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 // Fall through
242 case REGION_WORKING_RAM:
243 case REGION_WORKING_IRAM:
244 case REGION_VRAM:
245 _unLz77(gba, immediate == 0x11 ? 1 : 2);
246 break;
247 }
248 break;
249 case 0x13:
250 if (cpu->gprs[0] < BASE_WORKING_RAM) {
251 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman source");
252 break;
253 }
254 switch (cpu->gprs[1] >> BASE_OFFSET) {
255 default:
256 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman destination");
257 // Fall through
258 case REGION_WORKING_RAM:
259 case REGION_WORKING_IRAM:
260 case REGION_VRAM:
261 _unHuffman(gba);
262 break;
263 }
264 break;
265 case 0x14:
266 case 0x15:
267 if (cpu->gprs[0] < BASE_WORKING_RAM) {
268 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL source");
269 break;
270 }
271 switch (cpu->gprs[1] >> BASE_OFFSET) {
272 default:
273 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL destination");
274 // Fall through
275 case REGION_WORKING_RAM:
276 case REGION_WORKING_IRAM:
277 case REGION_VRAM:
278 _unRl(gba, immediate == 0x14 ? 1 : 2);
279 break;
280 }
281 break;
282 case 0x16:
283 case 0x17:
284 case 0x18:
285 if (cpu->gprs[0] < BASE_WORKING_RAM) {
286 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter source");
287 break;
288 }
289 switch (cpu->gprs[1] >> BASE_OFFSET) {
290 default:
291 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad UnFilter destination");
292 // Fall through
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 = 0;
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 cpu->gprs[0] = source;
462 cpu->gprs[1] = dest;
463}
464
465static void _unRl(struct GBA* gba, int width) {
466 struct ARMCore* cpu = gba->cpu;
467 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
468 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
469 int padding = (4 - remaining) & 0x3;
470 // We assume the signature byte (0x30) is correct
471 int blockheader;
472 int block;
473 source += 4;
474 uint32_t dest = cpu->gprs[1];
475 int halfword = 0;
476 while (remaining > 0) {
477 blockheader = cpu->memory.load8(cpu, source, 0);
478 ++source;
479 if (blockheader & 0x80) {
480 // Compressed
481 blockheader &= 0x7F;
482 blockheader += 3;
483 block = cpu->memory.load8(cpu, source, 0);
484 ++source;
485 while (blockheader-- && remaining) {
486 --remaining;
487 if (width == 2) {
488 if (dest & 1) {
489 halfword |= block << 8;
490 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
491 } else {
492 halfword = block;
493 }
494 } else {
495 cpu->memory.store8(cpu, dest, block, 0);
496 }
497 ++dest;
498 }
499 } else {
500 // Uncompressed
501 blockheader++;
502 while (blockheader-- && remaining) {
503 --remaining;
504 int byte = cpu->memory.load8(cpu, source, 0);
505 ++source;
506 if (width == 2) {
507 if (dest & 1) {
508 halfword |= byte << 8;
509 cpu->memory.store16(cpu, dest ^ 1, halfword, 0);
510 } else {
511 halfword = byte;
512 }
513 } else {
514 cpu->memory.store8(cpu, dest, byte, 0);
515 }
516 ++dest;
517 }
518 }
519 }
520 if (width == 2) {
521 if (dest & 1) {
522 --padding;
523 ++dest;
524 }
525 for (; padding > 0; padding -= 2, dest += 2) {
526 cpu->memory.store16(cpu, dest, 0, 0);
527 }
528 } else {
529 while (padding--) {
530 cpu->memory.store8(cpu, dest, 0, 0);
531 ++dest;
532 }
533 }
534 cpu->gprs[0] = source;
535 cpu->gprs[1] = dest;
536}
537
538static void _unFilter(struct GBA* gba, int inwidth, int outwidth) {
539 struct ARMCore* cpu = gba->cpu;
540 uint32_t source = cpu->gprs[0] & 0xFFFFFFFC;
541 uint32_t dest = cpu->gprs[1];
542 uint32_t header = cpu->memory.load32(cpu, source, 0);
543 int remaining = header >> 8;
544 // We assume the signature nybble (0x8) is correct
545 uint16_t halfword = 0;
546 uint16_t old = 0;
547 source += 4;
548 while (remaining > 0) {
549 uint16_t new;
550 if (inwidth == 1) {
551 new = cpu->memory.load8(cpu, source, 0);
552 } else {
553 new = cpu->memory.load16(cpu, source, 0);
554 }
555 new += old;
556 if (outwidth > inwidth) {
557 halfword >>= 8;
558 halfword |= (new << 8);
559 if (source & 1) {
560 cpu->memory.store16(cpu, dest, halfword, 0);
561 dest += outwidth;
562 remaining -= outwidth;
563 }
564 } else if (outwidth == 1) {
565 cpu->memory.store8(cpu, dest, new, 0);
566 dest += outwidth;
567 remaining -= outwidth;
568 } else {
569 cpu->memory.store16(cpu, dest, new, 0);
570 dest += outwidth;
571 remaining -= outwidth;
572 }
573 old = new;
574 source += inwidth;
575 }
576 cpu->gprs[0] = source;
577 cpu->gprs[1] = dest;
578}