all repos — mgba @ 31b9100f381fb7ee75ba8ee006a86ab65e6e0b35

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 FIXED_ROM_BUFFER
 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 FIXED_ROM_BUFFER
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 FIXED_ROM_BUFFER
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	if (gb->memory.cam && gb->memory.cam->stopRequestImage) {
298		gb->memory.cam->stopRequestImage(gb->memory.cam);
299	}
300}
301
302void GBSynthesizeROM(struct VFile* vf) {
303	if (!vf) {
304		return;
305	}
306	const struct GBCartridge cart = {
307		.logo = { _knownHeader[0], _knownHeader[1], _knownHeader[2], _knownHeader[3]}
308	};
309
310	vf->seek(vf, 0x100, SEEK_SET);
311	vf->write(vf, &cart, sizeof(cart));
312}
313
314void GBLoadBIOS(struct GB* gb, struct VFile* vf) {
315	gb->biosVf = vf;
316}
317
318void GBApplyPatch(struct GB* gb, struct Patch* patch) {
319	size_t patchedSize = patch->outputSize(patch, gb->memory.romSize);
320	if (!patchedSize) {
321		return;
322	}
323	if (patchedSize > GB_SIZE_CART_MAX) {
324		patchedSize = GB_SIZE_CART_MAX;
325	}
326	void* newRom = anonymousMemoryMap(GB_SIZE_CART_MAX);
327	if (!patch->applyPatch(patch, gb->memory.rom, gb->pristineRomSize, newRom, patchedSize)) {
328		mappedMemoryFree(newRom, GB_SIZE_CART_MAX);
329		return;
330	}
331	if (gb->romVf) {
332#ifndef FIXED_ROM_BUFFER
333		gb->romVf->unmap(gb->romVf, gb->memory.rom, gb->pristineRomSize);
334#endif
335		gb->romVf->close(gb->romVf);
336		gb->romVf = NULL;
337	}
338	gb->isPristine = false;
339	if (gb->memory.romBase == gb->memory.rom) {
340		gb->memory.romBase = newRom;
341	}
342	gb->memory.rom = newRom;
343	gb->memory.romSize = patchedSize;
344	gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
345	gb->cpu->memory.setActiveRegion(gb->cpu, gb->cpu->pc);
346}
347
348void GBDestroy(struct GB* gb) {
349	GBUnloadROM(gb);
350
351	if (gb->biosVf) {
352		gb->biosVf->close(gb->biosVf);
353		gb->biosVf = 0;
354	}
355
356	GBMemoryDeinit(gb);
357	GBAudioDeinit(&gb->audio);
358	GBVideoDeinit(&gb->video);
359	GBSIODeinit(&gb->sio);
360	mCoreCallbacksListDeinit(&gb->coreCallbacks);
361}
362
363void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh) {
364	irqh->reset = GBReset;
365	irqh->processEvents = GBProcessEvents;
366	irqh->setInterrupts = GBSetInterrupts;
367	irqh->hitIllegal = GBIllegal;
368	irqh->stop = GBStop;
369	irqh->halt = GBHalt;
370}
371
372static uint32_t _GBBiosCRC32(struct VFile* vf) {
373	ssize_t size = vf->size(vf);
374	if (size <= 0 || size > GB_SIZE_CART_BANK0) {
375		return 0;
376	}
377	void* bios = vf->map(vf, size, MAP_READ);
378	uint32_t biosCrc = doCrc32(bios, size);
379	vf->unmap(vf, bios, size);
380	return biosCrc;
381}
382
383bool GBIsBIOS(struct VFile* vf) {
384	switch (_GBBiosCRC32(vf)) {
385	case DMG_BIOS_CHECKSUM:
386	case DMG_2_BIOS_CHECKSUM:
387	case CGB_BIOS_CHECKSUM:
388		return true;
389	default:
390		return false;
391	}
392}
393
394void GBReset(struct LR35902Core* cpu) {
395	struct GB* gb = (struct GB*) cpu->master;
396	gb->memory.romBase = gb->memory.rom;
397	GBDetectModel(gb);
398
399	if (gb->biosVf) {
400		if (!GBIsBIOS(gb->biosVf)) {
401			gb->biosVf->close(gb->biosVf);
402			gb->biosVf = NULL;
403		} else {
404			gb->biosVf->seek(gb->biosVf, 0, SEEK_SET);
405			gb->memory.romBase = malloc(GB_SIZE_CART_BANK0);
406			ssize_t size = gb->biosVf->read(gb->biosVf, gb->memory.romBase, GB_SIZE_CART_BANK0);
407			memcpy(&gb->memory.romBase[size], &gb->memory.rom[size], GB_SIZE_CART_BANK0 - size);
408			if (size > 0x100) {
409				memcpy(&gb->memory.romBase[0x100], &gb->memory.rom[0x100], sizeof(struct GBCartridge));
410			}
411
412			cpu->a = 0;
413			cpu->f.packed = 0;
414			cpu->c = 0;
415			cpu->e = 0;
416			cpu->h = 0;
417			cpu->l = 0;
418			cpu->sp = 0;
419			cpu->pc = 0;
420		}
421	}
422
423	cpu->b = 0;
424	cpu->d = 0;
425
426	if (!gb->biosVf) {
427		switch (gb->model) {
428		case GB_MODEL_DMG:
429			// TODO: SGB
430		case GB_MODEL_SGB:
431		case GB_MODEL_AUTODETECT: // Silence warnings
432			gb->model = GB_MODEL_DMG;
433			cpu->a = 1;
434			cpu->f.packed = 0xB0;
435			cpu->c = 0x13;
436			cpu->e = 0xD8;
437			cpu->h = 1;
438			cpu->l = 0x4D;
439			gb->timer.internalDiv = 0x2AF3;
440			break;
441		case GB_MODEL_AGB:
442			cpu->b = 1;
443			// Fall through
444		case GB_MODEL_CGB:
445			cpu->a = 0x11;
446			cpu->f.packed = 0x80;
447			cpu->c = 0;
448			cpu->e = 0x08;
449			cpu->h = 0;
450			cpu->l = 0x7C;
451			gb->timer.internalDiv = 0x7A8;
452			break;
453		}
454
455		cpu->sp = 0xFFFE;
456		cpu->pc = 0x100;
457	}
458
459	gb->cpuBlocked = false;
460	gb->earlyExit = false;
461	gb->doubleSpeed = 0;
462
463	cpu->memory.setActiveRegion(cpu, cpu->pc);
464
465	if (gb->yankedRomSize) {
466		gb->memory.romSize = gb->yankedRomSize;
467		gb->yankedRomSize = 0;
468	}
469
470	mTimingClear(&gb->timing);
471
472	GBMemoryReset(gb);
473	GBVideoReset(&gb->video);
474	GBTimerReset(&gb->timer);
475	mTimingSchedule(&gb->timing, &gb->timer.event, GB_DMG_DIV_PERIOD);
476
477	GBAudioReset(&gb->audio);
478	GBIOReset(gb);
479	GBSIOReset(&gb->sio);
480
481	GBSavedataUnmask(gb);
482}
483
484void GBDetectModel(struct GB* gb) {
485	if (gb->model != GB_MODEL_AUTODETECT) {
486		return;
487	}
488	if (gb->biosVf) {
489		switch (_GBBiosCRC32(gb->biosVf)) {
490		case DMG_BIOS_CHECKSUM:
491		case DMG_2_BIOS_CHECKSUM:
492			gb->model = GB_MODEL_DMG;
493			break;
494		case CGB_BIOS_CHECKSUM:
495			gb->model = GB_MODEL_CGB;
496			break;
497		default:
498			gb->biosVf->close(gb->biosVf);
499			gb->biosVf = NULL;
500		}
501	}
502	if (gb->model == GB_MODEL_AUTODETECT && gb->memory.rom) {
503		const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
504		if (cart->cgb & 0x80) {
505			gb->model = GB_MODEL_CGB;
506		} else {
507			gb->model = GB_MODEL_DMG;
508		}
509	}
510
511	switch (gb->model) {
512	case GB_MODEL_DMG:
513	case GB_MODEL_SGB:
514	case GB_MODEL_AUTODETECT: //Silence warnings
515		gb->audio.style = GB_AUDIO_DMG;
516		break;
517	case GB_MODEL_AGB:
518	case GB_MODEL_CGB:
519		gb->audio.style = GB_AUDIO_CGB;
520		break;
521	}
522}
523
524void GBUpdateIRQs(struct GB* gb) {
525	int irqs = gb->memory.ie & gb->memory.io[REG_IF];
526	if (!irqs) {
527		return;
528	}
529	gb->cpu->halted = false;
530
531	if (!gb->memory.ime || gb->cpu->irqPending) {
532		return;
533	}
534
535	if (irqs & (1 << GB_IRQ_VBLANK)) {
536		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_VBLANK);
537		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_VBLANK);
538		return;
539	}
540	if (irqs & (1 << GB_IRQ_LCDSTAT)) {
541		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_LCDSTAT);
542		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
543		return;
544	}
545	if (irqs & (1 << GB_IRQ_TIMER)) {
546		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_TIMER);
547		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_TIMER);
548		return;
549	}
550	if (irqs & (1 << GB_IRQ_SIO)) {
551		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_SIO);
552		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_SIO);
553		return;
554	}
555	if (irqs & (1 << GB_IRQ_KEYPAD)) {
556		LR35902RaiseIRQ(gb->cpu, GB_VECTOR_KEYPAD);
557		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_KEYPAD);
558	}
559}
560
561void GBProcessEvents(struct LR35902Core* cpu) {
562	struct GB* gb = (struct GB*) cpu->master;
563	do {
564		int32_t cycles = cpu->cycles;
565		int32_t nextEvent;
566
567		cpu->cycles = 0;
568		cpu->nextEvent = INT_MAX;
569
570		nextEvent = cycles;
571		do {
572			nextEvent = mTimingTick(&gb->timing, nextEvent);
573		} while (gb->cpuBlocked);
574		cpu->nextEvent = nextEvent;
575
576		if (gb->earlyExit) {
577			gb->earlyExit = false;
578			break;
579		}
580		if (cpu->halted) {
581			cpu->cycles = cpu->nextEvent;
582			if (!gb->memory.ie || !gb->memory.ime) {
583				break;
584			}
585		}
586	} while (cpu->cycles >= cpu->nextEvent);
587}
588
589void GBSetInterrupts(struct LR35902Core* cpu, bool enable) {
590	struct GB* gb = (struct GB*) cpu->master;
591	if (!enable) {
592		gb->memory.ime = enable;
593		mTimingDeschedule(&gb->timing, &gb->eiPending);
594		GBUpdateIRQs(gb);
595	} else {
596		mTimingDeschedule(&gb->timing, &gb->eiPending);
597		mTimingSchedule(&gb->timing, &gb->eiPending, 4);
598	}
599}
600
601static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate) {
602	UNUSED(timing);
603	UNUSED(cyclesLate);
604	struct GB* gb = user;
605	gb->memory.ime = true;
606	GBUpdateIRQs(gb);
607}
608
609void GBHalt(struct LR35902Core* cpu) {
610	if (!cpu->irqPending) {
611		cpu->cycles = cpu->nextEvent;
612		cpu->halted = true;
613	}
614}
615
616void GBStop(struct LR35902Core* cpu) {
617	struct GB* gb = (struct GB*) cpu->master;
618	if (cpu->bus) {
619		mLOG(GB, GAME_ERROR, "Hit illegal stop at address %04X:%02X", cpu->pc, cpu->bus);
620	}
621	if (gb->memory.io[REG_KEY1] & 1) {
622		gb->doubleSpeed ^= 1;
623		gb->audio.timingFactor = gb->doubleSpeed + 1;
624		gb->memory.io[REG_KEY1] = 0;
625		gb->memory.io[REG_KEY1] |= gb->doubleSpeed << 7;
626	} else if (cpu->bus) {
627#ifdef USE_DEBUGGERS
628		if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
629			struct mDebuggerEntryInfo info = {
630				.address = cpu->pc - 1,
631				.opcode = 0x1000 | cpu->bus
632			};
633			mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
634		}
635#endif
636		// Hang forever
637		gb->memory.ime = 0;
638		cpu->pc -= 2;
639	}
640	// TODO: Actually stop
641}
642
643void GBIllegal(struct LR35902Core* cpu) {
644	struct GB* gb = (struct GB*) cpu->master;
645	mLOG(GB, GAME_ERROR, "Hit illegal opcode at address %04X:%02X", cpu->pc, cpu->bus);
646#ifdef USE_DEBUGGERS
647	if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
648		struct mDebuggerEntryInfo info = {
649			.address = cpu->pc,
650			.opcode = cpu->bus
651		};
652		mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
653	}
654#endif
655	// Hang forever
656	gb->memory.ime = 0;
657	--cpu->pc;
658}
659
660bool GBIsROM(struct VFile* vf) {
661	vf->seek(vf, 0x104, SEEK_SET);
662	uint8_t header[4];
663
664	if (vf->read(vf, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
665		return false;
666	}
667	if (memcmp(header, _knownHeader, sizeof(header))) {
668		return false;
669	}
670	return true;
671}
672
673void GBGetGameTitle(const struct GB* gb, char* out) {
674	const struct GBCartridge* cart = NULL;
675	if (gb->memory.rom) {
676		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
677	}
678	if (!cart) {
679		return;
680	}
681	if (cart->oldLicensee != 0x33) {
682		memcpy(out, cart->titleLong, 16);
683	} else {
684		memcpy(out, cart->titleShort, 11);
685	}
686}
687
688void GBGetGameCode(const struct GB* gb, char* out) {
689	memset(out, 0, 8);
690	const struct GBCartridge* cart = NULL;
691	if (gb->memory.rom) {
692		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
693	}
694	if (!cart) {
695		return;
696	}
697	if (cart->cgb == 0xC0) {
698		memcpy(out, "CGB-????", 8);
699	} else {
700		memcpy(out, "DMG-????", 8);
701	}
702	if (cart->oldLicensee == 0x33) {
703		memcpy(&out[4], cart->maker, 4);
704	}
705}
706
707void GBFrameEnded(struct GB* gb) {
708	GBSramClean(gb, gb->video.frameCounter);
709
710	if (gb->cpu->components && gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
711		struct mCheatDevice* device = (struct mCheatDevice*) gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
712		size_t i;
713		for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
714			struct mCheatSet* cheats = *mCheatSetsGetPointer(&device->cheats, i);
715			mCheatRefresh(device, cheats);
716		}
717	}
718
719	GBTestKeypadIRQ(gb);
720}