all repos — mgba @ ce2732823985041f17107a4178d43ac3234ea1f7

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 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 LR35902InterruptHandler* irqh);
 41static void GBProcessEvents(struct LR35902Core* cpu);
 42static void GBSetInterrupts(struct LR35902Core* cpu, bool enable);
 43static uint16_t GBIRQVector(struct LR35902Core* cpu);
 44static void GBIllegal(struct LR35902Core* cpu);
 45static void GBStop(struct LR35902Core* cpu);
 46
 47static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate);
 48
 49#ifdef FIXED_ROM_BUFFER
 50extern uint32_t* romBuffer;
 51extern size_t romBufferSize;
 52#endif
 53
 54void GBCreate(struct GB* gb) {
 55	gb->d.id = GB_COMPONENT_MAGIC;
 56	gb->d.init = GBInit;
 57	gb->d.deinit = GBDeinit;
 58}
 59
 60static void GBInit(void* cpu, struct mCPUComponent* component) {
 61	struct GB* gb = (struct GB*) component;
 62	gb->cpu = cpu;
 63	gb->sync = NULL;
 64
 65	GBInterruptHandlerInit(&gb->cpu->irqh);
 66	GBMemoryInit(gb);
 67
 68	gb->video.p = gb;
 69	GBVideoInit(&gb->video);
 70
 71	gb->audio.p = gb;
 72	GBAudioInit(&gb->audio, 2048, &gb->memory.io[REG_NR52], GB_AUDIO_DMG); // TODO: Remove magic constant
 73
 74	gb->sio.p = gb;
 75	GBSIOInit(&gb->sio);
 76
 77	gb->timer.p = gb;
 78
 79	gb->model = GB_MODEL_AUTODETECT;
 80
 81	gb->biosVf = NULL;
 82	gb->romVf = NULL;
 83	gb->sramVf = NULL;
 84	gb->sramRealVf = NULL;
 85
 86	gb->isPristine = false;
 87	gb->pristineRomSize = 0;
 88	gb->yankedRomSize = 0;
 89
 90	mCoreCallbacksListInit(&gb->coreCallbacks, 0);
 91	gb->stream = NULL;
 92
 93	mTimingInit(&gb->timing, &gb->cpu->cycles, &gb->cpu->nextEvent);
 94	gb->audio.timing = &gb->timing;
 95
 96	gb->eiPending.name = "GB EI";
 97	gb->eiPending.callback = _enableInterrupts;
 98	gb->eiPending.context = gb;
 99	gb->eiPending.priority = 0;
100}
101
102static void GBDeinit(struct mCPUComponent* component) {
103	struct GB* gb = (struct GB*) component;
104	mTimingDeinit(&gb->timing);
105}
106
107bool GBLoadROM(struct GB* gb, struct VFile* vf) {
108	if (!vf) {
109		return false;
110	}
111	GBUnloadROM(gb);
112	gb->romVf = vf;
113	gb->pristineRomSize = vf->size(vf);
114	vf->seek(vf, 0, SEEK_SET);
115	gb->isPristine = true;
116#ifdef FIXED_ROM_BUFFER
117	if (gb->pristineRomSize <= romBufferSize) {
118		gb->memory.rom = romBuffer;
119		vf->read(vf, romBuffer, gb->pristineRomSize);
120	}
121#else
122	gb->memory.rom = vf->map(vf, gb->pristineRomSize, MAP_READ);
123#endif
124	if (!gb->memory.rom) {
125		return false;
126	}
127	gb->yankedRomSize = 0;
128	gb->memory.romBase = gb->memory.rom;
129	gb->memory.romSize = gb->pristineRomSize;
130	gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
131	GBMBCInit(gb);
132
133	if (gb->cpu) {
134		struct LR35902Core* cpu = gb->cpu;
135		cpu->memory.setActiveRegion(cpu, cpu->pc);
136	}
137
138	// TODO: error check
139	return true;
140}
141
142static void GBSramDeinit(struct GB* gb) {
143	if (gb->sramVf) {
144		gb->sramVf->unmap(gb->sramVf, gb->memory.sram, gb->sramSize);
145		if (gb->memory.mbcType == GB_MBC3_RTC && gb->sramVf == gb->sramRealVf) {
146			GBMBCRTCWrite(gb);
147		}
148		gb->sramVf = NULL;
149	} else if (gb->memory.sram) {
150		mappedMemoryFree(gb->memory.sram, gb->sramSize);
151	}
152	gb->memory.sram = 0;
153}
154
155bool GBLoadSave(struct GB* gb, struct VFile* vf) {
156	GBSramDeinit(gb);
157	gb->sramVf = vf;
158	gb->sramRealVf = vf;
159	if (gb->sramSize) {
160		GBResizeSram(gb, gb->sramSize);
161		GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
162	}
163	return vf;
164}
165
166void GBResizeSram(struct GB* gb, size_t size) {
167	if (gb->memory.sram && size <= gb->sramSize) {
168		return;
169	}
170	struct VFile* vf = gb->sramVf;
171	if (vf) {
172		if (vf == gb->sramRealVf) {
173			ssize_t vfSize = vf->size(vf);
174			if (vfSize >= 0 && (size_t) vfSize < size) {
175				uint8_t extdataBuffer[0x100];
176				if (vfSize & 0xFF) {
177					vf->seek(vf, -(vfSize & 0xFF), SEEK_END);
178					vf->read(vf, extdataBuffer, vfSize & 0xFF);
179				}
180				if (gb->memory.sram) {
181					vf->unmap(vf, gb->memory.sram, gb->sramSize);
182				}
183				vf->truncate(vf, size + (vfSize & 0xFF));
184				if (vfSize & 0xFF) {
185					vf->seek(vf, size, SEEK_SET);
186					vf->write(vf, extdataBuffer, vfSize & 0xFF);
187				}
188				gb->memory.sram = vf->map(vf, size, MAP_WRITE);
189				memset(&gb->memory.sram[gb->sramSize], 0xFF, size - gb->sramSize);
190			} else if (size > gb->sramSize || !gb->memory.sram) {
191				if (gb->memory.sram) {
192					vf->unmap(vf, gb->memory.sram, gb->sramSize);
193				}
194				gb->memory.sram = vf->map(vf, size, MAP_WRITE);
195			}
196		} else {
197			if (gb->memory.sram) {
198				vf->unmap(vf, gb->memory.sram, gb->sramSize);
199			}
200			gb->memory.sram = vf->map(vf, size, MAP_READ);
201		}
202		if (gb->memory.sram == (void*) -1) {
203			gb->memory.sram = NULL;
204		}
205	} else if (size) {
206		uint8_t* newSram = anonymousMemoryMap(size);
207		if (gb->memory.sram) {
208			if (size > gb->sramSize) {
209				memcpy(newSram, gb->memory.sram, gb->sramSize);
210				memset(&newSram[gb->sramSize], 0xFF, size - gb->sramSize);
211			} else {
212				memcpy(newSram, gb->memory.sram, size);
213			}
214			mappedMemoryFree(gb->memory.sram, gb->sramSize);
215		} else {
216			memset(newSram, 0xFF, size);
217		}
218		gb->memory.sram = newSram;
219	}
220	if (gb->sramSize < size) {
221		gb->sramSize = size;
222	}
223}
224
225void GBSramClean(struct GB* gb, uint32_t frameCount) {
226	// TODO: Share with GBASavedataClean
227	if (!gb->sramVf) {
228		return;
229	}
230	if (gb->sramDirty & GB_SRAM_DIRT_NEW) {
231		gb->sramDirtAge = frameCount;
232		gb->sramDirty &= ~GB_SRAM_DIRT_NEW;
233		if (!(gb->sramDirty & GB_SRAM_DIRT_SEEN)) {
234			gb->sramDirty |= GB_SRAM_DIRT_SEEN;
235		}
236	} else if ((gb->sramDirty & GB_SRAM_DIRT_SEEN) && frameCount - gb->sramDirtAge > CLEANUP_THRESHOLD) {
237		if (gb->sramMaskWriteback) {
238			GBSavedataUnmask(gb);
239		}
240		if (gb->memory.mbcType == GB_MBC3_RTC) {
241			GBMBCRTCWrite(gb);
242		}
243		gb->sramDirty = 0;
244		if (gb->memory.sram && gb->sramVf->sync(gb->sramVf, gb->memory.sram, gb->sramSize)) {
245			mLOG(GB_MEM, INFO, "Savedata synced");
246		} else {
247			mLOG(GB_MEM, INFO, "Savedata failed to sync!");
248		}
249	}
250}
251
252void GBSavedataMask(struct GB* gb, struct VFile* vf, bool writeback) {
253	struct VFile* oldVf = gb->sramVf;
254	GBSramDeinit(gb);
255	if (oldVf && oldVf != gb->sramRealVf) {
256		oldVf->close(oldVf);
257	}
258	gb->sramVf = vf;
259	gb->sramMaskWriteback = writeback;
260	gb->memory.sram = vf->map(vf, gb->sramSize, MAP_READ);
261	GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
262}
263
264void GBSavedataUnmask(struct GB* gb) {
265	if (!gb->sramRealVf || gb->sramVf == gb->sramRealVf) {
266		return;
267	}
268	struct VFile* vf = gb->sramVf;
269	GBSramDeinit(gb);
270	gb->sramVf = gb->sramRealVf;
271	gb->memory.sram = gb->sramVf->map(gb->sramVf, gb->sramSize, MAP_WRITE);
272	if (gb->sramMaskWriteback) {
273		vf->seek(vf, 0, SEEK_SET);
274		vf->read(vf, gb->memory.sram, gb->sramSize);
275		gb->sramMaskWriteback = false;
276	}
277	GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
278	vf->close(vf);
279}
280
281void GBUnloadROM(struct GB* gb) {
282	// TODO: Share with GBAUnloadROM
283	if (gb->memory.rom && gb->memory.romBase != gb->memory.rom && !gb->isPristine) {
284		free(gb->memory.romBase);
285	}
286	if (gb->memory.rom && !gb->isPristine) {
287		if (gb->yankedRomSize) {
288			gb->yankedRomSize = 0;
289		}
290		mappedMemoryFree(gb->memory.rom, GB_SIZE_CART_MAX);
291	}
292
293	if (gb->romVf) {
294#ifndef FIXED_ROM_BUFFER
295		gb->romVf->unmap(gb->romVf, gb->memory.rom, gb->pristineRomSize);
296#endif
297		gb->romVf->close(gb->romVf);
298		gb->romVf = NULL;
299	}
300	gb->memory.rom = NULL;
301	gb->memory.mbcType = GB_MBC_AUTODETECT;
302	gb->isPristine = false;
303
304	gb->sramMaskWriteback = false;
305	GBSramDeinit(gb);
306	if (gb->sramRealVf) {
307		gb->sramRealVf->close(gb->sramRealVf);
308	}
309	gb->sramRealVf = NULL;
310	gb->sramVf = NULL;
311	if (gb->memory.cam && gb->memory.cam->stopRequestImage) {
312		gb->memory.cam->stopRequestImage(gb->memory.cam);
313	}
314}
315
316void GBSynthesizeROM(struct VFile* vf) {
317	if (!vf) {
318		return;
319	}
320	const struct GBCartridge cart = {
321		.logo = { _knownHeader[0], _knownHeader[1], _knownHeader[2], _knownHeader[3]}
322	};
323
324	vf->seek(vf, 0x100, SEEK_SET);
325	vf->write(vf, &cart, sizeof(cart));
326}
327
328void GBLoadBIOS(struct GB* gb, struct VFile* vf) {
329	gb->biosVf = vf;
330}
331
332void GBApplyPatch(struct GB* gb, struct Patch* patch) {
333	size_t patchedSize = patch->outputSize(patch, gb->memory.romSize);
334	if (!patchedSize) {
335		return;
336	}
337	if (patchedSize > GB_SIZE_CART_MAX) {
338		patchedSize = GB_SIZE_CART_MAX;
339	}
340	void* newRom = anonymousMemoryMap(GB_SIZE_CART_MAX);
341	if (!patch->applyPatch(patch, gb->memory.rom, gb->pristineRomSize, newRom, patchedSize)) {
342		mappedMemoryFree(newRom, GB_SIZE_CART_MAX);
343		return;
344	}
345	if (gb->romVf) {
346#ifndef FIXED_ROM_BUFFER
347		gb->romVf->unmap(gb->romVf, gb->memory.rom, gb->pristineRomSize);
348#endif
349		gb->romVf->close(gb->romVf);
350		gb->romVf = NULL;
351	}
352	gb->isPristine = false;
353	if (gb->memory.romBase == gb->memory.rom) {
354		gb->memory.romBase = newRom;
355	}
356	gb->memory.rom = newRom;
357	gb->memory.romSize = patchedSize;
358	gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
359	gb->cpu->memory.setActiveRegion(gb->cpu, gb->cpu->pc);
360}
361
362void GBDestroy(struct GB* gb) {
363	GBUnloadROM(gb);
364
365	if (gb->biosVf) {
366		gb->biosVf->close(gb->biosVf);
367		gb->biosVf = 0;
368	}
369
370	GBMemoryDeinit(gb);
371	GBAudioDeinit(&gb->audio);
372	GBVideoDeinit(&gb->video);
373	GBSIODeinit(&gb->sio);
374	mCoreCallbacksListDeinit(&gb->coreCallbacks);
375}
376
377void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh) {
378	irqh->reset = GBReset;
379	irqh->processEvents = GBProcessEvents;
380	irqh->setInterrupts = GBSetInterrupts;
381	irqh->irqVector = GBIRQVector;
382	irqh->hitIllegal = GBIllegal;
383	irqh->stop = GBStop;
384	irqh->halt = GBHalt;
385}
386
387static uint32_t _GBBiosCRC32(struct VFile* vf) {
388	ssize_t size = vf->size(vf);
389	if (size <= 0 || size > GB_SIZE_CART_BANK0) {
390		return 0;
391	}
392	void* bios = vf->map(vf, size, MAP_READ);
393	uint32_t biosCrc = doCrc32(bios, size);
394	vf->unmap(vf, bios, size);
395	return biosCrc;
396}
397
398bool GBIsBIOS(struct VFile* vf) {
399	switch (_GBBiosCRC32(vf)) {
400	case DMG_BIOS_CHECKSUM:
401	case DMG_2_BIOS_CHECKSUM:
402	case MGB_BIOS_CHECKSUM:
403	case SGB_BIOS_CHECKSUM:
404	case SGB2_BIOS_CHECKSUM:
405	case CGB_BIOS_CHECKSUM:
406		return true;
407	default:
408		return false;
409	}
410}
411
412void GBReset(struct LR35902Core* cpu) {
413	struct GB* gb = (struct GB*) cpu->master;
414	gb->memory.romBase = gb->memory.rom;
415	GBDetectModel(gb);
416
417	if (gb->biosVf) {
418		if (!GBIsBIOS(gb->biosVf)) {
419			gb->biosVf->close(gb->biosVf);
420			gb->biosVf = NULL;
421		} else {
422			gb->biosVf->seek(gb->biosVf, 0, SEEK_SET);
423			gb->memory.romBase = malloc(GB_SIZE_CART_BANK0);
424			ssize_t size = gb->biosVf->read(gb->biosVf, gb->memory.romBase, GB_SIZE_CART_BANK0);
425			memcpy(&gb->memory.romBase[size], &gb->memory.rom[size], GB_SIZE_CART_BANK0 - size);
426			if (size > 0x100) {
427				memcpy(&gb->memory.romBase[0x100], &gb->memory.rom[0x100], sizeof(struct GBCartridge));
428			}
429
430			cpu->a = 0;
431			cpu->f.packed = 0;
432			cpu->c = 0;
433			cpu->e = 0;
434			cpu->h = 0;
435			cpu->l = 0;
436			cpu->sp = 0;
437			cpu->pc = 0;
438		}
439	}
440
441	cpu->b = 0;
442	cpu->d = 0;
443
444	gb->timer.internalDiv = 0;
445
446	gb->cpuBlocked = false;
447	gb->earlyExit = false;
448	gb->doubleSpeed = 0;
449
450	if (gb->yankedRomSize) {
451		gb->memory.romSize = gb->yankedRomSize;
452		gb->yankedRomSize = 0;
453	}
454
455	gb->sgbBit = -1;
456	gb->sgbControllers = 0;
457	gb->sgbCurrentController = 0;
458	gb->currentSgbBits = 0;
459	memset(gb->sgbPacket, 0, sizeof(gb->sgbPacket));
460
461	mTimingClear(&gb->timing);
462
463	GBMemoryReset(gb);
464	GBVideoReset(&gb->video);
465	GBTimerReset(&gb->timer);
466	if (!gb->biosVf) {
467		GBSkipBIOS(gb);
468	} else {
469		mTimingSchedule(&gb->timing, &gb->timer.event, 0);
470	}
471
472	GBIOReset(gb);
473	GBAudioReset(&gb->audio);
474	GBSIOReset(&gb->sio);
475
476	cpu->memory.setActiveRegion(cpu, cpu->pc);
477
478	gb->sramMaskWriteback = false;
479	GBSavedataUnmask(gb);
480}
481
482void GBSkipBIOS(struct GB* gb) {
483	struct LR35902Core* cpu = gb->cpu;
484	int nextDiv = 0;
485
486	switch (gb->model) {
487	case GB_MODEL_AUTODETECT: // Silence warnings
488		gb->model = GB_MODEL_DMG;
489		// Fall through
490	case GB_MODEL_DMG:
491		cpu->a = 1;
492		cpu->f.packed = 0xB0;
493		cpu->c = 0x13;
494		cpu->e = 0xD8;
495		cpu->h = 1;
496		cpu->l = 0x4D;
497		gb->timer.internalDiv = 0xABC;
498		nextDiv = 4;
499		break;
500	case GB_MODEL_SGB:
501		cpu->a = 1;
502		cpu->f.packed = 0x00;
503		cpu->c = 0x14;
504		cpu->e = 0x00;
505		cpu->h = 0xC0;
506		cpu->l = 0x60;
507		gb->timer.internalDiv = 0xABC;
508		nextDiv = 4;
509		break;
510	case GB_MODEL_MGB:
511		cpu->a = 0xFF;
512		cpu->f.packed = 0xB0;
513		cpu->c = 0x13;
514		cpu->e = 0xD8;
515		cpu->h = 1;
516		cpu->l = 0x4D;
517		gb->timer.internalDiv = 0xABC;
518		nextDiv = 4;
519		break;
520	case GB_MODEL_SGB2:
521		cpu->a = 0xFF;
522		cpu->f.packed = 0x00;
523		cpu->c = 0x14;
524		cpu->e = 0x00;
525		cpu->h = 0xC0;
526		cpu->l = 0x60;
527		gb->timer.internalDiv = 0xABC;
528		nextDiv = 4;
529		break;
530	case GB_MODEL_AGB:
531		cpu->a = 0x11;
532		cpu->b = 1;
533		cpu->f.packed = 0x00;
534		cpu->c = 0;
535		cpu->e = 0x08;
536		cpu->h = 0;
537		cpu->l = 0x7C;
538		gb->timer.internalDiv = 0x1EA;
539		nextDiv = 0xC;
540		break;
541	case GB_MODEL_CGB:
542		cpu->a = 0x11;
543		cpu->f.packed = 0x80;
544		cpu->c = 0;
545		cpu->e = 0x08;
546		cpu->h = 0;
547		cpu->l = 0x7C;
548		gb->timer.internalDiv = 0x1EA;
549		nextDiv = 0xC;
550		break;
551	}
552
553	cpu->sp = 0xFFFE;
554	cpu->pc = 0x100;
555
556	mTimingDeschedule(&gb->timing, &gb->timer.event);
557	mTimingSchedule(&gb->timing, &gb->timer.event, 0);
558
559	GBIOWrite(gb, REG_LCDC, 0x91);
560
561	if (gb->biosVf) {
562		GBUnmapBIOS(gb);
563	}
564}
565
566void GBUnmapBIOS(struct GB* gb) {
567	if (gb->memory.romBase < gb->memory.rom || gb->memory.romBase > &gb->memory.rom[gb->memory.romSize - 1]) {
568		free(gb->memory.romBase);
569		gb->memory.romBase = gb->memory.rom;
570	}
571	// XXX: Force AGB registers for AGB-mode
572	if (gb->model == GB_MODEL_AGB && gb->cpu->pc == 0x100) {
573		gb->cpu->b = 1;
574	}
575}
576
577void GBDetectModel(struct GB* gb) {
578	if (gb->model != GB_MODEL_AUTODETECT) {
579		return;
580	}
581	if (gb->biosVf) {
582		switch (_GBBiosCRC32(gb->biosVf)) {
583		case DMG_BIOS_CHECKSUM:
584		case DMG_2_BIOS_CHECKSUM:
585			gb->model = GB_MODEL_DMG;
586			break;
587		case MGB_BIOS_CHECKSUM:
588			gb->model = GB_MODEL_MGB;
589			break;
590		case SGB_BIOS_CHECKSUM:
591			gb->model = GB_MODEL_SGB;
592			break;
593		case SGB2_BIOS_CHECKSUM:
594			gb->model = GB_MODEL_SGB2;
595			break;
596		case CGB_BIOS_CHECKSUM:
597			gb->model = GB_MODEL_CGB;
598			break;
599		default:
600			gb->biosVf->close(gb->biosVf);
601			gb->biosVf = NULL;
602		}
603	}
604	if (gb->model == GB_MODEL_AUTODETECT && gb->memory.rom) {
605		const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
606		if (cart->cgb & 0x80) {
607			gb->model = GB_MODEL_CGB;
608		} else if (cart->sgb == 0x03 && cart->oldLicensee == 0x33) {
609			gb->model = GB_MODEL_SGB;
610		} else {
611			gb->model = GB_MODEL_DMG;
612		}
613	}
614
615	switch (gb->model) {
616	case GB_MODEL_DMG:
617	case GB_MODEL_SGB:
618	case GB_MODEL_AUTODETECT: //Silence warnings
619		gb->audio.style = GB_AUDIO_DMG;
620		break;
621	case GB_MODEL_MGB:
622	case GB_MODEL_SGB2:
623		gb->audio.style = GB_AUDIO_MGB;
624		break;
625	case GB_MODEL_AGB:
626	case GB_MODEL_CGB:
627		gb->audio.style = GB_AUDIO_CGB;
628		break;
629	}
630}
631
632void GBUpdateIRQs(struct GB* gb) {
633	int irqs = gb->memory.ie & gb->memory.io[REG_IF];
634	if (!irqs) {
635		gb->cpu->irqPending = false;
636		return;
637	}
638	gb->cpu->halted = false;
639
640	if (!gb->memory.ime) {
641		gb->cpu->irqPending = false;
642		return;
643	}
644	if (gb->cpu->irqPending) {
645		return;
646	}
647	LR35902RaiseIRQ(gb->cpu);
648}
649
650void GBProcessEvents(struct LR35902Core* cpu) {
651	struct GB* gb = (struct GB*) cpu->master;
652	do {
653		int32_t cycles = cpu->cycles;
654		int32_t nextEvent;
655
656		cpu->cycles = 0;
657		cpu->nextEvent = INT_MAX;
658
659		nextEvent = cycles;
660		do {
661			nextEvent = mTimingTick(&gb->timing, nextEvent);
662		} while (gb->cpuBlocked);
663		cpu->nextEvent = nextEvent;
664
665		if (cpu->halted) {
666			cpu->cycles = cpu->nextEvent;
667			if (!gb->memory.ie || !gb->memory.ime) {
668				break;
669			}
670		}
671		if (gb->earlyExit) {
672			break;
673		}
674	} while (cpu->cycles >= cpu->nextEvent);
675	gb->earlyExit = false;
676}
677
678void GBSetInterrupts(struct LR35902Core* cpu, bool enable) {
679	struct GB* gb = (struct GB*) cpu->master;
680	mTimingDeschedule(&gb->timing, &gb->eiPending);
681	if (!enable) {
682		gb->memory.ime = false;
683		GBUpdateIRQs(gb);
684	} else {
685		mTimingSchedule(&gb->timing, &gb->eiPending, 4);
686	}
687}
688
689uint16_t GBIRQVector(struct LR35902Core* cpu) {
690	struct GB* gb = (struct GB*) cpu->master;
691	int irqs = gb->memory.ie & gb->memory.io[REG_IF];
692
693	if (irqs & (1 << GB_IRQ_VBLANK)) {
694		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_VBLANK);
695		return GB_VECTOR_VBLANK;
696	}
697	if (irqs & (1 << GB_IRQ_LCDSTAT)) {
698		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
699		return GB_VECTOR_LCDSTAT;
700	}
701	if (irqs & (1 << GB_IRQ_TIMER)) {
702		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_TIMER);
703		return GB_VECTOR_TIMER;
704	}
705	if (irqs & (1 << GB_IRQ_SIO)) {
706		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_SIO);
707		return GB_VECTOR_SIO;
708	}
709	if (irqs & (1 << GB_IRQ_KEYPAD)) {
710		gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_KEYPAD);
711		return GB_VECTOR_KEYPAD;
712	}
713	return 0;
714}
715
716static void _enableInterrupts(struct mTiming* timing, void* user, uint32_t cyclesLate) {
717	UNUSED(timing);
718	UNUSED(cyclesLate);
719	struct GB* gb = user;
720	gb->memory.ime = true;
721	GBUpdateIRQs(gb);
722}
723
724void GBHalt(struct LR35902Core* cpu) {
725	struct GB* gb = (struct GB*) cpu->master;
726	if (!(gb->memory.ie & gb->memory.io[REG_IF])) {
727		cpu->cycles = cpu->nextEvent;
728		cpu->halted = true;
729	} else if (gb->model < GB_MODEL_CGB) {
730		mLOG(GB, STUB, "Unimplemented HALT bug");
731	}
732}
733
734void GBStop(struct LR35902Core* cpu) {
735	struct GB* gb = (struct GB*) cpu->master;
736	if (cpu->bus) {
737		mLOG(GB, GAME_ERROR, "Hit illegal stop at address %04X:%02X", cpu->pc, cpu->bus);
738	}
739	if (gb->memory.io[REG_KEY1] & 1) {
740		gb->doubleSpeed ^= 1;
741		gb->audio.timingFactor = gb->doubleSpeed + 1;
742		gb->memory.io[REG_KEY1] = 0;
743		gb->memory.io[REG_KEY1] |= gb->doubleSpeed << 7;
744	} else if (cpu->bus) {
745#ifdef USE_DEBUGGERS
746		if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
747			struct mDebuggerEntryInfo info = {
748				.address = cpu->pc - 1,
749				.type.bp.opcode = 0x1000 | cpu->bus
750			};
751			mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
752		}
753#endif
754		// Hang forever
755		gb->memory.ime = 0;
756		cpu->pc -= 2;
757	}
758	// TODO: Actually stop
759}
760
761void GBIllegal(struct LR35902Core* cpu) {
762	struct GB* gb = (struct GB*) cpu->master;
763	mLOG(GB, GAME_ERROR, "Hit illegal opcode at address %04X:%02X", cpu->pc, cpu->bus);
764#ifdef USE_DEBUGGERS
765	if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
766		struct mDebuggerEntryInfo info = {
767			.address = cpu->pc,
768			.type.bp.opcode = cpu->bus
769		};
770		mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
771	}
772#endif
773	// Hang forever
774	gb->memory.ime = 0;
775	--cpu->pc;
776}
777
778bool GBIsROM(struct VFile* vf) {
779	if (!vf) {
780		return false;
781	}
782	vf->seek(vf, 0x104, SEEK_SET);
783	uint8_t header[4];
784
785	if (vf->read(vf, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
786		return false;
787	}
788	if (memcmp(header, _knownHeader, sizeof(header))) {
789		return false;
790	}
791	return true;
792}
793
794void GBGetGameTitle(const struct GB* gb, char* out) {
795	const struct GBCartridge* cart = NULL;
796	if (gb->memory.rom) {
797		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
798	}
799	if (!cart) {
800		return;
801	}
802	if (cart->oldLicensee != 0x33) {
803		memcpy(out, cart->titleLong, 16);
804	} else {
805		memcpy(out, cart->titleShort, 11);
806	}
807}
808
809void GBGetGameCode(const struct GB* gb, char* out) {
810	memset(out, 0, 8);
811	const struct GBCartridge* cart = NULL;
812	if (gb->memory.rom) {
813		cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
814	}
815	if (!cart) {
816		return;
817	}
818	if (cart->cgb == 0xC0) {
819		memcpy(out, "CGB-????", 8);
820	} else {
821		memcpy(out, "DMG-????", 8);
822	}
823	if (cart->oldLicensee == 0x33) {
824		memcpy(&out[4], cart->maker, 4);
825	}
826}
827
828void GBFrameStarted(struct GB* gb) {
829	GBTestKeypadIRQ(gb);
830
831	size_t c;
832	for (c = 0; c < mCoreCallbacksListSize(&gb->coreCallbacks); ++c) {
833		struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gb->coreCallbacks, c);
834		if (callbacks->videoFrameStarted) {
835			callbacks->videoFrameStarted(callbacks->context);
836		}
837	}
838}
839
840void GBFrameEnded(struct GB* gb) {
841	GBSramClean(gb, gb->video.frameCounter);
842
843	if (gb->cpu->components && gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
844		struct mCheatDevice* device = (struct mCheatDevice*) gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
845		size_t i;
846		for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
847			struct mCheatSet* cheats = *mCheatSetsGetPointer(&device->cheats, i);
848			mCheatRefresh(device, cheats);
849		}
850	}
851
852	// TODO: Move to common code
853	if (gb->stream && gb->stream->postVideoFrame) {
854		const color_t* pixels;
855		size_t stride;
856		gb->video.renderer->getPixels(gb->video.renderer, &stride, (const void**) &pixels);
857		gb->stream->postVideoFrame(gb->stream, pixels, stride);
858	}
859
860	size_t c;
861	for (c = 0; c < mCoreCallbacksListSize(&gb->coreCallbacks); ++c) {
862		struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gb->coreCallbacks, c);
863		if (callbacks->videoFrameEnded) {
864			callbacks->videoFrameEnded(callbacks->context);
865		}
866	}
867}
868
869enum GBModel GBNameToModel(const char* model) {
870	if (strcasecmp(model, "DMG") == 0) {
871		return GB_MODEL_DMG;
872	} else if (strcasecmp(model, "CGB") == 0) {
873		return GB_MODEL_CGB;
874	} else if (strcasecmp(model, "AGB") == 0) {
875		return GB_MODEL_AGB;
876	} else if (strcasecmp(model, "SGB") == 0) {
877		return GB_MODEL_SGB;
878	} else if (strcasecmp(model, "MGB") == 0) {
879		return GB_MODEL_MGB;
880	} else if (strcasecmp(model, "SGB2") == 0) {
881		return GB_MODEL_SGB2;
882	}
883	return GB_MODEL_AUTODETECT;
884}
885
886const char* GBModelToName(enum GBModel model) {
887	switch (model) {
888	case GB_MODEL_DMG:
889		return "DMG";
890	case GB_MODEL_SGB:
891		return "SGB";
892	case GB_MODEL_MGB:
893		return "MGB";
894	case GB_MODEL_SGB2:
895		return "SGB2";
896	case GB_MODEL_CGB:
897		return "CGB";
898	case GB_MODEL_AGB:
899		return "AGB";
900	default:
901	case GB_MODEL_AUTODETECT:
902		return NULL;
903	}
904}