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 GBALog(gba, GBA_LOG_STUB, "RegisterRamReset on Audio unimplemented");
75 }
76 if (registers & 0x80) {
77 GBALog(gba, GBA_LOG_STUB, "RegisterRamReset on IO unimplemented");
78 }
79}
80
81static void _BgAffineSet(struct GBA* gba) {
82 struct ARMCore* cpu = gba->cpu;
83 int i = cpu->gprs[2];
84 float ox, oy;
85 float cx, cy;
86 float sx, sy;
87 float theta;
88 int offset = cpu->gprs[0];
89 int destination = cpu->gprs[1];
90 float a, b, c, d;
91 float rx, ry;
92 while (i--) {
93 // [ sx 0 0 ] [ cos(theta) -sin(theta) 0 ] [ 1 0 cx - ox ] [ A B rx ]
94 // [ 0 sy 0 ] * [ sin(theta) cos(theta) 0 ] * [ 0 1 cy - oy ] = [ C D ry ]
95 // [ 0 0 1 ] [ 0 0 1 ] [ 0 0 1 ] [ 0 0 1 ]
96 ox = (int32_t) cpu->memory.load32(cpu, offset, 0) / 256.f;
97 oy = (int32_t) cpu->memory.load32(cpu, offset + 4, 0) / 256.f;
98 cx = (int16_t) cpu->memory.load16(cpu, offset + 8, 0);
99 cy = (int16_t) cpu->memory.load16(cpu, offset + 10, 0);
100 sx = (int16_t) cpu->memory.load16(cpu, offset + 12, 0) / 256.f;
101 sy = (int16_t) cpu->memory.load16(cpu, offset + 14, 0) / 256.f;
102 theta = (cpu->memory.load16(cpu, offset + 16, 0) >> 8) / 128.f * M_PI;
103 offset += 20;
104 // Rotation
105 a = d = cosf(theta);
106 b = c = sinf(theta);
107 // Scale
108 a *= sx;
109 b *= -sx;
110 c *= sy;
111 d *= sy;
112 // Translate
113 rx = ox - (a * cx + b * cy);
114 ry = oy - (c * cx + d * cy);
115 cpu->memory.store16(cpu, destination, a * 256, 0);
116 cpu->memory.store16(cpu, destination + 2, b * 256, 0);
117 cpu->memory.store16(cpu, destination + 4, c * 256, 0);
118 cpu->memory.store16(cpu, destination + 6, d * 256, 0);
119 cpu->memory.store32(cpu, destination + 8, rx * 256, 0);
120 cpu->memory.store32(cpu, destination + 12, ry * 256, 0);
121 destination += 16;
122 }
123}
124
125static void _ObjAffineSet(struct GBA* gba) {
126 struct ARMCore* cpu = gba->cpu;
127 int i = cpu->gprs[2];
128 float sx, sy;
129 float theta;
130 int offset = cpu->gprs[0];
131 int destination = cpu->gprs[1];
132 int diff = cpu->gprs[3];
133 float a, b, c, d;
134 while (i--) {
135 // [ sx 0 ] [ cos(theta) -sin(theta) ] [ A B ]
136 // [ 0 sy ] * [ sin(theta) cos(theta) ] = [ C D ]
137 sx = (int16_t) cpu->memory.load16(cpu, offset, 0) / 256.f;
138 sy = (int16_t) cpu->memory.load16(cpu, offset + 2, 0) / 256.f;
139 theta = (cpu->memory.load16(cpu, offset + 4, 0) >> 8) / 128.f * M_PI;
140 offset += 8;
141 // Rotation
142 a = d = cosf(theta);
143 b = c = sinf(theta);
144 // Scale
145 a *= sx;
146 b *= -sx;
147 c *= sy;
148 d *= sy;
149 cpu->memory.store16(cpu, destination, a * 256, 0);
150 cpu->memory.store16(cpu, destination + diff, b * 256, 0);
151 cpu->memory.store16(cpu, destination + diff * 2, c * 256, 0);
152 cpu->memory.store16(cpu, destination + diff * 3, d * 256, 0);
153 destination += diff * 4;
154 }
155}
156
157static void _MidiKey2Freq(struct GBA* gba) {
158 struct ARMCore* cpu = gba->cpu;
159 uint32_t key = cpu->memory.load32(cpu, cpu->gprs[0] + 4, 0);
160 cpu->gprs[0] = key / powf(2, (180.f - cpu->gprs[1] - cpu->gprs[2] / 256.f) / 12.f);
161}
162
163static void _Div(struct GBA* gba, int32_t num, int32_t denom) {
164 struct ARMCore* cpu = gba->cpu;
165 if (denom != 0) {
166 div_t result = div(num, denom);
167 cpu->gprs[0] = result.quot;
168 cpu->gprs[1] = result.rem;
169 cpu->gprs[3] = abs(result.quot);
170 } else {
171 GBALog(gba, GBA_LOG_GAME_ERROR, "Attempting to divide %i by zero!", num);
172 // If abs(num) > 1, this should hang, but that would be painful to
173 // emulate in HLE, and no game will get into a state where it hangs...
174 cpu->gprs[0] = (num < 0) ? -1 : 1;
175 cpu->gprs[1] = num;
176 cpu->gprs[3] = 1;
177 }
178}
179
180void GBASwi16(struct ARMCore* cpu, int immediate) {
181 struct GBA* gba = (struct GBA*) cpu->master;
182 GBALog(gba, GBA_LOG_SWI, "SWI: %02X r0: %08X r1: %08X r2: %08X r3: %08X",
183 immediate, cpu->gprs[0], cpu->gprs[1], cpu->gprs[2], cpu->gprs[3]);
184
185 if (gba->memory.fullBios) {
186 ARMRaiseSWI(cpu);
187 return;
188 }
189 switch (immediate) {
190 case 0x0:
191 _SoftReset(gba);
192 break;
193 case 0x1:
194 _RegisterRamReset(gba);
195 break;
196 case 0x2:
197 GBAHalt(gba);
198 break;
199 case 0x3:
200 GBAStop(gba);
201 break;
202 case 0x05:
203 // VBlankIntrWait
204 // Fall through:
205 case 0x04:
206 // IntrWait
207 ARMRaiseSWI(cpu);
208 break;
209 case 0x6:
210 _Div(gba, cpu->gprs[0], cpu->gprs[1]);
211 break;
212 case 0x7:
213 _Div(gba, cpu->gprs[1], cpu->gprs[0]);
214 break;
215 case 0x8:
216 cpu->gprs[0] = sqrt(cpu->gprs[0]);
217 break;
218 case 0xA:
219 cpu->gprs[0] = atan2f(cpu->gprs[1] / 16384.f, cpu->gprs[0] / 16384.f) / (2 * M_PI) * 0x10000;
220 break;
221 case 0xB:
222 case 0xC:
223 if (cpu->gprs[0] >> BASE_OFFSET == REGION_BIOS) {
224 GBALog(gba, GBA_LOG_GAME_ERROR, "Cannot CpuSet from BIOS");
225 return;
226 }
227 ARMRaiseSWI(cpu);
228 break;
229 case 0xD:
230 cpu->gprs[0] = GBA_BIOS_CHECKSUM;
231 cpu->gprs[1] = 1;
232 cpu->gprs[3] = SIZE_BIOS;
233 break;
234 case 0xE:
235 _BgAffineSet(gba);
236 break;
237 case 0xF:
238 _ObjAffineSet(gba);
239 break;
240 case 0x11:
241 case 0x12:
242 if (cpu->gprs[0] < BASE_WORKING_RAM) {
243 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 source");
244 break;
245 }
246 switch (cpu->gprs[1] >> BASE_OFFSET) {
247 default:
248 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 destination");
249 // Fall through
250 case REGION_WORKING_RAM:
251 case REGION_WORKING_IRAM:
252 case REGION_VRAM:
253 _unLz77(gba, immediate == 0x11 ? 1 : 2);
254 break;
255 }
256 break;
257 case 0x13:
258 if (cpu->gprs[0] < BASE_WORKING_RAM) {
259 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman source");
260 break;
261 }
262 switch (cpu->gprs[1] >> BASE_OFFSET) {
263 default:
264 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman destination");
265 // Fall through
266 case REGION_WORKING_RAM:
267 case REGION_WORKING_IRAM:
268 case REGION_VRAM:
269 _unHuffman(gba);
270 break;
271 }
272 break;
273 case 0x14:
274 case 0x15:
275 if (cpu->gprs[0] < BASE_WORKING_RAM) {
276 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL source");
277 break;
278 }
279 switch (cpu->gprs[1] >> BASE_OFFSET) {
280 default:
281 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL destination");
282 // Fall through
283 case REGION_WORKING_RAM:
284 case REGION_WORKING_IRAM:
285 case REGION_VRAM:
286 _unRl(gba, immediate == 0x14 ? 1 : 2);
287 break;
288 }
289 break;
290 case 0x16:
291 case 0x17:
292 case 0x18:
293 if (cpu->gprs[0] < BASE_WORKING_RAM) {
294 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter source");
295 break;
296 }
297 switch (cpu->gprs[1] >> BASE_OFFSET) {
298 default:
299 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter destination");
300 // Fall through
301 case REGION_WORKING_RAM:
302 case REGION_WORKING_IRAM:
303 case REGION_VRAM:
304 _unFilter(gba, immediate == 0x18 ? 2 : 1, immediate == 0x16 ? 1 : 2);
305 break;
306 }
307 break;
308 case 0x19:
309 // SoundBias is mostly meaningless here
310 GBALog(gba, GBA_LOG_STUB, "Stub software interrupt: SoundBias (19)");
311 break;
312 case 0x1F:
313 _MidiKey2Freq(gba);
314 break;
315 default:
316 GBALog(gba, GBA_LOG_STUB, "Stub software interrupt: %02X", immediate);
317 }
318 gba->memory.biosPrefetch = 0xE3A02004;
319}
320
321void GBASwi32(struct ARMCore* cpu, int immediate) {
322 GBASwi16(cpu, immediate >> 16);
323}
324
325uint32_t GBAChecksum(uint32_t* memory, size_t size) {
326 size_t i;
327 uint32_t sum = 0;
328 for (i = 0; i < size; i += 4) {
329 sum += memory[i >> 2];
330 }
331 return sum;
332}
333
334static void _unLz77(struct GBA* gba, int width) {
335 struct ARMCore* cpu = gba->cpu;
336 uint32_t source = cpu->gprs[0];
337 uint32_t dest = cpu->gprs[1];
338 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
339 // We assume the signature byte (0x10) is correct
340 int blockheader = 0; // Some compilers warn if this isn't set, even though it's trivially provably always set
341 source += 4;
342 int blocksRemaining = 0;
343 uint32_t disp;
344 int bytes;
345 int byte;
346 int halfword = 0;
347 while (remaining > 0) {
348 if (blocksRemaining) {
349 if (blockheader & 0x80) {
350 // Compressed
351 int block = cpu->memory.load8(cpu, source + 1, 0) | (cpu->memory.load8(cpu, source, 0) << 8);
352 source += 2;
353 disp = dest - (block & 0x0FFF) - 1;
354 bytes = (block >> 12) + 3;
355 while (bytes-- && remaining) {
356 --remaining;
357 if (width == 2) {
358 byte = (int16_t) cpu->memory.load16(cpu, disp & ~1, 0);
359 if (dest & 1) {
360 byte >>= (disp & 1) * 8;
361 halfword |= byte << 8;
362 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
363 } else {
364 byte >>= (disp & 1) * 8;
365 halfword = byte & 0xFF;
366 }
367 } else {
368 byte = cpu->memory.load8(cpu, disp, 0);
369 cpu->memory.store8(cpu, dest, byte, 0);
370 }
371 ++disp;
372 ++dest;
373 }
374 } else {
375 // Uncompressed
376 byte = cpu->memory.load8(cpu, source, 0);
377 ++source;
378 if (width == 2) {
379 if (dest & 1) {
380 halfword |= byte << 8;
381 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
382 } else {
383 halfword = byte;
384 }
385 } else {
386 cpu->memory.store8(cpu, dest, byte, 0);
387 }
388 ++dest;
389 --remaining;
390 }
391 blockheader <<= 1;
392 --blocksRemaining;
393 } else {
394 blockheader = cpu->memory.load8(cpu, source, 0);
395 ++source;
396 blocksRemaining = 8;
397 }
398 }
399 cpu->gprs[0] = source;
400 cpu->gprs[1] = dest;
401 cpu->gprs[3] = 0;
402}
403
404DECL_BITFIELD(HuffmanNode, uint8_t);
405DECL_BITS(HuffmanNode, Offset, 0, 6);
406DECL_BIT(HuffmanNode, RTerm, 6);
407DECL_BIT(HuffmanNode, LTerm, 7);
408
409static void _unHuffman(struct GBA* gba) {
410 struct ARMCore* cpu = gba->cpu;
411 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
412 uint32_t dest = cpu->gprs[1];
413 uint32_t header = cpu->memory.load32(cpu, source, 0);
414 int remaining = header >> 8;
415 int bits = header & 0xF;
416 if (bits == 0) {
417 GBALog(gba, GBA_LOG_GAME_ERROR, "Invalid Huffman bits");
418 bits = 8;
419 }
420 if (32 % bits || bits == 1) {
421 GBALog(gba, GBA_LOG_STUB, "Unimplemented unaligned Huffman");
422 return;
423 }
424 // We assume the signature byte (0x20) is correct
425 int treesize = (cpu->memory.load8(cpu, source + 4, 0) << 1) + 1;
426 int block = 0;
427 uint32_t treeBase = source + 5;
428 source += 5 + treesize;
429 uint32_t nPointer = treeBase;
430 HuffmanNode node;
431 int bitsRemaining;
432 int readBits;
433 int bitsSeen = 0;
434 node = cpu->memory.load8(cpu, nPointer, 0);
435 while (remaining > 0) {
436 uint32_t bitstream = cpu->memory.load32(cpu, source, 0);
437 source += 4;
438 for (bitsRemaining = 32; bitsRemaining > 0 && remaining > 0; --bitsRemaining, bitstream <<= 1) {
439 uint32_t next = (nPointer & ~1) + HuffmanNodeGetOffset(node) * 2 + 2;
440 if (bitstream & 0x80000000) {
441 // Go right
442 if (HuffmanNodeIsRTerm(node)) {
443 readBits = cpu->memory.load8(cpu, next + 1, 0);
444 } else {
445 nPointer = next + 1;
446 node = cpu->memory.load8(cpu, nPointer, 0);
447 continue;
448 }
449 } else {
450 // Go left
451 if (HuffmanNodeIsLTerm(node)) {
452 readBits = cpu->memory.load8(cpu, next, 0);
453 } else {
454 nPointer = next;
455 node = cpu->memory.load8(cpu, nPointer, 0);
456 continue;
457 }
458 }
459
460 block |= (readBits & ((1 << bits) - 1)) << bitsSeen;
461 bitsSeen += bits;
462 nPointer = treeBase;
463 node = cpu->memory.load8(cpu, nPointer, 0);
464 if (bitsSeen == 32) {
465 bitsSeen = 0;
466 cpu->memory.store32(cpu, dest, block, 0);
467 dest += 4;
468 remaining -= 4;
469 block = 0;
470 }
471 }
472 }
473 cpu->gprs[0] = source;
474 cpu->gprs[1] = dest;
475}
476
477static void _unRl(struct GBA* gba, int width) {
478 struct ARMCore* cpu = gba->cpu;
479 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
480 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
481 int padding = (4 - remaining) & 0x3;
482 // We assume the signature byte (0x30) is correct
483 int blockheader;
484 int block;
485 source += 4;
486 uint32_t dest = cpu->gprs[1];
487 int halfword = 0;
488 while (remaining > 0) {
489 blockheader = cpu->memory.load8(cpu, source, 0);
490 ++source;
491 if (blockheader & 0x80) {
492 // Compressed
493 blockheader &= 0x7F;
494 blockheader += 3;
495 block = cpu->memory.load8(cpu, source, 0);
496 ++source;
497 while (blockheader-- && remaining) {
498 --remaining;
499 if (width == 2) {
500 if (dest & 1) {
501 halfword |= block << 8;
502 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
503 } else {
504 halfword = block;
505 }
506 } else {
507 cpu->memory.store8(cpu, dest, block, 0);
508 }
509 ++dest;
510 }
511 } else {
512 // Uncompressed
513 blockheader++;
514 while (blockheader-- && remaining) {
515 --remaining;
516 int byte = cpu->memory.load8(cpu, source, 0);
517 ++source;
518 if (width == 2) {
519 if (dest & 1) {
520 halfword |= byte << 8;
521 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
522 } else {
523 halfword = byte;
524 }
525 } else {
526 cpu->memory.store8(cpu, dest, byte, 0);
527 }
528 ++dest;
529 }
530 }
531 }
532 if (width == 2) {
533 if (dest & 1) {
534 --padding;
535 ++dest;
536 }
537 for (; padding > 0; padding -= 2, dest += 2) {
538 cpu->memory.store16(cpu, dest, 0, 0);
539 }
540 } else {
541 while (padding--) {
542 cpu->memory.store8(cpu, dest, 0, 0);
543 ++dest;
544 }
545 }
546 cpu->gprs[0] = source;
547 cpu->gprs[1] = dest;
548}
549
550static void _unFilter(struct GBA* gba, int inwidth, int outwidth) {
551 struct ARMCore* cpu = gba->cpu;
552 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
553 uint32_t dest = cpu->gprs[1];
554 uint32_t header = cpu->memory.load32(cpu, source, 0);
555 int remaining = header >> 8;
556 // We assume the signature nybble (0x8) is correct
557 uint16_t halfword = 0;
558 uint16_t old = 0;
559 source += 4;
560 while (remaining > 0) {
561 uint16_t new;
562 if (inwidth == 1) {
563 new = cpu->memory.load8(cpu, source, 0);
564 } else {
565 new = cpu->memory.load16(cpu, source, 0);
566 }
567 new += old;
568 if (outwidth > inwidth) {
569 halfword >>= 8;
570 halfword |= (new << 8);
571 if (source & 1) {
572 cpu->memory.store16(cpu, dest, halfword, 0);
573 dest += outwidth;
574 remaining -= outwidth;
575 }
576 } else if (outwidth == 1) {
577 cpu->memory.store8(cpu, dest, new, 0);
578 dest += outwidth;
579 remaining -= outwidth;
580 } else {
581 cpu->memory.store16(cpu, dest, new, 0);
582 dest += outwidth;
583 remaining -= outwidth;
584 }
585 old = new;
586 source += inwidth;
587 }
588 cpu->gprs[0] = source;
589 cpu->gprs[1] = dest;
590}