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
13#ifndef M_PI
14#define M_PI 3.141592654f
15#endif
16
17const uint32_t GBA_BIOS_CHECKSUM = 0xBAAE187F;
18const uint32_t GBA_DS_BIOS_CHECKSUM = 0xBAAE1880;
19
20static void _unLz77(struct GBA* gba, int width);
21static void _unHuffman(struct GBA* gba);
22static void _unRl(struct GBA* gba, int width);
23static void _unFilter(struct GBA* gba, int inwidth, int outwidth);
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 int currentCycles = 0;
47 ARM_WRITE_PC;
48}
49
50static void _RegisterRamReset(struct GBA* gba) {
51 uint32_t registers = gba->cpu->gprs[0];
52 struct ARMCore* cpu = gba->cpu;
53 cpu->memory.store16(cpu, BASE_IO | REG_DISPCNT, 0x0080, 0);
54 if (registers & 0x01) {
55 memset(gba->memory.wram, 0, SIZE_WORKING_RAM);
56 }
57 if (registers & 0x02) {
58 memset(gba->memory.iwram, 0, SIZE_WORKING_IRAM - 0x200);
59 }
60 if (registers & 0x04) {
61 memset(gba->video.palette, 0, SIZE_PALETTE_RAM);
62 }
63 if (registers & 0x08) {
64 memset(gba->video.renderer->vram, 0, SIZE_VRAM);
65 }
66 if (registers & 0x10) {
67 memset(gba->video.oam.raw, 0, SIZE_OAM);
68 }
69 if (registers & 0x20) {
70 GBALog(gba, GBA_LOG_STUB, "RegisterRamReset on SIO unimplemented");
71 }
72 if (registers & 0x40) {
73 GBALog(gba, GBA_LOG_STUB, "RegisterRamReset on Audio unimplemented");
74 }
75 if (registers & 0x80) {
76 GBALog(gba, GBA_LOG_STUB, "RegisterRamReset on IO unimplemented");
77 }
78}
79
80static void _BgAffineSet(struct GBA* gba) {
81 struct ARMCore* cpu = gba->cpu;
82 int i = cpu->gprs[2];
83 float ox, oy;
84 float cx, cy;
85 float sx, sy;
86 float theta;
87 int offset = cpu->gprs[0];
88 int destination = cpu->gprs[1];
89 float a, b, c, d;
90 float rx, ry;
91 while (i--) {
92 // [ sx 0 0 ] [ cos(theta) -sin(theta) 0 ] [ 1 0 cx - ox ] [ A B rx ]
93 // [ 0 sy 0 ] * [ sin(theta) cos(theta) 0 ] * [ 0 1 cy - oy ] = [ C D ry ]
94 // [ 0 0 1 ] [ 0 0 1 ] [ 0 0 1 ] [ 0 0 1 ]
95 ox = (int32_t) cpu->memory.load32(cpu, offset, 0) / 256.f;
96 oy = (int32_t) cpu->memory.load32(cpu, offset + 4, 0) / 256.f;
97 cx = (int16_t) cpu->memory.load16(cpu, offset + 8, 0);
98 cy = (int16_t) cpu->memory.load16(cpu, offset + 10, 0);
99 sx = (int16_t) cpu->memory.load16(cpu, offset + 12, 0) / 256.f;
100 sy = (int16_t) cpu->memory.load16(cpu, offset + 14, 0) / 256.f;
101 theta = (cpu->memory.load16(cpu, offset + 16, 0) >> 8) / 128.f * M_PI;
102 offset += 20;
103 // Rotation
104 a = d = cosf(theta);
105 b = c = sinf(theta);
106 // Scale
107 a *= sx;
108 b *= -sx;
109 c *= sy;
110 d *= sy;
111 // Translate
112 rx = ox - (a * cx + b * cy);
113 ry = oy - (c * cx + d * cy);
114 cpu->memory.store16(cpu, destination, a * 256, 0);
115 cpu->memory.store16(cpu, destination + 2, b * 256, 0);
116 cpu->memory.store16(cpu, destination + 4, c * 256, 0);
117 cpu->memory.store16(cpu, destination + 6, d * 256, 0);
118 cpu->memory.store32(cpu, destination + 8, rx * 256, 0);
119 cpu->memory.store32(cpu, destination + 12, ry * 256, 0);
120 destination += 16;
121 }
122}
123
124static void _ObjAffineSet(struct GBA* gba) {
125 struct ARMCore* cpu = gba->cpu;
126 int i = cpu->gprs[2];
127 float sx, sy;
128 float theta;
129 int offset = cpu->gprs[0];
130 int destination = cpu->gprs[1];
131 int diff = cpu->gprs[3];
132 float a, b, c, d;
133 while (i--) {
134 // [ sx 0 ] [ cos(theta) -sin(theta) ] [ A B ]
135 // [ 0 sy ] * [ sin(theta) cos(theta) ] = [ C D ]
136 sx = (int16_t) cpu->memory.load16(cpu, offset, 0) / 256.f;
137 sy = (int16_t) cpu->memory.load16(cpu, offset + 2, 0) / 256.f;
138 theta = (cpu->memory.load16(cpu, offset + 4, 0) >> 8) / 128.f * M_PI;
139 offset += 8;
140 // Rotation
141 a = d = cosf(theta);
142 b = c = sinf(theta);
143 // Scale
144 a *= sx;
145 b *= -sx;
146 c *= sy;
147 d *= sy;
148 cpu->memory.store16(cpu, destination, a * 256, 0);
149 cpu->memory.store16(cpu, destination + diff, b * 256, 0);
150 cpu->memory.store16(cpu, destination + diff * 2, c * 256, 0);
151 cpu->memory.store16(cpu, destination + diff * 3, d * 256, 0);
152 destination += diff * 4;
153 }
154}
155
156static void _MidiKey2Freq(struct GBA* gba) {
157 struct ARMCore* cpu = gba->cpu;
158 uint32_t key = cpu->memory.load32(cpu, cpu->gprs[0] + 4, 0);
159 cpu->gprs[0] = key / powf(2, (180.f - cpu->gprs[1] - cpu->gprs[2] / 256.f) / 12.f);
160}
161
162static void _Div(struct GBA* gba, int32_t num, int32_t denom) {
163 struct ARMCore* cpu = gba->cpu;
164 if (denom != 0) {
165 div_t result = div(num, denom);
166 cpu->gprs[0] = result.quot;
167 cpu->gprs[1] = result.rem;
168 cpu->gprs[3] = abs(result.quot);
169 } else {
170 GBALog(gba, GBA_LOG_GAME_ERROR, "Attempting to divide %i by zero!", num);
171 // If abs(num) > 1, this should hang, but that would be painful to
172 // emulate in HLE, and no game will get into a state where it hangs...
173 cpu->gprs[0] = (num < 0) ? -1 : 1;
174 cpu->gprs[1] = num;
175 cpu->gprs[3] = 1;
176 }
177}
178
179void GBASwi16(struct ARMCore* cpu, int immediate) {
180 struct GBA* gba = (struct GBA*) cpu->master;
181 GBALog(gba, GBA_LOG_SWI, "SWI: %02X r0: %08X r1: %08X r2: %08X r3: %08X",
182 immediate, cpu->gprs[0], cpu->gprs[1], cpu->gprs[2], cpu->gprs[3]);
183
184 if (gba->memory.fullBios) {
185 ARMRaiseSWI(cpu);
186 return;
187 }
188 switch (immediate) {
189 case 0x0:
190 _SoftReset(gba);
191 break;
192 case 0x1:
193 _RegisterRamReset(gba);
194 break;
195 case 0x2:
196 GBAHalt(gba);
197 break;
198 case 0x05:
199 // VBlankIntrWait
200 // Fall through:
201 case 0x04:
202 // IntrWait
203 ARMRaiseSWI(cpu);
204 break;
205 case 0x6:
206 _Div(gba, cpu->gprs[0], cpu->gprs[1]);
207 break;
208 case 0x7:
209 _Div(gba, cpu->gprs[1], cpu->gprs[0]);
210 break;
211 case 0x8:
212 cpu->gprs[0] = sqrt(cpu->gprs[0]);
213 break;
214 case 0xA:
215 cpu->gprs[0] = atan2f(cpu->gprs[1] / 16384.f, cpu->gprs[0] / 16384.f) / (2 * M_PI) * 0x10000;
216 break;
217 case 0xB:
218 case 0xC:
219 if (cpu->gprs[0] >> BASE_OFFSET == REGION_BIOS) {
220 GBALog(gba, GBA_LOG_GAME_ERROR, "Cannot CpuSet from BIOS");
221 return;
222 }
223 ARMRaiseSWI(cpu);
224 break;
225 case 0xD:
226 cpu->gprs[0] = GBA_BIOS_CHECKSUM;
227 cpu->gprs[1] = 1;
228 cpu->gprs[3] = SIZE_BIOS;
229 break;
230 case 0xE:
231 _BgAffineSet(gba);
232 break;
233 case 0xF:
234 _ObjAffineSet(gba);
235 break;
236 case 0x11:
237 case 0x12:
238 if (cpu->gprs[0] < BASE_WORKING_RAM) {
239 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 source");
240 break;
241 }
242 switch (cpu->gprs[1] >> BASE_OFFSET) {
243 default:
244 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 destination");
245 case REGION_WORKING_RAM:
246 case REGION_WORKING_IRAM:
247 case REGION_VRAM:
248 _unLz77(gba, immediate == 0x11 ? 1 : 2);
249 break;
250 }
251 break;
252 case 0x13:
253 if (cpu->gprs[0] < BASE_WORKING_RAM) {
254 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman source");
255 break;
256 }
257 switch (cpu->gprs[1] >> BASE_OFFSET) {
258 default:
259 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman destination");
260 case REGION_WORKING_RAM:
261 case REGION_WORKING_IRAM:
262 case REGION_VRAM:
263 _unHuffman(gba);
264 break;
265 }
266 break;
267 case 0x14:
268 case 0x15:
269 if (cpu->gprs[0] < BASE_WORKING_RAM) {
270 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL source");
271 break;
272 }
273 switch (cpu->gprs[1] >> BASE_OFFSET) {
274 default:
275 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL destination");
276 case REGION_WORKING_RAM:
277 case REGION_WORKING_IRAM:
278 case REGION_VRAM:
279 _unRl(gba, immediate == 0x14 ? 1 : 2);
280 break;
281 }
282 break;
283 case 0x16:
284 case 0x17:
285 case 0x18:
286 if (cpu->gprs[0] < BASE_WORKING_RAM) {
287 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter source");
288 break;
289 }
290 switch (cpu->gprs[1] >> BASE_OFFSET) {
291 default:
292 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter destination");
293 case REGION_WORKING_RAM:
294 case REGION_WORKING_IRAM:
295 case REGION_VRAM:
296 _unFilter(gba, immediate == 0x18 ? 2 : 1, immediate == 0x16 ? 1 : 2);
297 break;
298 }
299 break;
300 case 0x1F:
301 _MidiKey2Freq(gba);
302 break;
303 default:
304 GBALog(gba, GBA_LOG_STUB, "Stub software interrupt: %02X", immediate);
305 }
306 gba->memory.biosPrefetch = 0xE3A02004;
307}
308
309void GBASwi32(struct ARMCore* cpu, int immediate) {
310 GBASwi16(cpu, immediate >> 16);
311}
312
313uint32_t GBAChecksum(uint32_t* memory, size_t size) {
314 size_t i;
315 uint32_t sum = 0;
316 for (i = 0; i < size; i += 4) {
317 sum += memory[i >> 2];
318 }
319 return sum;
320}
321
322static void _unLz77(struct GBA* gba, int width) {
323 struct ARMCore* cpu = gba->cpu;
324 uint32_t source = cpu->gprs[0];
325 uint32_t dest = cpu->gprs[1];
326 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
327 // We assume the signature byte (0x10) is correct
328 int blockheader = 0; // Some compilers warn if this isn't set, even though it's trivially provably always set
329 source += 4;
330 int blocksRemaining = 0;
331 uint32_t disp;
332 int bytes;
333 int byte;
334 int halfword;
335 while (remaining > 0) {
336 if (blocksRemaining) {
337 if (blockheader & 0x80) {
338 // Compressed
339 int block = cpu->memory.load8(cpu, source + 1, 0) | (cpu->memory.load8(cpu, source, 0) << 8);
340 source += 2;
341 disp = dest - (block & 0x0FFF) - 1;
342 bytes = (block >> 12) + 3;
343 while (bytes-- && remaining) {
344 --remaining;
345 if (width == 2) {
346 byte = (int16_t) cpu->memory.load16(cpu, disp & ~1, 0);
347 if (dest & 1) {
348 byte >>= (disp & 1) * 8;
349 halfword |= byte << 8;
350 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
351 } else {
352 byte >>= (disp & 1) * 8;
353 halfword = byte & 0xFF;
354 }
355 } else {
356 byte = cpu->memory.load8(cpu, disp, 0);
357 cpu->memory.store8(cpu, dest, byte, 0);
358 }
359 ++disp;
360 ++dest;
361 }
362 } else {
363 // Uncompressed
364 byte = cpu->memory.load8(cpu, source, 0);
365 ++source;
366 if (width == 2) {
367 if (dest & 1) {
368 halfword |= byte << 8;
369 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
370 } else {
371 halfword = byte;
372 }
373 } else {
374 cpu->memory.store8(cpu, dest, byte, 0);
375 }
376 ++dest;
377 --remaining;
378 }
379 blockheader <<= 1;
380 --blocksRemaining;
381 } else {
382 blockheader = cpu->memory.load8(cpu, source, 0);
383 ++source;
384 blocksRemaining = 8;
385 }
386 }
387 cpu->gprs[0] = source;
388 cpu->gprs[1] = dest;
389 cpu->gprs[3] = 0;
390}
391
392DECL_BITFIELD(HuffmanNode, uint8_t);
393DECL_BITS(HuffmanNode, Offset, 0, 6);
394DECL_BIT(HuffmanNode, RTerm, 6);
395DECL_BIT(HuffmanNode, LTerm, 7);
396
397static void _unHuffman(struct GBA* gba) {
398 struct ARMCore* cpu = gba->cpu;
399 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
400 uint32_t dest = cpu->gprs[1];
401 uint32_t header = cpu->memory.load32(cpu, source, 0);
402 int remaining = header >> 8;
403 int bits = header & 0xF;
404 if (bits == 0) {
405 GBALog(gba, GBA_LOG_GAME_ERROR, "Invalid Huffman bits");
406 bits = 8;
407 }
408 if (32 % bits || bits == 1) {
409 GBALog(gba, GBA_LOG_STUB, "Unimplemented unaligned Huffman");
410 return;
411 }
412 // We assume the signature byte (0x20) is correct
413 int treesize = (cpu->memory.load8(cpu, source + 4, 0) << 1) + 1;
414 int block = 0;
415 uint32_t treeBase = source + 5;
416 source += 5 + treesize;
417 uint32_t nPointer = treeBase;
418 HuffmanNode node;
419 int bitsRemaining;
420 int readBits;
421 int bitsSeen = 0;
422 node = cpu->memory.load8(cpu, nPointer, 0);
423 while (remaining > 0) {
424 uint32_t bitstream = cpu->memory.load32(cpu, source, 0);
425 source += 4;
426 for (bitsRemaining = 32; bitsRemaining > 0 && remaining > 0; --bitsRemaining, bitstream <<= 1) {
427 uint32_t next = (nPointer & ~1) + HuffmanNodeGetOffset(node) * 2 + 2;
428 if (bitstream & 0x80000000) {
429 // Go right
430 if (HuffmanNodeIsRTerm(node)) {
431 readBits = cpu->memory.load8(cpu, next + 1, 0);
432 } else {
433 nPointer = next + 1;
434 node = cpu->memory.load8(cpu, nPointer, 0);
435 continue;
436 }
437 } else {
438 // Go left
439 if (HuffmanNodeIsLTerm(node)) {
440 readBits = cpu->memory.load8(cpu, next, 0);
441 } else {
442 nPointer = next;
443 node = cpu->memory.load8(cpu, nPointer, 0);
444 continue;
445 }
446 }
447
448 block |= (readBits & ((1 << bits) - 1)) << bitsSeen;
449 bitsSeen += bits;
450 nPointer = treeBase;
451 node = cpu->memory.load8(cpu, nPointer, 0);
452 if (bitsSeen == 32) {
453 bitsSeen = 0;
454 cpu->memory.store32(cpu, dest, block, 0);
455 dest += 4;
456 remaining -= 4;
457 block = 0;
458 }
459 }
460
461 }
462 cpu->gprs[0] = source;
463 cpu->gprs[1] = dest;
464}
465
466static void _unRl(struct GBA* gba, int width) {
467 struct ARMCore* cpu = gba->cpu;
468 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
469 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
470 int padding = (4 - remaining) & 0x3;
471 // We assume the signature byte (0x30) is correct
472 int blockheader;
473 int block;
474 source += 4;
475 uint32_t dest = cpu->gprs[1];
476 int halfword = 0;
477 while (remaining > 0) {
478 blockheader = cpu->memory.load8(cpu, source, 0);
479 ++source;
480 if (blockheader & 0x80) {
481 // Compressed
482 blockheader &= 0x7F;
483 blockheader += 3;
484 block = cpu->memory.load8(cpu, source, 0);
485 ++source;
486 while (blockheader-- && remaining) {
487 --remaining;
488 if (width == 2) {
489 if (dest & 1) {
490 halfword |= block << 8;
491 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
492 } else {
493 halfword = block;
494 }
495 } else {
496 cpu->memory.store8(cpu, dest, block, 0);
497 }
498 ++dest;
499 }
500 } else {
501 // Uncompressed
502 blockheader++;
503 while (blockheader-- && remaining) {
504 --remaining;
505 int byte = cpu->memory.load8(cpu, source, 0);
506 ++source;
507 if (width == 2) {
508 if (dest & 1) {
509 halfword |= byte << 8;
510 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
511 } else {
512 halfword = byte;
513 }
514 } else {
515 cpu->memory.store8(cpu, dest, byte, 0);
516 }
517 ++dest;
518 }
519 }
520 }
521 if (width == 2) {
522 if (dest & 1) {
523 --padding;
524 ++dest;
525 }
526 for (; padding > 0; padding -= 2, dest += 2) {
527 cpu->memory.store16(cpu, dest, 0, 0);
528 }
529 } else {
530 while (padding--) {
531 cpu->memory.store8(cpu, dest, 0, 0);
532 ++dest;
533 }
534 }
535 cpu->gprs[0] = source;
536 cpu->gprs[1] = dest;
537}
538
539static void _unFilter(struct GBA* gba, int inwidth, int outwidth) {
540 struct ARMCore* cpu = gba->cpu;
541 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
542 uint32_t dest = cpu->gprs[1];
543 uint32_t header = cpu->memory.load32(cpu, source, 0);
544 int remaining = header >> 8;
545 // We assume the signature nybble (0x8) is correct
546 uint16_t halfword = 0;
547 uint16_t old = 0;
548 source += 4;
549 while (remaining > 0) {
550 uint16_t new;
551 if (inwidth == 1) {
552 new = cpu->memory.load8(cpu, source, 0);
553 } else {
554 new = cpu->memory.load16(cpu, source, 0);
555 }
556 new += old;
557 if (outwidth > inwidth) {
558 halfword >>= 8;
559 halfword |= (new << 8);
560 if (source & 1) {
561 cpu->memory.store16(cpu, dest, halfword, 0);
562 dest += outwidth;
563 remaining -= outwidth;
564 }
565 } else if (outwidth == 1) {
566 cpu->memory.store8(cpu, dest, new, 0);
567 dest += outwidth;
568 remaining -= outwidth;
569 } else {
570 cpu->memory.store16(cpu, dest, new, 0);
571 dest += outwidth;
572 remaining -= outwidth;
573 }
574 old = new;
575 source += inwidth;
576 }
577 cpu->gprs[0] = source;
578 cpu->gprs[1] = dest;
579}