Support loading BIOS

src/gba/gba-bios.c

@@ -162,6 +162,10 @@ static void _MidiKey2Freq(struct GBA* gba) {
 
 void GBASwi16(struct ARMBoard* board, int immediate) {
 	struct GBA* gba = ((struct GBABoard*) board)->p;
+	if (gba->memory.fullBios) {
+		ARMRaiseSWI(&gba->cpu);
+		return;
+	}
 	switch (immediate) {
 	case 0x1:
 		_RegisterRamReset(gba);

src/gba/gba-memory.c

@@ -31,6 +31,7 @@ void GBAMemoryInit(struct GBAMemory* memory) {
 	memory->d.store8 = GBAStore8;
 
 	memory->bios = (uint32_t*) hleBios;
+	memory->fullBios = 0;
 	memory->wram = mmap(0, SIZE_WORKING_RAM, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
 	memory->iwram = mmap(0, SIZE_WORKING_IRAM, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
 	memory->rom = 0;
@@ -125,7 +126,7 @@ int32_t GBALoad32(struct ARMMemory* memory, uint32_t address, int* cycleCounter)
 	switch (address & ~OFFSET_MASK) {
 	case BASE_BIOS:
 		if (gbaMemory->p->cpu.currentPC >> BASE_OFFSET == REGION_BIOS) {
-			if (address < hleBiosLength) {
+			if (address < SIZE_BIOS) {
 				value = gbaMemory->bios[address >> 2];
 			} else {
 				value = 0;
@@ -198,7 +199,15 @@ int16_t GBALoad16(struct ARMMemory* memory, uint32_t address, int* cycleCounter)
 
 	switch (address & ~OFFSET_MASK) {
 	case BASE_BIOS:
-		GBALog(gbaMemory->p, GBA_LOG_STUB, "Unimplemented memory Load16: 0x%08X", address);
+		if (gbaMemory->p->cpu.currentPC >> BASE_OFFSET == REGION_BIOS) {
+			if (address < SIZE_BIOS) {
+				value = ((int16_t*) gbaMemory->bios)[address >> 1];
+			} else {
+				value = 0;
+			}
+		} else {
+			value = gbaMemory->biosPrefetch;
+		}
 		break;
 	case BASE_WORKING_RAM:
 		value = ((int16_t*) gbaMemory->wram)[(address & (SIZE_WORKING_RAM - 1)) >> 1];
@@ -265,7 +274,15 @@ int8_t GBALoad8(struct ARMMemory* memory, uint32_t address, int* cycleCounter) {
 
 	switch (address & ~OFFSET_MASK) {
 	case BASE_BIOS:
-		GBALog(gbaMemory->p, GBA_LOG_STUB, "Unimplemented memory Load8: 0x%08X", address);
+		if (gbaMemory->p->cpu.currentPC >> BASE_OFFSET == REGION_BIOS) {
+			if (address < SIZE_BIOS) {
+				value = ((int8_t*) gbaMemory->bios)[address];
+			} else {
+				value = 0;
+			}
+		} else {
+			value = gbaMemory->biosPrefetch;
+		}
 		break;
 	case BASE_WORKING_RAM:
 		value = ((int8_t*) gbaMemory->wram)[address & (SIZE_WORKING_RAM - 1)];

src/gba/gba-memory.h

@@ -114,6 +114,7 @@ struct GBAMemory {
 
 	struct GBASavedata savedata;
 	size_t romSize;
+	int fullBios;
 
 	char waitstates32[256];
 	char waitstates16[256];

src/gba/gba.c

@@ -271,6 +271,15 @@ void GBALoadROM(struct GBA* gba, int fd, const char* fname) {
 	// TODO: error check
 }
 
+void GBALoadBIOS(struct GBA* gba, int fd) {
+	gba->memory.bios = mmap(0, SIZE_BIOS, PROT_READ, MAP_SHARED, fd, 0);
+	gba->memory.fullBios = 1;
+	if ((gba->cpu.gprs[ARM_PC] >> BASE_OFFSET) == BASE_BIOS) {
+		gba->memory.d.setActiveRegion(&gba->memory.d, gba->cpu.gprs[ARM_PC]);
+	}
+	// TODO: error check
+}
+
 void GBATimerUpdateRegister(struct GBA* gba, int timer) {
 	struct GBATimer* currentTimer = &gba->timers[timer];
 	if (currentTimer->enable && !currentTimer->countUp) {

src/gba/gba.h

@@ -116,6 +116,7 @@ int GBAHalt(struct GBA* gba);
 void GBAAttachDebugger(struct GBA* gba, struct ARMDebugger* debugger);
 
 void GBALoadROM(struct GBA* gba, int fd, const char* fname);
+void GBALoadBIOS(struct GBA* gba, int fd);
 
 __attribute__((format (printf, 3, 4)))
 void GBALog(struct GBA* gba, enum GBALogLevel level, const char* format, ...);