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_WORKING_RAM) {
224 GBALog(gba, GBA_LOG_GAME_ERROR, "Cannot CpuSet from BIOS");
225 return;
226 }
227 if (cpu->gprs[0] & (cpu->gprs[2] & (1 << 26) ? 3 : 1)) {
228 GBALog(gba, GBA_LOG_GAME_ERROR, "Misaligned CpuSet source");
229 }
230 if (cpu->gprs[1] & (cpu->gprs[2] & (1 << 26) ? 3 : 1)) {
231 GBALog(gba, GBA_LOG_GAME_ERROR, "Misaligned CpuSet destination");
232 }
233 ARMRaiseSWI(cpu);
234 break;
235 case 0xD:
236 cpu->gprs[0] = GBA_BIOS_CHECKSUM;
237 cpu->gprs[1] = 1;
238 cpu->gprs[3] = SIZE_BIOS;
239 break;
240 case 0xE:
241 _BgAffineSet(gba);
242 break;
243 case 0xF:
244 _ObjAffineSet(gba);
245 break;
246 case 0x11:
247 case 0x12:
248 if (cpu->gprs[0] < BASE_WORKING_RAM) {
249 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 source");
250 break;
251 }
252 switch (cpu->gprs[1] >> BASE_OFFSET) {
253 default:
254 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 destination");
255 // Fall through
256 case REGION_WORKING_RAM:
257 case REGION_WORKING_IRAM:
258 case REGION_VRAM:
259 _unLz77(gba, immediate == 0x11 ? 1 : 2);
260 break;
261 }
262 break;
263 case 0x13:
264 if (cpu->gprs[0] < BASE_WORKING_RAM) {
265 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman source");
266 break;
267 }
268 switch (cpu->gprs[1] >> BASE_OFFSET) {
269 default:
270 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman destination");
271 // Fall through
272 case REGION_WORKING_RAM:
273 case REGION_WORKING_IRAM:
274 case REGION_VRAM:
275 _unHuffman(gba);
276 break;
277 }
278 break;
279 case 0x14:
280 case 0x15:
281 if (cpu->gprs[0] < BASE_WORKING_RAM) {
282 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL source");
283 break;
284 }
285 switch (cpu->gprs[1] >> BASE_OFFSET) {
286 default:
287 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL destination");
288 // Fall through
289 case REGION_WORKING_RAM:
290 case REGION_WORKING_IRAM:
291 case REGION_VRAM:
292 _unRl(gba, immediate == 0x14 ? 1 : 2);
293 break;
294 }
295 break;
296 case 0x16:
297 case 0x17:
298 case 0x18:
299 if (cpu->gprs[0] < BASE_WORKING_RAM) {
300 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter source");
301 break;
302 }
303 switch (cpu->gprs[1] >> BASE_OFFSET) {
304 default:
305 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter destination");
306 // Fall through
307 case REGION_WORKING_RAM:
308 case REGION_WORKING_IRAM:
309 case REGION_VRAM:
310 _unFilter(gba, immediate == 0x18 ? 2 : 1, immediate == 0x16 ? 1 : 2);
311 break;
312 }
313 break;
314 case 0x19:
315 // SoundBias is mostly meaningless here
316 GBALog(gba, GBA_LOG_STUB, "Stub software interrupt: SoundBias (19)");
317 break;
318 case 0x1F:
319 _MidiKey2Freq(gba);
320 break;
321 default:
322 GBALog(gba, GBA_LOG_STUB, "Stub software interrupt: %02X", immediate);
323 }
324 gba->memory.biosPrefetch = 0xE3A02004;
325}
326
327void GBASwi32(struct ARMCore* cpu, int immediate) {
328 GBASwi16(cpu, immediate >> 16);
329}
330
331uint32_t GBAChecksum(uint32_t* memory, size_t size) {
332 size_t i;
333 uint32_t sum = 0;
334 for (i = 0; i < size; i += 4) {
335 sum += memory[i >> 2];
336 }
337 return sum;
338}
339
340static void _unLz77(struct GBA* gba, int width) {
341 struct ARMCore* cpu = gba->cpu;
342 uint32_t source = cpu->gprs[0];
343 uint32_t dest = cpu->gprs[1];
344 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
345 // We assume the signature byte (0x10) is correct
346 int blockheader = 0; // Some compilers warn if this isn't set, even though it's trivially provably always set
347 source += 4;
348 int blocksRemaining = 0;
349 uint32_t disp;
350 int bytes;
351 int byte;
352 int halfword = 0;
353 while (remaining > 0) {
354 if (blocksRemaining) {
355 if (blockheader & 0x80) {
356 // Compressed
357 int block = cpu->memory.load8(cpu, source + 1, 0) | (cpu->memory.load8(cpu, source, 0) << 8);
358 source += 2;
359 disp = dest - (block & 0x0FFF) - 1;
360 bytes = (block >> 12) + 3;
361 while (bytes-- && remaining) {
362 --remaining;
363 if (width == 2) {
364 byte = (int16_t) cpu->memory.load16(cpu, disp & ~1, 0);
365 if (dest & 1) {
366 byte >>= (disp & 1) * 8;
367 halfword |= byte << 8;
368 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
369 } else {
370 byte >>= (disp & 1) * 8;
371 halfword = byte & 0xFF;
372 }
373 } else {
374 byte = cpu->memory.load8(cpu, disp, 0);
375 cpu->memory.store8(cpu, dest, byte, 0);
376 }
377 ++disp;
378 ++dest;
379 }
380 } else {
381 // Uncompressed
382 byte = cpu->memory.load8(cpu, source, 0);
383 ++source;
384 if (width == 2) {
385 if (dest & 1) {
386 halfword |= byte << 8;
387 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
388 } else {
389 halfword = byte;
390 }
391 } else {
392 cpu->memory.store8(cpu, dest, byte, 0);
393 }
394 ++dest;
395 --remaining;
396 }
397 blockheader <<= 1;
398 --blocksRemaining;
399 } else {
400 blockheader = cpu->memory.load8(cpu, source, 0);
401 ++source;
402 blocksRemaining = 8;
403 }
404 }
405 cpu->gprs[0] = source;
406 cpu->gprs[1] = dest;
407 cpu->gprs[3] = 0;
408}
409
410DECL_BITFIELD(HuffmanNode, uint8_t);
411DECL_BITS(HuffmanNode, Offset, 0, 6);
412DECL_BIT(HuffmanNode, RTerm, 6);
413DECL_BIT(HuffmanNode, LTerm, 7);
414
415static void _unHuffman(struct GBA* gba) {
416 struct ARMCore* cpu = gba->cpu;
417 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
418 uint32_t dest = cpu->gprs[1];
419 uint32_t header = cpu->memory.load32(cpu, source, 0);
420 int remaining = header >> 8;
421 int bits = header & 0xF;
422 if (bits == 0) {
423 GBALog(gba, GBA_LOG_GAME_ERROR, "Invalid Huffman bits");
424 bits = 8;
425 }
426 if (32 % bits || bits == 1) {
427 GBALog(gba, GBA_LOG_STUB, "Unimplemented unaligned Huffman");
428 return;
429 }
430 // We assume the signature byte (0x20) is correct
431 int treesize = (cpu->memory.load8(cpu, source + 4, 0) << 1) + 1;
432 int block = 0;
433 uint32_t treeBase = source + 5;
434 source += 5 + treesize;
435 uint32_t nPointer = treeBase;
436 HuffmanNode node;
437 int bitsRemaining;
438 int readBits;
439 int bitsSeen = 0;
440 node = cpu->memory.load8(cpu, nPointer, 0);
441 while (remaining > 0) {
442 uint32_t bitstream = cpu->memory.load32(cpu, source, 0);
443 source += 4;
444 for (bitsRemaining = 32; bitsRemaining > 0 && remaining > 0; --bitsRemaining, bitstream <<= 1) {
445 uint32_t next = (nPointer & ~1) + HuffmanNodeGetOffset(node) * 2 + 2;
446 if (bitstream & 0x80000000) {
447 // Go right
448 if (HuffmanNodeIsRTerm(node)) {
449 readBits = cpu->memory.load8(cpu, next + 1, 0);
450 } else {
451 nPointer = next + 1;
452 node = cpu->memory.load8(cpu, nPointer, 0);
453 continue;
454 }
455 } else {
456 // Go left
457 if (HuffmanNodeIsLTerm(node)) {
458 readBits = cpu->memory.load8(cpu, next, 0);
459 } else {
460 nPointer = next;
461 node = cpu->memory.load8(cpu, nPointer, 0);
462 continue;
463 }
464 }
465
466 block |= (readBits & ((1 << bits) - 1)) << bitsSeen;
467 bitsSeen += bits;
468 nPointer = treeBase;
469 node = cpu->memory.load8(cpu, nPointer, 0);
470 if (bitsSeen == 32) {
471 bitsSeen = 0;
472 cpu->memory.store32(cpu, dest, block, 0);
473 dest += 4;
474 remaining -= 4;
475 block = 0;
476 }
477 }
478 }
479 cpu->gprs[0] = source;
480 cpu->gprs[1] = dest;
481}
482
483static void _unRl(struct GBA* gba, int width) {
484 struct ARMCore* cpu = gba->cpu;
485 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
486 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
487 int padding = (4 - remaining) & 0x3;
488 // We assume the signature byte (0x30) is correct
489 int blockheader;
490 int block;
491 source += 4;
492 uint32_t dest = cpu->gprs[1];
493 int halfword = 0;
494 while (remaining > 0) {
495 blockheader = cpu->memory.load8(cpu, source, 0);
496 ++source;
497 if (blockheader & 0x80) {
498 // Compressed
499 blockheader &= 0x7F;
500 blockheader += 3;
501 block = cpu->memory.load8(cpu, source, 0);
502 ++source;
503 while (blockheader-- && remaining) {
504 --remaining;
505 if (width == 2) {
506 if (dest & 1) {
507 halfword |= block << 8;
508 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
509 } else {
510 halfword = block;
511 }
512 } else {
513 cpu->memory.store8(cpu, dest, block, 0);
514 }
515 ++dest;
516 }
517 } else {
518 // Uncompressed
519 blockheader++;
520 while (blockheader-- && remaining) {
521 --remaining;
522 int byte = cpu->memory.load8(cpu, source, 0);
523 ++source;
524 if (width == 2) {
525 if (dest & 1) {
526 halfword |= byte << 8;
527 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
528 } else {
529 halfword = byte;
530 }
531 } else {
532 cpu->memory.store8(cpu, dest, byte, 0);
533 }
534 ++dest;
535 }
536 }
537 }
538 if (width == 2) {
539 if (dest & 1) {
540 --padding;
541 ++dest;
542 }
543 for (; padding > 0; padding -= 2, dest += 2) {
544 cpu->memory.store16(cpu, dest, 0, 0);
545 }
546 } else {
547 while (padding--) {
548 cpu->memory.store8(cpu, dest, 0, 0);
549 ++dest;
550 }
551 }
552 cpu->gprs[0] = source;
553 cpu->gprs[1] = dest;
554}
555
556static void _unFilter(struct GBA* gba, int inwidth, int outwidth) {
557 struct ARMCore* cpu = gba->cpu;
558 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
559 uint32_t dest = cpu->gprs[1];
560 uint32_t header = cpu->memory.load32(cpu, source, 0);
561 int remaining = header >> 8;
562 // We assume the signature nybble (0x8) is correct
563 uint16_t halfword = 0;
564 uint16_t old = 0;
565 source += 4;
566 while (remaining > 0) {
567 uint16_t new;
568 if (inwidth == 1) {
569 new = cpu->memory.load8(cpu, source, 0);
570 } else {
571 new = cpu->memory.load16(cpu, source, 0);
572 }
573 new += old;
574 if (outwidth > inwidth) {
575 halfword >>= 8;
576 halfword |= (new << 8);
577 if (source & 1) {
578 cpu->memory.store16(cpu, dest, halfword, 0);
579 dest += outwidth;
580 remaining -= outwidth;
581 }
582 } else if (outwidth == 1) {
583 cpu->memory.store8(cpu, dest, new, 0);
584 dest += outwidth;
585 remaining -= outwidth;
586 } else {
587 cpu->memory.store16(cpu, dest, new, 0);
588 dest += outwidth;
589 remaining -= outwidth;
590 }
591 old = new;
592 source += inwidth;
593 }
594 cpu->gprs[0] = source;
595 cpu->gprs[1] = dest;
596}