all repos — mgba @ 31dc70e6370239292dee9649b54e28ff71f08073

mGBA Game Boy Advance Emulator

src/gba/bios.c (view raw)

  1/* Copyright (c) 2013-2015 Jeffrey Pfau
  2 *
  3 * This Source Code Form is subject to the terms of the Mozilla Public
  4 * License, v. 2.0. If a copy of the MPL was not distributed with this
  5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
  6#include <mgba/internal/gba/bios.h>
  7
  8#include <mgba/internal/arm/isa-inlines.h>
  9#include <mgba/internal/arm/macros.h>
 10#include <mgba/internal/gba/gba.h>
 11#include <mgba/internal/gba/io.h>
 12#include <mgba/internal/gba/memory.h>
 13
 14const uint32_t GBA_BIOS_CHECKSUM = 0xBAAE187F;
 15const uint32_t GBA_DS_BIOS_CHECKSUM = 0xBAAE1880;
 16
 17mLOG_DEFINE_CATEGORY(GBA_BIOS, "GBA BIOS", "gba.bios");
 18
 19static void _unLz77(struct GBA* gba, int width);
 20static void _unHuffman(struct GBA* gba);
 21static void _unRl(struct GBA* gba, int width);
 22static void _unFilter(struct GBA* gba, int inwidth, int outwidth);
 23static void _unBitPack(struct GBA* gba);
 24
 25static void _SoftReset(struct GBA* gba) {
 26	struct ARMCore* cpu = gba->cpu;
 27	ARMSetPrivilegeMode(cpu, MODE_IRQ);
 28	cpu->spsr.packed = 0;
 29	cpu->gprs[ARM_LR] = 0;
 30	cpu->gprs[ARM_SP] = SP_BASE_IRQ;
 31	ARMSetPrivilegeMode(cpu, MODE_SUPERVISOR);
 32	cpu->spsr.packed = 0;
 33	cpu->gprs[ARM_LR] = 0;
 34	cpu->gprs[ARM_SP] = SP_BASE_SUPERVISOR;
 35	ARMSetPrivilegeMode(cpu, MODE_SYSTEM);
 36	cpu->gprs[ARM_LR] = 0;
 37	cpu->gprs[ARM_SP] = SP_BASE_SYSTEM;
 38	int8_t flag = ((int8_t*) gba->memory.iwram)[0x7FFA];
 39	memset(((int8_t*) gba->memory.iwram) + SIZE_WORKING_IRAM - 0x200, 0, 0x200);
 40	if (flag) {
 41		cpu->gprs[ARM_PC] = BASE_WORKING_RAM;
 42	} else {
 43		cpu->gprs[ARM_PC] = BASE_CART0;
 44	}
 45	_ARMSetMode(cpu, MODE_ARM);
 46	ARMWritePC(cpu);
 47}
 48
 49static void _RegisterRamReset(struct GBA* gba) {
 50	uint32_t registers = gba->cpu->gprs[0];
 51	struct ARMCore* cpu = gba->cpu;
 52	cpu->memory.store16(cpu, BASE_IO | REG_DISPCNT, 0x0080, 0);
 53	if (registers & 0x01) {
 54		memset(gba->memory.wram, 0, SIZE_WORKING_RAM);
 55	}
 56	if (registers & 0x02) {
 57		memset(gba->memory.iwram, 0, SIZE_WORKING_IRAM - 0x200);
 58	}
 59	if (registers & 0x04) {
 60		memset(gba->video.palette, 0, SIZE_PALETTE_RAM);
 61	}
 62	if (registers & 0x08) {
 63		memset(gba->video.vram, 0, SIZE_VRAM);
 64	}
 65	if (registers & 0x10) {
 66		memset(gba->video.oam.raw, 0, SIZE_OAM);
 67	}
 68	if (registers & 0x20) {
 69		cpu->memory.store16(cpu, BASE_IO | REG_SIOCNT, 0x0000, 0);
 70		cpu->memory.store16(cpu, BASE_IO | REG_RCNT, RCNT_INITIAL, 0);
 71		cpu->memory.store16(cpu, BASE_IO | REG_SIOMLT_SEND, 0, 0);
 72		cpu->memory.store16(cpu, BASE_IO | REG_JOYCNT, 0, 0);
 73		cpu->memory.store32(cpu, BASE_IO | REG_JOY_RECV_LO, 0, 0);
 74		cpu->memory.store32(cpu, BASE_IO | REG_JOY_TRANS_LO, 0, 0);
 75	}
 76	if (registers & 0x40) {
 77		cpu->memory.store16(cpu, BASE_IO | REG_SOUND1CNT_LO, 0, 0);
 78		cpu->memory.store16(cpu, BASE_IO | REG_SOUND1CNT_HI, 0, 0);
 79		cpu->memory.store16(cpu, BASE_IO | REG_SOUND1CNT_X, 0, 0);
 80		cpu->memory.store16(cpu, BASE_IO | REG_SOUND2CNT_LO, 0, 0);
 81		cpu->memory.store16(cpu, BASE_IO | REG_SOUND2CNT_HI, 0, 0);
 82		cpu->memory.store16(cpu, BASE_IO | REG_SOUND3CNT_LO, 0, 0);
 83		cpu->memory.store16(cpu, BASE_IO | REG_SOUND3CNT_HI, 0, 0);
 84		cpu->memory.store16(cpu, BASE_IO | REG_SOUND3CNT_X, 0, 0);
 85		cpu->memory.store16(cpu, BASE_IO | REG_SOUND4CNT_LO, 0, 0);
 86		cpu->memory.store16(cpu, BASE_IO | REG_SOUND4CNT_HI, 0, 0);
 87		cpu->memory.store16(cpu, BASE_IO | REG_SOUNDCNT_LO, 0, 0);
 88		cpu->memory.store16(cpu, BASE_IO | REG_SOUNDCNT_HI, 0, 0);
 89		cpu->memory.store16(cpu, BASE_IO | REG_SOUNDCNT_X, 0, 0);
 90		cpu->memory.store16(cpu, BASE_IO | REG_SOUNDBIAS, 0x200, 0);
 91		memset(gba->audio.psg.ch3.wavedata32, 0, sizeof(gba->audio.psg.ch3.wavedata32));
 92	}
 93	if (registers & 0x80) {
 94		cpu->memory.store16(cpu, BASE_IO | 0x04, 0, 0);
 95		cpu->memory.store16(cpu, BASE_IO | 0x06, 0, 0);
 96		cpu->memory.store16(cpu, BASE_IO | 0x08, 0, 0);
 97		cpu->memory.store16(cpu, BASE_IO | 0x0A, 0, 0);
 98		cpu->memory.store16(cpu, BASE_IO | 0x0C, 0, 0);
 99		cpu->memory.store16(cpu, BASE_IO | 0x0E, 0, 0);
100		cpu->memory.store16(cpu, BASE_IO | 0x10, 0, 0);
101		cpu->memory.store16(cpu, BASE_IO | 0x12, 0, 0);
102		cpu->memory.store16(cpu, BASE_IO | 0x14, 0, 0);
103		cpu->memory.store16(cpu, BASE_IO | 0x16, 0, 0);
104		cpu->memory.store16(cpu, BASE_IO | 0x18, 0, 0);
105		cpu->memory.store16(cpu, BASE_IO | 0x1A, 0, 0);
106		cpu->memory.store16(cpu, BASE_IO | 0x1C, 0, 0);
107		cpu->memory.store16(cpu, BASE_IO | 0x1E, 0, 0);
108		cpu->memory.store16(cpu, BASE_IO | REG_BG2PA, 0x100, 0);
109		cpu->memory.store16(cpu, BASE_IO | REG_BG2PB, 0, 0);
110		cpu->memory.store16(cpu, BASE_IO | REG_BG2PC, 0, 0);
111		cpu->memory.store16(cpu, BASE_IO | REG_BG2PD, 0x100, 0);
112		cpu->memory.store32(cpu, BASE_IO | 0x28, 0, 0);
113		cpu->memory.store32(cpu, BASE_IO | 0x2C, 0, 0);
114		cpu->memory.store16(cpu, BASE_IO | REG_BG3PA, 0x100, 0);
115		cpu->memory.store16(cpu, BASE_IO | REG_BG3PB, 0, 0);
116		cpu->memory.store16(cpu, BASE_IO | REG_BG3PC, 0, 0);
117		cpu->memory.store16(cpu, BASE_IO | REG_BG3PD, 0x100, 0);
118		cpu->memory.store32(cpu, BASE_IO | 0x38, 0, 0);
119		cpu->memory.store32(cpu, BASE_IO | 0x3C, 0, 0);
120		cpu->memory.store16(cpu, BASE_IO | 0x40, 0, 0);
121		cpu->memory.store16(cpu, BASE_IO | 0x42, 0, 0);
122		cpu->memory.store16(cpu, BASE_IO | 0x44, 0, 0);
123		cpu->memory.store16(cpu, BASE_IO | 0x46, 0, 0);
124		cpu->memory.store16(cpu, BASE_IO | 0x48, 0, 0);
125		cpu->memory.store16(cpu, BASE_IO | 0x4A, 0, 0);
126		cpu->memory.store16(cpu, BASE_IO | 0x4C, 0, 0);
127		cpu->memory.store16(cpu, BASE_IO | 0x50, 0, 0);
128		cpu->memory.store16(cpu, BASE_IO | 0x52, 0, 0);
129		cpu->memory.store16(cpu, BASE_IO | 0x54, 0, 0);
130		cpu->memory.store16(cpu, BASE_IO | 0xB0, 0, 0);
131		cpu->memory.store16(cpu, BASE_IO | 0xB2, 0, 0);
132		cpu->memory.store16(cpu, BASE_IO | 0xB4, 0, 0);
133		cpu->memory.store16(cpu, BASE_IO | 0xB6, 0, 0);
134		cpu->memory.store16(cpu, BASE_IO | 0xB8, 0, 0);
135		cpu->memory.store16(cpu, BASE_IO | 0xBA, 0, 0);
136		cpu->memory.store16(cpu, BASE_IO | 0xBC, 0, 0);
137		cpu->memory.store16(cpu, BASE_IO | 0xBE, 0, 0);
138		cpu->memory.store16(cpu, BASE_IO | 0xC0, 0, 0);
139		cpu->memory.store16(cpu, BASE_IO | 0xC2, 0, 0);
140		cpu->memory.store16(cpu, BASE_IO | 0xC4, 0, 0);
141		cpu->memory.store16(cpu, BASE_IO | 0xC6, 0, 0);
142		cpu->memory.store16(cpu, BASE_IO | 0xC8, 0, 0);
143		cpu->memory.store16(cpu, BASE_IO | 0xCA, 0, 0);
144		cpu->memory.store16(cpu, BASE_IO | 0xCC, 0, 0);
145		cpu->memory.store16(cpu, BASE_IO | 0xCE, 0, 0);
146		cpu->memory.store16(cpu, BASE_IO | 0xD0, 0, 0);
147		cpu->memory.store16(cpu, BASE_IO | 0xD2, 0, 0);
148		cpu->memory.store16(cpu, BASE_IO | 0xD4, 0, 0);
149		cpu->memory.store16(cpu, BASE_IO | 0xD6, 0, 0);
150		cpu->memory.store16(cpu, BASE_IO | 0xD8, 0, 0);
151		cpu->memory.store16(cpu, BASE_IO | 0xDA, 0, 0);
152		cpu->memory.store16(cpu, BASE_IO | 0xDC, 0, 0);
153		cpu->memory.store16(cpu, BASE_IO | 0xDE, 0, 0);
154		cpu->memory.store16(cpu, BASE_IO | 0x100, 0, 0);
155		cpu->memory.store16(cpu, BASE_IO | 0x102, 0, 0);
156		cpu->memory.store16(cpu, BASE_IO | 0x104, 0, 0);
157		cpu->memory.store16(cpu, BASE_IO | 0x106, 0, 0);
158		cpu->memory.store16(cpu, BASE_IO | 0x108, 0, 0);
159		cpu->memory.store16(cpu, BASE_IO | 0x10A, 0, 0);
160		cpu->memory.store16(cpu, BASE_IO | 0x10C, 0, 0);
161		cpu->memory.store16(cpu, BASE_IO | 0x10E, 0, 0);
162		cpu->memory.store16(cpu, BASE_IO | 0x200, 0, 0);
163		cpu->memory.store16(cpu, BASE_IO | 0x202, 0xFFFF, 0);
164		cpu->memory.store16(cpu, BASE_IO | 0x204, 0, 0);
165		cpu->memory.store16(cpu, BASE_IO | 0x208, 0, 0);
166	}
167}
168
169static void _BgAffineSet(struct GBA* gba) {
170	struct ARMCore* cpu = gba->cpu;
171	int i = cpu->gprs[2];
172	float ox, oy;
173	float cx, cy;
174	float sx, sy;
175	float theta;
176	int offset = cpu->gprs[0];
177	int destination = cpu->gprs[1];
178	float a, b, c, d;
179	float rx, ry;
180	while (i--) {
181		// [ sx   0  0 ]   [ cos(theta)  -sin(theta)  0 ]   [ 1  0  cx - ox ]   [ A B rx ]
182		// [  0  sy  0 ] * [ sin(theta)   cos(theta)  0 ] * [ 0  1  cy - oy ] = [ C D ry ]
183		// [  0   0  1 ]   [     0            0       1 ]   [ 0  0     1    ]   [ 0 0  1 ]
184		ox = (int32_t) cpu->memory.load32(cpu, offset, 0) / 256.f;
185		oy = (int32_t) cpu->memory.load32(cpu, offset + 4, 0) / 256.f;
186		cx = (int16_t) cpu->memory.load16(cpu, offset + 8, 0);
187		cy = (int16_t) cpu->memory.load16(cpu, offset + 10, 0);
188		sx = (int16_t) cpu->memory.load16(cpu, offset + 12, 0) / 256.f;
189		sy = (int16_t) cpu->memory.load16(cpu, offset + 14, 0) / 256.f;
190		theta = (cpu->memory.load16(cpu, offset + 16, 0) >> 8) / 128.f * M_PI;
191		offset += 20;
192		// Rotation
193		a = d = cosf(theta);
194		b = c = sinf(theta);
195		// Scale
196		a *= sx;
197		b *= -sx;
198		c *= sy;
199		d *= sy;
200		// Translate
201		rx = ox - (a * cx + b * cy);
202		ry = oy - (c * cx + d * cy);
203		cpu->memory.store16(cpu, destination, a * 256, 0);
204		cpu->memory.store16(cpu, destination + 2, b * 256, 0);
205		cpu->memory.store16(cpu, destination + 4, c * 256, 0);
206		cpu->memory.store16(cpu, destination + 6, d * 256, 0);
207		cpu->memory.store32(cpu, destination + 8, rx * 256, 0);
208		cpu->memory.store32(cpu, destination + 12, ry * 256, 0);
209		destination += 16;
210	}
211}
212
213static void _ObjAffineSet(struct GBA* gba) {
214	struct ARMCore* cpu = gba->cpu;
215	int i = cpu->gprs[2];
216	float sx, sy;
217	float theta;
218	int offset = cpu->gprs[0];
219	int destination = cpu->gprs[1];
220	int diff = cpu->gprs[3];
221	float a, b, c, d;
222	while (i--) {
223		// [ sx   0 ]   [ cos(theta)  -sin(theta) ]   [ A B ]
224		// [  0  sy ] * [ sin(theta)   cos(theta) ] = [ C D ]
225		sx = (int16_t) cpu->memory.load16(cpu, offset, 0) / 256.f;
226		sy = (int16_t) cpu->memory.load16(cpu, offset + 2, 0) / 256.f;
227		theta = (cpu->memory.load16(cpu, offset + 4, 0) >> 8) / 128.f * M_PI;
228		offset += 8;
229		// Rotation
230		a = d = cosf(theta);
231		b = c = sinf(theta);
232		// Scale
233		a *= sx;
234		b *= -sx;
235		c *= sy;
236		d *= sy;
237		cpu->memory.store16(cpu, destination, a * 256, 0);
238		cpu->memory.store16(cpu, destination + diff, b * 256, 0);
239		cpu->memory.store16(cpu, destination + diff * 2, c * 256, 0);
240		cpu->memory.store16(cpu, destination + diff * 3, d * 256, 0);
241		destination += diff * 4;
242	}
243}
244
245static void _MidiKey2Freq(struct GBA* gba) {
246	struct ARMCore* cpu = gba->cpu;
247
248	int oldRegion = gba->memory.activeRegion;
249	gba->memory.activeRegion = REGION_BIOS;
250	uint32_t key = cpu->memory.load32(cpu, cpu->gprs[0] + 4, 0);
251	gba->memory.activeRegion = oldRegion;
252
253	cpu->gprs[0] = key / exp2f((180.f - cpu->gprs[1] - cpu->gprs[2] / 256.f) / 12.f);
254}
255
256static void _Div(struct GBA* gba, int32_t num, int32_t denom) {
257	struct ARMCore* cpu = gba->cpu;
258	if (denom != 0 && (denom != -1 || num != INT32_MIN)) {
259		div_t result = div(num, denom);
260		cpu->gprs[0] = result.quot;
261		cpu->gprs[1] = result.rem;
262		cpu->gprs[3] = abs(result.quot);
263	} else if (denom == 0) {
264		mLOG(GBA_BIOS, GAME_ERROR, "Attempting to divide %i by zero!", num);
265		// If abs(num) > 1, this should hang, but that would be painful to
266		// emulate in HLE, and no game will get into a state where it hangs...
267		cpu->gprs[0] = (num < 0) ? -1 : 1;
268		cpu->gprs[1] = num;
269		cpu->gprs[3] = 1;
270	} else {
271		mLOG(GBA_BIOS, GAME_ERROR, "Attempting to divide INT_MIN by -1!");
272		cpu->gprs[0] = INT32_MIN;
273		cpu->gprs[1] = 0;
274		cpu->gprs[3] = INT32_MIN;
275	}
276}
277
278static int16_t _ArcTan(int32_t i, int32_t* r1, int32_t* r3) {
279	int32_t a = -((i * i) >> 14);
280	int32_t b = ((0xA9 * a) >> 14) + 0x390;
281	b = ((b * a) >> 14) + 0x91C;
282	b = ((b * a) >> 14) + 0xFB6;
283	b = ((b * a) >> 14) + 0x16AA;
284	b = ((b * a) >> 14) + 0x2081;
285	b = ((b * a) >> 14) + 0x3651;
286	b = ((b * a) >> 14) + 0xA2F9;
287	if (r1) {
288		*r1 = a;
289	}
290	if (r3) {
291		*r3 = b;
292	}
293	return (i * b) >> 16;
294}
295
296static int16_t _ArcTan2(int32_t x, int32_t y, int32_t* r1) {
297	if (!y) {
298		if (x >= 0) {
299			return 0;
300		}
301		return 0x8000;
302	}
303	if (!x) {
304		if (y >= 0) {
305			return 0x4000;
306		}
307		return 0xC000;
308	}
309	if (y >= 0) {
310		if (x >= 0) {
311			if (x >= y) {
312				return _ArcTan((y << 14) / x, r1, NULL);
313			}
314		} else if (-x >= y) {
315			return _ArcTan((y << 14) / x, r1, NULL) + 0x8000;
316		}
317		return 0x4000 - _ArcTan((x << 14) / y, r1, NULL);
318	} else {
319		if (x <= 0) {
320			if (-x > -y) {
321				return _ArcTan((y << 14) / x, r1, NULL) + 0x8000;
322			}
323		} else if (x >= -y) {
324			return _ArcTan((y << 14) / x, r1, NULL) + 0x10000;
325		}
326		return 0xC000 - _ArcTan((x << 14) / y, r1, NULL);
327	}
328}
329
330void GBASwi16(struct ARMCore* cpu, int immediate) {
331	struct GBA* gba = (struct GBA*) cpu->master;
332	mLOG(GBA_BIOS, DEBUG, "SWI: %02X r0: %08X r1: %08X r2: %08X r3: %08X",
333	    immediate, cpu->gprs[0], cpu->gprs[1], cpu->gprs[2], cpu->gprs[3]);
334
335	switch (immediate) {
336	case 0xFA:
337		GBAPrintFlush(gba);
338		return;
339	}
340
341	if (gba->memory.fullBios) {
342		ARMRaiseSWI(cpu);
343		return;
344	}
345	switch (immediate) {
346	case 0x0:
347		_SoftReset(gba);
348		break;
349	case 0x1:
350		_RegisterRamReset(gba);
351		break;
352	case 0x2:
353		GBAHalt(gba);
354		break;
355	case 0x3:
356		GBAStop(gba);
357		break;
358	case 0x05:
359	// VBlankIntrWait
360	// Fall through:
361	case 0x04:
362		// IntrWait
363		ARMRaiseSWI(cpu);
364		break;
365	case 0x6:
366		_Div(gba, cpu->gprs[0], cpu->gprs[1]);
367		break;
368	case 0x7:
369		_Div(gba, cpu->gprs[1], cpu->gprs[0]);
370		break;
371	case 0x8:
372		cpu->gprs[0] = sqrt((uint32_t) cpu->gprs[0]);
373		break;
374	case 0x9:
375		cpu->gprs[0] = _ArcTan(cpu->gprs[0], &cpu->gprs[1], &cpu->gprs[3]);
376		break;
377	case 0xA:
378		cpu->gprs[0] = (uint16_t) _ArcTan2(cpu->gprs[0], cpu->gprs[1], &cpu->gprs[1]);
379		cpu->gprs[3] = 0x170;
380		break;
381	case 0xB:
382	case 0xC:
383		if (cpu->gprs[0] >> BASE_OFFSET < REGION_WORKING_RAM) {
384			mLOG(GBA_BIOS, GAME_ERROR, "Cannot CpuSet from BIOS");
385			break;
386		}
387		if (cpu->gprs[0] & (cpu->gprs[2] & (1 << 26) ? 3 : 1)) {
388			mLOG(GBA_BIOS, GAME_ERROR, "Misaligned CpuSet source");
389		}
390		if (cpu->gprs[1] & (cpu->gprs[2] & (1 << 26) ? 3 : 1)) {
391			mLOG(GBA_BIOS, GAME_ERROR, "Misaligned CpuSet destination");
392		}
393		ARMRaiseSWI(cpu);
394		break;
395	case 0xD:
396		cpu->gprs[0] = GBA_BIOS_CHECKSUM;
397		cpu->gprs[1] = 1;
398		cpu->gprs[3] = SIZE_BIOS;
399		break;
400	case 0xE:
401		_BgAffineSet(gba);
402		break;
403	case 0xF:
404		_ObjAffineSet(gba);
405		break;
406	case 0x10:
407		if (cpu->gprs[0] < BASE_WORKING_RAM) {
408			mLOG(GBA_BIOS, GAME_ERROR, "Bad BitUnPack source");
409			break;
410		}
411		switch (cpu->gprs[1] >> BASE_OFFSET) {
412		default:
413			mLOG(GBA_BIOS, GAME_ERROR, "Bad BitUnPack destination");
414		// Fall through
415		case REGION_WORKING_RAM:
416		case REGION_WORKING_IRAM:
417		case REGION_VRAM:
418			_unBitPack(gba);
419			break;
420		}
421		break;
422	case 0x11:
423	case 0x12:
424		if (cpu->gprs[0] < BASE_WORKING_RAM) {
425			mLOG(GBA_BIOS, GAME_ERROR, "Bad LZ77 source");
426			break;
427		}
428		switch (cpu->gprs[1] >> BASE_OFFSET) {
429		default:
430			mLOG(GBA_BIOS, GAME_ERROR, "Bad LZ77 destination");
431		// Fall through
432		case REGION_WORKING_RAM:
433		case REGION_WORKING_IRAM:
434		case REGION_VRAM:
435			_unLz77(gba, immediate == 0x11 ? 1 : 2);
436			break;
437		}
438		break;
439	case 0x13:
440		if (cpu->gprs[0] < BASE_WORKING_RAM) {
441			mLOG(GBA_BIOS, GAME_ERROR, "Bad Huffman source");
442			break;
443		}
444		switch (cpu->gprs[1] >> BASE_OFFSET) {
445		default:
446			mLOG(GBA_BIOS, GAME_ERROR, "Bad Huffman destination");
447		// Fall through
448		case REGION_WORKING_RAM:
449		case REGION_WORKING_IRAM:
450		case REGION_VRAM:
451			_unHuffman(gba);
452			break;
453		}
454		break;
455	case 0x14:
456	case 0x15:
457		if (cpu->gprs[0] < BASE_WORKING_RAM) {
458			mLOG(GBA_BIOS, GAME_ERROR, "Bad RL source");
459			break;
460		}
461		switch (cpu->gprs[1] >> BASE_OFFSET) {
462		default:
463			mLOG(GBA_BIOS, GAME_ERROR, "Bad RL destination");
464		// Fall through
465		case REGION_WORKING_RAM:
466		case REGION_WORKING_IRAM:
467		case REGION_VRAM:
468			_unRl(gba, immediate == 0x14 ? 1 : 2);
469			break;
470		}
471		break;
472	case 0x16:
473	case 0x17:
474	case 0x18:
475		if (cpu->gprs[0] < BASE_WORKING_RAM) {
476			mLOG(GBA_BIOS, GAME_ERROR, "Bad UnFilter source");
477			break;
478		}
479		switch (cpu->gprs[1] >> BASE_OFFSET) {
480		default:
481			mLOG(GBA_BIOS, GAME_ERROR, "Bad UnFilter destination");
482		// Fall through
483		case REGION_WORKING_RAM:
484		case REGION_WORKING_IRAM:
485		case REGION_VRAM:
486			_unFilter(gba, immediate == 0x18 ? 2 : 1, immediate == 0x16 ? 1 : 2);
487			break;
488		}
489		break;
490	case 0x19:
491		// SoundBias is mostly meaningless here
492		mLOG(GBA_BIOS, STUB, "Stub software interrupt: SoundBias (19)");
493		break;
494	case 0x1F:
495		_MidiKey2Freq(gba);
496		break;
497	default:
498		mLOG(GBA_BIOS, STUB, "Stub software interrupt: %02X", immediate);
499	}
500	gba->memory.biosPrefetch = 0xE3A02004;
501}
502
503void GBASwi32(struct ARMCore* cpu, int immediate) {
504	GBASwi16(cpu, immediate >> 16);
505}
506
507uint32_t GBAChecksum(uint32_t* memory, size_t size) {
508	size_t i;
509	uint32_t sum = 0;
510	for (i = 0; i < size; i += 4) {
511		sum += memory[i >> 2];
512	}
513	return sum;
514}
515
516static void _unLz77(struct GBA* gba, int width) {
517	struct ARMCore* cpu = gba->cpu;
518	uint32_t source = cpu->gprs[0];
519	uint32_t dest = cpu->gprs[1];
520	int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
521	// We assume the signature byte (0x10) is correct
522	int blockheader = 0; // Some compilers warn if this isn't set, even though it's trivially provably always set
523	source += 4;
524	int blocksRemaining = 0;
525	uint32_t disp;
526	int bytes;
527	int byte;
528	int halfword = 0;
529	while (remaining > 0) {
530		if (blocksRemaining) {
531			if (blockheader & 0x80) {
532				// Compressed
533				int block = cpu->memory.load8(cpu, source + 1, 0) | (cpu->memory.load8(cpu, source, 0) << 8);
534				source += 2;
535				disp = dest - (block & 0x0FFF) - 1;
536				bytes = (block >> 12) + 3;
537				while (bytes--) {
538					if (remaining) {
539						--remaining;
540					}
541					if (width == 2) {
542						byte = (int16_t) cpu->memory.load16(cpu, disp & ~1, 0);
543						if (dest & 1) {
544							byte >>= (disp & 1) * 8;
545							halfword |= byte << 8;
546							cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
547						} else {
548							byte >>= (disp & 1) * 8;
549							halfword = byte & 0xFF;
550						}
551					} else {
552						byte = cpu->memory.load8(cpu, disp, 0);
553						cpu->memory.store8(cpu, dest, byte, 0);
554					}
555					++disp;
556					++dest;
557				}
558			} else {
559				// Uncompressed
560				byte = cpu->memory.load8(cpu, source, 0);
561				++source;
562				if (width == 2) {
563					if (dest & 1) {
564						halfword |= byte << 8;
565						cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
566					} else {
567						halfword = byte;
568					}
569				} else {
570					cpu->memory.store8(cpu, dest, byte, 0);
571				}
572				++dest;
573				--remaining;
574			}
575			blockheader <<= 1;
576			--blocksRemaining;
577		} else {
578			blockheader = cpu->memory.load8(cpu, source, 0);
579			++source;
580			blocksRemaining = 8;
581		}
582	}
583	cpu->gprs[0] = source;
584	cpu->gprs[1] = dest;
585	cpu->gprs[3] = 0;
586}
587
588DECL_BITFIELD(HuffmanNode, uint8_t);
589DECL_BITS(HuffmanNode, Offset, 0, 6);
590DECL_BIT(HuffmanNode, RTerm, 6);
591DECL_BIT(HuffmanNode, LTerm, 7);
592
593static void _unHuffman(struct GBA* gba) {
594	struct ARMCore* cpu = gba->cpu;
595	uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
596	uint32_t dest = cpu->gprs[1];
597	uint32_t header = cpu->memory.load32(cpu, source, 0);
598	int remaining = header >> 8;
599	unsigned bits = header & 0xF;
600	if (bits == 0) {
601		mLOG(GBA_BIOS, GAME_ERROR, "Invalid Huffman bits");
602		bits = 8;
603	}
604	if (32 % bits || bits == 1) {
605		mLOG(GBA_BIOS, STUB, "Unimplemented unaligned Huffman");
606		return;
607	}
608	// We assume the signature byte (0x20) is correct
609	int treesize = (cpu->memory.load8(cpu, source + 4, 0) << 1) + 1;
610	int block = 0;
611	uint32_t treeBase = source + 5;
612	source += 5 + treesize;
613	uint32_t nPointer = treeBase;
614	HuffmanNode node;
615	int bitsRemaining;
616	int readBits;
617	int bitsSeen = 0;
618	node = cpu->memory.load8(cpu, nPointer, 0);
619	while (remaining > 0) {
620		uint32_t bitstream = cpu->memory.load32(cpu, source, 0);
621		source += 4;
622		for (bitsRemaining = 32; bitsRemaining > 0 && remaining > 0; --bitsRemaining, bitstream <<= 1) {
623			uint32_t next = (nPointer & ~1) + HuffmanNodeGetOffset(node) * 2 + 2;
624			if (bitstream & 0x80000000) {
625				// Go right
626				if (HuffmanNodeIsRTerm(node)) {
627					readBits = cpu->memory.load8(cpu, next + 1, 0);
628				} else {
629					nPointer = next + 1;
630					node = cpu->memory.load8(cpu, nPointer, 0);
631					continue;
632				}
633			} else {
634				// Go left
635				if (HuffmanNodeIsLTerm(node)) {
636					readBits = cpu->memory.load8(cpu, next, 0);
637				} else {
638					nPointer = next;
639					node = cpu->memory.load8(cpu, nPointer, 0);
640					continue;
641				}
642			}
643
644			block |= (readBits & ((1 << bits) - 1)) << bitsSeen;
645			bitsSeen += bits;
646			nPointer = treeBase;
647			node = cpu->memory.load8(cpu, nPointer, 0);
648			if (bitsSeen == 32) {
649				bitsSeen = 0;
650				cpu->memory.store32(cpu, dest, block, 0);
651				dest += 4;
652				remaining -= 4;
653				block = 0;
654			}
655		}
656	}
657	cpu->gprs[0] = source;
658	cpu->gprs[1] = dest;
659}
660
661static void _unRl(struct GBA* gba, int width) {
662	struct ARMCore* cpu = gba->cpu;
663	uint32_t source = cpu->gprs[0];
664	int remaining = (cpu->memory.load32(cpu, source & 0xFFFFFFFC, 0) & 0xFFFFFF00) >> 8;
665	int padding = (4 - remaining) & 0x3;
666	// We assume the signature byte (0x30) is correct
667	int blockheader;
668	int block;
669	source += 4;
670	uint32_t dest = cpu->gprs[1];
671	int halfword = 0;
672	while (remaining > 0) {
673		blockheader = cpu->memory.load8(cpu, source, 0);
674		++source;
675		if (blockheader & 0x80) {
676			// Compressed
677			blockheader &= 0x7F;
678			blockheader += 3;
679			block = cpu->memory.load8(cpu, source, 0);
680			++source;
681			while (blockheader-- && remaining) {
682				--remaining;
683				if (width == 2) {
684					if (dest & 1) {
685						halfword |= block << 8;
686						cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
687					} else {
688						halfword = block;
689					}
690				} else {
691					cpu->memory.store8(cpu, dest, block, 0);
692				}
693				++dest;
694			}
695		} else {
696			// Uncompressed
697			blockheader++;
698			while (blockheader-- && remaining) {
699				--remaining;
700				int byte = cpu->memory.load8(cpu, source, 0);
701				++source;
702				if (width == 2) {
703					if (dest & 1) {
704						halfword |= byte << 8;
705						cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
706					} else {
707						halfword = byte;
708					}
709				} else {
710					cpu->memory.store8(cpu, dest, byte, 0);
711				}
712				++dest;
713			}
714		}
715	}
716	if (width == 2) {
717		if (dest & 1) {
718			--padding;
719			++dest;
720		}
721		for (; padding > 0; padding -= 2, dest += 2) {
722			cpu->memory.store16(cpu, dest, 0, 0);
723		}
724	} else {
725		while (padding--) {
726			cpu->memory.store8(cpu, dest, 0, 0);
727			++dest;
728		}
729	}
730	cpu->gprs[0] = source;
731	cpu->gprs[1] = dest;
732}
733
734static void _unFilter(struct GBA* gba, int inwidth, int outwidth) {
735	struct ARMCore* cpu = gba->cpu;
736	uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
737	uint32_t dest = cpu->gprs[1];
738	uint32_t header = cpu->memory.load32(cpu, source, 0);
739	int remaining = header >> 8;
740	// We assume the signature nybble (0x8) is correct
741	uint16_t halfword = 0;
742	uint16_t old = 0;
743	source += 4;
744	while (remaining > 0) {
745		uint16_t new;
746		if (inwidth == 1) {
747			new = cpu->memory.load8(cpu, source, 0);
748		} else {
749			new = cpu->memory.load16(cpu, source, 0);
750		}
751		new += old;
752		if (outwidth > inwidth) {
753			halfword >>= 8;
754			halfword |= (new << 8);
755			if (source & 1) {
756				cpu->memory.store16(cpu, dest, halfword, 0);
757				dest += outwidth;
758				remaining -= outwidth;
759			}
760		} else if (outwidth == 1) {
761			cpu->memory.store8(cpu, dest, new, 0);
762			dest += outwidth;
763			remaining -= outwidth;
764		} else {
765			cpu->memory.store16(cpu, dest, new, 0);
766			dest += outwidth;
767			remaining -= outwidth;
768		}
769		old = new;
770		source += inwidth;
771	}
772	cpu->gprs[0] = source;
773	cpu->gprs[1] = dest;
774}
775
776static void _unBitPack(struct GBA* gba) {
777	struct ARMCore* cpu = gba->cpu;
778	uint32_t source = cpu->gprs[0];
779	uint32_t dest = cpu->gprs[1];
780	uint32_t info = cpu->gprs[2];
781	unsigned sourceLen = cpu->memory.load16(cpu, info, 0);
782	unsigned sourceWidth = cpu->memory.load8(cpu, info + 2, 0);
783	unsigned destWidth = cpu->memory.load8(cpu, info + 3, 0);
784	switch (sourceWidth) {
785	case 1:
786	case 2:
787	case 4:
788	case 8:
789		break;
790	default:
791		mLOG(GBA_BIOS, GAME_ERROR, "Bad BitUnPack source width: %u", sourceWidth);
792		return;
793	}
794	switch (destWidth) {
795	case 1:
796	case 2:
797	case 4:
798	case 8:
799	case 16:
800	case 32:
801		break;
802	default:
803		mLOG(GBA_BIOS, GAME_ERROR, "Bad BitUnPack destination width: %u", destWidth);
804		return;
805	}
806	uint32_t bias = cpu->memory.load32(cpu, info + 4, 0);
807	uint8_t in = 0;
808	uint32_t out = 0;
809	int bitsRemaining = 0;
810	int bitsEaten = 0;
811	while (sourceLen > 0 || bitsRemaining) {
812		if (!bitsRemaining) {
813			in = cpu->memory.load8(cpu, source, 0);
814			bitsRemaining = 8;
815			++source;
816			--sourceLen;
817		}
818		unsigned scaled = in & ((1 << sourceWidth) - 1);
819		in >>= sourceWidth;
820		if (scaled || bias & 0x80000000) {
821			scaled += bias & 0x7FFFFFFF;
822		}
823		bitsRemaining -= sourceWidth;
824		out |= scaled << bitsEaten;
825		bitsEaten += destWidth;
826		if (bitsEaten == 32) {
827			cpu->memory.store32(cpu, dest, out, 0);
828			bitsEaten = 0;
829			out = 0;
830			dest += 4;
831		}
832	}
833	cpu->gprs[0] = source;
834	cpu->gprs[1] = dest;
835}