1 /* Copyright (c) 2013-2016 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 <mgba/internal/gb/gb.h>
7
8 #include <mgba/internal/gb/io.h>
9 #include <mgba/internal/gb/mbc.h>
10 #include <mgba/internal/sm83/sm83.h>
11
12 #include <mgba/core/core.h>
13 #include <mgba/core/cheats.h>
14 #include <mgba-util/crc32.h>
15 #include <mgba-util/memory.h>
16 #include <mgba-util/math.h>
17 #include <mgba-util/patch.h>
18 #include <mgba-util/vfs.h>
19
20 #define CLEANUP_THRESHOLD 15
21
22 const uint32_t CGB_SM83_FREQUENCY = 0x800000;
23 const uint32_t SGB_SM83_FREQUENCY = 0x418B1E;
24
25 const uint32_t GB_COMPONENT_MAGIC = 0x400000;
26
27 static const uint8_t _knownHeader[4] = { 0xCE, 0xED, 0x66, 0x66};
28
29 #define DMG_BIOS_CHECKSUM 0xC2F5CC97
30 #define DMG_2_BIOS_CHECKSUM 0x59C8598E
31 #define MGB_BIOS_CHECKSUM 0xE6920754
32 #define SGB_BIOS_CHECKSUM 0xEC8A83B9
33 #define SGB2_BIOS_CHECKSUM 0X53D0DD63
34 #define CGB_BIOS_CHECKSUM 0x41884E46
35
36 mLOG_DEFINE_CATEGORY(GB, "GB", "gb");
37
38 static void GBInit(void* cpu, struct mCPUComponent* component);
39 static void GBDeinit(struct mCPUComponent* component);
40 static void GBInterruptHandlerInit(struct SM83InterruptHandler* irqh);
41 static void GBProcessEvents(struct SM83Core* cpu);
42 static void GBSetInterrupts(struct SM83Core* cpu, bool enable);
43 static uint16_t GBIRQVector(struct SM83Core* cpu);
44 static void GBIllegal(struct SM83Core* cpu);
45 static void GBStop(struct SM83Core* cpu);
46
47 static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate);
48
GBCreate(struct GB * gb)49 void GBCreate(struct GB* gb) {
50 gb->d.id = GB_COMPONENT_MAGIC;
51 gb->d.init = GBInit;
52 gb->d.deinit = GBDeinit;
53 }
54
GBInit(void * cpu,struct mCPUComponent * component)55 static void GBInit(void* cpu, struct mCPUComponent* component) {
56 struct GB* gb = (struct GB*) component;
57 gb->cpu = cpu;
58 gb->sync = NULL;
59
60 GBInterruptHandlerInit(&gb->cpu->irqh);
61 GBMemoryInit(gb);
62
63 gb->video.p = gb;
64 GBVideoInit(&gb->video);
65
66 gb->audio.p = gb;
67 GBAudioInit(&gb->audio, 2048, &gb->memory.io[REG_NR52], GB_AUDIO_DMG); // TODO: Remove magic constant
68
69 gb->sio.p = gb;
70 GBSIOInit(&gb->sio);
71
72 gb->timer.p = gb;
73
74 gb->model = GB_MODEL_AUTODETECT;
75
76 gb->biosVf = NULL;
77 gb->romVf = NULL;
78 gb->sramVf = NULL;
79 gb->sramRealVf = NULL;
80
81 gb->isPristine = false;
82 gb->pristineRomSize = 0;
83 gb->yankedRomSize = 0;
84
85 mCoreCallbacksListInit(&gb->coreCallbacks, 0);
86 gb->stream = NULL;
87
88 mTimingInit(&gb->timing, &gb->cpu->cycles, &gb->cpu->nextEvent);
89 gb->audio.timing = &gb->timing;
90
91 gb->eiPending.name = "GB EI";
92 gb->eiPending.callback = _enableInterrupts;
93 gb->eiPending.context = gb;
94 gb->eiPending.priority = 0;
95 }
96
GBDeinit(struct mCPUComponent * component)97 static void GBDeinit(struct mCPUComponent* component) {
98 struct GB* gb = (struct GB*) component;
99 mTimingDeinit(&gb->timing);
100 }
101
GBLoadROM(struct GB * gb,struct VFile * vf)102 bool GBLoadROM(struct GB* gb, struct VFile* vf) {
103 if (!vf) {
104 return false;
105 }
106 GBUnloadROM(gb);
107 gb->romVf = vf;
108 gb->pristineRomSize = vf->size(vf);
109 vf->seek(vf, 0, SEEK_SET);
110 gb->isPristine = true;
111 gb->memory.rom = vf->map(vf, gb->pristineRomSize, MAP_READ);
112 if (!gb->memory.rom) {
113 return false;
114 }
115 gb->yankedRomSize = 0;
116 gb->memory.romBase = gb->memory.rom;
117 gb->memory.romSize = gb->pristineRomSize;
118 gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
119 GBMBCInit(gb);
120
121 if (gb->cpu) {
122 struct SM83Core* cpu = gb->cpu;
123 cpu->memory.setActiveRegion(cpu, cpu->pc);
124 }
125
126 // TODO: error check
127 return true;
128 }
129
GBYankROM(struct GB * gb)130 void GBYankROM(struct GB* gb) {
131 gb->yankedRomSize = gb->memory.romSize;
132 gb->yankedMbc = gb->memory.mbcType;
133 gb->memory.romSize = 0;
134 gb->memory.mbcType = GB_MBC_NONE;
135 gb->memory.sramAccess = false;
136
137 if (gb->cpu) {
138 struct SM83Core* cpu = gb->cpu;
139 cpu->memory.setActiveRegion(cpu, cpu->pc);
140 }
141 }
142
GBSramDeinit(struct GB * gb)143 static void GBSramDeinit(struct GB* gb) {
144 if (gb->sramVf) {
145 gb->sramVf->unmap(gb->sramVf, gb->memory.sram, gb->sramSize);
146 if (gb->memory.mbcType == GB_MBC3_RTC && gb->sramVf == gb->sramRealVf) {
147 GBMBCRTCWrite(gb);
148 }
149 gb->sramVf = NULL;
150 } else if (gb->memory.sram) {
151 mappedMemoryFree(gb->memory.sram, gb->sramSize);
152 }
153 gb->memory.sram = 0;
154 }
155
GBLoadSave(struct GB * gb,struct VFile * vf)156 bool GBLoadSave(struct GB* gb, struct VFile* vf) {
157 GBSramDeinit(gb);
158 gb->sramVf = vf;
159 gb->sramRealVf = vf;
160 if (gb->sramSize) {
161 GBResizeSram(gb, gb->sramSize);
162 GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
163 }
164 return vf;
165 }
166
GBResizeSram(struct GB * gb,size_t size)167 void GBResizeSram(struct GB* gb, size_t size) {
168 if (gb->memory.sram && size <= gb->sramSize) {
169 return;
170 }
171 struct VFile* vf = gb->sramVf;
172 if (vf) {
173 if (vf == gb->sramRealVf) {
174 ssize_t vfSize = vf->size(vf);
175 if (vfSize >= 0 && (size_t) vfSize < size) {
176 uint8_t extdataBuffer[0x100];
177 if (vfSize & 0xFF) {
178 vf->seek(vf, -(vfSize & 0xFF), SEEK_END);
179 vf->read(vf, extdataBuffer, vfSize & 0xFF);
180 }
181 if (gb->memory.sram) {
182 vf->unmap(vf, gb->memory.sram, gb->sramSize);
183 }
184 vf->truncate(vf, size + (vfSize & 0xFF));
185 if (vfSize & 0xFF) {
186 vf->seek(vf, size, SEEK_SET);
187 vf->write(vf, extdataBuffer, vfSize & 0xFF);
188 }
189 gb->memory.sram = vf->map(vf, size, MAP_WRITE);
190 memset(&gb->memory.sram[vfSize], 0xFF, size - vfSize);
191 } else if (size > gb->sramSize || !gb->memory.sram) {
192 if (gb->memory.sram) {
193 vf->unmap(vf, gb->memory.sram, gb->sramSize);
194 }
195 gb->memory.sram = vf->map(vf, size, MAP_WRITE);
196 }
197 } else {
198 if (gb->memory.sram) {
199 vf->unmap(vf, gb->memory.sram, gb->sramSize);
200 }
201 gb->memory.sram = vf->map(vf, size, MAP_READ);
202 }
203 if (gb->memory.sram == (void*) -1) {
204 gb->memory.sram = NULL;
205 }
206 } else if (size) {
207 uint8_t* newSram = anonymousMemoryMap(size);
208 if (gb->memory.sram) {
209 if (size > gb->sramSize) {
210 memcpy(newSram, gb->memory.sram, gb->sramSize);
211 memset(&newSram[gb->sramSize], 0xFF, size - gb->sramSize);
212 } else {
213 memcpy(newSram, gb->memory.sram, size);
214 }
215 mappedMemoryFree(gb->memory.sram, gb->sramSize);
216 } else {
217 memset(newSram, 0xFF, size);
218 }
219 gb->memory.sram = newSram;
220 }
221 if (gb->sramSize < size) {
222 gb->sramSize = size;
223 }
224 }
225
GBSramClean(struct GB * gb,uint32_t frameCount)226 void GBSramClean(struct GB* gb, uint32_t frameCount) {
227 // TODO: Share with GBASavedataClean
228 if (!gb->sramVf) {
229 return;
230 }
231 if (gb->sramDirty & GB_SRAM_DIRT_NEW) {
232 gb->sramDirtAge = frameCount;
233 gb->sramDirty &= ~GB_SRAM_DIRT_NEW;
234 if (!(gb->sramDirty & GB_SRAM_DIRT_SEEN)) {
235 gb->sramDirty |= GB_SRAM_DIRT_SEEN;
236 }
237 } else if ((gb->sramDirty & GB_SRAM_DIRT_SEEN) && frameCount - gb->sramDirtAge > CLEANUP_THRESHOLD) {
238 if (gb->sramMaskWriteback) {
239 GBSavedataUnmask(gb);
240 }
241 if (gb->memory.mbcType == GB_MBC3_RTC) {
242 GBMBCRTCWrite(gb);
243 }
244 gb->sramDirty = 0;
245 if (gb->memory.sram && gb->sramVf->sync(gb->sramVf, gb->memory.sram, gb->sramSize)) {
246 mLOG(GB_MEM, INFO, "Savedata synced");
247 } else {
248 mLOG(GB_MEM, INFO, "Savedata failed to sync!");
249 }
250 }
251 }
252
GBSavedataMask(struct GB * gb,struct VFile * vf,bool writeback)253 void GBSavedataMask(struct GB* gb, struct VFile* vf, bool writeback) {
254 struct VFile* oldVf = gb->sramVf;
255 GBSramDeinit(gb);
256 if (oldVf && oldVf != gb->sramRealVf) {
257 oldVf->close(oldVf);
258 }
259 gb->sramVf = vf;
260 gb->sramMaskWriteback = writeback;
261 gb->memory.sram = vf->map(vf, gb->sramSize, MAP_READ);
262 GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
263 }
264
GBSavedataUnmask(struct GB * gb)265 void GBSavedataUnmask(struct GB* gb) {
266 if (!gb->sramRealVf || gb->sramVf == gb->sramRealVf) {
267 return;
268 }
269 struct VFile* vf = gb->sramVf;
270 GBSramDeinit(gb);
271 gb->sramVf = gb->sramRealVf;
272 gb->memory.sram = gb->sramVf->map(gb->sramVf, gb->sramSize, MAP_WRITE);
273 if (gb->sramMaskWriteback) {
274 vf->seek(vf, 0, SEEK_SET);
275 vf->read(vf, gb->memory.sram, gb->sramSize);
276 gb->sramMaskWriteback = false;
277 }
278 GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
279 vf->close(vf);
280 }
281
GBUnloadROM(struct GB * gb)282 void GBUnloadROM(struct GB* gb) {
283 // TODO: Share with GBAUnloadROM
284 if (gb->memory.rom && gb->memory.romBase != gb->memory.rom && !gb->isPristine) {
285 free(gb->memory.romBase);
286 }
287 if (gb->memory.rom && !gb->isPristine) {
288 if (gb->yankedRomSize) {
289 gb->yankedRomSize = 0;
290 }
291 mappedMemoryFree(gb->memory.rom, GB_SIZE_CART_MAX);
292 }
293
294 if (gb->romVf) {
295 #ifndef FIXED_ROM_BUFFER
296 gb->romVf->unmap(gb->romVf, gb->memory.rom, gb->pristineRomSize);
297 #endif
298 gb->romVf->close(gb->romVf);
299 gb->romVf = NULL;
300 }
301 gb->memory.rom = NULL;
302 gb->memory.mbcType = GB_MBC_AUTODETECT;
303 gb->isPristine = false;
304
305 gb->sramMaskWriteback = false;
306 GBSramDeinit(gb);
307 if (gb->sramRealVf) {
308 gb->sramRealVf->close(gb->sramRealVf);
309 }
310 gb->sramRealVf = NULL;
311 gb->sramVf = NULL;
312 if (gb->memory.cam && gb->memory.cam->stopRequestImage) {
313 gb->memory.cam->stopRequestImage(gb->memory.cam);
314 }
315 }
316
GBSynthesizeROM(struct VFile * vf)317 void GBSynthesizeROM(struct VFile* vf) {
318 if (!vf) {
319 return;
320 }
321 const struct GBCartridge cart = {
322 .logo = { _knownHeader[0], _knownHeader[1], _knownHeader[2], _knownHeader[3]}
323 };
324
325 vf->seek(vf, 0x100, SEEK_SET);
326 vf->write(vf, &cart, sizeof(cart));
327 }
328
GBLoadBIOS(struct GB * gb,struct VFile * vf)329 void GBLoadBIOS(struct GB* gb, struct VFile* vf) {
330 gb->biosVf = vf;
331 }
332
GBApplyPatch(struct GB * gb,struct Patch * patch)333 void GBApplyPatch(struct GB* gb, struct Patch* patch) {
334 size_t patchedSize = patch->outputSize(patch, gb->memory.romSize);
335 if (!patchedSize) {
336 return;
337 }
338 if (patchedSize > GB_SIZE_CART_MAX) {
339 patchedSize = GB_SIZE_CART_MAX;
340 }
341 void* newRom = anonymousMemoryMap(GB_SIZE_CART_MAX);
342 if (!patch->applyPatch(patch, gb->memory.rom, gb->pristineRomSize, newRom, patchedSize)) {
343 mappedMemoryFree(newRom, GB_SIZE_CART_MAX);
344 return;
345 }
346 if (gb->romVf) {
347 #ifndef FIXED_ROM_BUFFER
348 gb->romVf->unmap(gb->romVf, gb->memory.rom, gb->pristineRomSize);
349 #endif
350 gb->romVf->close(gb->romVf);
351 gb->romVf = NULL;
352 }
353 gb->isPristine = false;
354 if (gb->memory.romBase == gb->memory.rom) {
355 gb->memory.romBase = newRom;
356 }
357 gb->memory.rom = newRom;
358 gb->memory.romSize = patchedSize;
359 gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
360 gb->cpu->memory.setActiveRegion(gb->cpu, gb->cpu->pc);
361 }
362
GBDestroy(struct GB * gb)363 void GBDestroy(struct GB* gb) {
364 GBUnloadROM(gb);
365
366 if (gb->biosVf) {
367 gb->biosVf->close(gb->biosVf);
368 gb->biosVf = 0;
369 }
370
371 GBMemoryDeinit(gb);
372 GBAudioDeinit(&gb->audio);
373 GBVideoDeinit(&gb->video);
374 GBSIODeinit(&gb->sio);
375 mCoreCallbacksListDeinit(&gb->coreCallbacks);
376 }
377
GBInterruptHandlerInit(struct SM83InterruptHandler * irqh)378 void GBInterruptHandlerInit(struct SM83InterruptHandler* irqh) {
379 irqh->reset = GBReset;
380 irqh->processEvents = GBProcessEvents;
381 irqh->setInterrupts = GBSetInterrupts;
382 irqh->irqVector = GBIRQVector;
383 irqh->hitIllegal = GBIllegal;
384 irqh->stop = GBStop;
385 irqh->halt = GBHalt;
386 }
387
_GBBiosCRC32(struct VFile * vf)388 static uint32_t _GBBiosCRC32(struct VFile* vf) {
389 ssize_t size = vf->size(vf);
390 if (size <= 0 || size > GB_SIZE_CART_BANK0) {
391 return 0;
392 }
393 void* bios = vf->map(vf, size, MAP_READ);
394 uint32_t biosCrc = doCrc32(bios, size);
395 vf->unmap(vf, bios, size);
396 return biosCrc;
397 }
398
GBIsBIOS(struct VFile * vf)399 bool GBIsBIOS(struct VFile* vf) {
400 switch (_GBBiosCRC32(vf)) {
401 case DMG_BIOS_CHECKSUM:
402 case DMG_2_BIOS_CHECKSUM:
403 case MGB_BIOS_CHECKSUM:
404 case SGB_BIOS_CHECKSUM:
405 case SGB2_BIOS_CHECKSUM:
406 case CGB_BIOS_CHECKSUM:
407 return true;
408 default:
409 return false;
410 }
411 }
412
GBReset(struct SM83Core * cpu)413 void GBReset(struct SM83Core* cpu) {
414 struct GB* gb = (struct GB*) cpu->master;
415 gb->memory.romBase = gb->memory.rom;
416 GBDetectModel(gb);
417
418 cpu->b = 0;
419 cpu->d = 0;
420
421 gb->timer.internalDiv = 0;
422
423 gb->cpuBlocked = false;
424 gb->earlyExit = false;
425 gb->doubleSpeed = 0;
426
427 if (gb->yankedRomSize) {
428 gb->memory.romSize = gb->yankedRomSize;
429 gb->memory.mbcType = gb->yankedMbc;
430 gb->yankedRomSize = 0;
431 }
432
433 gb->sgbBit = -1;
434 gb->sgbControllers = 0;
435 gb->sgbCurrentController = 0;
436 gb->currentSgbBits = 0;
437 gb->sgbIncrement = false;
438 memset(gb->sgbPacket, 0, sizeof(gb->sgbPacket));
439
440 mTimingClear(&gb->timing);
441
442 GBMemoryReset(gb);
443
444 if (gb->biosVf) {
445 if (!GBIsBIOS(gb->biosVf)) {
446 gb->biosVf->close(gb->biosVf);
447 gb->biosVf = NULL;
448 } else {
449 GBMapBIOS(gb);
450 cpu->a = 0;
451 cpu->f.packed = 0;
452 cpu->c = 0;
453 cpu->e = 0;
454 cpu->h = 0;
455 cpu->l = 0;
456 cpu->sp = 0;
457 cpu->pc = 0;
458 }
459 }
460
461 GBVideoReset(&gb->video);
462 GBTimerReset(&gb->timer);
463 if (!gb->biosVf) {
464 GBSkipBIOS(gb);
465 } else {
466 mTimingSchedule(&gb->timing, &gb->timer.event, 0);
467 }
468
469 GBIOReset(gb);
470 GBAudioReset(&gb->audio);
471 GBSIOReset(&gb->sio);
472
473 cpu->memory.setActiveRegion(cpu, cpu->pc);
474
475 gb->sramMaskWriteback = false;
476 GBSavedataUnmask(gb);
477 }
478
GBSkipBIOS(struct GB * gb)479 void GBSkipBIOS(struct GB* gb) {
480 struct SM83Core* cpu = gb->cpu;
481 const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
482 int nextDiv = 0;
483
484 switch (gb->model) {
485 case GB_MODEL_AUTODETECT: // Silence warnings
486 gb->model = GB_MODEL_DMG;
487 // Fall through
488 case GB_MODEL_DMG:
489 cpu->a = 1;
490 cpu->f.packed = 0xB0;
491 cpu->c = 0x13;
492 cpu->e = 0xD8;
493 cpu->h = 1;
494 cpu->l = 0x4D;
495 gb->timer.internalDiv = 0xABC;
496 nextDiv = 4;
497 break;
498 case GB_MODEL_SGB:
499 cpu->a = 1;
500 cpu->f.packed = 0x00;
501 cpu->c = 0x14;
502 cpu->e = 0x00;
503 cpu->h = 0xC0;
504 cpu->l = 0x60;
505 gb->timer.internalDiv = 0xABC;
506 nextDiv = 4;
507 break;
508 case GB_MODEL_MGB:
509 cpu->a = 0xFF;
510 cpu->f.packed = 0xB0;
511 cpu->c = 0x13;
512 cpu->e = 0xD8;
513 cpu->h = 1;
514 cpu->l = 0x4D;
515 gb->timer.internalDiv = 0xABC;
516 nextDiv = 4;
517 break;
518 case GB_MODEL_SGB2:
519 cpu->a = 0xFF;
520 cpu->f.packed = 0x00;
521 cpu->c = 0x14;
522 cpu->e = 0x00;
523 cpu->h = 0xC0;
524 cpu->l = 0x60;
525 gb->timer.internalDiv = 0xABC;
526 nextDiv = 4;
527 break;
528 case GB_MODEL_AGB:
529 cpu->a = 0x11;
530 cpu->b = 1;
531 cpu->f.packed = 0x00;
532 cpu->c = 0;
533 cpu->e = 0x08;
534 cpu->h = 0;
535 cpu->l = 0x7C;
536 gb->timer.internalDiv = 0x1EA;
537 nextDiv = 0xC;
538 break;
539 case GB_MODEL_CGB:
540 cpu->a = 0x11;
541 cpu->f.packed = 0x80;
542 cpu->c = 0;
543 cpu->h = 0;
544 if (cart->cgb & 0x80) {
545 cpu->d = 0xFF;
546 cpu->e = 0x56;
547 cpu->l = 0x0D;
548 } else {
549 cpu->e = 0x08;
550 cpu->l = 0x7C;
551 }
552 gb->timer.internalDiv = 0x1EA;
553 nextDiv = 0xC;
554 break;
555 }
556
557 cpu->sp = 0xFFFE;
558 cpu->pc = 0x100;
559
560 mTimingDeschedule(&gb->timing, &gb->timer.event);
561 mTimingSchedule(&gb->timing, &gb->timer.event, 0);
562
563 GBIOWrite(gb, REG_LCDC, 0x91);
564
565 if (gb->biosVf) {
566 GBUnmapBIOS(gb);
567 }
568 }
569
GBMapBIOS(struct GB * gb)570 void GBMapBIOS(struct GB* gb) {
571 gb->biosVf->seek(gb->biosVf, 0, SEEK_SET);
572 uint8_t* oldRomBase = gb->memory.romBase;
573 gb->memory.romBase = malloc(GB_SIZE_CART_BANK0);
574 ssize_t size = gb->biosVf->read(gb->biosVf, gb->memory.romBase, GB_SIZE_CART_BANK0);
575 memcpy(&gb->memory.romBase[size], &oldRomBase[size], GB_SIZE_CART_BANK0 - size);
576 if (size > 0x100) {
577 memcpy(&gb->memory.romBase[0x100], &oldRomBase[0x100], sizeof(struct GBCartridge));
578 }
579 }
580
GBUnmapBIOS(struct GB * gb)581 void GBUnmapBIOS(struct GB* gb) {
582 if (gb->memory.romBase < gb->memory.rom || gb->memory.romBase > &gb->memory.rom[gb->memory.romSize - 1]) {
583 free(gb->memory.romBase);
584 if (gb->memory.mbcType == GB_MMM01) {
585 GBMBCSwitchBank0(gb, gb->memory.romSize / GB_SIZE_CART_BANK0 - 2);
586 } else {
587 GBMBCSwitchBank0(gb, 0);
588 }
589 }
590 // XXX: Force AGB registers for AGB-mode
591 if (gb->model == GB_MODEL_AGB && gb->cpu->pc == 0x100) {
592 gb->cpu->b = 1;
593 }
594 }
595
GBDetectModel(struct GB * gb)596 void GBDetectModel(struct GB* gb) {
597 if (gb->model != GB_MODEL_AUTODETECT) {
598 return;
599 }
600 if (gb->biosVf) {
601 switch (_GBBiosCRC32(gb->biosVf)) {
602 case DMG_BIOS_CHECKSUM:
603 case DMG_2_BIOS_CHECKSUM:
604 gb->model = GB_MODEL_DMG;
605 break;
606 case MGB_BIOS_CHECKSUM:
607 gb->model = GB_MODEL_MGB;
608 break;
609 case SGB_BIOS_CHECKSUM:
610 gb->model = GB_MODEL_SGB;
611 break;
612 case SGB2_BIOS_CHECKSUM:
613 gb->model = GB_MODEL_SGB2;
614 break;
615 case CGB_BIOS_CHECKSUM:
616 gb->model = GB_MODEL_CGB;
617 break;
618 default:
619 gb->biosVf->close(gb->biosVf);
620 gb->biosVf = NULL;
621 }
622 }
623 if (gb->model == GB_MODEL_AUTODETECT && gb->memory.rom) {
624 const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
625 if (cart->cgb & 0x80) {
626 gb->model = GB_MODEL_CGB;
627 } else if (cart->sgb == 0x03 && cart->oldLicensee == 0x33) {
628 gb->model = GB_MODEL_SGB;
629 } else {
630 gb->model = GB_MODEL_DMG;
631 }
632 }
633
634 switch (gb->model) {
635 case GB_MODEL_DMG:
636 case GB_MODEL_SGB:
637 case GB_MODEL_AUTODETECT: //Silence warnings
638 gb->audio.style = GB_AUDIO_DMG;
639 break;
640 case GB_MODEL_MGB:
641 case GB_MODEL_SGB2:
642 gb->audio.style = GB_AUDIO_MGB;
643 break;
644 case GB_MODEL_AGB:
645 case GB_MODEL_CGB:
646 gb->audio.style = GB_AUDIO_CGB;
647 break;
648 }
649 }
650
GBUpdateIRQs(struct GB * gb)651 void GBUpdateIRQs(struct GB* gb) {
652 int irqs = gb->memory.ie & gb->memory.io[REG_IF] & 0x1F;
653 if (!irqs) {
654 gb->cpu->irqPending = false;
655 return;
656 }
657 gb->cpu->halted = false;
658
659 if (!gb->memory.ime) {
660 gb->cpu->irqPending = false;
661 return;
662 }
663 if (gb->cpu->irqPending) {
664 return;
665 }
666 SM83RaiseIRQ(gb->cpu);
667 }
668
GBProcessEvents(struct SM83Core * cpu)669 void GBProcessEvents(struct SM83Core* cpu) {
670 struct GB* gb = (struct GB*) cpu->master;
671 do {
672 int32_t cycles = cpu->cycles;
673 int32_t nextEvent;
674
675 cpu->cycles = 0;
676 cpu->nextEvent = INT_MAX;
677
678 nextEvent = cycles;
679 do {
680 nextEvent = mTimingTick(&gb->timing, nextEvent);
681 } while (gb->cpuBlocked);
682 cpu->nextEvent = nextEvent;
683
684 if (cpu->halted) {
685 cpu->cycles = cpu->nextEvent;
686 if (!gb->memory.ie || !gb->memory.ime) {
687 break;
688 }
689 }
690 if (gb->earlyExit) {
691 break;
692 }
693 } while (cpu->cycles >= cpu->nextEvent);
694 gb->earlyExit = false;
695 }
696
GBSetInterrupts(struct SM83Core * cpu,bool enable)697 void GBSetInterrupts(struct SM83Core* cpu, bool enable) {
698 struct GB* gb = (struct GB*) cpu->master;
699 mTimingDeschedule(&gb->timing, &gb->eiPending);
700 if (!enable) {
701 gb->memory.ime = false;
702 GBUpdateIRQs(gb);
703 } else {
704 mTimingSchedule(&gb->timing, &gb->eiPending, 4);
705 }
706 }
707
GBIRQVector(struct SM83Core * cpu)708 uint16_t GBIRQVector(struct SM83Core* cpu) {
709 struct GB* gb = (struct GB*) cpu->master;
710 int irqs = gb->memory.ie & gb->memory.io[REG_IF];
711
712 if (irqs & (1 << GB_IRQ_VBLANK)) {
713 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_VBLANK);
714 return GB_VECTOR_VBLANK;
715 }
716 if (irqs & (1 << GB_IRQ_LCDSTAT)) {
717 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
718 return GB_VECTOR_LCDSTAT;
719 }
720 if (irqs & (1 << GB_IRQ_TIMER)) {
721 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_TIMER);
722 return GB_VECTOR_TIMER;
723 }
724 if (irqs & (1 << GB_IRQ_SIO)) {
725 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_SIO);
726 return GB_VECTOR_SIO;
727 }
728 if (irqs & (1 << GB_IRQ_KEYPAD)) {
729 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_KEYPAD);
730 return GB_VECTOR_KEYPAD;
731 }
732 return 0;
733 }
734
_enableInterrupts(struct mTiming * timing,void * user,uint32_t cyclesLate)735 static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate) {
736 UNUSED(timing);
737 UNUSED(cyclesLate);
738 struct GB* gb = user;
739 gb->memory.ime = true;
740 GBUpdateIRQs(gb);
741 }
742
GBHalt(struct SM83Core * cpu)743 void GBHalt(struct SM83Core* cpu) {
744 struct GB* gb = (struct GB*) cpu->master;
745 if (!(gb->memory.ie & gb->memory.io[REG_IF] & 0x1F)) {
746 cpu->cycles = cpu->nextEvent;
747 cpu->halted = true;
748 } else if (gb->model < GB_MODEL_CGB) {
749 mLOG(GB, STUB, "Unimplemented HALT bug");
750 }
751 }
752
GBStop(struct SM83Core * cpu)753 void GBStop(struct SM83Core* cpu) {
754 struct GB* gb = (struct GB*) cpu->master;
755 if (cpu->bus) {
756 mLOG(GB, GAME_ERROR, "Hit illegal stop at address %04X:%02X", cpu->pc, cpu->bus);
757 }
758 if (gb->memory.io[REG_KEY1] & 1) {
759 gb->doubleSpeed ^= 1;
760 gb->audio.timingFactor = gb->doubleSpeed + 1;
761 gb->memory.io[REG_KEY1] = 0;
762 gb->memory.io[REG_KEY1] |= gb->doubleSpeed << 7;
763 } else if (cpu->bus) {
764 #ifdef USE_DEBUGGERS
765 if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
766 struct mDebuggerEntryInfo info = {
767 .address = cpu->pc - 1,
768 .type.bp.opcode = 0x1000 | cpu->bus,
769 };
770 mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
771 }
772 #endif
773 // Hang forever
774 gb->memory.ime = 0;
775 cpu->pc -= 2;
776 }
777 // TODO: Actually stop
778 }
779
GBIllegal(struct SM83Core * cpu)780 void GBIllegal(struct SM83Core* cpu) {
781 struct GB* gb = (struct GB*) cpu->master;
782 mLOG(GB, GAME_ERROR, "Hit illegal opcode at address %04X:%02X", cpu->pc, cpu->bus);
783 #ifdef USE_DEBUGGERS
784 if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
785 struct mDebuggerEntryInfo info = {
786 .address = cpu->pc,
787 .type.bp.opcode = cpu->bus
788 };
789 mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
790 }
791 #endif
792 // Hang forever
793 gb->memory.ime = 0;
794 --cpu->pc;
795 }
796
GBIsROM(struct VFile * vf)797 bool GBIsROM(struct VFile* vf) {
798 if (!vf) {
799 return false;
800 }
801 vf->seek(vf, 0x104, SEEK_SET);
802 uint8_t header[4];
803
804 if (vf->read(vf, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
805 return false;
806 }
807 if (memcmp(header, _knownHeader, sizeof(header))) {
808 return false;
809 }
810 return true;
811 }
812
GBGetGameTitle(const struct GB * gb,char * out)813 void GBGetGameTitle(const struct GB* gb, char* out) {
814 const struct GBCartridge* cart = NULL;
815 if (gb->memory.rom) {
816 cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
817 }
818 if (!cart) {
819 return;
820 }
821 if (cart->oldLicensee != 0x33) {
822 memcpy(out, cart->titleLong, 16);
823 } else {
824 memcpy(out, cart->titleShort, 11);
825 }
826 }
827
GBGetGameCode(const struct GB * gb,char * out)828 void GBGetGameCode(const struct GB* gb, char* out) {
829 memset(out, 0, 8);
830 const struct GBCartridge* cart = NULL;
831 if (gb->memory.rom) {
832 cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
833 }
834 if (!cart) {
835 return;
836 }
837 if (cart->cgb == 0xC0) {
838 memcpy(out, "CGB-????", 8);
839 } else {
840 memcpy(out, "DMG-????", 8);
841 }
842 if (cart->oldLicensee == 0x33) {
843 memcpy(&out[4], cart->maker, 4);
844 }
845 }
846
GBFrameStarted(struct GB * gb)847 void GBFrameStarted(struct GB* gb) {
848 GBTestKeypadIRQ(gb);
849
850 size_t c;
851 for (c = 0; c < mCoreCallbacksListSize(&gb->coreCallbacks); ++c) {
852 struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gb->coreCallbacks, c);
853 if (callbacks->videoFrameStarted) {
854 callbacks->videoFrameStarted(callbacks->context);
855 }
856 }
857 }
858
GBFrameEnded(struct GB * gb)859 void GBFrameEnded(struct GB* gb) {
860 GBSramClean(gb, gb->video.frameCounter);
861
862 if (gb->cpu->components && gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
863 struct mCheatDevice* device = (struct mCheatDevice*) gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
864 size_t i;
865 for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
866 struct mCheatSet* cheats = *mCheatSetsGetPointer(&device->cheats, i);
867 mCheatRefresh(device, cheats);
868 }
869 }
870
871 // TODO: Move to common code
872 if (gb->stream && gb->stream->postVideoFrame) {
873 const color_t* pixels;
874 size_t stride;
875 gb->video.renderer->getPixels(gb->video.renderer, &stride, (const void**) &pixels);
876 gb->stream->postVideoFrame(gb->stream, pixels, stride);
877 }
878
879 size_t c;
880 for (c = 0; c < mCoreCallbacksListSize(&gb->coreCallbacks); ++c) {
881 struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gb->coreCallbacks, c);
882 if (callbacks->videoFrameEnded) {
883 callbacks->videoFrameEnded(callbacks->context);
884 }
885 }
886 }
887
GBNameToModel(const char * model)888 enum GBModel GBNameToModel(const char* model) {
889 if (strcasecmp(model, "DMG") == 0) {
890 return GB_MODEL_DMG;
891 } else if (strcasecmp(model, "CGB") == 0) {
892 return GB_MODEL_CGB;
893 } else if (strcasecmp(model, "AGB") == 0) {
894 return GB_MODEL_AGB;
895 } else if (strcasecmp(model, "SGB") == 0) {
896 return GB_MODEL_SGB;
897 } else if (strcasecmp(model, "MGB") == 0) {
898 return GB_MODEL_MGB;
899 } else if (strcasecmp(model, "SGB2") == 0) {
900 return GB_MODEL_SGB2;
901 }
902 return GB_MODEL_AUTODETECT;
903 }
904
GBModelToName(enum GBModel model)905 const char* GBModelToName(enum GBModel model) {
906 switch (model) {
907 case GB_MODEL_DMG:
908 return "DMG";
909 case GB_MODEL_SGB:
910 return "SGB";
911 case GB_MODEL_MGB:
912 return "MGB";
913 case GB_MODEL_SGB2:
914 return "SGB2";
915 case GB_MODEL_CGB:
916 return "CGB";
917 case GB_MODEL_AGB:
918 return "AGB";
919 default:
920 case GB_MODEL_AUTODETECT:
921 return NULL;
922 }
923 }
924