GBA Memory: AGBPrint support

CHANGES

@@ -10,6 +10,7 @@ Features:
  - Map viewer
  - Automatic cheat loading and saving
  - GameShark and Action Replay button support
+ - AGBPrint support
 Bugfixes:
  - GB Audio: Make audio unsigned with bias (fixes mgba.io/i/749)
  - GB Serialize: Fix audio state loading

include/mgba/internal/gba/memory.h

@@ -69,7 +69,9 @@ enum {
 	SIZE_CART_FLASH512 = 0x00010000,
 	SIZE_CART_FLASH1M = 0x00020000,
 	SIZE_CART_EEPROM = 0x00002000,
-	SIZE_CART_EEPROM512 = 0x00000200
+	SIZE_CART_EEPROM512 = 0x00000200,
+
+	SIZE_AGB_PRINT = 0x10000
 };
 
 enum {
@@ -77,8 +79,23 @@ enum {
 	BASE_OFFSET = 24
 };
 
+enum {
+	AGB_PRINT_BASE = 0x00FD0000,
+	AGB_PRINT_TOP = 0x00FE0000,
+	AGB_PRINT_PROTECT = 0x00FE2FFE,
+	AGB_PRINT_STRUCT = 0x01FE20F8,
+	AGB_PRINT_FLUSH_ADDR = 0x01FE209C,
+};
+
 mLOG_DECLARE_CATEGORY(GBA_MEM);
 
+struct GBAPrintContext {
+	uint16_t request;
+	uint16_t bank;
+	uint16_t get;
+	uint16_t put;
+};
+
 struct GBAMemory {
 	uint32_t* bios;
 	uint32_t* wram;
@@ -108,6 +125,10 @@ struct GBAMemory {
 	int activeDMA;
 	uint32_t dmaTransferRegister;
 
+	uint16_t agbPrint;
+	struct GBAPrintContext agbPrintCtx;
+	uint16_t* agbPrintBuffer;
+
 	bool mirroring;
 };
 
@@ -146,6 +167,8 @@ struct GBASerializedState;
 void GBAMemorySerialize(const struct GBAMemory* memory, struct GBASerializedState* state);
 void GBAMemoryDeserialize(struct GBAMemory* memory, const struct GBASerializedState* state);
 
+void GBAPrintFlush(struct GBA* gba);
+
 CXX_GUARD_END
 
 #endif

src/gba/bios.c

@@ -333,6 +333,12 @@ void GBASwi16(struct ARMCore* cpu, int immediate) {
 	mLOG(GBA_BIOS, DEBUG, "SWI: %02X r0: %08X r1: %08X r2: %08X r3: %08X",
 	    immediate, cpu->gprs[0], cpu->gprs[1], cpu->gprs[2], cpu->gprs[3]);
 
+	switch (immediate) {
+	case 0xFA:
+		GBAPrintFlush(gba);
+		return;
+	}
+
 	if (gba->memory.fullBios) {
 		ARMRaiseSWI(cpu);
 		return;

src/gba/memory.c

@@ -22,7 +22,10 @@
 mLOG_DEFINE_CATEGORY(GBA_MEM, "GBA Memory", "gba.memory");
 
 static void _pristineCow(struct GBA* gba);
-static uint32_t _deadbeef[1] = { 0xE710B710 }; // Illegal instruction on both ARM and Thumb
+static void _agbPrintStore(struct GBA* gba, uint32_t address, int16_t value);
+static int16_t  _agbPrintLoad(struct GBA* gba, uint32_t address);
+static uint8_t _deadbeef[4] = { 0x10, 0xB7, 0x10, 0xE7 }; // Illegal instruction on both ARM and Thumb
+static uint8_t _agbPrintFunc[4] = { 0xFA, 0xDF /* swi 0xFF */, 0x70, 0x47 /* bx lr */ };
 
 static void GBASetActiveRegion(struct ARMCore* cpu, uint32_t region);
 static int32_t GBAMemoryStall(struct ARMCore* cpu, int32_t wait);
@@ -80,6 +83,10 @@ void GBAMemoryInit(struct GBA* gba) {
 	gba->memory.biosPrefetch = 0;
 	gba->memory.mirroring = false;
 
+	gba->memory.agbPrint = 0;
+	memset(&gba->memory.agbPrintCtx, 0, sizeof(gba->memory.agbPrintCtx));
+	gba->memory.agbPrintBuffer = NULL;
+
 	gba->memory.iwram = anonymousMemoryMap(SIZE_WORKING_IRAM);
 	gba->memory.wram = anonymousMemoryMap(SIZE_WORKING_RAM);
 
@@ -116,6 +123,12 @@ void GBAMemoryReset(struct GBA* gba) {
 
 	memset(gba->memory.io, 0, sizeof(gba->memory.io));
 
+	gba->memory.agbPrint = 0;
+	memset(&gba->memory.agbPrintCtx, 0, sizeof(gba->memory.agbPrintCtx));
+	if (gba->memory.agbPrintBuffer) {
+		gba->memory.agbPrintBuffer = NULL;
+	}
+
 	gba->memory.prefetch = false;
 	gba->memory.lastPrefetchedPc = 0;
 
@@ -295,10 +308,15 @@ static void GBASetActiveRegion(struct ARMCore* cpu, uint32_t address) {
 		if ((address & (SIZE_CART0 - 1)) < memory->romSize) {
 			break;
 		}
+		if ((address & (SIZE_CART0 - 1)) == AGB_PRINT_FLUSH_ADDR && memory->agbPrint == 0x20) {
+			cpu->memory.activeRegion = (uint32_t*) _agbPrintFunc;
+			cpu->memory.activeMask = sizeof(_agbPrintFunc) - 1;
+
+		}
 	// Fall through
 	default:
 		memory->activeRegion = -1;
-		cpu->memory.activeRegion = _deadbeef;
+		cpu->memory.activeRegion = (uint32_t*) _deadbeef;
 		cpu->memory.activeMask = 0;
 
 		if (!gba->yankedRomSize && mCoreCallbacksListSize(&gba->coreCallbacks)) {
@@ -528,6 +546,16 @@ uint32_t GBALoad16(struct ARMCore* cpu, uint32_t address, int* cycleCounter) {
 			LOAD_16(value, address & memory->romMask, memory->rom);
 		} else if (memory->vfame.cartType) {
 			value = GBAVFameGetPatternValue(address, 16);
+		} else if ((address & (SIZE_CART0 - 1)) >= AGB_PRINT_BASE) {
+			uint32_t agbPrintAddr = address & 0x00FFFFFF;
+			if (agbPrintAddr == AGB_PRINT_PROTECT) {
+				value = memory->agbPrint;
+			} else if (agbPrintAddr < AGB_PRINT_TOP || (agbPrintAddr & 0x00FFFFF8) == (AGB_PRINT_STRUCT & 0x00FFFFF8)) {
+				value = _agbPrintLoad(gba, address);
+			} else {
+				mLOG(GBA_MEM, GAME_ERROR, "Out of bounds ROM Load16: 0x%08X", address);
+				value = (address >> 1) & 0xFFFF;
+			}
 		} else {
 			mLOG(GBA_MEM, GAME_ERROR, "Out of bounds ROM Load16: 0x%08X", address);
 			value = (address >> 1) & 0xFFFF;
@@ -838,9 +866,23 @@ void GBAStore16(struct ARMCore* cpu, uint32_t address, int16_t value, int* cycle
 		if (memory->hw.devices != HW_NONE && IS_GPIO_REGISTER(address & 0xFFFFFE)) {
 			uint32_t reg = address & 0xFFFFFE;
 			GBAHardwareGPIOWrite(&memory->hw, reg, value);
-		} else {
+			break;
-			mLOG(GBA_MEM, GAME_ERROR, "Bad cartridge Store16: 0x%08X", address);
 		}
+		// Fall through
+	case REGION_CART0_EX:
+		if ((address & 0x00FFFFFF) >= AGB_PRINT_BASE) {
+			uint32_t agbPrintAddr = address & 0x00FFFFFF;
+			if (agbPrintAddr == AGB_PRINT_PROTECT) {
+				memory->agbPrint = value;
+				_agbPrintStore(gba, address, value);
+				break;
+			}
+			if (memory->agbPrint == 0x20 && (agbPrintAddr < AGB_PRINT_TOP || (agbPrintAddr & 0x00FFFFF8) == (AGB_PRINT_STRUCT & 0x00FFFFF8))) {
+				_agbPrintStore(gba, address, value);
+				break;
+			}
+		}
+		mLOG(GBA_MEM, GAME_ERROR, "Bad cartridge Store16: 0x%08X", address);
 		break;
 	case REGION_CART2_EX:
 		if (memory->savedata.type == SAVEDATA_AUTODETECT) {
@@ -1595,3 +1637,50 @@ void _pristineCow(struct GBA* gba) {
 	gba->memory.rom = newRom;
 	gba->memory.hw.gpioBase = &((uint16_t*) gba->memory.rom)[GPIO_REG_DATA >> 1];
 }
+
+void GBAPrintFlush(struct GBA* gba) {
+	char oolBuf[0x101];
+	size_t i;
+	for (i = 0; gba->memory.agbPrintCtx.get != gba->memory.agbPrintCtx.put && i < 0x100; ++i) {
+		int16_t value;
+		LOAD_16(value, gba->memory.agbPrintCtx.get & -2, gba->memory.agbPrintBuffer);
+		if (gba->memory.agbPrintCtx.get & 1) {
+			value >>= 8;
+		} else {
+			value &= 0xFF;
+		}
+		oolBuf[i] = value;
+		++gba->memory.agbPrintCtx.get;
+	}
+	_agbPrintStore(gba, AGB_PRINT_STRUCT + 4, gba->memory.agbPrintCtx.get);
+
+	mLOG(GBA_DEBUG, INFO, "%s", oolBuf);
+}
+
+static void _agbPrintStore(struct GBA* gba, uint32_t address, int16_t value) {
+	struct GBAMemory* memory = &gba->memory;
+	if ((address & 0x00FFFFFF) < AGB_PRINT_TOP) {
+		if (!memory->agbPrintBuffer) {
+			memory->agbPrintBuffer = anonymousMemoryMap(SIZE_AGB_PRINT);
+		}
+		STORE_16(value, address & (SIZE_AGB_PRINT - 2), memory->agbPrintBuffer);
+	} else if ((address & 0x00FFFFF8) == (AGB_PRINT_STRUCT & 0x00FFFFF8)) {
+		(&memory->agbPrintCtx.request)[(address & 7) >> 1] = value;
+	}
+	if (memory->romSize == SIZE_CART0) {
+		_pristineCow(gba);
+		memcpy(&memory->rom[AGB_PRINT_FLUSH_ADDR >> 2], _agbPrintFunc, sizeof(_agbPrintFunc));
+		STORE_16(value, address & (SIZE_CART0 - 2), memory->rom);
+	}
+}
+
+static int16_t _agbPrintLoad(struct GBA* gba, uint32_t address) {
+	struct GBAMemory* memory = &gba->memory;
+	int16_t value = 0xFFFF;
+	if (address < AGB_PRINT_TOP) {
+		LOAD_16(value, address & (SIZE_AGB_PRINT - 1), memory->agbPrintBuffer);
+	} else if ((address & 0x00FFFFF8) == (AGB_PRINT_STRUCT & 0x00FFFFF8)) {
+		value = (&memory->agbPrintCtx.request)[(address & 7) >> 1];
+	}
+	return value;
+}