all repos — mgba @ 4ac4733cfd4c4524c6a56d0406ba138d173fad61

mGBA Game Boy Advance Emulator

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 "gb.h"
  7
  8#include "gb/io.h"
  9#include "gb/mbc.h"
 10
 11#include "core/core.h"
 12#include "core/cheats.h"
 13#include "util/crc32.h"
 14#include "util/memory.h"
 15#include "util/math.h"
 16#include "util/patch.h"
 17#include "util/vfs.h"
 18
 19#define CLEANUP_THRESHOLD 15
 20
 21const uint32_t CGB_LR35902_FREQUENCY = 0x800000;
 22const uint32_t SGB_LR35902_FREQUENCY = 0x418B1E;
 23
 24const uint32_t GB_COMPONENT_MAGIC = 0x400000;
 25
 26static const uint8_t _knownHeader[4] = { 0xCE, 0xED, 0x66, 0x66};
 27
 28#define DMG_BIOS_CHECKSUM 0xC2F5CC97
 29#define DMG_2_BIOS_CHECKSUM 0x59C8598E
 30#define CGB_BIOS_CHECKSUM 0x41884E46
 31
 32mLOG_DEFINE_CATEGORY(GB, "GB");
 33
 34static void GBInit(void* cpu, struct mCPUComponent* component);
 35static void GBDeinit(struct mCPUComponent* component);
 36static void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh);
 37static void GBProcessEvents(struct LR35902Core* cpu);
 38static void GBSetInterrupts(struct LR35902Core* cpu, bool enable);
 39static void GBIllegal(struct LR35902Core* cpu);
 40static void GBStop(struct LR35902Core* cpu);
 41
 42static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate);
 43
 44#ifdef _3DS
 45extern uint32_t* romBuffer;
 46extern size_t romBufferSize;
 47#endif
 48
 49void GBCreate(struct GB* gb) {
 50	gb->d.id = GB_COMPONENT_MAGIC;
 51	gb->d.init = GBInit;
 52	gb->d.deinit = GBDeinit;
 53}
 54
 55static 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->pristineRom = 0;
 82	gb->pristineRomSize = 0;
 83	gb->yankedRomSize = 0;
 84
 85	gb->coreCallbacks = NULL;
 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
 97static void GBDeinit(struct mCPUComponent* component) {
 98	struct GB* gb = (struct GB*) component;
 99	mTimingDeinit(&gb->timing);
100}
101
102bool 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#ifdef _3DS
111	gb->pristineRom = 0;
112	if (gb->pristineRomSize <= romBufferSize) {
113		gb->pristineRom = romBuffer;
114		vf->read(vf, romBuffer, gb->pristineRomSize);
115	}
116#else
117	gb->pristineRom = vf->map(vf, gb->pristineRomSize, MAP_READ);
118#endif
119	if (!gb->pristineRom) {
120		return false;
121	}
122	gb->yankedRomSize = 0;
123	gb->memory.rom = gb->pristineRom;
124	gb->memory.romBase = gb->memory.rom;
125	gb->memory.romSize = gb->pristineRomSize;
126	gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
127	GBMBCSwitchBank(&gb->memory, gb->memory.currentBank);
128
129	if (gb->cpu) {
130		struct LR35902Core* cpu = gb->cpu;
131		cpu->memory.setActiveRegion(cpu, cpu->pc);
132	}
133
134	// TODO: error check
135	return true;
136}
137
138bool GBLoadSave(struct GB* gb, struct VFile* vf) {
139	gb->sramVf = vf;
140	gb->sramRealVf = vf;
141	return vf;
142}
143
144static void GBSramDeinit(struct GB* gb) {
145	if (gb->sramVf) {
146		gb->sramVf->unmap(gb->sramVf, gb->memory.sram, gb->sramSize);
147		if (gb->memory.mbcType == GB_MBC3_RTC && gb->sramVf == gb->sramRealVf) {
148			GBMBCRTCWrite(gb);
149		}
150		gb->sramVf = NULL;
151	} else if (gb->memory.sram) {
152		mappedMemoryFree(gb->memory.sram, gb->sramSize);
153	}
154	gb->memory.sram = 0;
155}
156
157void GBResizeSram(struct GB* gb, size_t size) {
158	if (gb->memory.sram && size <= gb->sramSize) {
159		return;
160	}
161	mLOG(GB, INFO, "Resizing SRAM to %"PRIz"u bytes", size);
162	struct VFile* vf = gb->sramVf;
163	if (vf) {
164		if (vf == gb->sramRealVf) {
165			ssize_t vfSize = vf->size(vf);
166			if (vfSize >= 0 && (size_t) vfSize < size) {
167				uint8_t extdataBuffer[0x100];
168				if (vfSize & 0xFF) {
169					vf->seek(vf, -(vfSize & 0xFF), SEEK_END);
170					vf->read(vf, extdataBuffer, vfSize & 0xFF);
171				}
172				if (gb->memory.sram) {
173					vf->unmap(vf, gb->memory.sram, gb->sramSize);
174				}
175				vf->truncate(vf, size + (vfSize & 0xFF));
176				if (vfSize & 0xFF) {
177					vf->seek(vf, size, SEEK_SET);
178					vf->write(vf, extdataBuffer, vfSize & 0xFF);
179				}
180				gb->memory.sram = vf->map(vf, size, MAP_WRITE);
181				memset(&gb->memory.sram[gb->sramSize], 0xFF, size - gb->sramSize);
182			} else if (size > gb->sramSize || !gb->memory.sram) {
183				if (gb->memory.sram) {
184					vf->unmap(vf, gb->memory.sram, gb->sramSize);
185				}
186				gb->memory.sram = vf->map(vf, size, MAP_WRITE);
187			}
188		} else {
189			if (gb->memory.sram) {
190				vf->unmap(vf, gb->memory.sram, gb->sramSize);
191			}
192			gb->memory.sram = vf->map(vf, size, MAP_READ);
193		}
194		if (gb->memory.sram == (void*) -1) {
195			gb->memory.sram = NULL;
196		}
197	} else {
198		uint8_t* newSram = anonymousMemoryMap(size);
199		if (gb->memory.sram) {
200			if (size > gb->sramSize) {
201				memcpy(newSram, gb->memory.sram, gb->sramSize);
202				memset(&newSram[gb->sramSize], 0xFF, size - gb->sramSize);
203			} else {
204				memcpy(newSram, gb->memory.sram, size);
205			}
206			mappedMemoryFree(gb->memory.sram, gb->sramSize);
207		} else {
208			memset(newSram, 0xFF, size);
209		}
210		gb->memory.sram = newSram;
211	}
212	if (gb->sramSize < size) {
213		gb->sramSize = size;
214	}
215}
216
217void GBSramClean(struct GB* gb, uint32_t frameCount) {
218	// TODO: Share with GBASavedataClean
219	if (!gb->sramVf || gb->sramVf != gb->sramRealVf) {
220		return;
221	}
222	if (gb->sramDirty & GB_SRAM_DIRT_NEW) {
223		gb->sramDirtAge = frameCount;
224		gb->sramDirty &= ~GB_SRAM_DIRT_NEW;
225		if (!(gb->sramDirty & GB_SRAM_DIRT_SEEN)) {
226			gb->sramDirty |= GB_SRAM_DIRT_SEEN;
227		}
228	} else if ((gb->sramDirty & GB_SRAM_DIRT_SEEN) && frameCount - gb->sramDirtAge > CLEANUP_THRESHOLD) {
229		if (gb->memory.mbcType == GB_MBC3_RTC) {
230			GBMBCRTCWrite(gb);
231		}
232		gb->sramDirty = 0;
233		if (gb->memory.sram && gb->sramVf->sync(gb->sramVf, gb->memory.sram, gb->sramSize)) {
234			mLOG(GB_MEM, INFO, "Savedata synced");
235		} else {
236			mLOG(GB_MEM, INFO, "Savedata failed to sync!");
237		}
238	}
239}
240
241void GBSavedataMask(struct GB* gb, struct VFile* vf, bool writeback) {
242	GBSramDeinit(gb);
243	gb->sramVf = vf;
244	gb->sramMaskWriteback = writeback;
245	gb->memory.sram = vf->map(vf, gb->sramSize, MAP_READ);
246	GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
247}
248
249void GBSavedataUnmask(struct GB* gb) {
250	if (gb->sramVf == gb->sramRealVf) {
251		return;
252	}
253	struct VFile* vf = gb->sramVf;
254	GBSramDeinit(gb);
255	gb->sramVf = gb->sramRealVf;
256	gb->memory.sram = gb->sramVf->map(gb->sramVf, gb->sramSize, MAP_WRITE);
257	if (gb->sramMaskWriteback) {
258		vf->read(vf, gb->memory.sram, gb->sramSize);
259	}
260	vf->close(vf);
261}
262
263void GBUnloadROM(struct GB* gb) {
264	// TODO: Share with GBAUnloadROM
265	if (gb->memory.rom && gb->memory.romBase != gb->memory.rom && gb->memory.romBase != gb->pristineRom) {
266		free(gb->memory.romBase);
267	}
268	if (gb->memory.rom && gb->pristineRom != gb->memory.rom) {
269		if (gb->yankedRomSize) {
270			gb->yankedRomSize = 0;
271		}
272		mappedMemoryFree(gb->memory.rom, GB_SIZE_CART_MAX);
273		gb->memory.rom = gb->pristineRom;
274	}
275	gb->memory.rom = 0;
276
277	if (gb->romVf) {
278#ifndef _3DS
279		gb->romVf->unmap(gb->romVf, gb->pristineRom, gb->pristineRomSize);
280#endif
281		gb->romVf->close(gb->romVf);
282		gb->romVf = 0;
283	}
284	gb->pristineRom = 0;
285
286	GBSavedataUnmask(gb);
287	GBSramDeinit(gb);
288	if (gb->sramRealVf) {
289		gb->sramRealVf->close(gb->sramRealVf);
290	}
291	gb->sramRealVf = NULL;
292	gb->sramVf = NULL;
293}
294
295void GBSynthesizeROM(struct VFile* vf) {
296	if (!vf) {
297		return;
298	}
299	const struct GBCartridge cart = {
300		.logo = { _knownHeader[0], _knownHeader[1], _knownHeader[2], _knownHeader[3]}
301	};
302
303	vf->seek(vf, 0x100, SEEK_SET);
304	vf->write(vf, &cart, sizeof(cart));
305}
306
307void GBLoadBIOS(struct GB* gb, struct VFile* vf) {
308	gb->biosVf = vf;
309}
310
311void GBApplyPatch(struct GB* gb, struct Patch* patch) {
312	size_t patchedSize = patch->outputSize(patch, gb->memory.romSize);
313	if (!patchedSize) {
314		return;
315	}
316	if (patchedSize > GB_SIZE_CART_MAX) {
317		patchedSize = GB_SIZE_CART_MAX;
318	}
319	gb->memory.rom = anonymousMemoryMap(GB_SIZE_CART_MAX);
320	if (!patch->applyPatch(patch, gb->pristineRom, gb->pristineRomSize, gb->memory.rom, patchedSize)) {
321		mappedMemoryFree(gb->memory.rom, patchedSize);
322		gb->memory.rom = gb->pristineRom;
323		return;
324	}
325	gb->memory.romSize = patchedSize;
326	gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
327}
328
329void GBDestroy(struct GB* gb) {
330	GBUnloadROM(gb);
331
332	if (gb->biosVf) {
333		gb->biosVf->close(gb->biosVf);
334		gb->biosVf = 0;
335	}
336
337	GBMemoryDeinit(gb);
338	GBAudioDeinit(&gb->audio);
339	GBVideoDeinit(&gb->video);
340	GBSIODeinit(&gb->sio);
341}
342
343void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh) {
344	irqh->reset = GBReset;
345	irqh->processEvents = GBProcessEvents;
346	irqh->setInterrupts = GBSetInterrupts;
347	irqh->hitIllegal = GBIllegal;
348	irqh->stop = GBStop;
349	irqh->halt = GBHalt;
350}
351
352static uint32_t _GBBiosCRC32(struct VFile* vf) {
353	ssize_t size = vf->size(vf);
354	if (size <= 0 || size > GB_SIZE_CART_BANK0) {
355		return 0;
356	}
357	void* bios = vf->map(vf, size, MAP_READ);
358	uint32_t biosCrc = doCrc32(bios, size);
359	vf->unmap(vf, bios, size);
360	return biosCrc;
361}
362
363bool GBIsBIOS(struct VFile* vf) {
364	switch (_GBBiosCRC32(vf)) {
365	case DMG_BIOS_CHECKSUM:
366	case DMG_2_BIOS_CHECKSUM:
367	case CGB_BIOS_CHECKSUM:
368		return true;
369	default:
370		return false;
371	}
372}
373
374void GBReset(struct LR35902Core* cpu) {
375	struct GB* gb = (struct GB*) cpu->master;
376	GBDetectModel(gb);
377	if (gb->biosVf) {
378		if (!GBIsBIOS(gb->biosVf)) {
379			gb->biosVf->close(gb->biosVf);
380			gb->biosVf = NULL;
381		} else {
382			gb->biosVf->seek(gb->biosVf, 0, SEEK_SET);
383			gb->memory.romBase = malloc(GB_SIZE_CART_BANK0);
384			ssize_t size = gb->biosVf->read(gb->biosVf, gb->memory.romBase, GB_SIZE_CART_BANK0);
385			memcpy(&gb->memory.romBase[size], &gb->memory.rom[size], GB_SIZE_CART_BANK0 - size);
386			if (size > 0x100) {
387				memcpy(&gb->memory.romBase[0x100], &gb->memory.rom[0x100], sizeof(struct GBCartridge));
388			}
389
390			cpu->a = 0;
391			cpu->f.packed = 0;
392			cpu->c = 0;
393			cpu->e = 0;
394			cpu->h = 0;
395			cpu->l = 0;
396			cpu->sp = 0;
397			cpu->pc = 0;
398		}
399	}
400
401	cpu->b = 0;
402	cpu->d = 0;
403
404	if (!gb->biosVf) {
405		switch (gb->model) {
406		case GB_MODEL_DMG:
407			// TODO: SGB
408		case GB_MODEL_SGB:
409		case GB_MODEL_AUTODETECT: // Silence warnings
410			gb->model = GB_MODEL_DMG;
411			cpu->a = 1;
412			cpu->f.packed = 0xB0;
413			cpu->c = 0x13;
414			cpu->e = 0xD8;
415			cpu->h = 1;
416			cpu->l = 0x4D;
417			break;
418		case GB_MODEL_AGB:
419			cpu->b = 1;
420			// Fall through
421		case GB_MODEL_CGB:
422			cpu->a = 0x11;
423			cpu->f.packed = 0x80;
424			cpu->c = 0;
425			cpu->e = 0x08;
426			cpu->h = 0;
427			cpu->l = 0x7C;
428			break;
429		}
430
431		cpu->sp = 0xFFFE;
432		cpu->pc = 0x100;
433	}
434
435	gb->cpuBlocked = false;
436	gb->doubleSpeed = 0;
437
438	cpu->memory.setActiveRegion(cpu, cpu->pc);
439
440	if (gb->yankedRomSize) {
441		gb->memory.romSize = gb->yankedRomSize;
442		gb->yankedRomSize = 0;
443	}
444
445	mTimingClear(&gb->timing);
446
447	GBMemoryReset(gb);
448	GBVideoReset(&gb->video);
449	GBTimerReset(&gb->timer);
450	mTimingSchedule(&gb->timing, &gb->timer.event, GB_DMG_DIV_PERIOD);
451
452	GBAudioReset(&gb->audio);
453	GBIOReset(gb);
454	GBSIOReset(&gb->sio);
455
456	GBSavedataUnmask(gb);
457}
458
459void GBDetectModel(struct GB* gb) {
460	if (gb->model != GB_MODEL_AUTODETECT) {
461		return;
462	}
463	if (gb->biosVf) {
464		switch (_GBBiosCRC32(gb->biosVf)) {
465		case DMG_BIOS_CHECKSUM:
466		case DMG_2_BIOS_CHECKSUM:
467			gb->model = GB_MODEL_DMG;
468			break;
469		case CGB_BIOS_CHECKSUM:
470			gb->model = GB_MODEL_CGB;
471			break;
472		default:
473			gb->biosVf->close(gb->biosVf);
474			gb->biosVf = NULL;
475		}
476	}
477	if (gb->model == GB_MODEL_AUTODETECT && gb->memory.rom) {
478		const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
479		if (cart->cgb & 0x80) {
480			gb->model = GB_MODEL_CGB;
481		} else {
482			gb->model = GB_MODEL_DMG;
483		}
484	}
485
486	switch (gb->model) {
487	case GB_MODEL_DMG:
488	case GB_MODEL_SGB:
489	case GB_MODEL_AUTODETECT: //Silence warnings
490		gb->audio.style = GB_AUDIO_DMG;
491		break;
492	case GB_MODEL_AGB:
493	case GB_MODEL_CGB:
494		gb->audio.style = GB_AUDIO_CGB;
495		break;
496	}
497}
498
499void GBUpdateIRQs(struct GB* gb) {
500	int irqs = gb->memory.ie & gb->memory.io[REG_IF];
501	if (!irqs) {
502		return;
503	}
504	gb->cpu->halted = false;
505
506	if (!gb->memory.ime || gb->cpu->irqPending) {
507		return;
508	}
509
510	if (irqs & (1 << GB_IRQ_VBLANK)) {
511		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_VBLANK);
512		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_VBLANK);
513		return;
514	}
515	if (irqs & (1 << GB_IRQ_LCDSTAT)) {
516		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_LCDSTAT);
517		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
518		return;
519	}
520	if (irqs & (1 << GB_IRQ_TIMER)) {
521		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_TIMER);
522		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_TIMER);
523		return;
524	}
525	if (irqs & (1 << GB_IRQ_SIO)) {
526		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_SIO);
527		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_SIO);
528		return;
529	}
530	if (irqs & (1 << GB_IRQ_KEYPAD)) {
531		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_KEYPAD);
532		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_KEYPAD);
533	}
534}
535
536void GBProcessEvents(struct LR35902Core* cpu) {
537	struct GB* gb = (struct GB*) cpu->master;
538	do {
539		int32_t cycles = cpu->cycles;
540		int32_t nextEvent;
541
542		cpu->cycles = 0;
543		cpu->nextEvent = INT_MAX;
544
545		nextEvent = cycles;
546		do {
547			nextEvent = mTimingTick(&gb->timing, nextEvent);
548		} while (gb->cpuBlocked);
549		cpu->nextEvent = nextEvent;
550
551		if (cpu->halted) {
552			cpu->cycles = cpu->nextEvent;
553			if (!gb->memory.ie || !gb->memory.ime) {
554				break;
555			}
556		}
557	} while (cpu->cycles >= cpu->nextEvent);
558}
559
560void GBSetInterrupts(struct LR35902Core* cpu, bool enable) {
561	struct GB* gb = (struct GB*) cpu->master;
562	if (!enable) {
563		gb->memory.ime = enable;
564		mTimingDeschedule(&gb->timing, &gb->eiPending);
565		GBUpdateIRQs(gb);
566	} else {
567		mTimingDeschedule(&gb->timing, &gb->eiPending);
568		mTimingSchedule(&gb->timing, &gb->eiPending, 4);
569	}
570}
571
572static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate) {
573	UNUSED(timing);
574	UNUSED(cyclesLate);
575	struct GB* gb = user;
576	gb->memory.ime = true;
577	GBUpdateIRQs(gb);
578}
579
580void GBHalt(struct LR35902Core* cpu) {
581	if (!cpu->irqPending) {
582		cpu->cycles = cpu->nextEvent;
583		cpu->halted = true;
584	}
585}
586
587void GBStop(struct LR35902Core* cpu) {
588	struct GB* gb = (struct GB*) cpu->master;
589	if (cpu->bus) {
590		mLOG(GB, GAME_ERROR, "Hit illegal stop at address %04X:%02X\n", cpu->pc, cpu->bus);
591	}
592	if (gb->memory.io[REG_KEY1] & 1) {
593		gb->doubleSpeed ^= 1;
594		gb->audio.timingFactor = gb->doubleSpeed + 1;
595		gb->memory.io[REG_KEY1] = 0;
596		gb->memory.io[REG_KEY1] |= gb->doubleSpeed << 7;
597	} else if (cpu->bus) {
598#ifdef USE_DEBUGGERS
599		if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
600			struct mDebuggerEntryInfo info = {
601				.address = cpu->pc - 1,
602				.opcode = 0x1000 | cpu->bus
603			};
604			mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
605		}
606#endif
607		// Hang forever
608		gb->memory.ime = 0;
609		cpu->pc -= 2;
610	}
611	// TODO: Actually stop
612}
613
614void GBIllegal(struct LR35902Core* cpu) {
615	struct GB* gb = (struct GB*) cpu->master;
616	mLOG(GB, GAME_ERROR, "Hit illegal opcode at address %04X:%02X\n", cpu->pc, cpu->bus);
617#ifdef USE_DEBUGGERS
618	if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
619		struct mDebuggerEntryInfo info = {
620			.address = cpu->pc,
621			.opcode = cpu->bus
622		};
623		mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
624	}
625#endif
626	// Hang forever
627	gb->memory.ime = 0;
628	--cpu->pc;
629}
630
631bool GBIsROM(struct VFile* vf) {
632	vf->seek(vf, 0x104, SEEK_SET);
633	uint8_t header[4];
634
635	if (vf->read(vf, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
636		return false;
637	}
638	if (memcmp(header, _knownHeader, sizeof(header))) {
639		return false;
640	}
641	return true;
642}
643
644void GBGetGameTitle(const struct GB* gb, char* out) {
645	const struct GBCartridge* cart = NULL;
646	if (gb->memory.rom) {
647		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
648	}
649	if (gb->pristineRom) {
650		cart = (const struct GBCartridge*) &((uint8_t*) gb->pristineRom)[0x100];
651	}
652	if (!cart) {
653		return;
654	}
655	if (cart->oldLicensee != 0x33) {
656		memcpy(out, cart->titleLong, 16);
657	} else {
658		memcpy(out, cart->titleShort, 11);
659	}
660}
661
662void GBGetGameCode(const struct GB* gb, char* out) {
663	memset(out, 0, 8);
664	const struct GBCartridge* cart = NULL;
665	if (gb->memory.rom) {
666		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
667	}
668	if (gb->pristineRom) {
669		cart = (const struct GBCartridge*) &((uint8_t*) gb->pristineRom)[0x100];
670	}
671	if (!cart) {
672		return;
673	}
674	if (cart->cgb == 0xC0) {
675		memcpy(out, "CGB-????", 8);
676	} else {
677		memcpy(out, "DMG-????", 8);
678	}
679	if (cart->oldLicensee == 0x33) {
680		memcpy(&out[4], cart->maker, 4);
681	}
682}
683
684void GBFrameEnded(struct GB* gb) {
685	GBSramClean(gb, gb->video.frameCounter);
686
687	if (gb->cpu->components && gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
688		struct mCheatDevice* device = (struct mCheatDevice*) gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
689		size_t i;
690		for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
691			struct mCheatSet* cheats = *mCheatSetsGetPointer(&device->cheats, i);
692			mCheatRefresh(device, cheats);
693		}
694	}
695}