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 "bios.h"
7
8#include "gba/gba.h"
9#include "gba/io.h"
10#include "gba/memory.h"
11#include "isa-inlines.h"
12
13const uint32_t GBA_BIOS_CHECKSUM = 0xBAAE187F;
14const uint32_t GBA_DS_BIOS_CHECKSUM = 0xBAAE1880;
15
16static void _unLz77(struct GBA* gba, int width);
17static void _unHuffman(struct GBA* gba);
18static void _unRl(struct GBA* gba, int width);
19static void _unFilter(struct GBA* gba, int inwidth, int outwidth);
20
21static void _SoftReset(struct GBA* gba) {
22 struct ARMCore* cpu = gba->cpu;
23 ARMSetPrivilegeMode(cpu, MODE_IRQ);
24 cpu->spsr.packed = 0;
25 cpu->gprs[ARM_LR] = 0;
26 cpu->gprs[ARM_SP] = SP_BASE_IRQ;
27 ARMSetPrivilegeMode(cpu, MODE_SUPERVISOR);
28 cpu->spsr.packed = 0;
29 cpu->gprs[ARM_LR] = 0;
30 cpu->gprs[ARM_SP] = SP_BASE_SUPERVISOR;
31 ARMSetPrivilegeMode(cpu, MODE_SYSTEM);
32 cpu->gprs[ARM_LR] = 0;
33 cpu->gprs[ARM_SP] = SP_BASE_SYSTEM;
34 int8_t flag = ((int8_t*) gba->memory.iwram)[0x7FFA];
35 memset(((int8_t*) gba->memory.iwram) + SIZE_WORKING_IRAM - 0x200, 0, 0x200);
36 if (flag) {
37 cpu->gprs[ARM_PC] = BASE_WORKING_RAM;
38 } else {
39 cpu->gprs[ARM_PC] = BASE_CART0;
40 }
41 _ARMSetMode(cpu, MODE_ARM);
42 int currentCycles = 0;
43 ARM_WRITE_PC;
44}
45
46static void _RegisterRamReset(struct GBA* gba) {
47 uint32_t registers = gba->cpu->gprs[0];
48 struct ARMCore* cpu = gba->cpu;
49 cpu->memory.store16(cpu, BASE_IO | REG_DISPCNT, 0x0080, 0);
50 if (registers & 0x01) {
51 memset(gba->memory.wram, 0, SIZE_WORKING_RAM);
52 }
53 if (registers & 0x02) {
54 memset(gba->memory.iwram, 0, SIZE_WORKING_IRAM - 0x200);
55 }
56 if (registers & 0x04) {
57 memset(gba->video.palette, 0, SIZE_PALETTE_RAM);
58 }
59 if (registers & 0x08) {
60 memset(gba->video.renderer->vram, 0, SIZE_VRAM);
61 }
62 if (registers & 0x10) {
63 memset(gba->video.oam.raw, 0, SIZE_OAM);
64 }
65 if (registers & 0x20) {
66 cpu->memory.store16(cpu, BASE_IO | REG_SIOCNT, 0x0000, 0);
67 cpu->memory.store16(cpu, BASE_IO | REG_RCNT, RCNT_INITIAL, 0);
68 cpu->memory.store16(cpu, BASE_IO | REG_SIOMLT_SEND, 0, 0);
69 cpu->memory.store16(cpu, BASE_IO | REG_JOYCNT, 0, 0);
70 cpu->memory.store32(cpu, BASE_IO | REG_JOY_RECV, 0, 0);
71 cpu->memory.store32(cpu, BASE_IO | REG_JOY_TRANS, 0, 0);
72 }
73 if (registers & 0x40) {
74 cpu->memory.store16(cpu, BASE_IO | REG_SOUND1CNT_LO, 0, 0);
75 cpu->memory.store16(cpu, BASE_IO | REG_SOUND1CNT_HI, 0, 0);
76 cpu->memory.store16(cpu, BASE_IO | REG_SOUND1CNT_X, 0, 0);
77 cpu->memory.store16(cpu, BASE_IO | REG_SOUND2CNT_LO, 0, 0);
78 cpu->memory.store16(cpu, BASE_IO | REG_SOUND2CNT_HI, 0, 0);
79 cpu->memory.store16(cpu, BASE_IO | REG_SOUND3CNT_LO, 0, 0);
80 cpu->memory.store16(cpu, BASE_IO | REG_SOUND3CNT_HI, 0, 0);
81 cpu->memory.store16(cpu, BASE_IO | REG_SOUND3CNT_X, 0, 0);
82 cpu->memory.store16(cpu, BASE_IO | REG_SOUND4CNT_LO, 0, 0);
83 cpu->memory.store16(cpu, BASE_IO | REG_SOUND4CNT_HI, 0, 0);
84 cpu->memory.store16(cpu, BASE_IO | REG_SOUNDCNT_LO, 0, 0);
85 cpu->memory.store16(cpu, BASE_IO | REG_SOUNDCNT_HI, 0, 0);
86 cpu->memory.store16(cpu, BASE_IO | REG_SOUNDCNT_X, 0, 0);
87 cpu->memory.store16(cpu, BASE_IO | REG_SOUNDBIAS, 0x200, 0);
88 memset(gba->audio.psg.ch3.wavedata, 0, sizeof(gba->audio.psg.ch3.wavedata));
89 }
90 if (registers & 0x80) {
91 cpu->memory.store16(cpu, BASE_IO | 0x00, 0, 0);
92 cpu->memory.store16(cpu, BASE_IO | 0x04, 0, 0);
93 cpu->memory.store16(cpu, BASE_IO | 0x06, 0, 0);
94 cpu->memory.store16(cpu, BASE_IO | 0x08, 0, 0);
95 cpu->memory.store16(cpu, BASE_IO | 0x0A, 0, 0);
96 cpu->memory.store16(cpu, BASE_IO | 0x0C, 0, 0);
97 cpu->memory.store16(cpu, BASE_IO | 0x0E, 0, 0);
98 cpu->memory.store16(cpu, BASE_IO | 0x10, 0, 0);
99 cpu->memory.store16(cpu, BASE_IO | 0x12, 0, 0);
100 cpu->memory.store16(cpu, BASE_IO | 0x14, 0, 0);
101 cpu->memory.store16(cpu, BASE_IO | 0x16, 0, 0);
102 cpu->memory.store16(cpu, BASE_IO | 0x18, 0, 0);
103 cpu->memory.store16(cpu, BASE_IO | 0x1A, 0, 0);
104 cpu->memory.store16(cpu, BASE_IO | 0x1C, 0, 0);
105 cpu->memory.store16(cpu, BASE_IO | 0x1E, 0, 0);
106 cpu->memory.store16(cpu, BASE_IO | REG_BG2PA, 0x100, 0);
107 cpu->memory.store16(cpu, BASE_IO | REG_BG2PB, 0, 0);
108 cpu->memory.store16(cpu, BASE_IO | REG_BG2PC, 0, 0);
109 cpu->memory.store16(cpu, BASE_IO | REG_BG2PD, 0x100, 0);
110 cpu->memory.store32(cpu, BASE_IO | 0x28, 0, 0);
111 cpu->memory.store32(cpu, BASE_IO | 0x2C, 0, 0);
112 cpu->memory.store16(cpu, BASE_IO | REG_BG3PA, 0x100, 0);
113 cpu->memory.store16(cpu, BASE_IO | REG_BG3PB, 0, 0);
114 cpu->memory.store16(cpu, BASE_IO | REG_BG3PC, 0, 0);
115 cpu->memory.store16(cpu, BASE_IO | REG_BG3PD, 0x100, 0);
116 cpu->memory.store32(cpu, BASE_IO | 0x38, 0, 0);
117 cpu->memory.store32(cpu, BASE_IO | 0x3C, 0, 0);
118 cpu->memory.store16(cpu, BASE_IO | 0x40, 0, 0);
119 cpu->memory.store16(cpu, BASE_IO | 0x42, 0, 0);
120 cpu->memory.store16(cpu, BASE_IO | 0x44, 0, 0);
121 cpu->memory.store16(cpu, BASE_IO | 0x46, 0, 0);
122 cpu->memory.store16(cpu, BASE_IO | 0x48, 0, 0);
123 cpu->memory.store16(cpu, BASE_IO | 0x4A, 0, 0);
124 cpu->memory.store16(cpu, BASE_IO | 0x4C, 0, 0);
125 cpu->memory.store16(cpu, BASE_IO | 0x50, 0, 0);
126 cpu->memory.store16(cpu, BASE_IO | 0x52, 0, 0);
127 cpu->memory.store16(cpu, BASE_IO | 0x54, 0, 0);
128 cpu->memory.store16(cpu, BASE_IO | 0xB0, 0, 0);
129 cpu->memory.store16(cpu, BASE_IO | 0xB2, 0, 0);
130 cpu->memory.store16(cpu, BASE_IO | 0xB4, 0, 0);
131 cpu->memory.store16(cpu, BASE_IO | 0xB6, 0, 0);
132 cpu->memory.store16(cpu, BASE_IO | 0xB8, 0, 0);
133 cpu->memory.store16(cpu, BASE_IO | 0xBA, 0, 0);
134 cpu->memory.store16(cpu, BASE_IO | 0xBC, 0, 0);
135 cpu->memory.store16(cpu, BASE_IO | 0xBE, 0, 0);
136 cpu->memory.store16(cpu, BASE_IO | 0xC0, 0, 0);
137 cpu->memory.store16(cpu, BASE_IO | 0xC2, 0, 0);
138 cpu->memory.store16(cpu, BASE_IO | 0xC4, 0, 0);
139 cpu->memory.store16(cpu, BASE_IO | 0xC6, 0, 0);
140 cpu->memory.store16(cpu, BASE_IO | 0xC8, 0, 0);
141 cpu->memory.store16(cpu, BASE_IO | 0xCA, 0, 0);
142 cpu->memory.store16(cpu, BASE_IO | 0xCC, 0, 0);
143 cpu->memory.store16(cpu, BASE_IO | 0xCE, 0, 0);
144 cpu->memory.store16(cpu, BASE_IO | 0xD0, 0, 0);
145 cpu->memory.store16(cpu, BASE_IO | 0xD2, 0, 0);
146 cpu->memory.store16(cpu, BASE_IO | 0xD4, 0, 0);
147 cpu->memory.store16(cpu, BASE_IO | 0xD6, 0, 0);
148 cpu->memory.store16(cpu, BASE_IO | 0xD8, 0, 0);
149 cpu->memory.store16(cpu, BASE_IO | 0xDA, 0, 0);
150 cpu->memory.store16(cpu, BASE_IO | 0xDC, 0, 0);
151 cpu->memory.store16(cpu, BASE_IO | 0xDE, 0, 0);
152 cpu->memory.store16(cpu, BASE_IO | 0x100, 0, 0);
153 cpu->memory.store16(cpu, BASE_IO | 0x102, 0, 0);
154 cpu->memory.store16(cpu, BASE_IO | 0x104, 0, 0);
155 cpu->memory.store16(cpu, BASE_IO | 0x106, 0, 0);
156 cpu->memory.store16(cpu, BASE_IO | 0x108, 0, 0);
157 cpu->memory.store16(cpu, BASE_IO | 0x10A, 0, 0);
158 cpu->memory.store16(cpu, BASE_IO | 0x10C, 0, 0);
159 cpu->memory.store16(cpu, BASE_IO | 0x10E, 0, 0);
160 cpu->memory.store16(cpu, BASE_IO | 0x200, 0, 0);
161 cpu->memory.store16(cpu, BASE_IO | 0x202, 0xFFFF, 0);
162 cpu->memory.store16(cpu, BASE_IO | 0x204, 0, 0);
163 cpu->memory.store16(cpu, BASE_IO | 0x208, 0, 0);
164 }
165}
166
167static void _BgAffineSet(struct GBA* gba) {
168 struct ARMCore* cpu = gba->cpu;
169 int i = cpu->gprs[2];
170 float ox, oy;
171 float cx, cy;
172 float sx, sy;
173 float theta;
174 int offset = cpu->gprs[0];
175 int destination = cpu->gprs[1];
176 float a, b, c, d;
177 float rx, ry;
178 while (i--) {
179 // [ sx 0 0 ] [ cos(theta) -sin(theta) 0 ] [ 1 0 cx - ox ] [ A B rx ]
180 // [ 0 sy 0 ] * [ sin(theta) cos(theta) 0 ] * [ 0 1 cy - oy ] = [ C D ry ]
181 // [ 0 0 1 ] [ 0 0 1 ] [ 0 0 1 ] [ 0 0 1 ]
182 ox = (int32_t) cpu->memory.load32(cpu, offset, 0) / 256.f;
183 oy = (int32_t) cpu->memory.load32(cpu, offset + 4, 0) / 256.f;
184 cx = (int16_t) cpu->memory.load16(cpu, offset + 8, 0);
185 cy = (int16_t) cpu->memory.load16(cpu, offset + 10, 0);
186 sx = (int16_t) cpu->memory.load16(cpu, offset + 12, 0) / 256.f;
187 sy = (int16_t) cpu->memory.load16(cpu, offset + 14, 0) / 256.f;
188 theta = (cpu->memory.load16(cpu, offset + 16, 0) >> 8) / 128.f * M_PI;
189 offset += 20;
190 // Rotation
191 a = d = cosf(theta);
192 b = c = sinf(theta);
193 // Scale
194 a *= sx;
195 b *= -sx;
196 c *= sy;
197 d *= sy;
198 // Translate
199 rx = ox - (a * cx + b * cy);
200 ry = oy - (c * cx + d * cy);
201 cpu->memory.store16(cpu, destination, a * 256, 0);
202 cpu->memory.store16(cpu, destination + 2, b * 256, 0);
203 cpu->memory.store16(cpu, destination + 4, c * 256, 0);
204 cpu->memory.store16(cpu, destination + 6, d * 256, 0);
205 cpu->memory.store32(cpu, destination + 8, rx * 256, 0);
206 cpu->memory.store32(cpu, destination + 12, ry * 256, 0);
207 destination += 16;
208 }
209}
210
211static void _ObjAffineSet(struct GBA* gba) {
212 struct ARMCore* cpu = gba->cpu;
213 int i = cpu->gprs[2];
214 float sx, sy;
215 float theta;
216 int offset = cpu->gprs[0];
217 int destination = cpu->gprs[1];
218 int diff = cpu->gprs[3];
219 float a, b, c, d;
220 while (i--) {
221 // [ sx 0 ] [ cos(theta) -sin(theta) ] [ A B ]
222 // [ 0 sy ] * [ sin(theta) cos(theta) ] = [ C D ]
223 sx = (int16_t) cpu->memory.load16(cpu, offset, 0) / 256.f;
224 sy = (int16_t) cpu->memory.load16(cpu, offset + 2, 0) / 256.f;
225 theta = (cpu->memory.load16(cpu, offset + 4, 0) >> 8) / 128.f * M_PI;
226 offset += 8;
227 // Rotation
228 a = d = cosf(theta);
229 b = c = sinf(theta);
230 // Scale
231 a *= sx;
232 b *= -sx;
233 c *= sy;
234 d *= sy;
235 cpu->memory.store16(cpu, destination, a * 256, 0);
236 cpu->memory.store16(cpu, destination + diff, b * 256, 0);
237 cpu->memory.store16(cpu, destination + diff * 2, c * 256, 0);
238 cpu->memory.store16(cpu, destination + diff * 3, d * 256, 0);
239 destination += diff * 4;
240 }
241}
242
243static void _MidiKey2Freq(struct GBA* gba) {
244 struct ARMCore* cpu = gba->cpu;
245 uint32_t key = cpu->memory.load32(cpu, cpu->gprs[0] + 4, 0);
246 cpu->gprs[0] = key / powf(2, (180.f - cpu->gprs[1] - cpu->gprs[2] / 256.f) / 12.f);
247}
248
249static void _Div(struct GBA* gba, int32_t num, int32_t denom) {
250 struct ARMCore* cpu = gba->cpu;
251 if (denom != 0) {
252 div_t result = div(num, denom);
253 cpu->gprs[0] = result.quot;
254 cpu->gprs[1] = result.rem;
255 cpu->gprs[3] = abs(result.quot);
256 } else {
257 GBALog(gba, GBA_LOG_GAME_ERROR, "Attempting to divide %i by zero!", num);
258 // If abs(num) > 1, this should hang, but that would be painful to
259 // emulate in HLE, and no game will get into a state where it hangs...
260 cpu->gprs[0] = (num < 0) ? -1 : 1;
261 cpu->gprs[1] = num;
262 cpu->gprs[3] = 1;
263 }
264}
265
266void GBASwi16(struct ARMCore* cpu, int immediate) {
267 struct GBA* gba = (struct GBA*) cpu->master;
268 GBALog(gba, GBA_LOG_SWI, "SWI: %02X r0: %08X r1: %08X r2: %08X r3: %08X",
269 immediate, cpu->gprs[0], cpu->gprs[1], cpu->gprs[2], cpu->gprs[3]);
270
271 if (gba->memory.fullBios) {
272 ARMRaiseSWI(cpu);
273 return;
274 }
275 switch (immediate) {
276 case 0x0:
277 _SoftReset(gba);
278 break;
279 case 0x1:
280 _RegisterRamReset(gba);
281 break;
282 case 0x2:
283 GBAHalt(gba);
284 break;
285 case 0x3:
286 GBAStop(gba);
287 break;
288 case 0x05:
289 // VBlankIntrWait
290 // Fall through:
291 case 0x04:
292 // IntrWait
293 ARMRaiseSWI(cpu);
294 break;
295 case 0x6:
296 _Div(gba, cpu->gprs[0], cpu->gprs[1]);
297 break;
298 case 0x7:
299 _Div(gba, cpu->gprs[1], cpu->gprs[0]);
300 break;
301 case 0x8:
302 cpu->gprs[0] = sqrt((uint32_t) cpu->gprs[0]);
303 break;
304 case 0xA:
305 cpu->gprs[0] = atan2f(cpu->gprs[1] / 16384.f, cpu->gprs[0] / 16384.f) / (2 * M_PI) * 0x10000;
306 break;
307 case 0xB:
308 case 0xC:
309 if (cpu->gprs[0] >> BASE_OFFSET < REGION_WORKING_RAM) {
310 GBALog(gba, GBA_LOG_GAME_ERROR, "Cannot CpuSet from BIOS");
311 return;
312 }
313 if (cpu->gprs[0] & (cpu->gprs[2] & (1 << 26) ? 3 : 1)) {
314 GBALog(gba, GBA_LOG_GAME_ERROR, "Misaligned CpuSet source");
315 }
316 if (cpu->gprs[1] & (cpu->gprs[2] & (1 << 26) ? 3 : 1)) {
317 GBALog(gba, GBA_LOG_GAME_ERROR, "Misaligned CpuSet destination");
318 }
319 ARMRaiseSWI(cpu);
320 break;
321 case 0xD:
322 cpu->gprs[0] = GBA_BIOS_CHECKSUM;
323 cpu->gprs[1] = 1;
324 cpu->gprs[3] = SIZE_BIOS;
325 break;
326 case 0xE:
327 _BgAffineSet(gba);
328 break;
329 case 0xF:
330 _ObjAffineSet(gba);
331 break;
332 case 0x11:
333 case 0x12:
334 if (cpu->gprs[0] < BASE_WORKING_RAM) {
335 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 source");
336 break;
337 }
338 switch (cpu->gprs[1] >> BASE_OFFSET) {
339 default:
340 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 destination");
341 // Fall through
342 case REGION_WORKING_RAM:
343 case REGION_WORKING_IRAM:
344 case REGION_VRAM:
345 _unLz77(gba, immediate == 0x11 ? 1 : 2);
346 break;
347 }
348 break;
349 case 0x13:
350 if (cpu->gprs[0] < BASE_WORKING_RAM) {
351 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman source");
352 break;
353 }
354 switch (cpu->gprs[1] >> BASE_OFFSET) {
355 default:
356 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman destination");
357 // Fall through
358 case REGION_WORKING_RAM:
359 case REGION_WORKING_IRAM:
360 case REGION_VRAM:
361 _unHuffman(gba);
362 break;
363 }
364 break;
365 case 0x14:
366 case 0x15:
367 if (cpu->gprs[0] < BASE_WORKING_RAM) {
368 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL source");
369 break;
370 }
371 switch (cpu->gprs[1] >> BASE_OFFSET) {
372 default:
373 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL destination");
374 // Fall through
375 case REGION_WORKING_RAM:
376 case REGION_WORKING_IRAM:
377 case REGION_VRAM:
378 _unRl(gba, immediate == 0x14 ? 1 : 2);
379 break;
380 }
381 break;
382 case 0x16:
383 case 0x17:
384 case 0x18:
385 if (cpu->gprs[0] < BASE_WORKING_RAM) {
386 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter source");
387 break;
388 }
389 switch (cpu->gprs[1] >> BASE_OFFSET) {
390 default:
391 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter destination");
392 // Fall through
393 case REGION_WORKING_RAM:
394 case REGION_WORKING_IRAM:
395 case REGION_VRAM:
396 _unFilter(gba, immediate == 0x18 ? 2 : 1, immediate == 0x16 ? 1 : 2);
397 break;
398 }
399 break;
400 case 0x19:
401 // SoundBias is mostly meaningless here
402 GBALog(gba, GBA_LOG_STUB, "Stub software interrupt: SoundBias (19)");
403 break;
404 case 0x1F:
405 _MidiKey2Freq(gba);
406 break;
407 default:
408 GBALog(gba, GBA_LOG_STUB, "Stub software interrupt: %02X", immediate);
409 }
410 gba->memory.biosPrefetch = 0xE3A02004;
411}
412
413void GBASwi32(struct ARMCore* cpu, int immediate) {
414 GBASwi16(cpu, immediate >> 16);
415}
416
417uint32_t GBAChecksum(uint32_t* memory, size_t size) {
418 size_t i;
419 uint32_t sum = 0;
420 for (i = 0; i < size; i += 4) {
421 sum += memory[i >> 2];
422 }
423 return sum;
424}
425
426static void _unLz77(struct GBA* gba, int width) {
427 struct ARMCore* cpu = gba->cpu;
428 uint32_t source = cpu->gprs[0];
429 uint32_t dest = cpu->gprs[1];
430 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
431 // We assume the signature byte (0x10) is correct
432 int blockheader = 0; // Some compilers warn if this isn't set, even though it's trivially provably always set
433 source += 4;
434 int blocksRemaining = 0;
435 uint32_t disp;
436 int bytes;
437 int byte;
438 int halfword = 0;
439 while (remaining > 0) {
440 if (blocksRemaining) {
441 if (blockheader & 0x80) {
442 // Compressed
443 int block = cpu->memory.load8(cpu, source + 1, 0) | (cpu->memory.load8(cpu, source, 0) << 8);
444 source += 2;
445 disp = dest - (block & 0x0FFF) - 1;
446 bytes = (block >> 12) + 3;
447 while (bytes-- && remaining) {
448 --remaining;
449 if (width == 2) {
450 byte = (int16_t) cpu->memory.load16(cpu, disp & ~1, 0);
451 if (dest & 1) {
452 byte >>= (disp & 1) * 8;
453 halfword |= byte << 8;
454 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
455 } else {
456 byte >>= (disp & 1) * 8;
457 halfword = byte & 0xFF;
458 }
459 } else {
460 byte = cpu->memory.load8(cpu, disp, 0);
461 cpu->memory.store8(cpu, dest, byte, 0);
462 }
463 ++disp;
464 ++dest;
465 }
466 } else {
467 // Uncompressed
468 byte = cpu->memory.load8(cpu, source, 0);
469 ++source;
470 if (width == 2) {
471 if (dest & 1) {
472 halfword |= byte << 8;
473 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
474 } else {
475 halfword = byte;
476 }
477 } else {
478 cpu->memory.store8(cpu, dest, byte, 0);
479 }
480 ++dest;
481 --remaining;
482 }
483 blockheader <<= 1;
484 --blocksRemaining;
485 } else {
486 blockheader = cpu->memory.load8(cpu, source, 0);
487 ++source;
488 blocksRemaining = 8;
489 }
490 }
491 cpu->gprs[0] = source;
492 cpu->gprs[1] = dest;
493 cpu->gprs[3] = 0;
494}
495
496DECL_BITFIELD(HuffmanNode, uint8_t);
497DECL_BITS(HuffmanNode, Offset, 0, 6);
498DECL_BIT(HuffmanNode, RTerm, 6);
499DECL_BIT(HuffmanNode, LTerm, 7);
500
501static void _unHuffman(struct GBA* gba) {
502 struct ARMCore* cpu = gba->cpu;
503 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
504 uint32_t dest = cpu->gprs[1];
505 uint32_t header = cpu->memory.load32(cpu, source, 0);
506 int remaining = header >> 8;
507 int bits = header & 0xF;
508 if (bits == 0) {
509 GBALog(gba, GBA_LOG_GAME_ERROR, "Invalid Huffman bits");
510 bits = 8;
511 }
512 if (32 % bits || bits == 1) {
513 GBALog(gba, GBA_LOG_STUB, "Unimplemented unaligned Huffman");
514 return;
515 }
516 // We assume the signature byte (0x20) is correct
517 int treesize = (cpu->memory.load8(cpu, source + 4, 0) << 1) + 1;
518 int block = 0;
519 uint32_t treeBase = source + 5;
520 source += 5 + treesize;
521 uint32_t nPointer = treeBase;
522 HuffmanNode node;
523 int bitsRemaining;
524 int readBits;
525 int bitsSeen = 0;
526 node = cpu->memory.load8(cpu, nPointer, 0);
527 while (remaining > 0) {
528 uint32_t bitstream = cpu->memory.load32(cpu, source, 0);
529 source += 4;
530 for (bitsRemaining = 32; bitsRemaining > 0 && remaining > 0; --bitsRemaining, bitstream <<= 1) {
531 uint32_t next = (nPointer & ~1) + HuffmanNodeGetOffset(node) * 2 + 2;
532 if (bitstream & 0x80000000) {
533 // Go right
534 if (HuffmanNodeIsRTerm(node)) {
535 readBits = cpu->memory.load8(cpu, next + 1, 0);
536 } else {
537 nPointer = next + 1;
538 node = cpu->memory.load8(cpu, nPointer, 0);
539 continue;
540 }
541 } else {
542 // Go left
543 if (HuffmanNodeIsLTerm(node)) {
544 readBits = cpu->memory.load8(cpu, next, 0);
545 } else {
546 nPointer = next;
547 node = cpu->memory.load8(cpu, nPointer, 0);
548 continue;
549 }
550 }
551
552 block |= (readBits & ((1 << bits) - 1)) << bitsSeen;
553 bitsSeen += bits;
554 nPointer = treeBase;
555 node = cpu->memory.load8(cpu, nPointer, 0);
556 if (bitsSeen == 32) {
557 bitsSeen = 0;
558 cpu->memory.store32(cpu, dest, block, 0);
559 dest += 4;
560 remaining -= 4;
561 block = 0;
562 }
563 }
564 }
565 cpu->gprs[0] = source;
566 cpu->gprs[1] = dest;
567}
568
569static void _unRl(struct GBA* gba, int width) {
570 struct ARMCore* cpu = gba->cpu;
571 uint32_t source = cpu->gprs[0];
572 int remaining = (cpu->memory.load32(cpu, source & 0xFFFFFFFC, 0) & 0xFFFFFF00) >> 8;
573 int padding = (4 - remaining) & 0x3;
574 // We assume the signature byte (0x30) is correct
575 int blockheader;
576 int block;
577 source += 4;
578 uint32_t dest = cpu->gprs[1];
579 int halfword = 0;
580 while (remaining > 0) {
581 blockheader = cpu->memory.load8(cpu, source, 0);
582 ++source;
583 if (blockheader & 0x80) {
584 // Compressed
585 blockheader &= 0x7F;
586 blockheader += 3;
587 block = cpu->memory.load8(cpu, source, 0);
588 ++source;
589 while (blockheader-- && remaining) {
590 --remaining;
591 if (width == 2) {
592 if (dest & 1) {
593 halfword |= block << 8;
594 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
595 } else {
596 halfword = block;
597 }
598 } else {
599 cpu->memory.store8(cpu, dest, block, 0);
600 }
601 ++dest;
602 }
603 } else {
604 // Uncompressed
605 blockheader++;
606 while (blockheader-- && remaining) {
607 --remaining;
608 int byte = cpu->memory.load8(cpu, source, 0);
609 ++source;
610 if (width == 2) {
611 if (dest & 1) {
612 halfword |= byte << 8;
613 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
614 } else {
615 halfword = byte;
616 }
617 } else {
618 cpu->memory.store8(cpu, dest, byte, 0);
619 }
620 ++dest;
621 }
622 }
623 }
624 if (width == 2) {
625 if (dest & 1) {
626 --padding;
627 ++dest;
628 }
629 for (; padding > 0; padding -= 2, dest += 2) {
630 cpu->memory.store16(cpu, dest, 0, 0);
631 }
632 } else {
633 while (padding--) {
634 cpu->memory.store8(cpu, dest, 0, 0);
635 ++dest;
636 }
637 }
638 cpu->gprs[0] = source;
639 cpu->gprs[1] = dest;
640}
641
642static void _unFilter(struct GBA* gba, int inwidth, int outwidth) {
643 struct ARMCore* cpu = gba->cpu;
644 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
645 uint32_t dest = cpu->gprs[1];
646 uint32_t header = cpu->memory.load32(cpu, source, 0);
647 int remaining = header >> 8;
648 // We assume the signature nybble (0x8) is correct
649 uint16_t halfword = 0;
650 uint16_t old = 0;
651 source += 4;
652 while (remaining > 0) {
653 uint16_t new;
654 if (inwidth == 1) {
655 new = cpu->memory.load8(cpu, source, 0);
656 } else {
657 new = cpu->memory.load16(cpu, source, 0);
658 }
659 new += old;
660 if (outwidth > inwidth) {
661 halfword >>= 8;
662 halfword |= (new << 8);
663 if (source & 1) {
664 cpu->memory.store16(cpu, dest, halfword, 0);
665 dest += outwidth;
666 remaining -= outwidth;
667 }
668 } else if (outwidth == 1) {
669 cpu->memory.store8(cpu, dest, new, 0);
670 dest += outwidth;
671 remaining -= outwidth;
672 } else {
673 cpu->memory.store16(cpu, dest, new, 0);
674 dest += outwidth;
675 remaining -= outwidth;
676 }
677 old = new;
678 source += inwidth;
679 }
680 cpu->gprs[0] = source;
681 cpu->gprs[1] = dest;
682}