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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			break;
437		case GB_MODEL_AGB:
438			cpu->b = 1;
439			// Fall through
440		case GB_MODEL_CGB:
441			cpu->a = 0x11;
442			cpu->f.packed = 0x80;
443			cpu->c = 0;
444			cpu->e = 0x08;
445			cpu->h = 0;
446			cpu->l = 0x7C;
447			break;
448		}
449
450		cpu->sp = 0xFFFE;
451		cpu->pc = 0x100;
452	}
453
454	gb->cpuBlocked = false;
455	gb->earlyExit = false;
456	gb->doubleSpeed = 0;
457
458	cpu->memory.setActiveRegion(cpu, cpu->pc);
459
460	if (gb->yankedRomSize) {
461		gb->memory.romSize = gb->yankedRomSize;
462		gb->yankedRomSize = 0;
463	}
464
465	mTimingClear(&gb->timing);
466
467	GBMemoryReset(gb);
468	GBVideoReset(&gb->video);
469	GBTimerReset(&gb->timer);
470	mTimingSchedule(&gb->timing, &gb->timer.event, GB_DMG_DIV_PERIOD);
471
472	GBAudioReset(&gb->audio);
473	GBIOReset(gb);
474	GBSIOReset(&gb->sio);
475
476	GBSavedataUnmask(gb);
477}
478
479void GBDetectModel(struct GB* gb) {
480	if (gb->model != GB_MODEL_AUTODETECT) {
481		return;
482	}
483	if (gb->biosVf) {
484		switch (_GBBiosCRC32(gb->biosVf)) {
485		case DMG_BIOS_CHECKSUM:
486		case DMG_2_BIOS_CHECKSUM:
487			gb->model = GB_MODEL_DMG;
488			break;
489		case CGB_BIOS_CHECKSUM:
490			gb->model = GB_MODEL_CGB;
491			break;
492		default:
493			gb->biosVf->close(gb->biosVf);
494			gb->biosVf = NULL;
495		}
496	}
497	if (gb->model == GB_MODEL_AUTODETECT && gb->memory.rom) {
498		const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
499		if (cart->cgb & 0x80) {
500			gb->model = GB_MODEL_CGB;
501		} else {
502			gb->model = GB_MODEL_DMG;
503		}
504	}
505
506	switch (gb->model) {
507	case GB_MODEL_DMG:
508	case GB_MODEL_SGB:
509	case GB_MODEL_AUTODETECT: //Silence warnings
510		gb->audio.style = GB_AUDIO_DMG;
511		break;
512	case GB_MODEL_AGB:
513	case GB_MODEL_CGB:
514		gb->audio.style = GB_AUDIO_CGB;
515		break;
516	}
517}
518
519void GBUpdateIRQs(struct GB* gb) {
520	int irqs = gb->memory.ie & gb->memory.io[REG_IF];
521	if (!irqs) {
522		return;
523	}
524	gb->cpu->halted = false;
525
526	if (!gb->memory.ime || gb->cpu->irqPending) {
527		return;
528	}
529
530	if (irqs & (1 << GB_IRQ_VBLANK)) {
531		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_VBLANK);
532		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_VBLANK);
533		return;
534	}
535	if (irqs & (1 << GB_IRQ_LCDSTAT)) {
536		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_LCDSTAT);
537		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
538		return;
539	}
540	if (irqs & (1 << GB_IRQ_TIMER)) {
541		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_TIMER);
542		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_TIMER);
543		return;
544	}
545	if (irqs & (1 << GB_IRQ_SIO)) {
546		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_SIO);
547		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_SIO);
548		return;
549	}
550	if (irqs & (1 << GB_IRQ_KEYPAD)) {
551		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_KEYPAD);
552		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_KEYPAD);
553	}
554}
555
556void GBProcessEvents(struct LR35902Core* cpu) {
557	struct GB* gb = (struct GB*) cpu->master;
558	do {
559		int32_t cycles = cpu->cycles;
560		int32_t nextEvent;
561
562		cpu->cycles = 0;
563		cpu->nextEvent = INT_MAX;
564
565		nextEvent = cycles;
566		do {
567			nextEvent = mTimingTick(&gb->timing, nextEvent);
568		} while (gb->cpuBlocked);
569		cpu->nextEvent = nextEvent;
570
571		if (gb->earlyExit) {
572			gb->earlyExit = false;
573			break;
574		}
575		if (cpu->halted) {
576			cpu->cycles = cpu->nextEvent;
577			if (!gb->memory.ie || !gb->memory.ime) {
578				break;
579			}
580		}
581	} while (cpu->cycles >= cpu->nextEvent);
582}
583
584void GBSetInterrupts(struct LR35902Core* cpu, bool enable) {
585	struct GB* gb = (struct GB*) cpu->master;
586	if (!enable) {
587		gb->memory.ime = enable;
588		mTimingDeschedule(&gb->timing, &gb->eiPending);
589		GBUpdateIRQs(gb);
590	} else {
591		mTimingDeschedule(&gb->timing, &gb->eiPending);
592		mTimingSchedule(&gb->timing, &gb->eiPending, 4);
593	}
594}
595
596static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate) {
597	UNUSED(timing);
598	UNUSED(cyclesLate);
599	struct GB* gb = user;
600	gb->memory.ime = true;
601	GBUpdateIRQs(gb);
602}
603
604void GBHalt(struct LR35902Core* cpu) {
605	if (!cpu->irqPending) {
606		cpu->cycles = cpu->nextEvent;
607		cpu->halted = true;
608	}
609}
610
611void GBStop(struct LR35902Core* cpu) {
612	struct GB* gb = (struct GB*) cpu->master;
613	if (cpu->bus) {
614		mLOG(GB, GAME_ERROR, "Hit illegal stop at address %04X:%02X\n", cpu->pc, cpu->bus);
615	}
616	if (gb->memory.io[REG_KEY1] & 1) {
617		gb->doubleSpeed ^= 1;
618		gb->audio.timingFactor = gb->doubleSpeed + 1;
619		gb->memory.io[REG_KEY1] = 0;
620		gb->memory.io[REG_KEY1] |= gb->doubleSpeed << 7;
621	} else if (cpu->bus) {
622#ifdef USE_DEBUGGERS
623		if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
624			struct mDebuggerEntryInfo info = {
625				.address = cpu->pc - 1,
626				.opcode = 0x1000 | cpu->bus
627			};
628			mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
629		}
630#endif
631		// Hang forever
632		gb->memory.ime = 0;
633		cpu->pc -= 2;
634	}
635	// TODO: Actually stop
636}
637
638void GBIllegal(struct LR35902Core* cpu) {
639	struct GB* gb = (struct GB*) cpu->master;
640	mLOG(GB, GAME_ERROR, "Hit illegal opcode at address %04X:%02X\n", cpu->pc, cpu->bus);
641#ifdef USE_DEBUGGERS
642	if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
643		struct mDebuggerEntryInfo info = {
644			.address = cpu->pc,
645			.opcode = cpu->bus
646		};
647		mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
648	}
649#endif
650	// Hang forever
651	gb->memory.ime = 0;
652	--cpu->pc;
653}
654
655bool GBIsROM(struct VFile* vf) {
656	vf->seek(vf, 0x104, SEEK_SET);
657	uint8_t header[4];
658
659	if (vf->read(vf, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
660		return false;
661	}
662	if (memcmp(header, _knownHeader, sizeof(header))) {
663		return false;
664	}
665	return true;
666}
667
668void GBGetGameTitle(const struct GB* gb, char* out) {
669	const struct GBCartridge* cart = NULL;
670	if (gb->memory.rom) {
671		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
672	}
673	if (!cart) {
674		return;
675	}
676	if (cart->oldLicensee != 0x33) {
677		memcpy(out, cart->titleLong, 16);
678	} else {
679		memcpy(out, cart->titleShort, 11);
680	}
681}
682
683void GBGetGameCode(const struct GB* gb, char* out) {
684	memset(out, 0, 8);
685	const struct GBCartridge* cart = NULL;
686	if (gb->memory.rom) {
687		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
688	}
689	if (!cart) {
690		return;
691	}
692	if (cart->cgb == 0xC0) {
693		memcpy(out, "CGB-????", 8);
694	} else {
695		memcpy(out, "DMG-????", 8);
696	}
697	if (cart->oldLicensee == 0x33) {
698		memcpy(&out[4], cart->maker, 4);
699	}
700}
701
702void GBFrameEnded(struct GB* gb) {
703	GBSramClean(gb, gb->video.frameCounter);
704
705	if (gb->cpu->components && gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
706		struct mCheatDevice* device = (struct mCheatDevice*) gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
707		size_t i;
708		for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
709			struct mCheatSet* cheats = *mCheatSetsGetPointer(&device->cheats, i);
710			mCheatRefresh(device, cheats);
711		}
712	}
713
714	GBTestKeypadIRQ(gb);
715}