src/gb/gb.c (view raw)
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/lr35902/lr35902.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
22const uint32_t CGB_LR35902_FREQUENCY = 0x800000;
23const uint32_t SGB_LR35902_FREQUENCY = 0x418B1E;
24
25const uint32_t GB_COMPONENT_MAGIC = 0x400000;
26
27static 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 CGB_BIOS_CHECKSUM 0x41884E46
32
33mLOG_DEFINE_CATEGORY(GB, "GB");
34
35static void GBInit(void* cpu, struct mCPUComponent* component);
36static void GBDeinit(struct mCPUComponent* component);
37static void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh);
38static void GBProcessEvents(struct LR35902Core* cpu);
39static void GBSetInterrupts(struct LR35902Core* cpu, bool enable);
40static void GBIllegal(struct LR35902Core* cpu);
41static void GBStop(struct LR35902Core* cpu);
42
43static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate);
44
45#ifdef _3DS
46extern uint32_t* romBuffer;
47extern size_t romBufferSize;
48#endif
49
50void GBCreate(struct GB* gb) {
51 gb->d.id = GB_COMPONENT_MAGIC;
52 gb->d.init = GBInit;
53 gb->d.deinit = GBDeinit;
54}
55
56static void GBInit(void* cpu, struct mCPUComponent* component) {
57 struct GB* gb = (struct GB*) component;
58 gb->cpu = cpu;
59 gb->sync = NULL;
60
61 GBInterruptHandlerInit(&gb->cpu->irqh);
62 GBMemoryInit(gb);
63
64 gb->video.p = gb;
65 GBVideoInit(&gb->video);
66
67 gb->audio.p = gb;
68 GBAudioInit(&gb->audio, 2048, &gb->memory.io[REG_NR52], GB_AUDIO_DMG); // TODO: Remove magic constant
69
70 gb->sio.p = gb;
71 GBSIOInit(&gb->sio);
72
73 gb->timer.p = gb;
74
75 gb->model = GB_MODEL_AUTODETECT;
76
77 gb->biosVf = NULL;
78 gb->romVf = NULL;
79 gb->sramVf = NULL;
80 gb->sramRealVf = NULL;
81
82 gb->pristineRom = 0;
83 gb->pristineRomSize = 0;
84 gb->yankedRomSize = 0;
85
86 gb->coreCallbacks = NULL;
87 gb->stream = NULL;
88
89 mTimingInit(&gb->timing, &gb->cpu->cycles, &gb->cpu->nextEvent);
90 gb->audio.timing = &gb->timing;
91
92 gb->eiPending.name = "GB EI";
93 gb->eiPending.callback = _enableInterrupts;
94 gb->eiPending.context = gb;
95 gb->eiPending.priority = 0;
96}
97
98static void GBDeinit(struct mCPUComponent* component) {
99 struct GB* gb = (struct GB*) component;
100 mTimingDeinit(&gb->timing);
101}
102
103bool GBLoadROM(struct GB* gb, struct VFile* vf) {
104 if (!vf) {
105 return false;
106 }
107 GBUnloadROM(gb);
108 gb->romVf = vf;
109 gb->pristineRomSize = vf->size(vf);
110 vf->seek(vf, 0, SEEK_SET);
111#ifdef _3DS
112 gb->pristineRom = 0;
113 if (gb->pristineRomSize <= romBufferSize) {
114 gb->pristineRom = romBuffer;
115 vf->read(vf, romBuffer, gb->pristineRomSize);
116 }
117#else
118 gb->pristineRom = vf->map(vf, gb->pristineRomSize, MAP_READ);
119#endif
120 if (!gb->pristineRom) {
121 return false;
122 }
123 gb->yankedRomSize = 0;
124 gb->memory.rom = gb->pristineRom;
125 gb->memory.romBase = gb->memory.rom;
126 gb->memory.romSize = gb->pristineRomSize;
127 gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
128 GBMBCSwitchBank(&gb->memory, gb->memory.currentBank);
129
130 if (gb->cpu) {
131 struct LR35902Core* cpu = gb->cpu;
132 cpu->memory.setActiveRegion(cpu, cpu->pc);
133 }
134
135 // TODO: error check
136 return true;
137}
138
139bool GBLoadSave(struct GB* gb, struct VFile* vf) {
140 gb->sramVf = vf;
141 gb->sramRealVf = vf;
142 return vf;
143}
144
145static void GBSramDeinit(struct GB* gb) {
146 if (gb->sramVf) {
147 gb->sramVf->unmap(gb->sramVf, gb->memory.sram, gb->sramSize);
148 if (gb->memory.mbcType == GB_MBC3_RTC && gb->sramVf == gb->sramRealVf) {
149 GBMBCRTCWrite(gb);
150 }
151 gb->sramVf = NULL;
152 } else if (gb->memory.sram) {
153 mappedMemoryFree(gb->memory.sram, gb->sramSize);
154 }
155 gb->memory.sram = 0;
156}
157
158void GBResizeSram(struct GB* gb, size_t size) {
159 if (gb->memory.sram && size <= gb->sramSize) {
160 return;
161 }
162 mLOG(GB, INFO, "Resizing SRAM to %"PRIz"u bytes", size);
163 struct VFile* vf = gb->sramVf;
164 if (vf) {
165 if (vf == gb->sramRealVf) {
166 ssize_t vfSize = vf->size(vf);
167 if (vfSize >= 0 && (size_t) vfSize < size) {
168 uint8_t extdataBuffer[0x100];
169 if (vfSize & 0xFF) {
170 vf->seek(vf, -(vfSize & 0xFF), SEEK_END);
171 vf->read(vf, extdataBuffer, vfSize & 0xFF);
172 }
173 if (gb->memory.sram) {
174 vf->unmap(vf, gb->memory.sram, gb->sramSize);
175 }
176 vf->truncate(vf, size + (vfSize & 0xFF));
177 if (vfSize & 0xFF) {
178 vf->seek(vf, size, SEEK_SET);
179 vf->write(vf, extdataBuffer, vfSize & 0xFF);
180 }
181 gb->memory.sram = vf->map(vf, size, MAP_WRITE);
182 memset(&gb->memory.sram[gb->sramSize], 0xFF, size - gb->sramSize);
183 } else if (size > gb->sramSize || !gb->memory.sram) {
184 if (gb->memory.sram) {
185 vf->unmap(vf, gb->memory.sram, gb->sramSize);
186 }
187 gb->memory.sram = vf->map(vf, size, MAP_WRITE);
188 }
189 } else {
190 if (gb->memory.sram) {
191 vf->unmap(vf, gb->memory.sram, gb->sramSize);
192 }
193 gb->memory.sram = vf->map(vf, size, MAP_READ);
194 }
195 if (gb->memory.sram == (void*) -1) {
196 gb->memory.sram = NULL;
197 }
198 } else {
199 uint8_t* newSram = anonymousMemoryMap(size);
200 if (gb->memory.sram) {
201 if (size > gb->sramSize) {
202 memcpy(newSram, gb->memory.sram, gb->sramSize);
203 memset(&newSram[gb->sramSize], 0xFF, size - gb->sramSize);
204 } else {
205 memcpy(newSram, gb->memory.sram, size);
206 }
207 mappedMemoryFree(gb->memory.sram, gb->sramSize);
208 } else {
209 memset(newSram, 0xFF, size);
210 }
211 gb->memory.sram = newSram;
212 }
213 if (gb->sramSize < size) {
214 gb->sramSize = size;
215 }
216}
217
218void GBSramClean(struct GB* gb, uint32_t frameCount) {
219 // TODO: Share with GBASavedataClean
220 if (!gb->sramVf || gb->sramVf != gb->sramRealVf) {
221 return;
222 }
223 if (gb->sramDirty & GB_SRAM_DIRT_NEW) {
224 gb->sramDirtAge = frameCount;
225 gb->sramDirty &= ~GB_SRAM_DIRT_NEW;
226 if (!(gb->sramDirty & GB_SRAM_DIRT_SEEN)) {
227 gb->sramDirty |= GB_SRAM_DIRT_SEEN;
228 }
229 } else if ((gb->sramDirty & GB_SRAM_DIRT_SEEN) && frameCount - gb->sramDirtAge > CLEANUP_THRESHOLD) {
230 if (gb->memory.mbcType == GB_MBC3_RTC) {
231 GBMBCRTCWrite(gb);
232 }
233 gb->sramDirty = 0;
234 if (gb->memory.sram && gb->sramVf->sync(gb->sramVf, gb->memory.sram, gb->sramSize)) {
235 mLOG(GB_MEM, INFO, "Savedata synced");
236 } else {
237 mLOG(GB_MEM, INFO, "Savedata failed to sync!");
238 }
239 }
240}
241
242void GBSavedataMask(struct GB* gb, struct VFile* vf, bool writeback) {
243 GBSramDeinit(gb);
244 gb->sramVf = vf;
245 gb->sramMaskWriteback = writeback;
246 gb->memory.sram = vf->map(vf, gb->sramSize, MAP_READ);
247 GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
248}
249
250void GBSavedataUnmask(struct GB* gb) {
251 if (gb->sramVf == gb->sramRealVf) {
252 return;
253 }
254 struct VFile* vf = gb->sramVf;
255 GBSramDeinit(gb);
256 gb->sramVf = gb->sramRealVf;
257 gb->memory.sram = gb->sramVf->map(gb->sramVf, gb->sramSize, MAP_WRITE);
258 if (gb->sramMaskWriteback) {
259 vf->read(vf, gb->memory.sram, gb->sramSize);
260 }
261 vf->close(vf);
262}
263
264void GBUnloadROM(struct GB* gb) {
265 // TODO: Share with GBAUnloadROM
266 if (gb->memory.rom && gb->memory.romBase != gb->memory.rom && gb->memory.romBase != gb->pristineRom) {
267 free(gb->memory.romBase);
268 }
269 if (gb->memory.rom && gb->pristineRom != gb->memory.rom) {
270 if (gb->yankedRomSize) {
271 gb->yankedRomSize = 0;
272 }
273 mappedMemoryFree(gb->memory.rom, GB_SIZE_CART_MAX);
274 gb->memory.rom = gb->pristineRom;
275 }
276 gb->memory.rom = 0;
277
278 if (gb->romVf) {
279#ifndef _3DS
280 gb->romVf->unmap(gb->romVf, gb->pristineRom, gb->pristineRomSize);
281#endif
282 gb->romVf->close(gb->romVf);
283 gb->romVf = 0;
284 }
285 gb->pristineRom = 0;
286
287 GBSavedataUnmask(gb);
288 GBSramDeinit(gb);
289 if (gb->sramRealVf) {
290 gb->sramRealVf->close(gb->sramRealVf);
291 }
292 gb->sramRealVf = NULL;
293 gb->sramVf = NULL;
294}
295
296void GBSynthesizeROM(struct VFile* vf) {
297 if (!vf) {
298 return;
299 }
300 const struct GBCartridge cart = {
301 .logo = { _knownHeader[0], _knownHeader[1], _knownHeader[2], _knownHeader[3]}
302 };
303
304 vf->seek(vf, 0x100, SEEK_SET);
305 vf->write(vf, &cart, sizeof(cart));
306}
307
308void GBLoadBIOS(struct GB* gb, struct VFile* vf) {
309 gb->biosVf = vf;
310}
311
312void GBApplyPatch(struct GB* gb, struct Patch* patch) {
313 size_t patchedSize = patch->outputSize(patch, gb->memory.romSize);
314 if (!patchedSize) {
315 return;
316 }
317 if (patchedSize > GB_SIZE_CART_MAX) {
318 patchedSize = GB_SIZE_CART_MAX;
319 }
320 gb->memory.rom = anonymousMemoryMap(GB_SIZE_CART_MAX);
321 if (!patch->applyPatch(patch, gb->pristineRom, gb->pristineRomSize, gb->memory.rom, patchedSize)) {
322 mappedMemoryFree(gb->memory.rom, patchedSize);
323 gb->memory.rom = gb->pristineRom;
324 return;
325 }
326 gb->memory.romSize = patchedSize;
327 gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
328}
329
330void GBDestroy(struct GB* gb) {
331 GBUnloadROM(gb);
332
333 if (gb->biosVf) {
334 gb->biosVf->close(gb->biosVf);
335 gb->biosVf = 0;
336 }
337
338 GBMemoryDeinit(gb);
339 GBAudioDeinit(&gb->audio);
340 GBVideoDeinit(&gb->video);
341 GBSIODeinit(&gb->sio);
342}
343
344void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh) {
345 irqh->reset = GBReset;
346 irqh->processEvents = GBProcessEvents;
347 irqh->setInterrupts = GBSetInterrupts;
348 irqh->hitIllegal = GBIllegal;
349 irqh->stop = GBStop;
350 irqh->halt = GBHalt;
351}
352
353static uint32_t _GBBiosCRC32(struct VFile* vf) {
354 ssize_t size = vf->size(vf);
355 if (size <= 0 || size > GB_SIZE_CART_BANK0) {
356 return 0;
357 }
358 void* bios = vf->map(vf, size, MAP_READ);
359 uint32_t biosCrc = doCrc32(bios, size);
360 vf->unmap(vf, bios, size);
361 return biosCrc;
362}
363
364bool GBIsBIOS(struct VFile* vf) {
365 switch (_GBBiosCRC32(vf)) {
366 case DMG_BIOS_CHECKSUM:
367 case DMG_2_BIOS_CHECKSUM:
368 case CGB_BIOS_CHECKSUM:
369 return true;
370 default:
371 return false;
372 }
373}
374
375void GBReset(struct LR35902Core* cpu) {
376 struct GB* gb = (struct GB*) cpu->master;
377 GBDetectModel(gb);
378 if (gb->biosVf) {
379 if (!GBIsBIOS(gb->biosVf)) {
380 gb->biosVf->close(gb->biosVf);
381 gb->biosVf = NULL;
382 } else {
383 gb->biosVf->seek(gb->biosVf, 0, SEEK_SET);
384 gb->memory.romBase = malloc(GB_SIZE_CART_BANK0);
385 ssize_t size = gb->biosVf->read(gb->biosVf, gb->memory.romBase, GB_SIZE_CART_BANK0);
386 memcpy(&gb->memory.romBase[size], &gb->memory.rom[size], GB_SIZE_CART_BANK0 - size);
387 if (size > 0x100) {
388 memcpy(&gb->memory.romBase[0x100], &gb->memory.rom[0x100], sizeof(struct GBCartridge));
389 }
390
391 cpu->a = 0;
392 cpu->f.packed = 0;
393 cpu->c = 0;
394 cpu->e = 0;
395 cpu->h = 0;
396 cpu->l = 0;
397 cpu->sp = 0;
398 cpu->pc = 0;
399 }
400 }
401
402 cpu->b = 0;
403 cpu->d = 0;
404
405 if (!gb->biosVf) {
406 switch (gb->model) {
407 case GB_MODEL_DMG:
408 // TODO: SGB
409 case GB_MODEL_SGB:
410 case GB_MODEL_AUTODETECT: // Silence warnings
411 gb->model = GB_MODEL_DMG;
412 cpu->a = 1;
413 cpu->f.packed = 0xB0;
414 cpu->c = 0x13;
415 cpu->e = 0xD8;
416 cpu->h = 1;
417 cpu->l = 0x4D;
418 break;
419 case GB_MODEL_AGB:
420 cpu->b = 1;
421 // Fall through
422 case GB_MODEL_CGB:
423 cpu->a = 0x11;
424 cpu->f.packed = 0x80;
425 cpu->c = 0;
426 cpu->e = 0x08;
427 cpu->h = 0;
428 cpu->l = 0x7C;
429 break;
430 }
431
432 cpu->sp = 0xFFFE;
433 cpu->pc = 0x100;
434 }
435
436 gb->cpuBlocked = false;
437 gb->earlyExit = false;
438 gb->doubleSpeed = 0;
439
440 cpu->memory.setActiveRegion(cpu, cpu->pc);
441
442 if (gb->yankedRomSize) {
443 gb->memory.romSize = gb->yankedRomSize;
444 gb->yankedRomSize = 0;
445 }
446
447 mTimingClear(&gb->timing);
448
449 GBMemoryReset(gb);
450 GBVideoReset(&gb->video);
451 GBTimerReset(&gb->timer);
452 mTimingSchedule(&gb->timing, &gb->timer.event, GB_DMG_DIV_PERIOD);
453
454 GBAudioReset(&gb->audio);
455 GBIOReset(gb);
456 GBSIOReset(&gb->sio);
457
458 GBSavedataUnmask(gb);
459}
460
461void GBDetectModel(struct GB* gb) {
462 if (gb->model != GB_MODEL_AUTODETECT) {
463 return;
464 }
465 if (gb->biosVf) {
466 switch (_GBBiosCRC32(gb->biosVf)) {
467 case DMG_BIOS_CHECKSUM:
468 case DMG_2_BIOS_CHECKSUM:
469 gb->model = GB_MODEL_DMG;
470 break;
471 case CGB_BIOS_CHECKSUM:
472 gb->model = GB_MODEL_CGB;
473 break;
474 default:
475 gb->biosVf->close(gb->biosVf);
476 gb->biosVf = NULL;
477 }
478 }
479 if (gb->model == GB_MODEL_AUTODETECT && gb->memory.rom) {
480 const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
481 if (cart->cgb & 0x80) {
482 gb->model = GB_MODEL_CGB;
483 } else {
484 gb->model = GB_MODEL_DMG;
485 }
486 }
487
488 switch (gb->model) {
489 case GB_MODEL_DMG:
490 case GB_MODEL_SGB:
491 case GB_MODEL_AUTODETECT: //Silence warnings
492 gb->audio.style = GB_AUDIO_DMG;
493 break;
494 case GB_MODEL_AGB:
495 case GB_MODEL_CGB:
496 gb->audio.style = GB_AUDIO_CGB;
497 break;
498 }
499}
500
501void GBUpdateIRQs(struct GB* gb) {
502 int irqs = gb->memory.ie & gb->memory.io[REG_IF];
503 if (!irqs) {
504 return;
505 }
506 gb->cpu->halted = false;
507
508 if (!gb->memory.ime || gb->cpu->irqPending) {
509 return;
510 }
511
512 if (irqs & (1 << GB_IRQ_VBLANK)) {
513 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_VBLANK);
514 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_VBLANK);
515 return;
516 }
517 if (irqs & (1 << GB_IRQ_LCDSTAT)) {
518 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_LCDSTAT);
519 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
520 return;
521 }
522 if (irqs & (1 << GB_IRQ_TIMER)) {
523 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_TIMER);
524 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_TIMER);
525 return;
526 }
527 if (irqs & (1 << GB_IRQ_SIO)) {
528 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_SIO);
529 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_SIO);
530 return;
531 }
532 if (irqs & (1 << GB_IRQ_KEYPAD)) {
533 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_KEYPAD);
534 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_KEYPAD);
535 }
536}
537
538void GBProcessEvents(struct LR35902Core* cpu) {
539 struct GB* gb = (struct GB*) cpu->master;
540 do {
541 int32_t cycles = cpu->cycles;
542 int32_t nextEvent;
543
544 cpu->cycles = 0;
545 cpu->nextEvent = INT_MAX;
546
547 nextEvent = cycles;
548 do {
549 nextEvent = mTimingTick(&gb->timing, nextEvent);
550 } while (gb->cpuBlocked);
551 cpu->nextEvent = nextEvent;
552
553 if (gb->earlyExit) {
554 gb->earlyExit = false;
555 break;
556 }
557 if (cpu->halted) {
558 cpu->cycles = cpu->nextEvent;
559 if (!gb->memory.ie || !gb->memory.ime) {
560 break;
561 }
562 }
563 } while (cpu->cycles >= cpu->nextEvent);
564}
565
566void GBSetInterrupts(struct LR35902Core* cpu, bool enable) {
567 struct GB* gb = (struct GB*) cpu->master;
568 if (!enable) {
569 gb->memory.ime = enable;
570 mTimingDeschedule(&gb->timing, &gb->eiPending);
571 GBUpdateIRQs(gb);
572 } else {
573 mTimingDeschedule(&gb->timing, &gb->eiPending);
574 mTimingSchedule(&gb->timing, &gb->eiPending, 4);
575 }
576}
577
578static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate) {
579 UNUSED(timing);
580 UNUSED(cyclesLate);
581 struct GB* gb = user;
582 gb->memory.ime = true;
583 GBUpdateIRQs(gb);
584}
585
586void GBHalt(struct LR35902Core* cpu) {
587 if (!cpu->irqPending) {
588 cpu->cycles = cpu->nextEvent;
589 cpu->halted = true;
590 }
591}
592
593void GBStop(struct LR35902Core* cpu) {
594 struct GB* gb = (struct GB*) cpu->master;
595 if (cpu->bus) {
596 mLOG(GB, GAME_ERROR, "Hit illegal stop at address %04X:%02X\n", cpu->pc, cpu->bus);
597 }
598 if (gb->memory.io[REG_KEY1] & 1) {
599 gb->doubleSpeed ^= 1;
600 gb->audio.timingFactor = gb->doubleSpeed + 1;
601 gb->memory.io[REG_KEY1] = 0;
602 gb->memory.io[REG_KEY1] |= gb->doubleSpeed << 7;
603 } else if (cpu->bus) {
604#ifdef USE_DEBUGGERS
605 if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
606 struct mDebuggerEntryInfo info = {
607 .address = cpu->pc - 1,
608 .opcode = 0x1000 | cpu->bus
609 };
610 mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
611 }
612#endif
613 // Hang forever
614 gb->memory.ime = 0;
615 cpu->pc -= 2;
616 }
617 // TODO: Actually stop
618}
619
620void GBIllegal(struct LR35902Core* cpu) {
621 struct GB* gb = (struct GB*) cpu->master;
622 mLOG(GB, GAME_ERROR, "Hit illegal opcode at address %04X:%02X\n", cpu->pc, cpu->bus);
623#ifdef USE_DEBUGGERS
624 if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
625 struct mDebuggerEntryInfo info = {
626 .address = cpu->pc,
627 .opcode = cpu->bus
628 };
629 mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
630 }
631#endif
632 // Hang forever
633 gb->memory.ime = 0;
634 --cpu->pc;
635}
636
637bool GBIsROM(struct VFile* vf) {
638 vf->seek(vf, 0x104, SEEK_SET);
639 uint8_t header[4];
640
641 if (vf->read(vf, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
642 return false;
643 }
644 if (memcmp(header, _knownHeader, sizeof(header))) {
645 return false;
646 }
647 return true;
648}
649
650void GBGetGameTitle(const struct GB* gb, char* out) {
651 const struct GBCartridge* cart = NULL;
652 if (gb->memory.rom) {
653 cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
654 }
655 if (gb->pristineRom) {
656 cart = (const struct GBCartridge*) &((uint8_t*) gb->pristineRom)[0x100];
657 }
658 if (!cart) {
659 return;
660 }
661 if (cart->oldLicensee != 0x33) {
662 memcpy(out, cart->titleLong, 16);
663 } else {
664 memcpy(out, cart->titleShort, 11);
665 }
666}
667
668void GBGetGameCode(const struct GB* gb, char* out) {
669 memset(out, 0, 8);
670 const struct GBCartridge* cart = NULL;
671 if (gb->memory.rom) {
672 cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
673 }
674 if (gb->pristineRom) {
675 cart = (const struct GBCartridge*) &((uint8_t*) gb->pristineRom)[0x100];
676 }
677 if (!cart) {
678 return;
679 }
680 if (cart->cgb == 0xC0) {
681 memcpy(out, "CGB-????", 8);
682 } else {
683 memcpy(out, "DMG-????", 8);
684 }
685 if (cart->oldLicensee == 0x33) {
686 memcpy(&out[4], cart->maker, 4);
687 }
688}
689
690void GBFrameEnded(struct GB* gb) {
691 GBSramClean(gb, gb->video.frameCounter);
692
693 if (gb->cpu->components && gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
694 struct mCheatDevice* device = (struct mCheatDevice*) gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
695 size_t i;
696 for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
697 struct mCheatSet* cheats = *mCheatSetsGetPointer(&device->cheats, i);
698 mCheatRefresh(device, cheats);
699 }
700 }
701}