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GBA BIOS: Implement Diff8bitUnFilterWram and Diff16bitUnFilter

This commit is contained in:
Jeffrey Pfau 2015-01-06 23:07:59 -08:00
parent f97ba6517b
commit fac82c2ca1
2 changed files with 51 additions and 0 deletions
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1
CHANGES
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@ -14,6 +14,7 @@ Features:
- Support for games using the tilt sensor
- Remappable shortcuts for keyboard and gamepad
- Rewinding of emulation
- Implemented BIOS routines Diff8bitUnFilterWram, and Diff16bitUnFilter
Bugfixes:
- Qt: Fix issue with set frame sizes being the wrong height
- Qt: Fix emulator crashing when full screen if a game is not running

50
src/gba/gba-bios.c
View File

@ -15,6 +15,7 @@ const uint32_t GBA_DS_BIOS_CHECKSUM = 0xBAAE1880;
static void _unLz77(struct GBA* gba, uint32_t source, uint32_t dest, int width);
static void _unHuffman(struct GBA* gba, uint32_t source, uint32_t dest);
static void _unRl(struct GBA* gba, uint32_t source, uint32_t dest, int width);
static void _unFilter(struct GBA* gba, uint32_t source, uint32_t dest, int inwidth, int outwidth);
static void _RegisterRamReset(struct GBA* gba) {
uint32_t registers = gba->cpu->gprs[0];
@ -212,6 +213,22 @@ void GBASwi16(struct ARMCore* cpu, int immediate) {
break;
}
break;
case 0x16:
case 0x17:
case 0x18:
if (cpu->gprs[0] < BASE_WORKING_RAM) {
GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter source");
}
switch (cpu->gprs[1] >> BASE_OFFSET) {
default:
GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter destination");
case REGION_WORKING_RAM:
case REGION_WORKING_IRAM:
case REGION_VRAM:
_unFilter(gba, cpu->gprs[0], cpu->gprs[1], immediate == 0x18 ? 2 : 1, immediate == 0x16 ? 1 : 2);
break;
}
break;
case 0x1F:
_MidiKey2Freq(gba);
break;
@ -438,3 +455,36 @@ static void _unRl(struct GBA* gba, uint32_t source, uint32_t dest, int width) {
}
}
}
static void _unFilter(struct GBA* gba, uint32_t source, uint32_t dest, int inwidth, int outwidth) {
struct ARMCore* cpu = gba->cpu;
source = source & 0xFFFFFFFC;
uint32_t header = cpu->memory.load32(cpu, source, 0);
int remaining = header >> 8;
// We assume the signature nybble (0x8) is correct
uint16_t halfword = 0;
uint16_t old = 0;
source += 4;
while (remaining > 0) {
if (inwidth == 1) {
halfword = cpu->memory.loadU8(cpu, source, 0);
} else {
halfword = cpu->memory.loadU16(cpu, source, 0);
}
halfword += old;
if (outwidth > inwidth) {
GBALog(gba, GBA_LOG_STUB, "Unimplemented Diff8bitUnFilterVram");
} else {
if (outwidth == 1) {
halfword &= 0xFF;
cpu->memory.store8(cpu, dest, halfword, 0);
} else {
cpu->memory.store16(cpu, dest, halfword, 0);
}
old = halfword;
dest += outwidth;
}
source += inwidth;
--remaining;
}
}