vblank_callback(gpu_vblank_cb cb);
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#ifdef __cplusplus
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}
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#endif
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#endif /* PSXRECOMP_V4_GPU_H */
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