all repos — mgba @ 817dec97c2c54ffb63ce536525f55bfa7b746b9b

mGBA Game Boy Advance Emulator

src/gba/gba.c (view raw)

  1/* Copyright (c) 2013-2015 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 "gba.h"
  7
  8#include "gba/bios.h"
  9#include "gba/cheats.h"
 10#include "gba/io.h"
 11#include "gba/supervisor/rr.h"
 12#include "gba/supervisor/thread.h"
 13#include "gba/serialize.h"
 14#include "gba/sio.h"
 15
 16#include "isa-inlines.h"
 17
 18#include "util/crc32.h"
 19#include "util/memory.h"
 20#include "util/patch.h"
 21#include "util/vfs.h"
 22
 23const uint32_t GBA_ARM7TDMI_FREQUENCY = 0x1000000;
 24const uint32_t GBA_COMPONENT_MAGIC = 0x1000000;
 25
 26static const size_t GBA_ROM_MAGIC_OFFSET = 3;
 27static const uint8_t GBA_ROM_MAGIC[] = { 0xEA };
 28
 29static void GBAInit(struct ARMCore* cpu, struct ARMComponent* component);
 30static void GBAInterruptHandlerInit(struct ARMInterruptHandler* irqh);
 31static void GBAProcessEvents(struct ARMCore* cpu);
 32static int32_t GBATimersProcessEvents(struct GBA* gba, int32_t cycles);
 33static void GBAHitStub(struct ARMCore* cpu, uint32_t opcode);
 34static void GBAIllegal(struct ARMCore* cpu, uint32_t opcode);
 35static void GBABreakpoint(struct ARMCore* cpu, int immediate);
 36
 37static bool _setSoftwareBreakpoint(struct ARMDebugger*, uint32_t address, enum ExecutionMode mode, uint32_t* opcode);
 38static bool _clearSoftwareBreakpoint(struct ARMDebugger*, uint32_t address, enum ExecutionMode mode, uint32_t opcode);
 39
 40void GBACreate(struct GBA* gba) {
 41	gba->d.id = GBA_COMPONENT_MAGIC;
 42	gba->d.init = GBAInit;
 43	gba->d.deinit = 0;
 44}
 45
 46static void GBAInit(struct ARMCore* cpu, struct ARMComponent* component) {
 47	struct GBA* gba = (struct GBA*) component;
 48	gba->cpu = cpu;
 49	gba->debugger = 0;
 50	gba->sync = 0;
 51
 52	GBAInterruptHandlerInit(&cpu->irqh);
 53	GBAMemoryInit(gba);
 54	GBASavedataInit(&gba->memory.savedata, 0);
 55
 56	gba->video.p = gba;
 57	GBAVideoInit(&gba->video);
 58
 59	gba->audio.p = gba;
 60	GBAAudioInit(&gba->audio, GBA_AUDIO_SAMPLES);
 61
 62	GBAIOInit(gba);
 63
 64	gba->sio.p = gba;
 65	GBASIOInit(&gba->sio);
 66
 67	gba->timersEnabled = 0;
 68	memset(gba->timers, 0, sizeof(gba->timers));
 69
 70	gba->springIRQ = 0;
 71	gba->keySource = 0;
 72	gba->rotationSource = 0;
 73	gba->luminanceSource = 0;
 74	gba->rtcSource = 0;
 75	gba->rumble = 0;
 76	gba->rr = 0;
 77
 78	gba->romVf = 0;
 79	gba->biosVf = 0;
 80
 81	gba->logHandler = 0;
 82	gba->logLevel = GBA_LOG_INFO | GBA_LOG_WARN | GBA_LOG_ERROR | GBA_LOG_FATAL;
 83	gba->stream = 0;
 84
 85	gba->biosChecksum = GBAChecksum(gba->memory.bios, SIZE_BIOS);
 86
 87	gba->idleOptimization = IDLE_LOOP_REMOVE;
 88	gba->idleLoop = IDLE_LOOP_NONE;
 89	gba->lastJump = 0;
 90	gba->haltPending = false;
 91	gba->idleDetectionStep = 0;
 92	gba->idleDetectionFailures = 0;
 93	gba->performingDMA = false;
 94}
 95
 96void GBADestroy(struct GBA* gba) {
 97	if (gba->pristineRom == gba->memory.rom) {
 98		gba->memory.rom = 0;
 99	}
100
101	if (gba->romVf) {
102		gba->romVf->unmap(gba->romVf, gba->pristineRom, gba->pristineRomSize);
103	}
104
105	if (gba->biosVf) {
106		gba->biosVf->unmap(gba->biosVf, gba->memory.bios, SIZE_BIOS);
107	}
108
109	GBAMemoryDeinit(gba);
110	GBAVideoDeinit(&gba->video);
111	GBAAudioDeinit(&gba->audio);
112	GBASIODeinit(&gba->sio);
113	gba->rr = 0;
114}
115
116void GBAInterruptHandlerInit(struct ARMInterruptHandler* irqh) {
117	irqh->reset = GBAReset;
118	irqh->processEvents = GBAProcessEvents;
119	irqh->swi16 = GBASwi16;
120	irqh->swi32 = GBASwi32;
121	irqh->hitIllegal = GBAIllegal;
122	irqh->readCPSR = GBATestIRQ;
123	irqh->hitStub = GBAHitStub;
124	irqh->bkpt16 = GBABreakpoint;
125	irqh->bkpt32 = GBABreakpoint;
126}
127
128void GBAReset(struct ARMCore* cpu) {
129	ARMSetPrivilegeMode(cpu, MODE_IRQ);
130	cpu->gprs[ARM_SP] = SP_BASE_IRQ;
131	ARMSetPrivilegeMode(cpu, MODE_SUPERVISOR);
132	cpu->gprs[ARM_SP] = SP_BASE_SUPERVISOR;
133	ARMSetPrivilegeMode(cpu, MODE_SYSTEM);
134	cpu->gprs[ARM_SP] = SP_BASE_SYSTEM;
135
136	struct GBA* gba = (struct GBA*) cpu->master;
137	if (!gba->rr || (!gba->rr->isPlaying(gba->rr) && !gba->rr->isRecording(gba->rr))) {
138		GBASavedataUnmask(&gba->memory.savedata);
139	}
140	GBAMemoryReset(gba);
141	GBAVideoReset(&gba->video);
142	GBAAudioReset(&gba->audio);
143	GBAIOInit(gba);
144
145	GBASIODeinit(&gba->sio);
146	GBASIOInit(&gba->sio);
147
148	gba->timersEnabled = 0;
149	memset(gba->timers, 0, sizeof(gba->timers));
150}
151
152void GBASkipBIOS(struct ARMCore* cpu) {
153	if (cpu->gprs[ARM_PC] == BASE_RESET + WORD_SIZE_ARM) {
154		cpu->gprs[ARM_PC] = BASE_CART0;
155		int currentCycles = 0;
156		ARM_WRITE_PC;
157	}
158}
159
160static void GBAProcessEvents(struct ARMCore* cpu) {
161	do {
162		struct GBA* gba = (struct GBA*) cpu->master;
163		int32_t cycles = cpu->nextEvent;
164		int32_t nextEvent = INT_MAX;
165		int32_t testEvent;
166
167		gba->bus = cpu->prefetch[1];
168		if (cpu->executionMode == MODE_THUMB) {
169			gba->bus |= cpu->prefetch[1] << 16;
170		}
171
172		if (gba->springIRQ) {
173			ARMRaiseIRQ(cpu);
174			gba->springIRQ = 0;
175		}
176
177		testEvent = GBAVideoProcessEvents(&gba->video, cycles);
178		if (testEvent < nextEvent) {
179			nextEvent = testEvent;
180		}
181
182		testEvent = GBAAudioProcessEvents(&gba->audio, cycles);
183		if (testEvent < nextEvent) {
184			nextEvent = testEvent;
185		}
186
187		testEvent = GBATimersProcessEvents(gba, cycles);
188		if (testEvent < nextEvent) {
189			nextEvent = testEvent;
190		}
191
192		testEvent = GBAMemoryRunDMAs(gba, cycles);
193		if (testEvent < nextEvent) {
194			nextEvent = testEvent;
195		}
196
197		testEvent = GBASIOProcessEvents(&gba->sio, cycles);
198		if (testEvent < nextEvent) {
199			nextEvent = testEvent;
200		}
201
202		cpu->cycles -= cycles;
203		cpu->nextEvent = nextEvent;
204
205		if (cpu->halted) {
206			cpu->cycles = cpu->nextEvent;
207		}
208	} while (cpu->cycles >= cpu->nextEvent);
209}
210
211static int32_t GBATimersProcessEvents(struct GBA* gba, int32_t cycles) {
212	int32_t nextEvent = INT_MAX;
213	if (gba->timersEnabled) {
214		struct GBATimer* timer;
215		struct GBATimer* nextTimer;
216
217		timer = &gba->timers[0];
218		if (timer->enable) {
219			timer->nextEvent -= cycles;
220			timer->lastEvent -= cycles;
221			if (timer->nextEvent <= 0) {
222				timer->lastEvent = timer->nextEvent;
223				timer->nextEvent += timer->overflowInterval;
224				gba->memory.io[REG_TM0CNT_LO >> 1] = timer->reload;
225				timer->oldReload = timer->reload;
226
227				if (timer->doIrq) {
228					GBARaiseIRQ(gba, IRQ_TIMER0);
229				}
230
231				if (gba->audio.enable) {
232					if ((gba->audio.chALeft || gba->audio.chARight) && gba->audio.chATimer == 0) {
233						GBAAudioSampleFIFO(&gba->audio, 0, timer->lastEvent);
234					}
235
236					if ((gba->audio.chBLeft || gba->audio.chBRight) && gba->audio.chBTimer == 0) {
237						GBAAudioSampleFIFO(&gba->audio, 1, timer->lastEvent);
238					}
239				}
240
241				nextTimer = &gba->timers[1];
242				if (nextTimer->countUp) {
243					++gba->memory.io[REG_TM1CNT_LO >> 1];
244					if (!gba->memory.io[REG_TM1CNT_LO >> 1]) {
245						nextTimer->nextEvent = 0;
246					}
247				}
248			}
249			nextEvent = timer->nextEvent;
250		}
251
252		timer = &gba->timers[1];
253		if (timer->enable) {
254			timer->nextEvent -= cycles;
255			timer->lastEvent -= cycles;
256			if (timer->nextEvent <= 0) {
257				timer->lastEvent = timer->nextEvent;
258				timer->nextEvent += timer->overflowInterval;
259				gba->memory.io[REG_TM1CNT_LO >> 1] = timer->reload;
260				timer->oldReload = timer->reload;
261
262				if (timer->doIrq) {
263					GBARaiseIRQ(gba, IRQ_TIMER1);
264				}
265
266				if (gba->audio.enable) {
267					if ((gba->audio.chALeft || gba->audio.chARight) && gba->audio.chATimer == 1) {
268						GBAAudioSampleFIFO(&gba->audio, 0, timer->lastEvent);
269					}
270
271					if ((gba->audio.chBLeft || gba->audio.chBRight) && gba->audio.chBTimer == 1) {
272						GBAAudioSampleFIFO(&gba->audio, 1, timer->lastEvent);
273					}
274				}
275
276				if (timer->countUp) {
277					timer->nextEvent = INT_MAX;
278				}
279
280				nextTimer = &gba->timers[2];
281				if (nextTimer->countUp) {
282					++gba->memory.io[REG_TM2CNT_LO >> 1];
283					if (!gba->memory.io[REG_TM2CNT_LO >> 1]) {
284						nextTimer->nextEvent = 0;
285					}
286				}
287			}
288			if (timer->nextEvent < nextEvent) {
289				nextEvent = timer->nextEvent;
290			}
291		}
292
293		timer = &gba->timers[2];
294		if (timer->enable) {
295			timer->nextEvent -= cycles;
296			timer->lastEvent -= cycles;
297			if (timer->nextEvent <= 0) {
298				timer->lastEvent = timer->nextEvent;
299				timer->nextEvent += timer->overflowInterval;
300				gba->memory.io[REG_TM2CNT_LO >> 1] = timer->reload;
301				timer->oldReload = timer->reload;
302
303				if (timer->doIrq) {
304					GBARaiseIRQ(gba, IRQ_TIMER2);
305				}
306
307				if (timer->countUp) {
308					timer->nextEvent = INT_MAX;
309				}
310
311				nextTimer = &gba->timers[3];
312				if (nextTimer->countUp) {
313					++gba->memory.io[REG_TM3CNT_LO >> 1];
314					if (!gba->memory.io[REG_TM3CNT_LO >> 1]) {
315						nextTimer->nextEvent = 0;
316					}
317				}
318			}
319			if (timer->nextEvent < nextEvent) {
320				nextEvent = timer->nextEvent;
321			}
322		}
323
324		timer = &gba->timers[3];
325		if (timer->enable) {
326			timer->nextEvent -= cycles;
327			timer->lastEvent -= cycles;
328			if (timer->nextEvent <= 0) {
329				timer->lastEvent = timer->nextEvent;
330				timer->nextEvent += timer->overflowInterval;
331				gba->memory.io[REG_TM3CNT_LO >> 1] = timer->reload;
332				timer->oldReload = timer->reload;
333
334				if (timer->doIrq) {
335					GBARaiseIRQ(gba, IRQ_TIMER3);
336				}
337
338				if (timer->countUp) {
339					timer->nextEvent = INT_MAX;
340				}
341			}
342			if (timer->nextEvent < nextEvent) {
343				nextEvent = timer->nextEvent;
344			}
345		}
346	}
347	return nextEvent;
348}
349
350void GBAAttachDebugger(struct GBA* gba, struct ARMDebugger* debugger) {
351	debugger->setSoftwareBreakpoint = _setSoftwareBreakpoint;
352	debugger->clearSoftwareBreakpoint = _clearSoftwareBreakpoint;
353	gba->debugger = debugger;
354	gba->cpu->components[GBA_COMPONENT_DEBUGGER] = &debugger->d;
355	ARMHotplugAttach(gba->cpu, GBA_COMPONENT_DEBUGGER);
356}
357
358void GBADetachDebugger(struct GBA* gba) {
359	gba->debugger = 0;
360	ARMHotplugDetach(gba->cpu, GBA_COMPONENT_DEBUGGER);
361	gba->cpu->components[GBA_COMPONENT_DEBUGGER] = 0;
362}
363
364void GBALoadROM(struct GBA* gba, struct VFile* vf, struct VFile* sav, const char* fname) {
365	gba->romVf = vf;
366	gba->pristineRomSize = vf->size(vf);
367	vf->seek(vf, 0, SEEK_SET);
368	if (gba->pristineRomSize > SIZE_CART0) {
369		gba->pristineRomSize = SIZE_CART0;
370	}
371	gba->pristineRom = vf->map(vf, gba->pristineRomSize, MAP_READ);
372	if (!gba->pristineRom) {
373		GBALog(gba, GBA_LOG_WARN, "Couldn't map ROM");
374		return;
375	}
376	gba->memory.rom = gba->pristineRom;
377	gba->activeFile = fname;
378	gba->memory.romSize = gba->pristineRomSize;
379	gba->romCrc32 = doCrc32(gba->memory.rom, gba->memory.romSize);
380	GBASavedataInit(&gba->memory.savedata, sav);
381	GBAHardwareInit(&gba->memory.hw, &((uint16_t*) gba->memory.rom)[GPIO_REG_DATA >> 1]);
382	// TODO: error check
383}
384
385void GBALoadBIOS(struct GBA* gba, struct VFile* vf) {
386	gba->biosVf = vf;
387	uint32_t* bios = vf->map(vf, SIZE_BIOS, MAP_READ);
388	if (!bios) {
389		GBALog(gba, GBA_LOG_WARN, "Couldn't map BIOS");
390		return;
391	}
392	gba->memory.bios = bios;
393	gba->memory.fullBios = 1;
394	uint32_t checksum = GBAChecksum(gba->memory.bios, SIZE_BIOS);
395	GBALog(gba, GBA_LOG_DEBUG, "BIOS Checksum: 0x%X", checksum);
396	if (checksum == GBA_BIOS_CHECKSUM) {
397		GBALog(gba, GBA_LOG_INFO, "Official GBA BIOS detected");
398	} else if (checksum == GBA_DS_BIOS_CHECKSUM) {
399		GBALog(gba, GBA_LOG_INFO, "Official GBA (DS) BIOS detected");
400	} else {
401		GBALog(gba, GBA_LOG_WARN, "BIOS checksum incorrect");
402	}
403	gba->biosChecksum = checksum;
404	if (gba->memory.activeRegion == REGION_BIOS) {
405		gba->cpu->memory.activeRegion = gba->memory.bios;
406	}
407	// TODO: error check
408}
409
410void GBAApplyPatch(struct GBA* gba, struct Patch* patch) {
411	size_t patchedSize = patch->outputSize(patch, gba->memory.romSize);
412	if (!patchedSize) {
413		return;
414	}
415	gba->memory.rom = anonymousMemoryMap(patchedSize);
416	if (!patch->applyPatch(patch, gba->pristineRom, gba->pristineRomSize, gba->memory.rom, patchedSize)) {
417		mappedMemoryFree(gba->memory.rom, patchedSize);
418		gba->memory.rom = gba->pristineRom;
419		return;
420	}
421	gba->memory.romSize = patchedSize;
422	gba->romCrc32 = doCrc32(gba->memory.rom, gba->memory.romSize);
423}
424
425void GBATimerUpdateRegister(struct GBA* gba, int timer) {
426	struct GBATimer* currentTimer = &gba->timers[timer];
427	if (currentTimer->enable && !currentTimer->countUp) {
428		gba->memory.io[(REG_TM0CNT_LO + (timer << 2)) >> 1] = currentTimer->oldReload + ((gba->cpu->cycles - currentTimer->lastEvent) >> currentTimer->prescaleBits);
429	}
430}
431
432void GBATimerWriteTMCNT_LO(struct GBA* gba, int timer, uint16_t reload) {
433	gba->timers[timer].reload = reload;
434}
435
436void GBATimerWriteTMCNT_HI(struct GBA* gba, int timer, uint16_t control) {
437	struct GBATimer* currentTimer = &gba->timers[timer];
438	GBATimerUpdateRegister(gba, timer);
439
440	int oldPrescale = currentTimer->prescaleBits;
441	switch (control & 0x0003) {
442	case 0x0000:
443		currentTimer->prescaleBits = 0;
444		break;
445	case 0x0001:
446		currentTimer->prescaleBits = 6;
447		break;
448	case 0x0002:
449		currentTimer->prescaleBits = 8;
450		break;
451	case 0x0003:
452		currentTimer->prescaleBits = 10;
453		break;
454	}
455	currentTimer->countUp = !!(control & 0x0004);
456	currentTimer->doIrq = !!(control & 0x0040);
457	currentTimer->overflowInterval = (0x10000 - currentTimer->reload) << currentTimer->prescaleBits;
458	int wasEnabled = currentTimer->enable;
459	currentTimer->enable = !!(control & 0x0080);
460	if (!wasEnabled && currentTimer->enable) {
461		if (!currentTimer->countUp) {
462			currentTimer->nextEvent = gba->cpu->cycles + currentTimer->overflowInterval;
463		} else {
464			currentTimer->nextEvent = INT_MAX;
465		}
466		gba->memory.io[(REG_TM0CNT_LO + (timer << 2)) >> 1] = currentTimer->reload;
467		currentTimer->oldReload = currentTimer->reload;
468		currentTimer->lastEvent = 0;
469		gba->timersEnabled |= 1 << timer;
470	} else if (wasEnabled && !currentTimer->enable) {
471		if (!currentTimer->countUp) {
472			gba->memory.io[(REG_TM0CNT_LO + (timer << 2)) >> 1] = currentTimer->oldReload + ((gba->cpu->cycles - currentTimer->lastEvent) >> oldPrescale);
473		}
474		gba->timersEnabled &= ~(1 << timer);
475	} else if (currentTimer->prescaleBits != oldPrescale && !currentTimer->countUp) {
476		// FIXME: this might be before present
477		currentTimer->nextEvent = currentTimer->lastEvent + currentTimer->overflowInterval;
478	}
479
480	if (currentTimer->nextEvent < gba->cpu->nextEvent) {
481		gba->cpu->nextEvent = currentTimer->nextEvent;
482	}
483};
484
485void GBAWriteIE(struct GBA* gba, uint16_t value) {
486	if (value & (1 << IRQ_KEYPAD)) {
487		GBALog(gba, GBA_LOG_STUB, "Keypad interrupts not implemented");
488	}
489
490	if (value & (1 << IRQ_GAMEPAK)) {
491		GBALog(gba, GBA_LOG_STUB, "Gamepak interrupts not implemented");
492	}
493
494	if (gba->memory.io[REG_IME >> 1] && value & gba->memory.io[REG_IF >> 1]) {
495		ARMRaiseIRQ(gba->cpu);
496	}
497}
498
499void GBAWriteIME(struct GBA* gba, uint16_t value) {
500	if (value && gba->memory.io[REG_IE >> 1] & gba->memory.io[REG_IF >> 1]) {
501		ARMRaiseIRQ(gba->cpu);
502	}
503}
504
505void GBARaiseIRQ(struct GBA* gba, enum GBAIRQ irq) {
506	gba->memory.io[REG_IF >> 1] |= 1 << irq;
507	gba->cpu->halted = 0;
508
509	if (gba->memory.io[REG_IME >> 1] && (gba->memory.io[REG_IE >> 1] & 1 << irq)) {
510		ARMRaiseIRQ(gba->cpu);
511	}
512}
513
514void GBATestIRQ(struct ARMCore* cpu) {
515	struct GBA* gba = (struct GBA*) cpu->master;
516	if (gba->memory.io[REG_IME >> 1] && gba->memory.io[REG_IE >> 1] & gba->memory.io[REG_IF >> 1]) {
517		gba->springIRQ = 1;
518		gba->cpu->nextEvent = 0;
519	}
520}
521
522void GBAHalt(struct GBA* gba) {
523	gba->cpu->nextEvent = 0;
524	gba->cpu->halted = 1;
525}
526
527static void _GBAVLog(struct GBA* gba, enum GBALogLevel level, const char* format, va_list args) {
528	struct GBAThread* threadContext = GBAThreadGetContext();
529	enum GBALogLevel logLevel = -1;
530
531	if (gba) {
532		logLevel = gba->logLevel;
533	}
534
535	if (threadContext) {
536		logLevel = threadContext->logLevel;
537		gba = threadContext->gba;
538	}
539
540	if (!(level & logLevel) && level != GBA_LOG_FATAL) {
541		return;
542	}
543
544	if (level == GBA_LOG_FATAL && gba) {
545		gba->cpu->nextEvent = 0;
546	}
547
548	if (threadContext) {
549		if (level == GBA_LOG_FATAL) {
550			MutexLock(&threadContext->stateMutex);
551			threadContext->state = THREAD_CRASHED;
552			MutexUnlock(&threadContext->stateMutex);
553		}
554	}
555	if (gba && gba->logHandler) {
556		gba->logHandler(threadContext, level, format, args);
557		return;
558	}
559
560	vprintf(format, args);
561	printf("\n");
562
563	if (level == GBA_LOG_FATAL && !threadContext) {
564		abort();
565	}
566}
567
568void GBALog(struct GBA* gba, enum GBALogLevel level, const char* format, ...) {
569	va_list args;
570	va_start(args, format);
571	_GBAVLog(gba, level, format, args);
572	va_end(args);
573}
574
575void GBADebuggerLogShim(struct ARMDebugger* debugger, enum DebuggerLogLevel level, const char* format, ...) {
576	struct GBA* gba = 0;
577	if (debugger->cpu) {
578		gba = (struct GBA*) debugger->cpu->master;
579	}
580
581	enum GBALogLevel gbaLevel;
582	switch (level) {
583	default: // Avoids compiler warning
584	case DEBUGGER_LOG_DEBUG:
585		gbaLevel = GBA_LOG_DEBUG;
586		break;
587	case DEBUGGER_LOG_INFO:
588		gbaLevel = GBA_LOG_INFO;
589		break;
590	case DEBUGGER_LOG_WARN:
591		gbaLevel = GBA_LOG_WARN;
592		break;
593	case DEBUGGER_LOG_ERROR:
594		gbaLevel = GBA_LOG_ERROR;
595		break;
596	}
597	va_list args;
598	va_start(args, format);
599	_GBAVLog(gba, gbaLevel, format, args);
600	va_end(args);
601}
602
603bool GBAIsROM(struct VFile* vf) {
604	if (vf->seek(vf, GBA_ROM_MAGIC_OFFSET, SEEK_SET) < 0) {
605		return false;
606	}
607	uint8_t signature[sizeof(GBA_ROM_MAGIC)];
608	if (vf->read(vf, &signature, sizeof(signature)) != sizeof(signature)) {
609		return false;
610	}
611	return memcmp(signature, GBA_ROM_MAGIC, sizeof(signature)) == 0;
612}
613
614bool GBAIsBIOS(struct VFile* vf) {
615	if (vf->seek(vf, 0, SEEK_SET) < 0) {
616		return false;
617	}
618	uint32_t interruptTable[7];
619	if (vf->read(vf, &interruptTable, sizeof(interruptTable)) != sizeof(interruptTable)) {
620		return false;
621	}
622	int i;
623	for (i = 0; i < 7; ++i) {
624		if ((interruptTable[i] & 0xFFFF0000) != 0xEA000000) {
625			return false;
626		}
627	}
628	return true;
629}
630
631void GBAGetGameCode(struct GBA* gba, char* out) {
632	memcpy(out, &((struct GBACartridge*) gba->memory.rom)->id, 4);
633}
634
635void GBAGetGameTitle(struct GBA* gba, char* out) {
636	memcpy(out, &((struct GBACartridge*) gba->memory.rom)->title, 12);
637}
638
639void GBAHitStub(struct ARMCore* cpu, uint32_t opcode) {
640	struct GBA* gba = (struct GBA*) cpu->master;
641	enum GBALogLevel level = GBA_LOG_FATAL;
642	if (gba->debugger) {
643		level = GBA_LOG_STUB;
644		struct DebuggerEntryInfo info = {
645			.address = _ARMPCAddress(cpu),
646			.opcode = opcode
647		};
648		ARMDebuggerEnter(gba->debugger, DEBUGGER_ENTER_ILLEGAL_OP, &info);
649	}
650	GBALog(gba, level, "Stub opcode: %08x", opcode);
651}
652
653void GBAIllegal(struct ARMCore* cpu, uint32_t opcode) {
654	struct GBA* gba = (struct GBA*) cpu->master;
655	GBALog(gba, GBA_LOG_WARN, "Illegal opcode: %08x", opcode);
656	if (gba->debugger) {
657		struct DebuggerEntryInfo info = {
658			.address = _ARMPCAddress(cpu),
659			.opcode = opcode
660		};
661		ARMDebuggerEnter(gba->debugger, DEBUGGER_ENTER_ILLEGAL_OP, &info);
662	}
663}
664
665void GBABreakpoint(struct ARMCore* cpu, int immediate) {
666	struct GBA* gba = (struct GBA*) cpu->master;
667	if (immediate >= GBA_COMPONENT_MAX) {
668		return;
669	}
670	switch (immediate) {
671	case GBA_COMPONENT_DEBUGGER:
672		if (gba->debugger) {
673			struct DebuggerEntryInfo info = {
674				.address = _ARMPCAddress(cpu)
675			};
676			ARMDebuggerEnter(gba->debugger, DEBUGGER_ENTER_BREAKPOINT, &info);
677		}
678		break;
679	case GBA_COMPONENT_CHEAT_DEVICE:
680		if (gba->cpu->components[GBA_COMPONENT_CHEAT_DEVICE]) {
681			struct GBACheatDevice* device = (struct GBACheatDevice*) gba->cpu->components[GBA_COMPONENT_CHEAT_DEVICE];
682			struct GBACheatHook* hook = 0;
683			size_t i;
684			for (i = 0; i < GBACheatSetsSize(&device->cheats); ++i) {
685				struct GBACheatSet* cheats = *GBACheatSetsGetPointer(&device->cheats, i);
686				if (cheats->hook && cheats->hook->address == _ARMPCAddress(cpu)) {
687					GBACheatRefresh(device, cheats);
688					hook = cheats->hook;
689				}
690			}
691			if (hook) {
692				ARMRunFake(cpu, hook->patchedOpcode);
693			}
694		}
695		break;
696	default:
697		break;
698	}
699}
700
701void GBAFrameStarted(struct GBA* gba) {
702	UNUSED(gba);
703
704	struct GBAThread* thread = GBAThreadGetContext();
705	if (!thread) {
706		return;
707	}
708
709	if (thread->rewindBuffer) {
710		--thread->rewindBufferNext;
711		if (thread->rewindBufferNext <= 0) {
712			thread->rewindBufferNext = thread->rewindBufferInterval;
713			GBARecordFrame(thread);
714		}
715	}
716}
717
718void GBAFrameEnded(struct GBA* gba) {
719	if (gba->rr) {
720		gba->rr->nextFrame(gba->rr);
721	}
722
723	if (gba->cpu->components && gba->cpu->components[GBA_COMPONENT_CHEAT_DEVICE]) {
724		struct GBACheatDevice* device = (struct GBACheatDevice*) gba->cpu->components[GBA_COMPONENT_CHEAT_DEVICE];
725		size_t i;
726		for (i = 0; i < GBACheatSetsSize(&device->cheats); ++i) {
727			struct GBACheatSet* cheats = *GBACheatSetsGetPointer(&device->cheats, i);
728			if (!cheats->hook) {
729				GBACheatRefresh(device, cheats);
730			}
731		}
732	}
733
734
735	struct GBAThread* thread = GBAThreadGetContext();
736	if (!thread) {
737		return;
738	}
739
740	if (gba->stream) {
741		gba->stream->postVideoFrame(gba->stream, gba->video.renderer);
742	}
743
744	if (thread->frameCallback) {
745		thread->frameCallback(thread);
746	}
747}
748
749void GBASetBreakpoint(struct GBA* gba, struct ARMComponent* component, uint32_t address, enum ExecutionMode mode, uint32_t* opcode) {
750	size_t immediate;
751	for (immediate = 0; immediate < gba->cpu->numComponents; ++immediate) {
752		if (gba->cpu->components[immediate] == component) {
753			break;
754		}
755	}
756	if (immediate == gba->cpu->numComponents) {
757		return;
758	}
759	if (mode == MODE_ARM) {
760		int32_t value;
761		int32_t old;
762		value = 0xE1200070;
763		value |= immediate & 0xF;
764		value |= (immediate & 0xFFF0) << 4;
765		GBAPatch32(gba->cpu, address, value, &old);
766		*opcode = old;
767	} else {
768		int16_t value;
769		int16_t old;
770		value = 0xBE00;
771		value |= immediate & 0xFF;
772		GBAPatch16(gba->cpu, address, value, &old);
773		*opcode = (uint16_t) old;
774	}
775}
776
777void GBAClearBreakpoint(struct GBA* gba, uint32_t address, enum ExecutionMode mode, uint32_t opcode) {
778	if (mode == MODE_ARM) {
779		GBAPatch32(gba->cpu, address, opcode, 0);
780	} else {
781		GBAPatch16(gba->cpu, address, opcode, 0);
782	}
783}
784
785static bool _setSoftwareBreakpoint(struct ARMDebugger* debugger, uint32_t address, enum ExecutionMode mode, uint32_t* opcode) {
786	GBASetBreakpoint((struct GBA*) debugger->cpu->master, &debugger->d, address, mode, opcode);
787	return true;
788}
789
790static bool _clearSoftwareBreakpoint(struct ARMDebugger* debugger, uint32_t address, enum ExecutionMode mode, uint32_t opcode) {
791	GBAClearBreakpoint((struct GBA*) debugger->cpu->master, address, mode, opcode);
792	return true;
793}