src/gba/gba-bios.c (view raw)
1/* Copyright (c) 2013-2014 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 "gba-bios.h"
7
8#include "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 GBALog(gba, GBA_LOG_STUB, "RegisterRamReset on SIO unimplemented");
67 }
68 if (registers & 0x40) {
69 GBALog(gba, GBA_LOG_STUB, "RegisterRamReset on Audio unimplemented");
70 }
71 if (registers & 0x80) {
72 GBALog(gba, GBA_LOG_STUB, "RegisterRamReset on IO unimplemented");
73 }
74}
75
76static void _BgAffineSet(struct GBA* gba) {
77 struct ARMCore* cpu = gba->cpu;
78 int i = cpu->gprs[2];
79 float ox, oy;
80 float cx, cy;
81 float sx, sy;
82 float theta;
83 int offset = cpu->gprs[0];
84 int destination = cpu->gprs[1];
85 float a, b, c, d;
86 float rx, ry;
87 while (i--) {
88 // [ sx 0 0 ] [ cos(theta) -sin(theta) 0 ] [ 1 0 cx - ox ] [ A B rx ]
89 // [ 0 sy 0 ] * [ sin(theta) cos(theta) 0 ] * [ 0 1 cy - oy ] = [ C D ry ]
90 // [ 0 0 1 ] [ 0 0 1 ] [ 0 0 1 ] [ 0 0 1 ]
91 ox = cpu->memory.load32(cpu, offset, 0) / 256.f;
92 oy = cpu->memory.load32(cpu, offset + 4, 0) / 256.f;
93 cx = cpu->memory.load16(cpu, offset + 8, 0);
94 cy = cpu->memory.load16(cpu, offset + 10, 0);
95 sx = cpu->memory.load16(cpu, offset + 12, 0) / 256.f;
96 sy = cpu->memory.load16(cpu, offset + 14, 0) / 256.f;
97 theta = (cpu->memory.load16(cpu, offset + 16, 0) >> 8) / 128.f * M_PI;
98 offset += 20;
99 // Rotation
100 a = d = cosf(theta);
101 b = c = sinf(theta);
102 // Scale
103 a *= sx;
104 b *= -sx;
105 c *= sy;
106 d *= sy;
107 // Translate
108 rx = ox - (a * cx + b * cy);
109 ry = oy - (c * cx + d * cy);
110 cpu->memory.store16(cpu, destination, a * 256, 0);
111 cpu->memory.store16(cpu, destination + 2, b * 256, 0);
112 cpu->memory.store16(cpu, destination + 4, c * 256, 0);
113 cpu->memory.store16(cpu, destination + 6, d * 256, 0);
114 cpu->memory.store32(cpu, destination + 8, rx * 256, 0);
115 cpu->memory.store32(cpu, destination + 12, ry * 256, 0);
116 destination += 16;
117 }
118}
119
120static void _ObjAffineSet(struct GBA* gba) {
121 struct ARMCore* cpu = gba->cpu;
122 int i = cpu->gprs[2];
123 float sx, sy;
124 float theta;
125 int offset = cpu->gprs[0];
126 int destination = cpu->gprs[1];
127 int diff = cpu->gprs[3];
128 float a, b, c, d;
129 while (i--) {
130 // [ sx 0 ] [ cos(theta) -sin(theta) ] [ A B ]
131 // [ 0 sy ] * [ sin(theta) cos(theta) ] = [ C D ]
132 sx = cpu->memory.load16(cpu, offset, 0) / 256.f;
133 sy = cpu->memory.load16(cpu, offset + 2, 0) / 256.f;
134 theta = (cpu->memory.load16(cpu, offset + 4, 0) >> 8) / 128.f * M_PI;
135 offset += 8;
136 // Rotation
137 a = d = cosf(theta);
138 b = c = sinf(theta);
139 // Scale
140 a *= sx;
141 b *= -sx;
142 c *= sy;
143 d *= sy;
144 cpu->memory.store16(cpu, destination, a * 256, 0);
145 cpu->memory.store16(cpu, destination + diff, b * 256, 0);
146 cpu->memory.store16(cpu, destination + diff * 2, c * 256, 0);
147 cpu->memory.store16(cpu, destination + diff * 3, d * 256, 0);
148 destination += diff * 4;
149 }
150}
151
152static void _MidiKey2Freq(struct GBA* gba) {
153 struct ARMCore* cpu = gba->cpu;
154 uint32_t key = cpu->memory.load32(cpu, cpu->gprs[0] + 4, 0);
155 cpu->gprs[0] = key / powf(2, (180.f - cpu->gprs[1] - cpu->gprs[2] / 256.f) / 12.f);
156}
157
158static void _Div(struct GBA* gba, int32_t num, int32_t denom) {
159 struct ARMCore* cpu = gba->cpu;
160 if (denom != 0) {
161 div_t result = div(num, denom);
162 cpu->gprs[0] = result.quot;
163 cpu->gprs[1] = result.rem;
164 cpu->gprs[3] = abs(result.quot);
165 } else {
166 GBALog(gba, GBA_LOG_GAME_ERROR, "Attempting to divide %i by zero!", num);
167 // If abs(num) > 1, this should hang, but that would be painful to
168 // emulate in HLE, and no game will get into a state where it hangs...
169 cpu->gprs[0] = (num < 0) ? -1 : 1;
170 cpu->gprs[1] = num;
171 cpu->gprs[3] = 1;
172 }
173}
174
175void GBASwi16(struct ARMCore* cpu, int immediate) {
176 struct GBA* gba = (struct GBA*) cpu->master;
177 GBALog(gba, GBA_LOG_SWI, "SWI: %02X r0: %08X r1: %08X r2: %08X r3: %08X",
178 immediate, cpu->gprs[0], cpu->gprs[1], cpu->gprs[2], cpu->gprs[3]);
179
180 if (gba->memory.fullBios) {
181 ARMRaiseSWI(cpu);
182 return;
183 }
184 switch (immediate) {
185 case 0x0:
186 _SoftReset(gba);
187 break;
188 case 0x1:
189 _RegisterRamReset(gba);
190 break;
191 case 0x2:
192 GBAHalt(gba);
193 break;
194 case 0x05:
195 // VBlankIntrWait
196 // Fall through:
197 case 0x04:
198 // IntrWait
199 ARMRaiseSWI(cpu);
200 break;
201 case 0x6:
202 _Div(gba, cpu->gprs[0], cpu->gprs[1]);
203 break;
204 case 0x7:
205 _Div(gba, cpu->gprs[1], cpu->gprs[0]);
206 break;
207 case 0x8:
208 cpu->gprs[0] = sqrt(cpu->gprs[0]);
209 break;
210 case 0xA:
211 cpu->gprs[0] = atan2f(cpu->gprs[1] / 16384.f, cpu->gprs[0] / 16384.f) / (2 * M_PI) * 0x10000;
212 break;
213 case 0xB:
214 case 0xC:
215 ARMRaiseSWI(cpu);
216 break;
217 case 0xD:
218 cpu->gprs[0] = GBA_BIOS_CHECKSUM;
219 cpu->gprs[1] = 1;
220 cpu->gprs[3] = SIZE_BIOS;
221 break;
222 case 0xE:
223 _BgAffineSet(gba);
224 break;
225 case 0xF:
226 _ObjAffineSet(gba);
227 break;
228 case 0x11:
229 case 0x12:
230 if (cpu->gprs[0] < BASE_WORKING_RAM) {
231 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 source");
232 }
233 switch (cpu->gprs[1] >> BASE_OFFSET) {
234 default:
235 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 destination");
236 case REGION_WORKING_RAM:
237 case REGION_WORKING_IRAM:
238 case REGION_VRAM:
239 _unLz77(gba, immediate == 0x11 ? 1 : 2);
240 break;
241 }
242 break;
243 case 0x13:
244 if (cpu->gprs[0] < BASE_WORKING_RAM) {
245 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman source");
246 }
247 switch (cpu->gprs[1] >> BASE_OFFSET) {
248 default:
249 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman destination");
250 case REGION_WORKING_RAM:
251 case REGION_WORKING_IRAM:
252 case REGION_VRAM:
253 _unHuffman(gba);
254 break;
255 }
256 break;
257 case 0x14:
258 case 0x15:
259 if (cpu->gprs[0] < BASE_WORKING_RAM) {
260 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL source");
261 }
262 switch (cpu->gprs[1] >> BASE_OFFSET) {
263 default:
264 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL destination");
265 case REGION_WORKING_RAM:
266 case REGION_WORKING_IRAM:
267 case REGION_VRAM:
268 _unRl(gba, immediate == 0x14 ? 1 : 2);
269 break;
270 }
271 break;
272 case 0x16:
273 case 0x17:
274 case 0x18:
275 if (cpu->gprs[0] < BASE_WORKING_RAM) {
276 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter source");
277 }
278 switch (cpu->gprs[1] >> BASE_OFFSET) {
279 default:
280 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter destination");
281 case REGION_WORKING_RAM:
282 case REGION_WORKING_IRAM:
283 case REGION_VRAM:
284 _unFilter(gba, immediate == 0x18 ? 2 : 1, immediate == 0x16 ? 1 : 2);
285 break;
286 }
287 break;
288 case 0x1F:
289 _MidiKey2Freq(gba);
290 break;
291 default:
292 GBALog(gba, GBA_LOG_STUB, "Stub software interrupt: %02X", immediate);
293 }
294 gba->memory.biosPrefetch = 0xE3A02004;
295}
296
297void GBASwi32(struct ARMCore* cpu, int immediate) {
298 GBASwi16(cpu, immediate >> 16);
299}
300
301uint32_t GBAChecksum(uint32_t* memory, size_t size) {
302 size_t i;
303 uint32_t sum = 0;
304 for (i = 0; i < size; i += 4) {
305 sum += memory[i >> 2];
306 }
307 return sum;
308}
309
310static void _unLz77(struct GBA* gba, int width) {
311 struct ARMCore* cpu = gba->cpu;
312 uint32_t source = cpu->gprs[0];
313 uint32_t dest = cpu->gprs[1];
314 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
315 // We assume the signature byte (0x10) is correct
316 int blockheader = 0; // Some compilers warn if this isn't set, even though it's trivially provably always set
317 source += 4;
318 int blocksRemaining = 0;
319 uint32_t disp;
320 int bytes;
321 int byte;
322 int halfword;
323 while (remaining > 0) {
324 if (blocksRemaining) {
325 if (blockheader & 0x80) {
326 // Compressed
327 int block = cpu->memory.load8(cpu, source + 1, 0) | (cpu->memory.load8(cpu, source, 0) << 8);
328 source += 2;
329 disp = dest - (block & 0x0FFF) - 1;
330 bytes = (block >> 12) + 3;
331 while (bytes-- && remaining) {
332 --remaining;
333 if (width == 2) {
334 byte = cpu->memory.load16(cpu, disp & ~1, 0);
335 if (dest & 1) {
336 byte >>= (disp & 1) * 8;
337 halfword |= byte << 8;
338 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
339 } else {
340 byte >>= (disp & 1) * 8;
341 halfword = byte & 0xFF;
342 }
343 } else {
344 byte = cpu->memory.load8(cpu, disp, 0);
345 cpu->memory.store8(cpu, dest, byte, 0);
346 }
347 ++disp;
348 ++dest;
349 }
350 } else {
351 // Uncompressed
352 byte = cpu->memory.load8(cpu, source, 0);
353 ++source;
354 if (width == 2) {
355 if (dest & 1) {
356 halfword |= byte << 8;
357 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
358 } else {
359 halfword = byte;
360 }
361 } else {
362 cpu->memory.store8(cpu, dest, byte, 0);
363 }
364 ++dest;
365 --remaining;
366 }
367 blockheader <<= 1;
368 --blocksRemaining;
369 } else {
370 blockheader = cpu->memory.load8(cpu, source, 0);
371 ++source;
372 blocksRemaining = 8;
373 }
374 }
375 cpu->gprs[0] = source;
376 cpu->gprs[1] = dest;
377 cpu->gprs[3] = 0;
378}
379
380DECL_BITFIELD(HuffmanNode, uint8_t);
381DECL_BITS(HuffmanNode, Offset, 0, 6);
382DECL_BIT(HuffmanNode, RTerm, 6);
383DECL_BIT(HuffmanNode, LTerm, 7);
384
385static void _unHuffman(struct GBA* gba) {
386 struct ARMCore* cpu = gba->cpu;
387 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
388 uint32_t dest = cpu->gprs[1];
389 uint32_t header = cpu->memory.load32(cpu, source, 0);
390 int remaining = header >> 8;
391 int bits = header & 0xF;
392 if (bits == 0) {
393 GBALog(gba, GBA_LOG_GAME_ERROR, "Invalid Huffman bits");
394 bits = 8;
395 }
396 if (32 % bits || bits == 1) {
397 GBALog(gba, GBA_LOG_STUB, "Unimplemented unaligned Huffman");
398 return;
399 }
400 // We assume the signature byte (0x20) is correct
401 int treesize = (cpu->memory.load8(cpu, source + 4, 0) << 1) + 1;
402 int block = 0;
403 uint32_t treeBase = source + 5;
404 source += 5 + treesize;
405 uint32_t nPointer = treeBase;
406 HuffmanNode node;
407 int bitsRemaining;
408 int readBits;
409 int bitsSeen = 0;
410 node = cpu->memory.load8(cpu, nPointer, 0);
411 while (remaining > 0) {
412 uint32_t bitstream = cpu->memory.load32(cpu, source, 0);
413 source += 4;
414 for (bitsRemaining = 32; bitsRemaining > 0 && remaining > 0; --bitsRemaining, bitstream <<= 1) {
415 uint32_t next = (nPointer & ~1) + HuffmanNodeGetOffset(node) * 2 + 2;
416 if (bitstream & 0x80000000) {
417 // Go right
418 if (HuffmanNodeIsRTerm(node)) {
419 readBits = cpu->memory.load8(cpu, next + 1, 0);
420 } else {
421 nPointer = next + 1;
422 node = cpu->memory.load8(cpu, nPointer, 0);
423 continue;
424 }
425 } else {
426 // Go left
427 if (HuffmanNodeIsLTerm(node)) {
428 readBits = cpu->memory.load8(cpu, next, 0);
429 } else {
430 nPointer = next;
431 node = cpu->memory.load8(cpu, nPointer, 0);
432 continue;
433 }
434 }
435
436 block |= (readBits & ((1 << bits) - 1)) << bitsSeen;
437 bitsSeen += bits;
438 nPointer = treeBase;
439 node = cpu->memory.load8(cpu, nPointer, 0);
440 if (bitsSeen == 32) {
441 bitsSeen = 0;
442 cpu->memory.store32(cpu, dest, block, 0);
443 dest += 4;
444 remaining -= 4;
445 block = 0;
446 }
447 }
448
449 }
450 cpu->gprs[0] = source;
451 cpu->gprs[1] = dest;
452}
453
454static void _unRl(struct GBA* gba, int width) {
455 struct ARMCore* cpu = gba->cpu;
456 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
457 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
458 int padding = (4 - remaining) & 0x3;
459 // We assume the signature byte (0x30) is correct
460 int blockheader;
461 int block;
462 source += 4;
463 uint32_t dest = cpu->gprs[1];
464 int halfword = 0;
465 while (remaining > 0) {
466 blockheader = cpu->memory.load8(cpu, source, 0);
467 ++source;
468 if (blockheader & 0x80) {
469 // Compressed
470 blockheader &= 0x7F;
471 blockheader += 3;
472 block = cpu->memory.load8(cpu, source, 0);
473 ++source;
474 while (blockheader-- && remaining) {
475 --remaining;
476 if (width == 2) {
477 if (dest & 1) {
478 halfword |= block << 8;
479 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
480 } else {
481 halfword = block;
482 }
483 } else {
484 cpu->memory.store8(cpu, dest, block, 0);
485 }
486 ++dest;
487 }
488 } else {
489 // Uncompressed
490 blockheader++;
491 while (blockheader-- && remaining) {
492 --remaining;
493 int byte = cpu->memory.load8(cpu, source, 0);
494 ++source;
495 if (width == 2) {
496 if (dest & 1) {
497 halfword |= byte << 8;
498 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
499 } else {
500 halfword = byte;
501 }
502 } else {
503 cpu->memory.store8(cpu, dest, byte, 0);
504 }
505 ++dest;
506 }
507 }
508 }
509 if (width == 2) {
510 if (dest & 1) {
511 --padding;
512 ++dest;
513 }
514 for (; padding > 0; padding -= 2, dest += 2) {
515 cpu->memory.store16(cpu, dest, 0, 0);
516 }
517 } else {
518 while (padding--) {
519 cpu->memory.store8(cpu, dest, 0, 0);
520 ++dest;
521 }
522 }
523 cpu->gprs[0] = source;
524 cpu->gprs[1] = dest;
525}
526
527static void _unFilter(struct GBA* gba, int inwidth, int outwidth) {
528 struct ARMCore* cpu = gba->cpu;
529 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
530 uint32_t dest = cpu->gprs[1];
531 uint32_t header = cpu->memory.load32(cpu, source, 0);
532 int remaining = header >> 8;
533 // We assume the signature nybble (0x8) is correct
534 uint16_t halfword = 0;
535 uint16_t old = 0;
536 source += 4;
537 while (remaining > 0) {
538 uint16_t new;
539 if (inwidth == 1) {
540 new = cpu->memory.load8(cpu, source, 0);
541 } else {
542 new = cpu->memory.load16(cpu, source, 0);
543 }
544 new += old;
545 if (outwidth > inwidth) {
546 halfword >>= 8;
547 halfword |= (new << 8);
548 if (source & 1) {
549 cpu->memory.store16(cpu, dest, halfword, 0);
550 dest += outwidth;
551 remaining -= outwidth;
552 }
553 } else if (outwidth == 1) {
554 cpu->memory.store8(cpu, dest, new, 0);
555 dest += outwidth;
556 remaining -= outwidth;
557 } else {
558 cpu->memory.store16(cpu, dest, new, 0);
559 dest += outwidth;
560 remaining -= outwidth;
561 }
562 old = new;
563 source += inwidth;
564 }
565 cpu->gprs[0] = source;
566 cpu->gprs[1] = dest;
567}