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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 <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", "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->isPristine = false;
 83	gb->pristineRomSize = 0;
 84	gb->yankedRomSize = 0;
 85
 86	mCoreCallbacksListInit(&gb->coreCallbacks, 0);
 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	gb->isPristine = true;
112#ifdef _3DS
113	if (gb->pristineRomSize <= romBufferSize) {
114		gb->memory.rom = romBuffer;
115		vf->read(vf, romBuffer, gb->pristineRomSize);
116	}
117#else
118	gb->memory.rom = vf->map(vf, gb->pristineRomSize, MAP_READ);
119#endif
120	if (!gb->memory.rom) {
121		return false;
122	}
123	gb->yankedRomSize = 0;
124	gb->memory.romBase = gb->memory.rom;
125	gb->memory.romSize = gb->pristineRomSize;
126	gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
127	GBMBCInit(gb);
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
138static void GBSramDeinit(struct GB* gb) {
139	if (gb->sramVf) {
140		gb->sramVf->unmap(gb->sramVf, gb->memory.sram, gb->sramSize);
141		if (gb->memory.mbcType == GB_MBC3_RTC && gb->sramVf == gb->sramRealVf) {
142			GBMBCRTCWrite(gb);
143		}
144		gb->sramVf = NULL;
145	} else if (gb->memory.sram) {
146		mappedMemoryFree(gb->memory.sram, gb->sramSize);
147	}
148	gb->memory.sram = 0;
149}
150
151bool GBLoadSave(struct GB* gb, struct VFile* vf) {
152	GBSramDeinit(gb);
153	gb->sramVf = vf;
154	gb->sramRealVf = vf;
155	if (gb->sramSize) {
156		GBResizeSram(gb, gb->sramSize);
157	}
158	return vf;
159}
160
161void GBResizeSram(struct GB* gb, size_t size) {
162	if (gb->memory.sram && size <= gb->sramSize) {
163		return;
164	}
165	mLOG(GB, INFO, "Resizing SRAM to %"PRIz"u bytes", size);
166	struct VFile* vf = gb->sramVf;
167	if (vf) {
168		if (vf == gb->sramRealVf) {
169			ssize_t vfSize = vf->size(vf);
170			if (vfSize >= 0 && (size_t) vfSize < size) {
171				uint8_t extdataBuffer[0x100];
172				if (vfSize & 0xFF) {
173					vf->seek(vf, -(vfSize & 0xFF), SEEK_END);
174					vf->read(vf, extdataBuffer, vfSize & 0xFF);
175				}
176				if (gb->memory.sram) {
177					vf->unmap(vf, gb->memory.sram, gb->sramSize);
178				}
179				vf->truncate(vf, size + (vfSize & 0xFF));
180				if (vfSize & 0xFF) {
181					vf->seek(vf, size, SEEK_SET);
182					vf->write(vf, extdataBuffer, vfSize & 0xFF);
183				}
184				gb->memory.sram = vf->map(vf, size, MAP_WRITE);
185				memset(&gb->memory.sram[gb->sramSize], 0xFF, size - gb->sramSize);
186			} else if (size > gb->sramSize || !gb->memory.sram) {
187				if (gb->memory.sram) {
188					vf->unmap(vf, gb->memory.sram, gb->sramSize);
189				}
190				gb->memory.sram = vf->map(vf, size, MAP_WRITE);
191			}
192		} else {
193			if (gb->memory.sram) {
194				vf->unmap(vf, gb->memory.sram, gb->sramSize);
195			}
196			gb->memory.sram = vf->map(vf, size, MAP_READ);
197		}
198		if (gb->memory.sram == (void*) -1) {
199			gb->memory.sram = NULL;
200		}
201	} else {
202		uint8_t* newSram = anonymousMemoryMap(size);
203		if (gb->memory.sram) {
204			if (size > gb->sramSize) {
205				memcpy(newSram, gb->memory.sram, gb->sramSize);
206				memset(&newSram[gb->sramSize], 0xFF, size - gb->sramSize);
207			} else {
208				memcpy(newSram, gb->memory.sram, size);
209			}
210			mappedMemoryFree(gb->memory.sram, gb->sramSize);
211		} else {
212			memset(newSram, 0xFF, size);
213		}
214		gb->memory.sram = newSram;
215	}
216	if (gb->sramSize < size) {
217		gb->sramSize = size;
218	}
219}
220
221void GBSramClean(struct GB* gb, uint32_t frameCount) {
222	// TODO: Share with GBASavedataClean
223	if (!gb->sramVf || gb->sramVf != gb->sramRealVf) {
224		return;
225	}
226	if (gb->sramDirty & GB_SRAM_DIRT_NEW) {
227		gb->sramDirtAge = frameCount;
228		gb->sramDirty &= ~GB_SRAM_DIRT_NEW;
229		if (!(gb->sramDirty & GB_SRAM_DIRT_SEEN)) {
230			gb->sramDirty |= GB_SRAM_DIRT_SEEN;
231		}
232	} else if ((gb->sramDirty & GB_SRAM_DIRT_SEEN) && frameCount - gb->sramDirtAge > CLEANUP_THRESHOLD) {
233		if (gb->memory.mbcType == GB_MBC3_RTC) {
234			GBMBCRTCWrite(gb);
235		}
236		gb->sramDirty = 0;
237		if (gb->memory.sram && gb->sramVf->sync(gb->sramVf, gb->memory.sram, gb->sramSize)) {
238			mLOG(GB_MEM, INFO, "Savedata synced");
239		} else {
240			mLOG(GB_MEM, INFO, "Savedata failed to sync!");
241		}
242	}
243}
244
245void GBSavedataMask(struct GB* gb, struct VFile* vf, bool writeback) {
246	GBSramDeinit(gb);
247	gb->sramVf = vf;
248	gb->sramMaskWriteback = writeback;
249	gb->memory.sram = vf->map(vf, gb->sramSize, MAP_READ);
250	GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
251}
252
253void GBSavedataUnmask(struct GB* gb) {
254	if (gb->sramVf == gb->sramRealVf) {
255		return;
256	}
257	struct VFile* vf = gb->sramVf;
258	GBSramDeinit(gb);
259	gb->sramVf = gb->sramRealVf;
260	gb->memory.sram = gb->sramVf->map(gb->sramVf, gb->sramSize, MAP_WRITE);
261	if (gb->sramMaskWriteback) {
262		vf->read(vf, gb->memory.sram, gb->sramSize);
263	}
264	vf->close(vf);
265}
266
267void GBUnloadROM(struct GB* gb) {
268	// TODO: Share with GBAUnloadROM
269	if (gb->memory.rom && gb->memory.romBase != gb->memory.rom && !gb->isPristine) {
270		free(gb->memory.romBase);
271	}
272	if (gb->memory.rom && !gb->isPristine) {
273		if (gb->yankedRomSize) {
274			gb->yankedRomSize = 0;
275		}
276		mappedMemoryFree(gb->memory.rom, GB_SIZE_CART_MAX);
277	}
278
279	if (gb->romVf) {
280#ifndef _3DS
281		gb->romVf->unmap(gb->romVf, gb->memory.rom, gb->pristineRomSize);
282#endif
283		gb->romVf->close(gb->romVf);
284		gb->romVf = NULL;
285	}
286	gb->memory.rom = NULL;
287	gb->memory.mbcType = GB_MBC_AUTODETECT;
288	gb->isPristine = false;
289
290	GBSavedataUnmask(gb);
291	GBSramDeinit(gb);
292	if (gb->sramRealVf) {
293		gb->sramRealVf->close(gb->sramRealVf);
294	}
295	gb->sramRealVf = NULL;
296	gb->sramVf = NULL;
297}
298
299void GBSynthesizeROM(struct VFile* vf) {
300	if (!vf) {
301		return;
302	}
303	const struct GBCartridge cart = {
304		.logo = { _knownHeader[0], _knownHeader[1], _knownHeader[2], _knownHeader[3]}
305	};
306
307	vf->seek(vf, 0x100, SEEK_SET);
308	vf->write(vf, &cart, sizeof(cart));
309}
310
311void GBLoadBIOS(struct GB* gb, struct VFile* vf) {
312	gb->biosVf = vf;
313}
314
315void GBApplyPatch(struct GB* gb, struct Patch* patch) {
316	size_t patchedSize = patch->outputSize(patch, gb->memory.romSize);
317	if (!patchedSize) {
318		return;
319	}
320	if (patchedSize > GB_SIZE_CART_MAX) {
321		patchedSize = GB_SIZE_CART_MAX;
322	}
323	void* newRom = anonymousMemoryMap(GB_SIZE_CART_MAX);
324	if (!patch->applyPatch(patch, gb->memory.rom, gb->pristineRomSize, newRom, patchedSize)) {
325		mappedMemoryFree(newRom, GB_SIZE_CART_MAX);
326		return;
327	}
328	if (gb->romVf) {
329#ifndef _3DS
330		gb->romVf->unmap(gb->romVf, gb->memory.rom, gb->pristineRomSize);
331#endif
332		gb->romVf->close(gb->romVf);
333		gb->romVf = NULL;
334	}
335	gb->isPristine = false;
336	if (gb->memory.romBase == gb->memory.rom) {
337		gb->memory.romBase = newRom;
338	}
339	gb->memory.rom = newRom;
340	gb->memory.romSize = patchedSize;
341	gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
342	gb->cpu->memory.setActiveRegion(gb->cpu, gb->cpu->pc);
343}
344
345void GBDestroy(struct GB* gb) {
346	GBUnloadROM(gb);
347
348	if (gb->biosVf) {
349		gb->biosVf->close(gb->biosVf);
350		gb->biosVf = 0;
351	}
352
353	GBMemoryDeinit(gb);
354	GBAudioDeinit(&gb->audio);
355	GBVideoDeinit(&gb->video);
356	GBSIODeinit(&gb->sio);
357	mCoreCallbacksListDeinit(&gb->coreCallbacks);
358}
359
360void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh) {
361	irqh->reset = GBReset;
362	irqh->processEvents = GBProcessEvents;
363	irqh->setInterrupts = GBSetInterrupts;
364	irqh->hitIllegal = GBIllegal;
365	irqh->stop = GBStop;
366	irqh->halt = GBHalt;
367}
368
369static uint32_t _GBBiosCRC32(struct VFile* vf) {
370	ssize_t size = vf->size(vf);
371	if (size <= 0 || size > GB_SIZE_CART_BANK0) {
372		return 0;
373	}
374	void* bios = vf->map(vf, size, MAP_READ);
375	uint32_t biosCrc = doCrc32(bios, size);
376	vf->unmap(vf, bios, size);
377	return biosCrc;
378}
379
380bool GBIsBIOS(struct VFile* vf) {
381	switch (_GBBiosCRC32(vf)) {
382	case DMG_BIOS_CHECKSUM:
383	case DMG_2_BIOS_CHECKSUM:
384	case CGB_BIOS_CHECKSUM:
385		return true;
386	default:
387		return false;
388	}
389}
390
391void GBReset(struct LR35902Core* cpu) {
392	struct GB* gb = (struct GB*) cpu->master;
393	gb->memory.romBase = gb->memory.rom;
394	GBDetectModel(gb);
395
396	if (gb->biosVf) {
397		if (!GBIsBIOS(gb->biosVf)) {
398			gb->biosVf->close(gb->biosVf);
399			gb->biosVf = NULL;
400		} else {
401			gb->biosVf->seek(gb->biosVf, 0, SEEK_SET);
402			gb->memory.romBase = malloc(GB_SIZE_CART_BANK0);
403			ssize_t size = gb->biosVf->read(gb->biosVf, gb->memory.romBase, GB_SIZE_CART_BANK0);
404			memcpy(&gb->memory.romBase[size], &gb->memory.rom[size], GB_SIZE_CART_BANK0 - size);
405			if (size > 0x100) {
406				memcpy(&gb->memory.romBase[0x100], &gb->memory.rom[0x100], sizeof(struct GBCartridge));
407			}
408
409			cpu->a = 0;
410			cpu->f.packed = 0;
411			cpu->c = 0;
412			cpu->e = 0;
413			cpu->h = 0;
414			cpu->l = 0;
415			cpu->sp = 0;
416			cpu->pc = 0;
417		}
418	}
419
420	cpu->b = 0;
421	cpu->d = 0;
422
423	if (!gb->biosVf) {
424		switch (gb->model) {
425		case GB_MODEL_DMG:
426			// TODO: SGB
427		case GB_MODEL_SGB:
428		case GB_MODEL_AUTODETECT: // Silence warnings
429			gb->model = GB_MODEL_DMG;
430			cpu->a = 1;
431			cpu->f.packed = 0xB0;
432			cpu->c = 0x13;
433			cpu->e = 0xD8;
434			cpu->h = 1;
435			cpu->l = 0x4D;
436			gb->timer.internalDiv = 0x2AF3;
437			break;
438		case GB_MODEL_AGB:
439			cpu->b = 1;
440			// Fall through
441		case GB_MODEL_CGB:
442			cpu->a = 0x11;
443			cpu->f.packed = 0x80;
444			cpu->c = 0;
445			cpu->e = 0x08;
446			cpu->h = 0;
447			cpu->l = 0x7C;
448			gb->timer.internalDiv = 0x7A8;
449			break;
450		}
451
452		cpu->sp = 0xFFFE;
453		cpu->pc = 0x100;
454	}
455
456	gb->cpuBlocked = false;
457	gb->earlyExit = false;
458	gb->doubleSpeed = 0;
459
460	cpu->memory.setActiveRegion(cpu, cpu->pc);
461
462	if (gb->yankedRomSize) {
463		gb->memory.romSize = gb->yankedRomSize;
464		gb->yankedRomSize = 0;
465	}
466
467	mTimingClear(&gb->timing);
468
469	GBMemoryReset(gb);
470	GBVideoReset(&gb->video);
471	GBTimerReset(&gb->timer);
472	mTimingSchedule(&gb->timing, &gb->timer.event, GB_DMG_DIV_PERIOD);
473
474	GBAudioReset(&gb->audio);
475	GBIOReset(gb);
476	GBSIOReset(&gb->sio);
477
478	GBSavedataUnmask(gb);
479}
480
481void GBDetectModel(struct GB* gb) {
482	if (gb->model != GB_MODEL_AUTODETECT) {
483		return;
484	}
485	if (gb->biosVf) {
486		switch (_GBBiosCRC32(gb->biosVf)) {
487		case DMG_BIOS_CHECKSUM:
488		case DMG_2_BIOS_CHECKSUM:
489			gb->model = GB_MODEL_DMG;
490			break;
491		case CGB_BIOS_CHECKSUM:
492			gb->model = GB_MODEL_CGB;
493			break;
494		default:
495			gb->biosVf->close(gb->biosVf);
496			gb->biosVf = NULL;
497		}
498	}
499	if (gb->model == GB_MODEL_AUTODETECT && gb->memory.rom) {
500		const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
501		if (cart->cgb & 0x80) {
502			gb->model = GB_MODEL_CGB;
503		} else {
504			gb->model = GB_MODEL_DMG;
505		}
506	}
507
508	switch (gb->model) {
509	case GB_MODEL_DMG:
510	case GB_MODEL_SGB:
511	case GB_MODEL_AUTODETECT: //Silence warnings
512		gb->audio.style = GB_AUDIO_DMG;
513		break;
514	case GB_MODEL_AGB:
515	case GB_MODEL_CGB:
516		gb->audio.style = GB_AUDIO_CGB;
517		break;
518	}
519}
520
521void GBUpdateIRQs(struct GB* gb) {
522	int irqs = gb->memory.ie & gb->memory.io[REG_IF];
523	if (!irqs) {
524		return;
525	}
526	gb->cpu->halted = false;
527
528	if (!gb->memory.ime || gb->cpu->irqPending) {
529		return;
530	}
531
532	if (irqs & (1 << GB_IRQ_VBLANK)) {
533		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_VBLANK);
534		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_VBLANK);
535		return;
536	}
537	if (irqs & (1 << GB_IRQ_LCDSTAT)) {
538		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_LCDSTAT);
539		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
540		return;
541	}
542	if (irqs & (1 << GB_IRQ_TIMER)) {
543		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_TIMER);
544		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_TIMER);
545		return;
546	}
547	if (irqs & (1 << GB_IRQ_SIO)) {
548		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_SIO);
549		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_SIO);
550		return;
551	}
552	if (irqs & (1 << GB_IRQ_KEYPAD)) {
553		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_KEYPAD);
554		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_KEYPAD);
555	}
556}
557
558void GBProcessEvents(struct LR35902Core* cpu) {
559	struct GB* gb = (struct GB*) cpu->master;
560	do {
561		int32_t cycles = cpu->cycles;
562		int32_t nextEvent;
563
564		cpu->cycles = 0;
565		cpu->nextEvent = INT_MAX;
566
567		nextEvent = cycles;
568		do {
569			nextEvent = mTimingTick(&gb->timing, nextEvent);
570		} while (gb->cpuBlocked);
571		cpu->nextEvent = nextEvent;
572
573		if (gb->earlyExit) {
574			gb->earlyExit = false;
575			break;
576		}
577		if (cpu->halted) {
578			cpu->cycles = cpu->nextEvent;
579			if (!gb->memory.ie || !gb->memory.ime) {
580				break;
581			}
582		}
583	} while (cpu->cycles >= cpu->nextEvent);
584}
585
586void GBSetInterrupts(struct LR35902Core* cpu, bool enable) {
587	struct GB* gb = (struct GB*) cpu->master;
588	if (!enable) {
589		gb->memory.ime = enable;
590		mTimingDeschedule(&gb->timing, &gb->eiPending);
591		GBUpdateIRQs(gb);
592	} else {
593		mTimingDeschedule(&gb->timing, &gb->eiPending);
594		mTimingSchedule(&gb->timing, &gb->eiPending, 4);
595	}
596}
597
598static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate) {
599	UNUSED(timing);
600	UNUSED(cyclesLate);
601	struct GB* gb = user;
602	gb->memory.ime = true;
603	GBUpdateIRQs(gb);
604}
605
606void GBHalt(struct LR35902Core* cpu) {
607	if (!cpu->irqPending) {
608		cpu->cycles = cpu->nextEvent;
609		cpu->halted = true;
610	}
611}
612
613void GBStop(struct LR35902Core* cpu) {
614	struct GB* gb = (struct GB*) cpu->master;
615	if (cpu->bus) {
616		mLOG(GB, GAME_ERROR, "Hit illegal stop at address %04X:%02X\n", cpu->pc, cpu->bus);
617	}
618	if (gb->memory.io[REG_KEY1] & 1) {
619		gb->doubleSpeed ^= 1;
620		gb->audio.timingFactor = gb->doubleSpeed + 1;
621		gb->memory.io[REG_KEY1] = 0;
622		gb->memory.io[REG_KEY1] |= gb->doubleSpeed << 7;
623	} else if (cpu->bus) {
624#ifdef USE_DEBUGGERS
625		if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
626			struct mDebuggerEntryInfo info = {
627				.address = cpu->pc - 1,
628				.opcode = 0x1000 | cpu->bus
629			};
630			mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
631		}
632#endif
633		// Hang forever
634		gb->memory.ime = 0;
635		cpu->pc -= 2;
636	}
637	// TODO: Actually stop
638}
639
640void GBIllegal(struct LR35902Core* cpu) {
641	struct GB* gb = (struct GB*) cpu->master;
642	mLOG(GB, GAME_ERROR, "Hit illegal opcode at address %04X:%02X\n", cpu->pc, cpu->bus);
643#ifdef USE_DEBUGGERS
644	if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
645		struct mDebuggerEntryInfo info = {
646			.address = cpu->pc,
647			.opcode = cpu->bus
648		};
649		mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
650	}
651#endif
652	// Hang forever
653	gb->memory.ime = 0;
654	--cpu->pc;
655}
656
657bool GBIsROM(struct VFile* vf) {
658	vf->seek(vf, 0x104, SEEK_SET);
659	uint8_t header[4];
660
661	if (vf->read(vf, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
662		return false;
663	}
664	if (memcmp(header, _knownHeader, sizeof(header))) {
665		return false;
666	}
667	return true;
668}
669
670void GBGetGameTitle(const struct GB* gb, char* out) {
671	const struct GBCartridge* cart = NULL;
672	if (gb->memory.rom) {
673		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
674	}
675	if (!cart) {
676		return;
677	}
678	if (cart->oldLicensee != 0x33) {
679		memcpy(out, cart->titleLong, 16);
680	} else {
681		memcpy(out, cart->titleShort, 11);
682	}
683}
684
685void GBGetGameCode(const struct GB* gb, char* out) {
686	memset(out, 0, 8);
687	const struct GBCartridge* cart = NULL;
688	if (gb->memory.rom) {
689		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
690	}
691	if (!cart) {
692		return;
693	}
694	if (cart->cgb == 0xC0) {
695		memcpy(out, "CGB-????", 8);
696	} else {
697		memcpy(out, "DMG-????", 8);
698	}
699	if (cart->oldLicensee == 0x33) {
700		memcpy(&out[4], cart->maker, 4);
701	}
702}
703
704void GBFrameEnded(struct GB* gb) {
705	GBSramClean(gb, gb->video.frameCounter);
706
707	if (gb->cpu->components && gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
708		struct mCheatDevice* device = (struct mCheatDevice*) gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
709		size_t i;
710		for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
711			struct mCheatSet* cheats = *mCheatSetsGetPointer(&device->cheats, i);
712			mCheatRefresh(device, cheats);
713		}
714	}
715
716	GBTestKeypadIRQ(gb);
717}