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 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 = (int32_t) cpu->memory.load32(cpu, offset, 0) / 256.f;
92 oy = (int32_t) cpu->memory.load32(cpu, offset + 4, 0) / 256.f;
93 cx = (int16_t) cpu->memory.load16(cpu, offset + 8, 0);
94 cy = (int16_t) cpu->memory.load16(cpu, offset + 10, 0);
95 sx = (int16_t) cpu->memory.load16(cpu, offset + 12, 0) / 256.f;
96 sy = (int16_t) 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 = (int16_t) cpu->memory.load16(cpu, offset, 0) / 256.f;
133 sy = (int16_t) 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 if (cpu->gprs[0] >> BASE_OFFSET == REGION_BIOS) {
216 GBALog(gba, GBA_LOG_GAME_ERROR, "Cannot CpuSet from BIOS");
217 return;
218 }
219 ARMRaiseSWI(cpu);
220 break;
221 case 0xD:
222 cpu->gprs[0] = GBA_BIOS_CHECKSUM;
223 cpu->gprs[1] = 1;
224 cpu->gprs[3] = SIZE_BIOS;
225 break;
226 case 0xE:
227 _BgAffineSet(gba);
228 break;
229 case 0xF:
230 _ObjAffineSet(gba);
231 break;
232 case 0x11:
233 case 0x12:
234 if (cpu->gprs[0] < BASE_WORKING_RAM) {
235 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 source");
236 break;
237 }
238 switch (cpu->gprs[1] >> BASE_OFFSET) {
239 default:
240 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 destination");
241 case REGION_WORKING_RAM:
242 case REGION_WORKING_IRAM:
243 case REGION_VRAM:
244 _unLz77(gba, immediate == 0x11 ? 1 : 2);
245 break;
246 }
247 break;
248 case 0x13:
249 if (cpu->gprs[0] < BASE_WORKING_RAM) {
250 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman source");
251 break;
252 }
253 switch (cpu->gprs[1] >> BASE_OFFSET) {
254 default:
255 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman destination");
256 case REGION_WORKING_RAM:
257 case REGION_WORKING_IRAM:
258 case REGION_VRAM:
259 _unHuffman(gba);
260 break;
261 }
262 break;
263 case 0x14:
264 case 0x15:
265 if (cpu->gprs[0] < BASE_WORKING_RAM) {
266 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL source");
267 break;
268 }
269 switch (cpu->gprs[1] >> BASE_OFFSET) {
270 default:
271 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL destination");
272 case REGION_WORKING_RAM:
273 case REGION_WORKING_IRAM:
274 case REGION_VRAM:
275 _unRl(gba, immediate == 0x14 ? 1 : 2);
276 break;
277 }
278 break;
279 case 0x16:
280 case 0x17:
281 case 0x18:
282 if (cpu->gprs[0] < BASE_WORKING_RAM) {
283 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter source");
284 break;
285 }
286 switch (cpu->gprs[1] >> BASE_OFFSET) {
287 default:
288 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter destination");
289 case REGION_WORKING_RAM:
290 case REGION_WORKING_IRAM:
291 case REGION_VRAM:
292 _unFilter(gba, immediate == 0x18 ? 2 : 1, immediate == 0x16 ? 1 : 2);
293 break;
294 }
295 break;
296 case 0x1F:
297 _MidiKey2Freq(gba);
298 break;
299 default:
300 GBALog(gba, GBA_LOG_STUB, "Stub software interrupt: %02X", immediate);
301 }
302 gba->memory.biosPrefetch = 0xE3A02004;
303}
304
305void GBASwi32(struct ARMCore* cpu, int immediate) {
306 GBASwi16(cpu, immediate >> 16);
307}
308
309uint32_t GBAChecksum(uint32_t* memory, size_t size) {
310 size_t i;
311 uint32_t sum = 0;
312 for (i = 0; i < size; i += 4) {
313 sum += memory[i >> 2];
314 }
315 return sum;
316}
317
318static void _unLz77(struct GBA* gba, int width) {
319 struct ARMCore* cpu = gba->cpu;
320 uint32_t source = cpu->gprs[0];
321 uint32_t dest = cpu->gprs[1];
322 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
323 // We assume the signature byte (0x10) is correct
324 int blockheader = 0; // Some compilers warn if this isn't set, even though it's trivially provably always set
325 source += 4;
326 int blocksRemaining = 0;
327 uint32_t disp;
328 int bytes;
329 int byte;
330 int halfword;
331 while (remaining > 0) {
332 if (blocksRemaining) {
333 if (blockheader & 0x80) {
334 // Compressed
335 int block = cpu->memory.load8(cpu, source + 1, 0) | (cpu->memory.load8(cpu, source, 0) << 8);
336 source += 2;
337 disp = dest - (block & 0x0FFF) - 1;
338 bytes = (block >> 12) + 3;
339 while (bytes-- && remaining) {
340 --remaining;
341 if (width == 2) {
342 byte = (int16_t) cpu->memory.load16(cpu, disp & ~1, 0);
343 if (dest & 1) {
344 byte >>= (disp & 1) * 8;
345 halfword |= byte << 8;
346 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
347 } else {
348 byte >>= (disp & 1) * 8;
349 halfword = byte & 0xFF;
350 }
351 } else {
352 byte = cpu->memory.load8(cpu, disp, 0);
353 cpu->memory.store8(cpu, dest, byte, 0);
354 }
355 ++disp;
356 ++dest;
357 }
358 } else {
359 // Uncompressed
360 byte = cpu->memory.load8(cpu, source, 0);
361 ++source;
362 if (width == 2) {
363 if (dest & 1) {
364 halfword |= byte << 8;
365 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
366 } else {
367 halfword = byte;
368 }
369 } else {
370 cpu->memory.store8(cpu, dest, byte, 0);
371 }
372 ++dest;
373 --remaining;
374 }
375 blockheader <<= 1;
376 --blocksRemaining;
377 } else {
378 blockheader = cpu->memory.load8(cpu, source, 0);
379 ++source;
380 blocksRemaining = 8;
381 }
382 }
383 cpu->gprs[0] = source;
384 cpu->gprs[1] = dest;
385 cpu->gprs[3] = 0;
386}
387
388DECL_BITFIELD(HuffmanNode, uint8_t);
389DECL_BITS(HuffmanNode, Offset, 0, 6);
390DECL_BIT(HuffmanNode, RTerm, 6);
391DECL_BIT(HuffmanNode, LTerm, 7);
392
393static void _unHuffman(struct GBA* gba) {
394 struct ARMCore* cpu = gba->cpu;
395 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
396 uint32_t dest = cpu->gprs[1];
397 uint32_t header = cpu->memory.load32(cpu, source, 0);
398 int remaining = header >> 8;
399 int bits = header & 0xF;
400 if (bits == 0) {
401 GBALog(gba, GBA_LOG_GAME_ERROR, "Invalid Huffman bits");
402 bits = 8;
403 }
404 if (32 % bits || bits == 1) {
405 GBALog(gba, GBA_LOG_STUB, "Unimplemented unaligned Huffman");
406 return;
407 }
408 // We assume the signature byte (0x20) is correct
409 int treesize = (cpu->memory.load8(cpu, source + 4, 0) << 1) + 1;
410 int block = 0;
411 uint32_t treeBase = source + 5;
412 source += 5 + treesize;
413 uint32_t nPointer = treeBase;
414 HuffmanNode node;
415 int bitsRemaining;
416 int readBits;
417 int bitsSeen = 0;
418 node = cpu->memory.load8(cpu, nPointer, 0);
419 while (remaining > 0) {
420 uint32_t bitstream = cpu->memory.load32(cpu, source, 0);
421 source += 4;
422 for (bitsRemaining = 32; bitsRemaining > 0 && remaining > 0; --bitsRemaining, bitstream <<= 1) {
423 uint32_t next = (nPointer & ~1) + HuffmanNodeGetOffset(node) * 2 + 2;
424 if (bitstream & 0x80000000) {
425 // Go right
426 if (HuffmanNodeIsRTerm(node)) {
427 readBits = cpu->memory.load8(cpu, next + 1, 0);
428 } else {
429 nPointer = next + 1;
430 node = cpu->memory.load8(cpu, nPointer, 0);
431 continue;
432 }
433 } else {
434 // Go left
435 if (HuffmanNodeIsLTerm(node)) {
436 readBits = cpu->memory.load8(cpu, next, 0);
437 } else {
438 nPointer = next;
439 node = cpu->memory.load8(cpu, nPointer, 0);
440 continue;
441 }
442 }
443
444 block |= (readBits & ((1 << bits) - 1)) << bitsSeen;
445 bitsSeen += bits;
446 nPointer = treeBase;
447 node = cpu->memory.load8(cpu, nPointer, 0);
448 if (bitsSeen == 32) {
449 bitsSeen = 0;
450 cpu->memory.store32(cpu, dest, block, 0);
451 dest += 4;
452 remaining -= 4;
453 block = 0;
454 }
455 }
456
457 }
458 cpu->gprs[0] = source;
459 cpu->gprs[1] = dest;
460}
461
462static void _unRl(struct GBA* gba, int width) {
463 struct ARMCore* cpu = gba->cpu;
464 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
465 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
466 int padding = (4 - remaining) & 0x3;
467 // We assume the signature byte (0x30) is correct
468 int blockheader;
469 int block;
470 source += 4;
471 uint32_t dest = cpu->gprs[1];
472 int halfword = 0;
473 while (remaining > 0) {
474 blockheader = cpu->memory.load8(cpu, source, 0);
475 ++source;
476 if (blockheader & 0x80) {
477 // Compressed
478 blockheader &= 0x7F;
479 blockheader += 3;
480 block = cpu->memory.load8(cpu, source, 0);
481 ++source;
482 while (blockheader-- && remaining) {
483 --remaining;
484 if (width == 2) {
485 if (dest & 1) {
486 halfword |= block << 8;
487 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
488 } else {
489 halfword = block;
490 }
491 } else {
492 cpu->memory.store8(cpu, dest, block, 0);
493 }
494 ++dest;
495 }
496 } else {
497 // Uncompressed
498 blockheader++;
499 while (blockheader-- && remaining) {
500 --remaining;
501 int byte = cpu->memory.load8(cpu, source, 0);
502 ++source;
503 if (width == 2) {
504 if (dest & 1) {
505 halfword |= byte << 8;
506 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
507 } else {
508 halfword = byte;
509 }
510 } else {
511 cpu->memory.store8(cpu, dest, byte, 0);
512 }
513 ++dest;
514 }
515 }
516 }
517 if (width == 2) {
518 if (dest & 1) {
519 --padding;
520 ++dest;
521 }
522 for (; padding > 0; padding -= 2, dest += 2) {
523 cpu->memory.store16(cpu, dest, 0, 0);
524 }
525 } else {
526 while (padding--) {
527 cpu->memory.store8(cpu, dest, 0, 0);
528 ++dest;
529 }
530 }
531 cpu->gprs[0] = source;
532 cpu->gprs[1] = dest;
533}
534
535static void _unFilter(struct GBA* gba, int inwidth, int outwidth) {
536 struct ARMCore* cpu = gba->cpu;
537 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
538 uint32_t dest = cpu->gprs[1];
539 uint32_t header = cpu->memory.load32(cpu, source, 0);
540 int remaining = header >> 8;
541 // We assume the signature nybble (0x8) is correct
542 uint16_t halfword = 0;
543 uint16_t old = 0;
544 source += 4;
545 while (remaining > 0) {
546 uint16_t new;
547 if (inwidth == 1) {
548 new = cpu->memory.load8(cpu, source, 0);
549 } else {
550 new = cpu->memory.load16(cpu, source, 0);
551 }
552 new += old;
553 if (outwidth > inwidth) {
554 halfword >>= 8;
555 halfword |= (new << 8);
556 if (source & 1) {
557 cpu->memory.store16(cpu, dest, halfword, 0);
558 dest += outwidth;
559 remaining -= outwidth;
560 }
561 } else if (outwidth == 1) {
562 cpu->memory.store8(cpu, dest, new, 0);
563 dest += outwidth;
564 remaining -= outwidth;
565 } else {
566 cpu->memory.store16(cpu, dest, new, 0);
567 dest += outwidth;
568 remaining -= outwidth;
569 }
570 old = new;
571 source += inwidth;
572 }
573 cpu->gprs[0] = source;
574 cpu->gprs[1] = dest;
575}