@@ -0,0 +1,72 @@
+#include "gba-audio.h"
+
+#include "gba.h"
+
+void GBAAudioInit(struct GBAAudio* audio) {
+	(void)(audio);
+}
+
+void GBAAudioDeinit(struct GBAAudio* audio) {
+	(void)(audio);	
+}
+
+void GBAAudioWriteSOUND1CNT_LO(struct GBAAudio* audio, uint16_t value) {
+	audio->ch1.sweep.packed = value;
+}
+
+void GBAAudioWriteSOUND1CNT_HI(struct GBAAudio* audio, uint16_t value) {
+	audio->ch1.wave.packed = value;
+}
+
+void GBAAudioWriteSOUND1CNT_X(struct GBAAudio* audio, uint16_t value) {
+	audio->ch1.control.packed = value;
+}
+
+void GBAAudioWriteSOUND2CNT_LO(struct GBAAudio* audio, uint16_t value) {
+	audio->ch2.wave.packed = value;
+}
+
+void GBAAudioWriteSOUND2CNT_HI(struct GBAAudio* audio, uint16_t value) {
+	audio->ch2.control.packed = value;
+}
+
+void GBAAudioWriteSOUND3CNT_LO(struct GBAAudio* audio, uint16_t value) {
+	audio->ch3.bank.packed = value;
+}
+
+void GBAAudioWriteSOUND3CNT_HI(struct GBAAudio* audio, uint16_t value) {
+	audio->ch3.wave.packed = value;
+}
+
+void GBAAudioWriteSOUND3CNT_X(struct GBAAudio* audio, uint16_t value) {
+	audio->ch3.control.packed = value;
+}
+
+void GBAAudioWriteSOUND4CNT_LO(struct GBAAudio* audio, uint16_t value) {
+	audio->ch4.wave.packed = value;
+}
+
+void GBAAudioWriteSOUND4CNT_HI(struct GBAAudio* audio, uint16_t value) {
+	audio->ch4.control.packed = value;
+}
+
+void GBAAudioWriteSOUNDCNT_LO(struct GBAAudio* audio, uint16_t value) {
+	GBALog(audio->p, GBA_LOG_STUB, "Audio unimplemented");
+}
+
+void GBAAudioWriteSOUNDCNT_HI(struct GBAAudio* audio, uint16_t value) {
+	GBALog(audio->p, GBA_LOG_STUB, "Audio unimplemented");
+}
+
+void GBAAudioWriteSOUNDCNT_X(struct GBAAudio* audio, uint16_t value) {
+	GBALog(audio->p, GBA_LOG_STUB, "Audio unimplemented");
+}
+
+void GBAAudioWriteWaveRAM(struct GBAAudio* audio, int address, uint32_t value) {
+	GBALog(audio->p, GBA_LOG_STUB, "Audio unimplemented");
+}
+
+void GBAAudioWriteFIFO(struct GBAAudio* audio, int address, uint32_t value) {
+	GBALog(audio->p, GBA_LOG_STUB, "Audio unimplemented");
+}
+

@@ -0,0 +1,132 @@
+#ifndef GBA_AUDIO_H
+#define GBA_AUDIO_H
+
+#include <stdint.h>
+
+union GBAAudioWave {
+	struct {
+		unsigned length : 6;
+		unsigned duty : 2;
+		unsigned stepTime : 3;
+		unsigned direction : 1;
+		unsigned initialVolume : 4;
+	};
+	uint16_t packed;
+};
+
+union GBAAudioSquareControl {
+	struct {
+		unsigned frequency : 11;
+		unsigned : 3;
+		unsigned stop : 1;
+		unsigned restart : 1;
+	};
+	uint16_t packed;
+};
+
+struct GBAAudioChannel1 {
+	union GBAAudioSquareSweep {
+		struct {
+			unsigned shift : 3;
+			unsigned direction : 1;
+			unsigned time : 3;
+			unsigned : 9;
+		};
+		uint16_t packed;
+	} sweep;
+
+	union GBAAudioWave wave;
+	union GBAAudioSquareControl control;
+};
+
+struct GBAAudioChannel2 {
+	union GBAAudioWave wave;
+	union GBAAudioSquareControl control;
+};
+
+struct GBAAudioChannel3 {
+	union {
+		struct {
+			unsigned : 5;
+			unsigned size : 1;
+			unsigned bank : 1;
+			unsigned disable : 1;
+			unsigned : 7;
+		};
+		uint16_t packed;
+	} bank;
+
+	union {
+		struct {
+			unsigned length : 8;
+			unsigned : 5;
+			unsigned volume : 3;
+			unsigned disable : 1;
+			unsigned : 7;
+		};
+		uint16_t packed;
+	} wave;
+
+	union {
+		struct {
+			unsigned rate : 11;
+			unsigned : 3;
+			unsigned stop : 1;
+			unsigned restart : 1;
+		};
+		uint16_t packed;
+	} control;
+};
+
+struct GBAAudioChannel4 {
+	union GBAAudioWave wave;
+	union {
+		struct {
+			unsigned ratio : 3;
+			unsigned power : 1;
+			unsigned frequency : 4;
+			unsigned : 6;
+			unsigned stop : 1;
+			unsigned restart : 1;
+		};
+		uint16_t packed;
+	} control;
+};
+
+struct GBAAudioFIFO {
+
+};
+
+struct GBAAudio {
+	struct GBA* p;
+
+	struct GBAAudioChannel1 ch1;
+	struct GBAAudioChannel2 ch2;
+	struct GBAAudioChannel3 ch3;
+	struct GBAAudioChannel4 ch4;
+
+	struct GBAAudioFIFO chA;
+	struct GBAAudioFIFO chB;
+};
+
+void GBAAudioInit(struct GBAAudio* audio);
+void GBAAudioDeinit(struct GBAAudio* audio);
+
+void GBAAudioWriteSOUND1CNT_LO(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUND1CNT_HI(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUND1CNT_X(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUND2CNT_LO(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUND2CNT_HI(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUND3CNT_LO(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUND3CNT_HI(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUND3CNT_X(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUND4CNT_LO(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUND4CNT_HI(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUNDCNT_LO(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUNDCNT_HI(struct GBAAudio* audio, uint16_t value);
+void GBAAudioWriteSOUNDCNT_X(struct GBAAudio* audio, uint16_t value);
+
+void GBAAudioWriteWaveRAM(struct GBAAudio* audio, int address, uint32_t value);
+void GBAAudioWriteFIFO(struct GBAAudio* audio, int address, uint32_t value);
+
+#endif

@@ -17,6 +17,65 @@ case REG_DISPSTAT:
 			GBAVideoWriteDISPSTAT(&gba->video, value);
 			break;
 
+		// Audio
+		case REG_SOUND1CNT_LO:
+			GBAAudioWriteSOUND1CNT_LO(&gba->audio, value);
+			break;
+		case REG_SOUND1CNT_HI:
+			GBAAudioWriteSOUND1CNT_HI(&gba->audio, value);
+			break;
+		case REG_SOUND1CNT_X:
+			GBAAudioWriteSOUND1CNT_X(&gba->audio, value);
+			break;
+		case REG_SOUND2CNT_LO:
+			GBAAudioWriteSOUND2CNT_LO(&gba->audio, value);
+			break;
+		case REG_SOUND2CNT_HI:
+			GBAAudioWriteSOUND2CNT_HI(&gba->audio, value);
+			break;
+		case REG_SOUND3CNT_LO:
+			GBAAudioWriteSOUND3CNT_LO(&gba->audio, value);
+			break;
+		case REG_SOUND3CNT_HI:
+			GBAAudioWriteSOUND3CNT_HI(&gba->audio, value);
+			break;
+		case REG_SOUND3CNT_X:
+			GBAAudioWriteSOUND3CNT_X(&gba->audio, value);
+			break;
+		case REG_SOUND4CNT_LO:
+			GBAAudioWriteSOUND4CNT_LO(&gba->audio, value);
+			break;
+		case REG_SOUND4CNT_HI:
+			GBAAudioWriteSOUND4CNT_HI(&gba->audio, value);
+			break;
+		case REG_SOUNDCNT_LO:
+			GBAAudioWriteSOUNDCNT_LO(&gba->audio, value);
+			break;
+		case REG_SOUNDCNT_HI:
+			GBAAudioWriteSOUNDCNT_HI(&gba->audio, value);
+			break;
+		case REG_SOUNDCNT_X:
+			GBAAudioWriteSOUNDCNT_X(&gba->audio, value);
+			break;
+
+		case REG_WAVE_RAM0_LO:
+		case REG_WAVE_RAM1_LO:
+		case REG_WAVE_RAM2_LO:
+		case REG_WAVE_RAM3_LO:
+		case REG_FIFO_A_LO:
+		case REG_FIFO_B_LO:
+			GBAIOWrite32(gba, address, (gba->memory.io[(address >> 1) + 1] << 16) | value);
+			break;
+
+		case REG_WAVE_RAM0_HI:
+		case REG_WAVE_RAM1_HI:
+		case REG_WAVE_RAM2_HI:
+		case REG_WAVE_RAM3_HI:
+		case REG_FIFO_A_HI:
+		case REG_FIFO_B_HI:
+			GBAIOWrite32(gba, address - 2, gba->memory.io[(address >> 1) - 1] | (value << 16));
+			break;
+
 		// DMA
 		case REG_DMA0SAD_LO:
 		case REG_DMA0DAD_LO:
@@ -137,6 +196,24 @@ }
 
 void GBAIOWrite32(struct GBA* gba, uint32_t address, uint32_t value) {
 	switch (address) {
+	case REG_WAVE_RAM0_LO:
+		GBAAudioWriteWaveRAM(&gba->audio, 0, value);
+		break;
+	case REG_WAVE_RAM1_LO:
+		GBAAudioWriteWaveRAM(&gba->audio, 1, value);
+		break;
+	case REG_WAVE_RAM2_LO:
+		GBAAudioWriteWaveRAM(&gba->audio, 2, value);
+		break;
+	case REG_WAVE_RAM3_LO:
+		GBAAudioWriteWaveRAM(&gba->audio, 3, value);
+		break;
+	case REG_FIFO_A_LO:
+		GBAAudioWriteFIFO(&gba->audio, 0, value);
+		break;
+	case REG_FIFO_B_LO:
+		GBAAudioWriteFIFO(&gba->audio, 1, value);
+		break;
 	case REG_DMA0SAD_LO:
 		GBAMemoryWriteDMASAD(&gba->memory, 0, value);
 		break;

@@ -40,6 +40,9 @@
 	gba->video.p = gba;
 	GBAVideoInit(&gba->video);
 
+	gba->audio.p = gba;
+	GBAAudioInit(&gba->audio);
+
 	GBAIOInit(gba);
 
 	memset(gba->timers, 0, sizeof(gba->timers));

@@ -5,6 +5,7 @@ #include "arm.h"
 
 #include "gba-memory.h"
 #include "gba-video.h"
+#include "gba-audio.h"
 
 enum GBAIRQ {
 	IRQ_VBLANK = 0x0,
@@ -61,6 +62,7 @@ struct ARMCore cpu;
 	struct GBABoard board;
 	struct GBAMemory memory;
 	struct GBAVideo video;
+	struct GBAAudio audio;
 
 	struct ARMDebugger* debugger;