all repos — mgba @ 35be6c121b93ef43c9249b8497121d1eb18c1d0c

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/sm83/sm83.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_SM83_FREQUENCY = 0x800000;
 23const uint32_t SGB_SM83_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 MGB_BIOS_CHECKSUM 0xE6920754
 32#define SGB_BIOS_CHECKSUM 0xEC8A83B9
 33#define SGB2_BIOS_CHECKSUM 0X53D0DD63
 34#define CGB_BIOS_CHECKSUM 0x41884E46
 35
 36mLOG_DEFINE_CATEGORY(GB, "GB", "gb");
 37
 38static void GBInit(void* cpu, struct mCPUComponent* component);
 39static void GBDeinit(struct mCPUComponent* component);
 40static void GBInterruptHandlerInit(struct SM83InterruptHandler* irqh);
 41static void GBProcessEvents(struct SM83Core* cpu);
 42static void GBSetInterrupts(struct SM83Core* cpu, bool enable);
 43static uint16_t GBIRQVector(struct SM83Core* cpu);
 44static void GBIllegal(struct SM83Core* cpu);
 45static void GBStop(struct SM83Core* cpu);
 46
 47static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate);
 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->isPristine = false;
 82	gb->pristineRomSize = 0;
 83	gb->yankedRomSize = 0;
 84
 85	mCoreCallbacksListInit(&gb->coreCallbacks, 0);
 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	gb->isPristine = true;
111	gb->memory.rom = vf->map(vf, gb->pristineRomSize, MAP_READ);
112	if (!gb->memory.rom) {
113		return false;
114	}
115	gb->yankedRomSize = 0;
116	gb->memory.romBase = gb->memory.rom;
117	gb->memory.romSize = gb->pristineRomSize;
118	gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
119	GBMBCInit(gb);
120
121	if (gb->cpu) {
122		struct SM83Core* cpu = gb->cpu;
123		cpu->memory.setActiveRegion(cpu, cpu->pc);
124	}
125
126	// TODO: error check
127	return true;
128}
129
130void GBYankROM(struct GB* gb) {
131	gb->yankedRomSize = gb->memory.romSize;
132	gb->yankedMbc = gb->memory.mbcType;
133	gb->memory.romSize = 0;
134	gb->memory.mbcType = GB_MBC_NONE;
135	gb->memory.sramAccess = false;
136
137	if (gb->cpu) {
138		struct SM83Core* cpu = gb->cpu;
139		cpu->memory.setActiveRegion(cpu, cpu->pc);
140	}
141}
142
143static void GBSramDeinit(struct GB* gb) {
144	if (gb->sramVf) {
145		gb->sramVf->unmap(gb->sramVf, gb->memory.sram, gb->sramSize);
146		if (gb->memory.mbcType == GB_MBC3_RTC && gb->sramVf == gb->sramRealVf) {
147			GBMBCRTCWrite(gb);
148		}
149		gb->sramVf = NULL;
150	} else if (gb->memory.sram) {
151		mappedMemoryFree(gb->memory.sram, gb->sramSize);
152	}
153	gb->memory.sram = 0;
154}
155
156bool GBLoadSave(struct GB* gb, struct VFile* vf) {
157	GBSramDeinit(gb);
158	gb->sramVf = vf;
159	gb->sramRealVf = vf;
160	if (gb->sramSize) {
161		GBResizeSram(gb, gb->sramSize);
162		GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
163	}
164	return vf;
165}
166
167void GBResizeSram(struct GB* gb, size_t size) {
168	if (gb->memory.sram && size <= gb->sramSize) {
169		return;
170	}
171	struct VFile* vf = gb->sramVf;
172	if (vf) {
173		if (vf == gb->sramRealVf) {
174			ssize_t vfSize = vf->size(vf);
175			if (vfSize >= 0 && (size_t) vfSize < size) {
176				uint8_t extdataBuffer[0x100];
177				if (vfSize & 0xFF) {
178					vf->seek(vf, -(vfSize & 0xFF), SEEK_END);
179					vf->read(vf, extdataBuffer, vfSize & 0xFF);
180				}
181				if (gb->memory.sram) {
182					vf->unmap(vf, gb->memory.sram, gb->sramSize);
183				}
184				vf->truncate(vf, size + (vfSize & 0xFF));
185				if (vfSize & 0xFF) {
186					vf->seek(vf, size, SEEK_SET);
187					vf->write(vf, extdataBuffer, vfSize & 0xFF);
188				}
189				gb->memory.sram = vf->map(vf, size, MAP_WRITE);
190				memset(&gb->memory.sram[vfSize], 0xFF, size - vfSize);
191			} else if (size > gb->sramSize || !gb->memory.sram) {
192				if (gb->memory.sram) {
193					vf->unmap(vf, gb->memory.sram, gb->sramSize);
194				}
195				gb->memory.sram = vf->map(vf, size, MAP_WRITE);
196			}
197		} else {
198			if (gb->memory.sram) {
199				vf->unmap(vf, gb->memory.sram, gb->sramSize);
200			}
201			gb->memory.sram = vf->map(vf, size, MAP_READ);
202		}
203		if (gb->memory.sram == (void*) -1) {
204			gb->memory.sram = NULL;
205		}
206	} else if (size) {
207		uint8_t* newSram = anonymousMemoryMap(size);
208		if (gb->memory.sram) {
209			if (size > gb->sramSize) {
210				memcpy(newSram, gb->memory.sram, gb->sramSize);
211				memset(&newSram[gb->sramSize], 0xFF, size - gb->sramSize);
212			} else {
213				memcpy(newSram, gb->memory.sram, size);
214			}
215			mappedMemoryFree(gb->memory.sram, gb->sramSize);
216		} else {
217			memset(newSram, 0xFF, size);
218		}
219		gb->memory.sram = newSram;
220	}
221	if (gb->sramSize < size) {
222		gb->sramSize = size;
223	}
224}
225
226void GBSramClean(struct GB* gb, uint32_t frameCount) {
227	// TODO: Share with GBASavedataClean
228	if (!gb->sramVf) {
229		return;
230	}
231	if (gb->sramDirty & GB_SRAM_DIRT_NEW) {
232		gb->sramDirtAge = frameCount;
233		gb->sramDirty &= ~GB_SRAM_DIRT_NEW;
234		if (!(gb->sramDirty & GB_SRAM_DIRT_SEEN)) {
235			gb->sramDirty |= GB_SRAM_DIRT_SEEN;
236		}
237	} else if ((gb->sramDirty & GB_SRAM_DIRT_SEEN) && frameCount - gb->sramDirtAge > CLEANUP_THRESHOLD) {
238		if (gb->sramMaskWriteback) {
239			GBSavedataUnmask(gb);
240		}
241		if (gb->memory.mbcType == GB_MBC3_RTC) {
242			GBMBCRTCWrite(gb);
243		}
244		gb->sramDirty = 0;
245		if (gb->memory.sram && gb->sramVf->sync(gb->sramVf, gb->memory.sram, gb->sramSize)) {
246			mLOG(GB_MEM, INFO, "Savedata synced");
247		} else {
248			mLOG(GB_MEM, INFO, "Savedata failed to sync!");
249		}
250	}
251}
252
253void GBSavedataMask(struct GB* gb, struct VFile* vf, bool writeback) {
254	struct VFile* oldVf = gb->sramVf;
255	GBSramDeinit(gb);
256	if (oldVf && oldVf != gb->sramRealVf) {
257		oldVf->close(oldVf);
258	}
259	gb->sramVf = vf;
260	gb->sramMaskWriteback = writeback;
261	gb->memory.sram = vf->map(vf, gb->sramSize, MAP_READ);
262	GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
263}
264
265void GBSavedataUnmask(struct GB* gb) {
266	if (!gb->sramRealVf || gb->sramVf == gb->sramRealVf) {
267		return;
268	}
269	struct VFile* vf = gb->sramVf;
270	GBSramDeinit(gb);
271	gb->sramVf = gb->sramRealVf;
272	gb->memory.sram = gb->sramVf->map(gb->sramVf, gb->sramSize, MAP_WRITE);
273	if (gb->sramMaskWriteback) {
274		vf->seek(vf, 0, SEEK_SET);
275		vf->read(vf, gb->memory.sram, gb->sramSize);
276		gb->sramMaskWriteback = false;
277	}
278	GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
279	vf->close(vf);
280}
281
282void GBUnloadROM(struct GB* gb) {
283	// TODO: Share with GBAUnloadROM
284	if (gb->memory.rom && gb->memory.romBase != gb->memory.rom && !gb->isPristine) {
285		free(gb->memory.romBase);
286	}
287	if (gb->memory.rom && !gb->isPristine) {
288		if (gb->yankedRomSize) {
289			gb->yankedRomSize = 0;
290		}
291		mappedMemoryFree(gb->memory.rom, GB_SIZE_CART_MAX);
292	}
293
294	if (gb->romVf) {
295#ifndef FIXED_ROM_BUFFER
296		gb->romVf->unmap(gb->romVf, gb->memory.rom, gb->pristineRomSize);
297#endif
298		gb->romVf->close(gb->romVf);
299		gb->romVf = NULL;
300	}
301	gb->memory.rom = NULL;
302	gb->memory.mbcType = GB_MBC_AUTODETECT;
303	gb->isPristine = false;
304
305	gb->sramMaskWriteback = false;
306	GBSramDeinit(gb);
307	if (gb->sramRealVf) {
308		gb->sramRealVf->close(gb->sramRealVf);
309	}
310	gb->sramRealVf = NULL;
311	gb->sramVf = NULL;
312	if (gb->memory.cam && gb->memory.cam->stopRequestImage) {
313		gb->memory.cam->stopRequestImage(gb->memory.cam);
314	}
315}
316
317void GBSynthesizeROM(struct VFile* vf) {
318	if (!vf) {
319		return;
320	}
321	const struct GBCartridge cart = {
322		.logo = { _knownHeader[0], _knownHeader[1], _knownHeader[2], _knownHeader[3]}
323	};
324
325	vf->seek(vf, 0x100, SEEK_SET);
326	vf->write(vf, &cart, sizeof(cart));
327}
328
329void GBLoadBIOS(struct GB* gb, struct VFile* vf) {
330	gb->biosVf = vf;
331}
332
333void GBApplyPatch(struct GB* gb, struct Patch* patch) {
334	size_t patchedSize = patch->outputSize(patch, gb->memory.romSize);
335	if (!patchedSize) {
336		return;
337	}
338	if (patchedSize > GB_SIZE_CART_MAX) {
339		patchedSize = GB_SIZE_CART_MAX;
340	}
341	void* newRom = anonymousMemoryMap(GB_SIZE_CART_MAX);
342	if (!patch->applyPatch(patch, gb->memory.rom, gb->pristineRomSize, newRom, patchedSize)) {
343		mappedMemoryFree(newRom, GB_SIZE_CART_MAX);
344		return;
345	}
346	if (gb->romVf) {
347#ifndef FIXED_ROM_BUFFER
348		gb->romVf->unmap(gb->romVf, gb->memory.rom, gb->pristineRomSize);
349#endif
350		gb->romVf->close(gb->romVf);
351		gb->romVf = NULL;
352	}
353	gb->isPristine = false;
354	if (gb->memory.romBase == gb->memory.rom) {
355		gb->memory.romBase = newRom;
356	}
357	gb->memory.rom = newRom;
358	gb->memory.romSize = patchedSize;
359	gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
360	gb->cpu->memory.setActiveRegion(gb->cpu, gb->cpu->pc);
361}
362
363void GBDestroy(struct GB* gb) {
364	GBUnloadROM(gb);
365
366	if (gb->biosVf) {
367		gb->biosVf->close(gb->biosVf);
368		gb->biosVf = 0;
369	}
370
371	GBMemoryDeinit(gb);
372	GBAudioDeinit(&gb->audio);
373	GBVideoDeinit(&gb->video);
374	GBSIODeinit(&gb->sio);
375	mCoreCallbacksListDeinit(&gb->coreCallbacks);
376}
377
378void GBInterruptHandlerInit(struct SM83InterruptHandler* irqh) {
379	irqh->reset = GBReset;
380	irqh->processEvents = GBProcessEvents;
381	irqh->setInterrupts = GBSetInterrupts;
382	irqh->irqVector = GBIRQVector;
383	irqh->hitIllegal = GBIllegal;
384	irqh->stop = GBStop;
385	irqh->halt = GBHalt;
386}
387
388static uint32_t _GBBiosCRC32(struct VFile* vf) {
389	ssize_t size = vf->size(vf);
390	if (size <= 0 || size > GB_SIZE_CART_BANK0) {
391		return 0;
392	}
393	void* bios = vf->map(vf, size, MAP_READ);
394	uint32_t biosCrc = doCrc32(bios, size);
395	vf->unmap(vf, bios, size);
396	return biosCrc;
397}
398
399bool GBIsBIOS(struct VFile* vf) {
400	switch (_GBBiosCRC32(vf)) {
401	case DMG_BIOS_CHECKSUM:
402	case DMG_2_BIOS_CHECKSUM:
403	case MGB_BIOS_CHECKSUM:
404	case SGB_BIOS_CHECKSUM:
405	case SGB2_BIOS_CHECKSUM:
406	case CGB_BIOS_CHECKSUM:
407		return true;
408	default:
409		return false;
410	}
411}
412
413void GBReset(struct SM83Core* cpu) {
414	struct GB* gb = (struct GB*) cpu->master;
415	gb->memory.romBase = gb->memory.rom;
416	GBDetectModel(gb);
417
418	cpu->b = 0;
419	cpu->d = 0;
420
421	gb->timer.internalDiv = 0;
422
423	gb->cpuBlocked = false;
424	gb->earlyExit = false;
425	gb->doubleSpeed = 0;
426
427	if (gb->yankedRomSize) {
428		gb->memory.romSize = gb->yankedRomSize;
429		gb->memory.mbcType = gb->yankedMbc;
430		gb->yankedRomSize = 0;
431	}
432
433	gb->sgbBit = -1;
434	gb->sgbControllers = 0;
435	gb->sgbCurrentController = 0;
436	gb->currentSgbBits = 0;
437	gb->sgbIncrement = false;
438	memset(gb->sgbPacket, 0, sizeof(gb->sgbPacket));
439
440	mTimingClear(&gb->timing);
441
442	GBMemoryReset(gb);
443
444	if (gb->biosVf) {
445		if (!GBIsBIOS(gb->biosVf)) {
446			gb->biosVf->close(gb->biosVf);
447			gb->biosVf = NULL;
448		} else {
449			GBMapBIOS(gb);
450			cpu->a = 0;
451			cpu->f.packed = 0;
452			cpu->c = 0;
453			cpu->e = 0;
454			cpu->h = 0;
455			cpu->l = 0;
456			cpu->sp = 0;
457			cpu->pc = 0;
458		}
459	}
460
461	GBVideoReset(&gb->video);
462	GBTimerReset(&gb->timer);
463	GBIOReset(gb);
464	if (!gb->biosVf) {
465		GBSkipBIOS(gb);
466	} else {
467		mTimingSchedule(&gb->timing, &gb->timer.event, 0);
468	}
469
470	GBAudioReset(&gb->audio);
471	GBSIOReset(&gb->sio);
472
473	cpu->memory.setActiveRegion(cpu, cpu->pc);
474
475	gb->sramMaskWriteback = false;
476	GBSavedataUnmask(gb);
477}
478
479void GBSkipBIOS(struct GB* gb) {
480	struct SM83Core* cpu = gb->cpu;
481	const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
482	int nextDiv = 0;
483
484	switch (gb->model) {
485	case GB_MODEL_AUTODETECT: // Silence warnings
486		gb->model = GB_MODEL_DMG;
487		// Fall through
488	case GB_MODEL_DMG:
489		cpu->a = 1;
490		cpu->f.packed = 0xB0;
491		cpu->c = 0x13;
492		cpu->e = 0xD8;
493		cpu->h = 1;
494		cpu->l = 0x4D;
495		gb->timer.internalDiv = 0xABC;
496		nextDiv = 4;
497		break;
498	case GB_MODEL_SGB:
499		cpu->a = 1;
500		cpu->f.packed = 0x00;
501		cpu->c = 0x14;
502		cpu->e = 0x00;
503		cpu->h = 0xC0;
504		cpu->l = 0x60;
505		gb->timer.internalDiv = 0xABC;
506		nextDiv = 4;
507		break;
508	case GB_MODEL_MGB:
509		cpu->a = 0xFF;
510		cpu->f.packed = 0xB0;
511		cpu->c = 0x13;
512		cpu->e = 0xD8;
513		cpu->h = 1;
514		cpu->l = 0x4D;
515		gb->timer.internalDiv = 0xABC;
516		nextDiv = 4;
517		break;
518	case GB_MODEL_SGB2:
519		cpu->a = 0xFF;
520		cpu->f.packed = 0x00;
521		cpu->c = 0x14;
522		cpu->e = 0x00;
523		cpu->h = 0xC0;
524		cpu->l = 0x60;
525		gb->timer.internalDiv = 0xABC;
526		nextDiv = 4;
527		break;
528	case GB_MODEL_AGB:
529		cpu->a = 0x11;
530		cpu->b = 1;
531		cpu->f.packed = 0x00;
532		cpu->c = 0;
533		cpu->e = 0x08;
534		cpu->h = 0;
535		cpu->l = 0x7C;
536		gb->timer.internalDiv = 0x1EA;
537		nextDiv = 0xC;
538		break;
539	case GB_MODEL_CGB:
540		cpu->a = 0x11;
541		cpu->f.packed = 0x80;
542		cpu->c = 0;
543		cpu->h = 0;
544		if (cart->cgb & 0x80) {
545			cpu->d = 0xFF;
546			cpu->e = 0x56;
547			cpu->l = 0x0D;
548		} else {
549			cpu->e = 0x08;
550			cpu->l = 0x7C;
551		}
552		gb->timer.internalDiv = 0x1EA;
553		nextDiv = 0xC;
554		break;
555	}
556
557	cpu->sp = 0xFFFE;
558	cpu->pc = 0x100;
559
560	mTimingDeschedule(&gb->timing, &gb->timer.event);
561	mTimingSchedule(&gb->timing, &gb->timer.event, 0);
562
563	GBIOWrite(gb, REG_LCDC, 0x91);
564	GBVideoSkipBIOS(&gb->video);
565
566	if (gb->biosVf) {
567		GBUnmapBIOS(gb);
568	}
569}
570
571void GBMapBIOS(struct GB* gb) {
572	gb->biosVf->seek(gb->biosVf, 0, SEEK_SET);
573	uint8_t* oldRomBase = gb->memory.romBase;
574	gb->memory.romBase = malloc(GB_SIZE_CART_BANK0);
575	ssize_t size = gb->biosVf->read(gb->biosVf, gb->memory.romBase, GB_SIZE_CART_BANK0);
576	memcpy(&gb->memory.romBase[size], &oldRomBase[size], GB_SIZE_CART_BANK0 - size);
577	if (size > 0x100) {
578		memcpy(&gb->memory.romBase[0x100], &oldRomBase[0x100], sizeof(struct GBCartridge));
579	}
580}
581
582void GBUnmapBIOS(struct GB* gb) {
583	if (gb->memory.romBase < gb->memory.rom || gb->memory.romBase > &gb->memory.rom[gb->memory.romSize - 1]) {
584		free(gb->memory.romBase);
585		if (gb->memory.mbcType == GB_MMM01) {
586			GBMBCSwitchBank0(gb, gb->memory.romSize / GB_SIZE_CART_BANK0 - 2);
587		} else {
588			GBMBCSwitchBank0(gb, 0);
589		}
590	}
591	// XXX: Force AGB registers for AGB-mode
592	if (gb->model == GB_MODEL_AGB && gb->cpu->pc == 0x100) {
593		gb->cpu->b = 1;
594	}
595}
596
597void GBDetectModel(struct GB* gb) {
598	if (gb->model != GB_MODEL_AUTODETECT) {
599		return;
600	}
601	if (gb->biosVf) {
602		switch (_GBBiosCRC32(gb->biosVf)) {
603		case DMG_BIOS_CHECKSUM:
604		case DMG_2_BIOS_CHECKSUM:
605			gb->model = GB_MODEL_DMG;
606			break;
607		case MGB_BIOS_CHECKSUM:
608			gb->model = GB_MODEL_MGB;
609			break;
610		case SGB_BIOS_CHECKSUM:
611			gb->model = GB_MODEL_SGB;
612			break;
613		case SGB2_BIOS_CHECKSUM:
614			gb->model = GB_MODEL_SGB2;
615			break;
616		case CGB_BIOS_CHECKSUM:
617			gb->model = GB_MODEL_CGB;
618			break;
619		default:
620			gb->biosVf->close(gb->biosVf);
621			gb->biosVf = NULL;
622		}
623	}
624	if (gb->model == GB_MODEL_AUTODETECT && gb->memory.rom) {
625		const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
626		if (cart->cgb & 0x80) {
627			gb->model = GB_MODEL_CGB;
628		} else if (cart->sgb == 0x03 && cart->oldLicensee == 0x33) {
629			gb->model = GB_MODEL_SGB;
630		} else {
631			gb->model = GB_MODEL_DMG;
632		}
633	}
634
635	switch (gb->model) {
636	case GB_MODEL_DMG:
637	case GB_MODEL_SGB:
638	case GB_MODEL_AUTODETECT: //Silence warnings
639		gb->audio.style = GB_AUDIO_DMG;
640		break;
641	case GB_MODEL_MGB:
642	case GB_MODEL_SGB2:
643		gb->audio.style = GB_AUDIO_MGB;
644		break;
645	case GB_MODEL_AGB:
646	case GB_MODEL_CGB:
647		gb->audio.style = GB_AUDIO_CGB;
648		break;
649	}
650}
651
652void GBUpdateIRQs(struct GB* gb) {
653	int irqs = gb->memory.ie & gb->memory.io[REG_IF] & 0x1F;
654	if (!irqs) {
655		gb->cpu->irqPending = false;
656		return;
657	}
658	gb->cpu->halted = false;
659
660	if (!gb->memory.ime) {
661		gb->cpu->irqPending = false;
662		return;
663	}
664	if (gb->cpu->irqPending) {
665		return;
666	}
667	SM83RaiseIRQ(gb->cpu);
668}
669
670void GBProcessEvents(struct SM83Core* cpu) {
671	struct GB* gb = (struct GB*) cpu->master;
672	do {
673		int32_t cycles = cpu->cycles;
674		int32_t nextEvent;
675
676		cpu->cycles = 0;
677#ifdef USE_DEBUGGERS
678		gb->timing.globalCycles += cycles;
679#endif
680		cpu->nextEvent = INT_MAX;
681
682		nextEvent = cycles;
683		do {
684			nextEvent = mTimingTick(&gb->timing, nextEvent);
685		} while (gb->cpuBlocked);
686		cpu->nextEvent = nextEvent;
687
688		if (cpu->halted) {
689			cpu->cycles = cpu->nextEvent;
690			if (!gb->memory.ie || !gb->memory.ime) {
691				break;
692			}
693		}
694		if (gb->earlyExit) {
695			break;
696		}
697	} while (cpu->cycles >= cpu->nextEvent);
698	gb->earlyExit = false;
699}
700
701void GBSetInterrupts(struct SM83Core* cpu, bool enable) {
702	struct GB* gb = (struct GB*) cpu->master;
703	mTimingDeschedule(&gb->timing, &gb->eiPending);
704	if (!enable) {
705		gb->memory.ime = false;
706		GBUpdateIRQs(gb);
707	} else {
708		mTimingSchedule(&gb->timing, &gb->eiPending, 4);
709	}
710}
711
712uint16_t GBIRQVector(struct SM83Core* cpu) {
713	struct GB* gb = (struct GB*) cpu->master;
714	int irqs = gb->memory.ie & gb->memory.io[REG_IF];
715
716	if (irqs & (1 << GB_IRQ_VBLANK)) {
717		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_VBLANK);
718		return GB_VECTOR_VBLANK;
719	}
720	if (irqs & (1 << GB_IRQ_LCDSTAT)) {
721		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
722		return GB_VECTOR_LCDSTAT;
723	}
724	if (irqs & (1 << GB_IRQ_TIMER)) {
725		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_TIMER);
726		return GB_VECTOR_TIMER;
727	}
728	if (irqs & (1 << GB_IRQ_SIO)) {
729		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_SIO);
730		return GB_VECTOR_SIO;
731	}
732	if (irqs & (1 << GB_IRQ_KEYPAD)) {
733		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_KEYPAD);
734		return GB_VECTOR_KEYPAD;
735	}
736	return 0;
737}
738
739static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate) {
740	UNUSED(timing);
741	UNUSED(cyclesLate);
742	struct GB* gb = user;
743	gb->memory.ime = true;
744	GBUpdateIRQs(gb);
745}
746
747void GBHalt(struct SM83Core* cpu) {
748	struct GB* gb = (struct GB*) cpu->master;
749	if (!(gb->memory.ie & gb->memory.io[REG_IF] & 0x1F)) {
750		cpu->cycles = cpu->nextEvent;
751		cpu->halted = true;
752	} else if (!gb->memory.ime) {
753		mLOG(GB, GAME_ERROR, "HALT bug");
754		cpu->executionState = SM83_CORE_HALT_BUG;
755	}
756}
757
758void GBStop(struct SM83Core* cpu) {
759	struct GB* gb = (struct GB*) cpu->master;
760	if (cpu->bus) {
761		mLOG(GB, GAME_ERROR, "Hit illegal stop at address %04X:%02X", cpu->pc, cpu->bus);
762	}
763	if (gb->memory.io[REG_KEY1] & 1) {
764		gb->doubleSpeed ^= 1;
765		gb->audio.timingFactor = gb->doubleSpeed + 1;
766		gb->memory.io[REG_KEY1] = 0;
767		gb->memory.io[REG_KEY1] |= gb->doubleSpeed << 7;
768	} else if (cpu->bus) {
769#ifdef USE_DEBUGGERS
770		if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
771			struct mDebuggerEntryInfo info = {
772				.address = cpu->pc - 1,
773				.type.bp.opcode = 0x1000 | cpu->bus,
774			};
775			mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
776		}
777#endif
778		// Hang forever
779		gb->memory.ime = 0;
780		cpu->pc -= 2;
781	}
782	// TODO: Actually stop
783}
784
785void GBIllegal(struct SM83Core* cpu) {
786	struct GB* gb = (struct GB*) cpu->master;
787	mLOG(GB, GAME_ERROR, "Hit illegal opcode at address %04X:%02X", cpu->pc, cpu->bus);
788#ifdef USE_DEBUGGERS
789	if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
790		struct mDebuggerEntryInfo info = {
791			.address = cpu->pc,
792			.type.bp.opcode = cpu->bus
793		};
794		mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
795	}
796#endif
797	// Hang forever
798	gb->memory.ime = 0;
799	--cpu->pc;
800}
801
802bool GBIsROM(struct VFile* vf) {
803	if (!vf) {
804		return false;
805	}
806	vf->seek(vf, 0x104, SEEK_SET);
807	uint8_t header[4];
808
809	if (vf->read(vf, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
810		return false;
811	}
812	if (memcmp(header, _knownHeader, sizeof(header))) {
813		return false;
814	}
815	return true;
816}
817
818void GBGetGameTitle(const struct GB* gb, char* out) {
819	const struct GBCartridge* cart = NULL;
820	if (gb->memory.rom) {
821		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
822	}
823	if (!cart) {
824		return;
825	}
826	if (cart->oldLicensee != 0x33) {
827		memcpy(out, cart->titleLong, 16);
828	} else {
829		memcpy(out, cart->titleShort, 11);
830	}
831}
832
833void GBGetGameCode(const struct GB* gb, char* out) {
834	memset(out, 0, 8);
835	const struct GBCartridge* cart = NULL;
836	if (gb->memory.rom) {
837		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
838	}
839	if (!cart) {
840		return;
841	}
842	if (cart->cgb == 0xC0) {
843		memcpy(out, "CGB-????", 8);
844	} else {
845		memcpy(out, "DMG-????", 8);
846	}
847	if (cart->oldLicensee == 0x33) {
848		memcpy(&out[4], cart->maker, 4);
849	}
850}
851
852void GBFrameStarted(struct GB* gb) {
853	GBTestKeypadIRQ(gb);
854
855	size_t c;
856	for (c = 0; c < mCoreCallbacksListSize(&gb->coreCallbacks); ++c) {
857		struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gb->coreCallbacks, c);
858		if (callbacks->videoFrameStarted) {
859			callbacks->videoFrameStarted(callbacks->context);
860		}
861	}
862}
863
864void GBFrameEnded(struct GB* gb) {
865	GBSramClean(gb, gb->video.frameCounter);
866
867	if (gb->cpu->components && gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
868		struct mCheatDevice* device = (struct mCheatDevice*) gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
869		size_t i;
870		for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
871			struct mCheatSet* cheats = *mCheatSetsGetPointer(&device->cheats, i);
872			mCheatRefresh(device, cheats);
873		}
874	}
875
876	// TODO: Move to common code
877	if (gb->stream && gb->stream->postVideoFrame) {
878		const color_t* pixels;
879		size_t stride;
880		gb->video.renderer->getPixels(gb->video.renderer, &stride, (const void**) &pixels);
881		gb->stream->postVideoFrame(gb->stream, pixels, stride);
882	}
883
884	size_t c;
885	for (c = 0; c < mCoreCallbacksListSize(&gb->coreCallbacks); ++c) {
886		struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gb->coreCallbacks, c);
887		if (callbacks->videoFrameEnded) {
888			callbacks->videoFrameEnded(callbacks->context);
889		}
890	}
891}
892
893enum GBModel GBNameToModel(const char* model) {
894	if (strcasecmp(model, "DMG") == 0) {
895		return GB_MODEL_DMG;
896	} else if (strcasecmp(model, "CGB") == 0) {
897		return GB_MODEL_CGB;
898	} else if (strcasecmp(model, "AGB") == 0) {
899		return GB_MODEL_AGB;
900	} else if (strcasecmp(model, "SGB") == 0) {
901		return GB_MODEL_SGB;
902	} else if (strcasecmp(model, "MGB") == 0) {
903		return GB_MODEL_MGB;
904	} else if (strcasecmp(model, "SGB2") == 0) {
905		return GB_MODEL_SGB2;
906	}
907	return GB_MODEL_AUTODETECT;
908}
909
910const char* GBModelToName(enum GBModel model) {
911	switch (model) {
912	case GB_MODEL_DMG:
913		return "DMG";
914	case GB_MODEL_SGB:
915		return "SGB";
916	case GB_MODEL_MGB:
917		return "MGB";
918	case GB_MODEL_SGB2:
919		return "SGB2";
920	case GB_MODEL_CGB:
921		return "CGB";
922	case GB_MODEL_AGB:
923		return "AGB";
924	default:
925	case GB_MODEL_AUTODETECT:
926		return NULL;
927	}
928}