M CHANGES → CHANGES

@@ -30,6 +30,7 @@ - GB Memory: Fix starting HDMAs during mode 0
  - Qt: Fix Qt Multimedia audio driver on big endian
  - GBA: Fix IRQs firing after already being cleared
  - All: Fix fullscreen config option being ignored
+ - GBA BIOS: Implement BitUnPack
 Misc:
  - SDL: Remove scancode key input
  - GBA Video: Clean up unused timers

M src/gba/bios.c → src/gba/bios.c

@@ -20,6 +20,7 @@ static void _unLz77(struct GBA* gba, int width);
 static void _unHuffman(struct GBA* gba);
 static void _unRl(struct GBA* gba, int width);
 static void _unFilter(struct GBA* gba, int inwidth, int outwidth);
+static void _unBitPack(struct GBA* gba);
 
 static void _SoftReset(struct GBA* gba) {
 	struct ARMCore* cpu = gba->cpu;
@@ -385,6 +386,22 @@ break;
 	case 0xF:
 		_ObjAffineSet(gba);
 		break;
+	case 0x10:
+		if (cpu->gprs[0] < BASE_WORKING_RAM) {
+			mLOG(GBA_BIOS, GAME_ERROR, "Bad BitUnPack source");
+			break;
+		}
+		switch (cpu->gprs[1] >> BASE_OFFSET) {
+		default:
+			mLOG(GBA_BIOS, GAME_ERROR, "Bad BitUnPack destination");
+		// Fall through
+		case REGION_WORKING_RAM:
+		case REGION_WORKING_IRAM:
+		case REGION_VRAM:
+			_unBitPack(gba);
+			break;
+		}
+		break;
 	case 0x11:
 	case 0x12:
 		if (cpu->gprs[0] < BASE_WORKING_RAM) {
@@ -736,3 +753,63 @@ }
 	cpu->gprs[0] = source;
 	cpu->gprs[1] = dest;
 }
+
+static void _unBitPack(struct GBA* gba) {
+	struct ARMCore* cpu = gba->cpu;
+	uint32_t source = cpu->gprs[0];
+	uint32_t dest = cpu->gprs[1];
+	uint32_t info = cpu->gprs[2];
+	unsigned sourceLen = cpu->memory.load16(cpu, info, 0);
+	unsigned sourceWidth = cpu->memory.load8(cpu, info + 2, 0);
+	unsigned destWidth = cpu->memory.load8(cpu, info + 3, 0);
+	switch (sourceWidth) {
+	case 1:
+	case 2:
+	case 4:
+	case 8:
+		break;
+	default:
+		mLOG(GBA_BIOS, GAME_ERROR, "Bad BitUnPack source width: %u", sourceWidth);
+		return;
+	}
+	switch (destWidth) {
+	case 1:
+	case 2:
+	case 4:
+	case 8:
+	case 16:
+	case 32:
+		break;
+	default:
+		mLOG(GBA_BIOS, GAME_ERROR, "Bad BitUnPack destination width: %u", destWidth);
+		return;
+	}
+	uint32_t bias = cpu->memory.load32(cpu, info + 4, 0);
+	uint8_t in = 0;
+	uint32_t out = 0;
+	int bitsRemaining = 0;
+	int bitsEaten = 0;
+	while (sourceLen > 0) {
+		if (!bitsRemaining) {
+			in = cpu->memory.load8(cpu, source, 0);
+			bitsRemaining = 8;
+			++source;
+			--sourceLen;
+		}
+		unsigned scaled = in & ((1 << sourceWidth) - 1);
+		in >>= sourceWidth;
+		if (scaled || bias & 0x80000000) {
+			scaled += bias & 0x7FFFFFFF;
+			scaled &= (1 << destWidth) - 1;
+		}
+		bitsRemaining -= sourceWidth;
+		out |= scaled << bitsEaten;
+		bitsEaten += destWidth;
+		if (bitsEaten == 32) {
+			cpu->memory.store32(cpu, dest, out, 0);
+			bitsEaten = 0;
+			out = 0;
+			dest += 4;
+		}
+	}
+}