M src/gba/gba-io.c → src/gba/gba-io.c

@@ -2,17 +2,24 @@ #include "gba-io.h"
 
 void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value) {
 	switch (address) {
+	case REG_WAITCNT:
+		GBAAdjustWaitstates(&gba->memory, value);
+		break;
 	default:
 		GBALog(GBA_LOG_STUB, "Stub I/O register write: %03x", address);
 		break;
 	}
+	gba->memory.io[address >> 1] = value;
 }
 
 uint16_t GBAIORead(struct GBA* gba, uint32_t address) {
 	switch (address) {
+	case REG_WAITCNT:
+		// Handled transparently by registers
+		break;
 	default:
 		GBALog(GBA_LOG_STUB, "Stub I/O register read: %03x", address);
 		break;
 	}
-	return 0;
+	return gba->memory.io[address >> 1];
 }

M src/gba/gba-memory.c → src/gba/gba-memory.c

@@ -11,6 +11,8 @@ static void GBASetActiveRegion(struct ARMMemory* memory, uint32_t region);
 
 static const char GBA_BASE_WAITSTATES[16] = { 0, 0, 2, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4, 4, 4 };
 static const char GBA_BASE_WAITSTATES_SEQ[16] = { 0, 0, 2, 0, 0, 0, 0, 0, 2, 2, 4, 4, 8, 8, 4 };
+static const char GBA_ROM_WAITSTATES[] = { 4, 3, 2, 8 };
+static const char GBA_ROM_WAITSTATES_SEQ[] = { 2, 1, 4, 1, 8, 1 };
 
 void GBAMemoryInit(struct GBAMemory* memory) {
 	memory->d.load32 = GBALoad32;
@@ -48,9 +50,12 @@ memory->waitstates32[i] = 0;
 		memory->waitstatesSeq32[i] = 0;
 	}
 
+	memory->activeRegion = 0;
 	memory->d.activeRegion = 0;
 	memory->d.activeMask = 0;
 	memory->d.setActiveRegion = GBASetActiveRegion;
+	memory->d.activePrefetchCycles32 = 0;
+	memory->d.activePrefetchCycles16 = 0;
 }
 
 void GBAMemoryDeinit(struct GBAMemory* memory) {
@@ -63,6 +68,7 @@ struct GBAMemory* gbaMemory = (struct GBAMemory*) memory;
 
 	memory->activePrefetchCycles32 = gbaMemory->waitstates32[address >> BASE_OFFSET];
 	memory->activePrefetchCycles16 = gbaMemory->waitstates16[address >> BASE_OFFSET];
+	gbaMemory->activeRegion = address >> BASE_OFFSET;
 	switch (address & ~OFFSET_MASK) {
 	case BASE_BIOS:
 		memory->activeRegion = gbaMemory->bios;
@@ -351,3 +357,38 @@ default:
 		break;
 	}
 }
+
+void GBAAdjustWaitstates(struct GBAMemory* memory, uint16_t parameters) {
+	int sram = parameters & 0x0003;
+	int ws0 = (parameters & 0x000C) >> 2;
+	int ws0seq = (parameters & 0x0010) >> 4;
+	int ws1 = (parameters & 0x0060) >> 5;
+	int ws1seq = (parameters & 0x0080) >> 7;
+	int ws2 = (parameters & 0x0300) >> 8;
+	int ws2seq = (parameters & 0x0400) >> 10;
+	int prefetch = parameters & 0x4000;
+
+	memory->waitstates16[REGION_CART_SRAM] =  GBA_ROM_WAITSTATES[sram];
+	memory->waitstatesSeq16[REGION_CART_SRAM] = GBA_ROM_WAITSTATES[sram];
+	memory->waitstates32[REGION_CART_SRAM] = 2 * GBA_ROM_WAITSTATES[sram] + 1;
+	memory->waitstatesSeq32[REGION_CART_SRAM] = 2 * GBA_ROM_WAITSTATES[sram] + 1;
+
+	memory->waitstates16[REGION_CART0] = memory->waitstates16[REGION_CART0_EX] = GBA_ROM_WAITSTATES[ws0];
+	memory->waitstates16[REGION_CART1] = memory->waitstates16[REGION_CART1_EX] = GBA_ROM_WAITSTATES[ws1];
+	memory->waitstates16[REGION_CART2] = memory->waitstates16[REGION_CART2_EX] = GBA_ROM_WAITSTATES[ws2];
+
+	memory->waitstatesSeq16[REGION_CART0] = memory->waitstatesSeq16[REGION_CART0_EX] = GBA_ROM_WAITSTATES_SEQ[ws0seq];
+	memory->waitstatesSeq16[REGION_CART1] = memory->waitstatesSeq16[REGION_CART1_EX] = GBA_ROM_WAITSTATES_SEQ[ws1seq + 2];
+	memory->waitstatesSeq16[REGION_CART2] = memory->waitstatesSeq16[REGION_CART2_EX] = GBA_ROM_WAITSTATES_SEQ[ws2seq + 4];
+
+	memory->waitstates32[REGION_CART0] = memory->waitstates32[REGION_CART0_EX] = memory->waitstates16[REGION_CART0] + 1 + memory->waitstatesSeq16[REGION_CART0];
+	memory->waitstates32[REGION_CART1] = memory->waitstates32[REGION_CART1_EX] = memory->waitstates16[REGION_CART1] + 1 + memory->waitstatesSeq16[REGION_CART1];
+	memory->waitstates32[REGION_CART2] = memory->waitstates32[REGION_CART2_EX] = memory->waitstates16[REGION_CART2] + 1 + memory->waitstatesSeq16[REGION_CART2];
+
+	memory->waitstatesSeq32[REGION_CART0] = memory->waitstatesSeq32[REGION_CART0 + 1] = 2 * memory->waitstatesSeq16[REGION_CART0] + 1;
+	memory->waitstatesSeq32[REGION_CART1] = memory->waitstatesSeq32[REGION_CART1 + 1] = 2 * memory->waitstatesSeq16[REGION_CART1] + 1;
+	memory->waitstatesSeq32[REGION_CART2] = memory->waitstatesSeq32[REGION_CART2 + 1] = 2 * memory->waitstatesSeq16[REGION_CART2] + 1;
+
+	memory->d.activePrefetchCycles32 = memory->waitstates32[memory->activeRegion];
+	memory->d.activePrefetchCycles16 = memory->waitstates16[memory->activeRegion];
+}

M src/gba/gba-memory.h → src/gba/gba-memory.h

@@ -73,6 +73,7 @@ char waitstates32[256];
 	char waitstates16[256];
 	char waitstatesSeq32[256];
 	char waitstatesSeq16[256];
+	int activeRegion;
 };
 
 int32_t GBALoad32(struct ARMMemory* memory, uint32_t address);
@@ -84,5 +85,7 @@
 void GBAStore32(struct ARMMemory* memory, uint32_t address, int32_t value);
 void GBAStore16(struct ARMMemory* memory, uint32_t address, int16_t value);
 void GBAStore8(struct ARMMemory* memory, uint32_t address, int8_t value);
+
+void GBAAdjustWaitstates(struct GBAMemory* memory, uint16_t parameters);
 
 #endif

M src/gba/gba.c → src/gba/gba.c

@@ -17,8 +17,6 @@ };
 
 static void GBAHitStub(struct ARMBoard* board, uint32_t opcode);
 
-static void _GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value);
-
 void GBAInit(struct GBA* gba) {
 	gba->errno = GBA_NO_ERROR;
 	gba->errstr = 0;