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GBA I/O: Fix HALTCNT access behavior (fixes #2309)

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This commit is contained in:
Vicki Pfau 2023-12-20 22:05:17 -08:00
parent 6ee880c58b
commit 5bd5a8d998
2 changed files with 19 additions and 18 deletions
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3
CHANGES
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@ -21,8 +21,9 @@ Emulation fixes:
- GBA Audio: Fix sample timing drifting when changing sample interval
- GBA Audio: Fix initial channel 3 wave RAM (fixes mgba.io/i/2947)
- GBA Audio: Fix sample position issues when rate changes (fixes mgba.io/i/3006)
- GBA GPIO: Fix tilt scale and orientation (fixes mgba.io/i/2703)
- GBA BIOS: Fix clobbering registers with word-sized CpuSet
- GBA GPIO: Fix tilt scale and orientation (fixes mgba.io/i/2703)
- GBA I/O: Fix HALTCNT access behavior (fixes mgba.io/i/2309)
- GBA SIO: Fix normal mode SI/SO semantics (fixes mgba.io/i/2925)
- GBA Video: Disable BG target 1 blending when OBJ blending (fixes mgba.io/i/2722)
Other fixes:

34
src/gba/io.c
View File

@ -531,6 +531,21 @@ void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value) {
case GBA_REG_MAX:
// Some bad interrupt libraries will write to this
break;
case GBA_REG_POSTFLG:
if (gba->memory.activeRegion == GBA_REGION_BIOS) {
if (gba->memory.io[address >> 1]) {
if (value & 0x8000) {
GBAStop(gba);
} else {
GBAHalt(gba);
}
}
value &= ~0x8000;
} else {
mLOG(GBA_IO, GAME_ERROR, "Write to BIOS-only I/O register: %03X", address);
return;
}
break;
case GBA_REG_EXWAITCNT_HI:
// This register sits outside of the normal I/O block, so we need to stash it somewhere unused
address = GBA_REG_INTERNAL_EXWAITCNT_HI;
@ -563,19 +578,6 @@ void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value) {
}
void GBAIOWrite8(struct GBA* gba, uint32_t address, uint8_t value) {
if (address == GBA_REG_HALTCNT) {
value &= 0x80;
if (!value) {
GBAHalt(gba);
} else {
GBAStop(gba);
}
return;
}
if (address == GBA_REG_POSTFLG) {
gba->memory.io[(address & (GBA_SIZE_IO - 1)) >> 1] = value;
return;
}
if (address >= GBA_REG_DEBUG_STRING && address - GBA_REG_DEBUG_STRING < sizeof(gba->debugString)) {
gba->debugString[address - GBA_REG_DEBUG_STRING] = value;
return;
@ -806,10 +808,6 @@ uint16_t GBAIORead(struct GBA* gba, uint32_t address) {
gba->memory.io[GBA_REG(JOYSTAT)] &= ~JOYSTAT_RECV;
break;
case GBA_REG_POSTFLG:
mLOG(GBA_IO, STUB, "Stub I/O register read: %03x", address);
break;
// Wave RAM can be written and read even if the audio hardware is disabled.
// However, it is not possible to switch between the two banks because it
// isn't possible to write to register SOUND3CNT_LO.
@ -883,6 +881,7 @@ uint16_t GBAIORead(struct GBA* gba, uint32_t address) {
case GBA_REG_IF:
case GBA_REG_WAITCNT:
case GBA_REG_IME:
case GBA_REG_POSTFLG:
// Handled transparently by registers
break;
case 0x066:
@ -897,6 +896,7 @@ uint16_t GBAIORead(struct GBA* gba, uint32_t address) {
case 0x142:
case 0x15A:
case 0x206:
case 0x302:
mLOG(GBA_IO, GAME_ERROR, "Read from unused I/O register: %03X", address);
return 0;
// These registers sit outside of the normal I/O block, so we need to stash them somewhere unused