all repos — mgba @ 5b319cfd91fff2fcd3df0e1fce3e498454796da0

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 <mgba/internal/gba/gba.h>
  7
  8#include <mgba/internal/arm/isa-inlines.h>
  9#include <mgba/internal/arm/debugger/debugger.h>
 10#include <mgba/internal/arm/decoder.h>
 11
 12#include <mgba/internal/gba/bios.h>
 13#include <mgba/internal/gba/cheats.h>
 14#include <mgba/internal/gba/io.h>
 15#include <mgba/internal/gba/overrides.h>
 16
 17#include <mgba-util/patch.h>
 18#include <mgba-util/crc32.h>
 19#include <mgba-util/math.h>
 20#include <mgba-util/memory.h>
 21#include <mgba-util/vfs.h>
 22
 23#ifdef USE_ELF
 24#include <mgba-util/elf-read.h>
 25#endif
 26
 27#define GBA_IRQ_DELAY 7
 28
 29mLOG_DEFINE_CATEGORY(GBA, "GBA", "gba");
 30mLOG_DEFINE_CATEGORY(GBA_DEBUG, "GBA Debug", "gba.debug");
 31
 32const uint32_t GBA_COMPONENT_MAGIC = 0x1000000;
 33
 34static const size_t GBA_ROM_MAGIC_OFFSET = 3;
 35static const uint8_t GBA_ROM_MAGIC[] = { 0xEA };
 36
 37static const size_t GBA_ROM_MAGIC_OFFSET2 = 0xB2;
 38static const uint8_t GBA_ROM_MAGIC2[] = { 0x96 };
 39
 40static const size_t GBA_MB_MAGIC_OFFSET = 0xC0;
 41
 42static void GBAInit(void* cpu, struct mCPUComponent* component);
 43static void GBAInterruptHandlerInit(struct ARMInterruptHandler* irqh);
 44static void GBAProcessEvents(struct ARMCore* cpu);
 45static void GBAHitStub(struct ARMCore* cpu, uint32_t opcode);
 46static void GBAIllegal(struct ARMCore* cpu, uint32_t opcode);
 47static void GBABreakpoint(struct ARMCore* cpu, int immediate);
 48static void GBATestIRQNoDelay(struct ARMCore* cpu);
 49
 50static void _triggerIRQ(struct mTiming*, void* user, uint32_t cyclesLate);
 51
 52#ifdef USE_DEBUGGERS
 53static bool _setSoftwareBreakpoint(struct ARMDebugger*, uint32_t address, enum ExecutionMode mode, uint32_t* opcode);
 54static void _clearSoftwareBreakpoint(struct ARMDebugger*, const struct ARMDebugBreakpoint*);
 55#endif
 56
 57#ifdef FIXED_ROM_BUFFER
 58extern uint32_t* romBuffer;
 59extern size_t romBufferSize;
 60#endif
 61
 62void GBACreate(struct GBA* gba) {
 63	gba->d.id = GBA_COMPONENT_MAGIC;
 64	gba->d.init = GBAInit;
 65	gba->d.deinit = 0;
 66}
 67
 68static void GBAInit(void* cpu, struct mCPUComponent* component) {
 69	struct GBA* gba = (struct GBA*) component;
 70	gba->cpu = cpu;
 71	gba->debugger = 0;
 72	gba->sync = 0;
 73
 74	GBAInterruptHandlerInit(&gba->cpu->irqh);
 75	GBAMemoryInit(gba);
 76
 77	gba->memory.savedata.timing = &gba->timing;
 78	GBASavedataInit(&gba->memory.savedata, NULL);
 79
 80	gba->video.p = gba;
 81	GBAVideoInit(&gba->video);
 82
 83	gba->audio.p = gba;
 84	GBAAudioInit(&gba->audio, GBA_AUDIO_SAMPLES);
 85
 86	GBAIOInit(gba);
 87
 88	gba->sio.p = gba;
 89	GBASIOInit(&gba->sio);
 90
 91	GBAHardwareInit(&gba->memory.hw, NULL);
 92
 93	gba->keySource = 0;
 94	gba->rotationSource = 0;
 95	gba->luminanceSource = 0;
 96	gba->rtcSource = 0;
 97	gba->rumble = 0;
 98
 99	gba->romVf = 0;
100	gba->biosVf = 0;
101
102	gba->stream = NULL;
103	gba->keyCallback = NULL;
104	mCoreCallbacksListInit(&gba->coreCallbacks, 0);
105
106	gba->biosChecksum = GBAChecksum(gba->memory.bios, SIZE_BIOS);
107
108	gba->idleOptimization = IDLE_LOOP_REMOVE;
109	gba->idleLoop = IDLE_LOOP_NONE;
110
111	gba->hardCrash = true;
112	gba->allowOpposingDirections = true;
113
114	gba->performingDMA = false;
115
116	gba->isPristine = false;
117	gba->pristineRomSize = 0;
118	gba->yankedRomSize = 0;
119
120	mTimingInit(&gba->timing, &gba->cpu->cycles, &gba->cpu->nextEvent);
121
122	gba->irqEvent.name = "GBA IRQ Event";
123	gba->irqEvent.callback = _triggerIRQ;
124	gba->irqEvent.context = gba;
125	gba->irqEvent.priority = 0;
126}
127
128void GBAUnloadROM(struct GBA* gba) {
129	if (gba->memory.rom && !gba->isPristine) {
130		if (gba->yankedRomSize) {
131			gba->yankedRomSize = 0;
132		}
133		mappedMemoryFree(gba->memory.rom, SIZE_CART0);
134	}
135
136	if (gba->romVf) {
137#ifndef FIXED_ROM_BUFFER
138		if (gba->isPristine) {
139			gba->romVf->unmap(gba->romVf, gba->memory.rom, gba->pristineRomSize);
140		}
141#endif
142		gba->romVf->close(gba->romVf);
143		gba->romVf = NULL;
144	}
145	gba->memory.rom = NULL;
146	gba->isPristine = false;
147
148	gba->memory.savedata.maskWriteback = false;
149	GBASavedataUnmask(&gba->memory.savedata);
150	GBASavedataDeinit(&gba->memory.savedata);
151	if (gba->memory.savedata.realVf) {
152		gba->memory.savedata.realVf->close(gba->memory.savedata.realVf);
153		gba->memory.savedata.realVf = 0;
154	}
155	gba->idleLoop = IDLE_LOOP_NONE;
156}
157
158void GBADestroy(struct GBA* gba) {
159	GBAUnloadROM(gba);
160
161	if (gba->biosVf) {
162		gba->biosVf->unmap(gba->biosVf, gba->memory.bios, SIZE_BIOS);
163		gba->biosVf->close(gba->biosVf);
164		gba->biosVf = 0;
165	}
166
167	GBAMemoryDeinit(gba);
168	GBAVideoDeinit(&gba->video);
169	GBAAudioDeinit(&gba->audio);
170	GBASIODeinit(&gba->sio);
171	mTimingDeinit(&gba->timing);
172	mCoreCallbacksListDeinit(&gba->coreCallbacks);
173}
174
175void GBAInterruptHandlerInit(struct ARMInterruptHandler* irqh) {
176	irqh->reset = GBAReset;
177	irqh->processEvents = GBAProcessEvents;
178	irqh->swi16 = GBASwi16;
179	irqh->swi32 = GBASwi32;
180	irqh->hitIllegal = GBAIllegal;
181	irqh->readCPSR = GBATestIRQNoDelay;
182	irqh->hitStub = GBAHitStub;
183	irqh->bkpt16 = GBABreakpoint;
184	irqh->bkpt32 = GBABreakpoint;
185}
186
187void GBAReset(struct ARMCore* cpu) {
188	ARMSetPrivilegeMode(cpu, MODE_IRQ);
189	cpu->gprs[ARM_SP] = SP_BASE_IRQ;
190	ARMSetPrivilegeMode(cpu, MODE_SUPERVISOR);
191	cpu->gprs[ARM_SP] = SP_BASE_SUPERVISOR;
192	ARMSetPrivilegeMode(cpu, MODE_SYSTEM);
193	cpu->gprs[ARM_SP] = SP_BASE_SYSTEM;
194
195	struct GBA* gba = (struct GBA*) cpu->master;
196	gba->memory.savedata.maskWriteback = false;
197	GBASavedataUnmask(&gba->memory.savedata);
198
199	gba->cpuBlocked = false;
200	gba->earlyExit = false;
201	gba->dmaPC = 0;
202	if (gba->yankedRomSize) {
203		gba->memory.romSize = gba->yankedRomSize;
204		gba->memory.romMask = toPow2(gba->memory.romSize) - 1;
205		gba->yankedRomSize = 0;
206	}
207	mTimingClear(&gba->timing);
208	GBAMemoryReset(gba);
209	GBAVideoReset(&gba->video);
210	GBAAudioReset(&gba->audio);
211	GBAIOInit(gba);
212	GBATimerInit(gba);
213
214	GBASIOReset(&gba->sio);
215
216	bool isELF = false;
217#ifdef USE_ELF
218	struct ELF* elf = ELFOpen(gba->romVf);
219	if (elf) {
220		isELF = true;
221		ELFClose(elf);
222	}
223#endif
224
225	if (GBAIsMB(gba->romVf) && !isELF) {
226		gba->romVf->seek(gba->romVf, 0, SEEK_SET);
227		gba->romVf->read(gba->romVf, gba->memory.wram, gba->pristineRomSize);
228	}
229
230	gba->lastJump = 0;
231	gba->haltPending = false;
232	gba->idleDetectionStep = 0;
233	gba->idleDetectionFailures = 0;
234
235	gba->debug = false;
236	memset(gba->debugString, 0, sizeof(gba->debugString));
237
238
239	if (gba->romVf && gba->pristineRomSize > SIZE_CART0) {
240		char ident;
241		gba->romVf->seek(gba->romVf, 0xAC, SEEK_SET);
242		gba->romVf->read(gba->romVf, &ident, 1);
243		gba->romVf->seek(gba->romVf, 0, SEEK_SET);
244		if (ident == 'M') {
245			GBAMatrixReset(gba);
246		}
247	}
248}
249
250void GBASkipBIOS(struct GBA* gba) {
251	struct ARMCore* cpu = gba->cpu;
252	if (cpu->gprs[ARM_PC] == BASE_RESET + WORD_SIZE_ARM) {
253		if (gba->memory.rom) {
254			cpu->gprs[ARM_PC] = BASE_CART0;
255		} else {
256			cpu->gprs[ARM_PC] = BASE_WORKING_RAM + 0xC0;
257		}
258		gba->video.vcount = 0x7D;
259		gba->memory.io[REG_VCOUNT >> 1] = 0x7D;
260		gba->memory.io[REG_POSTFLG >> 1] = 1;
261		ARMWritePC(cpu);
262	}
263}
264
265static void GBAProcessEvents(struct ARMCore* cpu) {
266	struct GBA* gba = (struct GBA*) cpu->master;
267
268	gba->bus = cpu->prefetch[1];
269	if (cpu->executionMode == MODE_THUMB) {
270		gba->bus |= cpu->prefetch[1] << 16;
271	}
272
273	int32_t nextEvent = cpu->nextEvent;
274	while (cpu->cycles >= nextEvent) {
275		cpu->nextEvent = INT_MAX;
276		nextEvent = 0;
277		do {
278			int32_t cycles = cpu->cycles;
279			cpu->cycles = 0;
280#ifdef USE_DEBUGGERS
281			gba->timing.globalCycles += cycles;
282#endif
283#ifndef NDEBUG
284			if (cycles < 0) {
285				mLOG(GBA, FATAL, "Negative cycles passed: %i", cycles);
286			}
287#endif
288			nextEvent = mTimingTick(&gba->timing, cycles < nextEvent ? nextEvent : cycles);
289		} while (gba->cpuBlocked);
290
291		cpu->nextEvent = nextEvent;
292		if (cpu->halted) {
293			cpu->cycles = nextEvent;
294			if (!gba->memory.io[REG_IME >> 1] || !gba->memory.io[REG_IE >> 1]) {
295				break;
296			}
297		}
298#ifndef NDEBUG
299		else if (nextEvent < 0) {
300			mLOG(GBA, FATAL, "Negative cycles will pass: %i", nextEvent);
301		}
302#endif
303		if (gba->earlyExit) {
304			break;
305		}
306	}
307	gba->earlyExit = false;
308#ifndef NDEBUG
309	if (gba->cpuBlocked) {
310		mLOG(GBA, FATAL, "CPU is blocked!");
311	}
312#endif
313}
314
315#ifdef USE_DEBUGGERS
316void GBAAttachDebugger(struct GBA* gba, struct mDebugger* debugger) {
317	gba->debugger = (struct ARMDebugger*) debugger->platform;
318	gba->debugger->setSoftwareBreakpoint = _setSoftwareBreakpoint;
319	gba->debugger->clearSoftwareBreakpoint = _clearSoftwareBreakpoint;
320	gba->cpu->components[CPU_COMPONENT_DEBUGGER] = &debugger->d;
321	ARMHotplugAttach(gba->cpu, CPU_COMPONENT_DEBUGGER);
322}
323
324void GBADetachDebugger(struct GBA* gba) {
325	if (gba->debugger) {
326		ARMHotplugDetach(gba->cpu, CPU_COMPONENT_DEBUGGER);
327	}
328	gba->cpu->components[CPU_COMPONENT_DEBUGGER] = NULL;
329	gba->debugger = NULL;
330}
331#endif
332
333bool GBALoadNull(struct GBA* gba) {
334	GBAUnloadROM(gba);
335	gba->romVf = NULL;
336	gba->pristineRomSize = 0;
337#ifndef FIXED_ROM_BUFFER
338	gba->memory.rom = anonymousMemoryMap(SIZE_CART0);
339#else
340	gba->memory.rom = romBuffer;
341#endif
342	gba->isPristine = false;
343	gba->yankedRomSize = 0;
344	gba->memory.romSize = SIZE_CART0;
345	gba->memory.romMask = SIZE_CART0 - 1;
346	gba->memory.mirroring = false;
347	gba->romCrc32 = 0;
348
349	if (gba->cpu) {
350		gba->cpu->memory.setActiveRegion(gba->cpu, gba->cpu->gprs[ARM_PC]);
351	}
352	GBAHardwareInit(&gba->memory.hw, &((uint16_t*) gba->memory.rom)[GPIO_REG_DATA >> 1]);
353	return true;
354}
355
356bool GBALoadMB(struct GBA* gba, struct VFile* vf) {
357	GBAUnloadROM(gba);
358	gba->romVf = vf;
359	gba->pristineRomSize = vf->size(vf);
360	vf->seek(vf, 0, SEEK_SET);
361	if (gba->pristineRomSize > SIZE_WORKING_RAM) {
362		gba->pristineRomSize = SIZE_WORKING_RAM;
363	}
364	gba->isPristine = true;
365	memset(gba->memory.wram, 0, SIZE_WORKING_RAM);
366	gba->yankedRomSize = 0;
367	gba->memory.romSize = 0;
368	gba->memory.romMask = 0;
369	gba->romCrc32 = doCrc32(gba->memory.wram, gba->pristineRomSize);
370	if (gba->cpu && gba->memory.activeRegion == REGION_WORKING_RAM) {
371		gba->cpu->memory.setActiveRegion(gba->cpu, gba->cpu->gprs[ARM_PC]);
372	}
373	return true;
374}
375
376bool GBALoadROM(struct GBA* gba, struct VFile* vf) {
377	if (!vf) {
378		return false;
379	}
380	GBAUnloadROM(gba);
381	gba->romVf = vf;
382	gba->pristineRomSize = vf->size(vf);
383	vf->seek(vf, 0, SEEK_SET);
384	if (gba->pristineRomSize > SIZE_CART0) {
385		gba->isPristine = false;
386		char ident;
387		vf->seek(vf, 0xAC, SEEK_SET);
388		vf->read(vf, &ident, 1);
389		if (ident == 'M') {
390			gba->memory.romSize = 0x01000000;
391#ifdef FIXED_ROM_BUFFER
392			gba->memory.rom = romBuffer;
393#else
394			gba->memory.rom = anonymousMemoryMap(SIZE_CART0);
395#endif
396		} else {
397			gba->memory.rom = vf->map(vf, SIZE_CART0, MAP_READ);
398			gba->memory.romSize = SIZE_CART0;
399		}
400	} else {
401		gba->isPristine = true;
402		gba->memory.rom = vf->map(vf, gba->pristineRomSize, MAP_READ);
403		gba->memory.romSize = gba->pristineRomSize;
404	}
405	if (!gba->memory.rom) {
406		mLOG(GBA, WARN, "Couldn't map ROM");
407		return false;
408	}
409	gba->yankedRomSize = 0;
410	gba->memory.romMask = toPow2(gba->memory.romSize) - 1;
411	gba->memory.mirroring = false;
412	gba->romCrc32 = doCrc32(gba->memory.rom, gba->memory.romSize);
413	if (popcount32(gba->memory.romSize) != 1) {
414		// This ROM is either a bad dump or homebrew. Emulate flash cart behavior.
415#ifndef FIXED_ROM_BUFFER
416		void* newRom = anonymousMemoryMap(SIZE_CART0);
417		memcpy(newRom, gba->memory.rom, gba->pristineRomSize);
418		gba->memory.rom = newRom;
419#endif
420		gba->memory.romSize = SIZE_CART0;
421		gba->memory.romMask = SIZE_CART0 - 1;
422		gba->isPristine = false;
423	}
424	if (gba->cpu && gba->memory.activeRegion >= REGION_CART0) {
425		gba->cpu->memory.setActiveRegion(gba->cpu, gba->cpu->gprs[ARM_PC]);
426	}
427	GBAHardwareInit(&gba->memory.hw, &((uint16_t*) gba->memory.rom)[GPIO_REG_DATA >> 1]);
428	GBAVFameDetect(&gba->memory.vfame, gba->memory.rom, gba->memory.romSize);
429	// TODO: error check
430	return true;
431}
432
433bool GBALoadSave(struct GBA* gba, struct VFile* sav) {
434	GBASavedataInit(&gba->memory.savedata, sav);
435	return sav;
436}
437
438void GBAYankROM(struct GBA* gba) {
439	gba->yankedRomSize = gba->memory.romSize;
440	gba->memory.romSize = 0;
441	gba->memory.romMask = 0;
442	GBARaiseIRQ(gba, IRQ_GAMEPAK, 0);
443}
444
445void GBALoadBIOS(struct GBA* gba, struct VFile* vf) {
446	gba->biosVf = vf;
447	if (vf->size(vf) != SIZE_BIOS) {
448		mLOG(GBA, WARN, "Incorrect BIOS size");
449		return;
450	}
451	uint32_t* bios = vf->map(vf, SIZE_BIOS, MAP_READ);
452	if (!bios) {
453		mLOG(GBA, WARN, "Couldn't map BIOS");
454		return;
455	}
456	gba->memory.bios = bios;
457	gba->memory.fullBios = 1;
458	uint32_t checksum = GBAChecksum(gba->memory.bios, SIZE_BIOS);
459	mLOG(GBA, DEBUG, "BIOS Checksum: 0x%X", checksum);
460	if (checksum == GBA_BIOS_CHECKSUM) {
461		mLOG(GBA, INFO, "Official GBA BIOS detected");
462	} else if (checksum == GBA_DS_BIOS_CHECKSUM) {
463		mLOG(GBA, INFO, "Official GBA (DS) BIOS detected");
464	} else {
465		mLOG(GBA, WARN, "BIOS checksum incorrect");
466	}
467	gba->biosChecksum = checksum;
468	if (gba->memory.activeRegion == REGION_BIOS) {
469		gba->cpu->memory.activeRegion = gba->memory.bios;
470	}
471	// TODO: error check
472}
473
474void GBAApplyPatch(struct GBA* gba, struct Patch* patch) {
475	size_t patchedSize = patch->outputSize(patch, gba->memory.romSize);
476	if (!patchedSize || patchedSize > SIZE_CART0) {
477		return;
478	}
479	void* newRom = anonymousMemoryMap(SIZE_CART0);
480	if (!patch->applyPatch(patch, gba->memory.rom, gba->pristineRomSize, newRom, patchedSize)) {
481		mappedMemoryFree(newRom, SIZE_CART0);
482		return;
483	}
484	if (gba->romVf) {
485#ifndef FIXED_ROM_BUFFER
486		gba->romVf->unmap(gba->romVf, gba->memory.rom, gba->pristineRomSize);
487#endif
488		gba->romVf->close(gba->romVf);
489		gba->romVf = NULL;
490	}
491	gba->isPristine = false;
492	gba->memory.rom = newRom;
493	gba->memory.hw.gpioBase = &((uint16_t*) gba->memory.rom)[GPIO_REG_DATA >> 1];
494	gba->memory.romSize = patchedSize;
495	gba->memory.romMask = SIZE_CART0 - 1;
496	gba->romCrc32 = doCrc32(gba->memory.rom, gba->memory.romSize);
497}
498
499void GBARaiseIRQ(struct GBA* gba, enum GBAIRQ irq, uint32_t cyclesLate) {
500	gba->memory.io[REG_IF >> 1] |= 1 << irq;
501	GBATestIRQ(gba, cyclesLate);
502}
503
504void GBATestIRQNoDelay(struct ARMCore* cpu) {
505	struct GBA* gba = (struct GBA*) cpu->master;
506	GBATestIRQ(gba, 0);
507}
508
509void GBATestIRQ(struct GBA* gba, uint32_t cyclesLate) {
510	if (gba->memory.io[REG_IE >> 1] & gba->memory.io[REG_IF >> 1]) {
511		if (!mTimingIsScheduled(&gba->timing, &gba->irqEvent)) {
512			mTimingSchedule(&gba->timing, &gba->irqEvent, GBA_IRQ_DELAY - cyclesLate);
513		}
514	}
515}
516
517void GBAHalt(struct GBA* gba) {
518	gba->cpu->nextEvent = gba->cpu->cycles;
519	gba->cpu->halted = 1;
520}
521
522void GBAStop(struct GBA* gba) {
523	size_t c;
524	for (c = 0; c < mCoreCallbacksListSize(&gba->coreCallbacks); ++c) {
525		struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gba->coreCallbacks, c);
526		if (callbacks->sleep) {
527			callbacks->sleep(callbacks->context);
528		}
529	}
530	gba->cpu->nextEvent = gba->cpu->cycles;
531}
532
533void GBADebug(struct GBA* gba, uint16_t flags) {
534	gba->debugFlags = flags;
535	if (GBADebugFlagsIsSend(gba->debugFlags)) {
536		int level = 1 << GBADebugFlagsGetLevel(gba->debugFlags);
537		level &= 0x1F;
538		char oolBuf[0x101];
539		strncpy(oolBuf, gba->debugString, sizeof(oolBuf) - 1);
540		memset(gba->debugString, 0, sizeof(gba->debugString));
541		oolBuf[0x100] = '\0';
542		mLog(_mLOG_CAT_GBA_DEBUG, level, "%s", oolBuf);
543	}
544	gba->debugFlags = GBADebugFlagsClearSend(gba->debugFlags);
545}
546
547bool GBAIsROM(struct VFile* vf) {
548#ifdef USE_ELF
549	struct ELF* elf = ELFOpen(vf);
550	if (elf) {
551		uint32_t entry = ELFEntry(elf);
552		bool isGBA = true;
553		isGBA = isGBA && ELFMachine(elf) == EM_ARM;
554		isGBA = isGBA && (entry == BASE_CART0 || entry == BASE_WORKING_RAM);
555		ELFClose(elf);
556		return isGBA;
557	}
558#endif
559	if (!vf) {
560		return false;
561	}
562
563	uint8_t signature[sizeof(GBA_ROM_MAGIC) + sizeof(GBA_ROM_MAGIC2)];
564	if (vf->seek(vf, GBA_ROM_MAGIC_OFFSET, SEEK_SET) < 0) {
565		return false;
566	}
567	if (vf->read(vf, &signature, sizeof(GBA_ROM_MAGIC)) != sizeof(GBA_ROM_MAGIC)) {
568		return false;
569	}
570	if (memcmp(signature, GBA_ROM_MAGIC, sizeof(GBA_ROM_MAGIC)) != 0) {
571		return false;
572	}
573
574	if (vf->seek(vf, GBA_ROM_MAGIC_OFFSET2, SEEK_SET) < 0) {
575		return false;
576	}
577	if (vf->read(vf, &signature, sizeof(GBA_ROM_MAGIC2)) != sizeof(GBA_ROM_MAGIC2)) {
578		return false;
579	}
580	if (memcmp(signature, GBA_ROM_MAGIC2, sizeof(GBA_ROM_MAGIC2)) != 0) {
581		// If the signature byte is missing then we must be using an unfixed ROM
582		uint32_t buffer[0x9C / sizeof(uint32_t)];
583		if (vf->seek(vf, 0x4, SEEK_SET) < 0) {
584			return false;
585		}
586		if (vf->read(vf, &buffer, sizeof(buffer)) != sizeof(buffer)) {
587			return false;
588		}
589		uint32_t bits = 0;
590		size_t i;
591		for (i = 0; i < sizeof(buffer) / sizeof(*buffer); ++i) {
592			bits |= buffer[i];
593		}
594		if (bits) {
595			return false;
596		}
597	}
598
599
600	if (GBAIsBIOS(vf)) {
601		return false;
602	}
603	return true;
604}
605
606bool GBAIsMB(struct VFile* vf) {
607	if (!GBAIsROM(vf)) {
608		return false;
609	}
610#ifdef USE_ELF
611	struct ELF* elf = ELFOpen(vf);
612	if (elf) {
613		bool isMB = ELFEntry(elf) == BASE_WORKING_RAM;
614		ELFClose(elf);
615		return isMB;
616	}
617#endif
618	if (vf->size(vf) > SIZE_WORKING_RAM) {
619		return false;
620	}
621	if (vf->seek(vf, GBA_MB_MAGIC_OFFSET, SEEK_SET) < 0) {
622		return false;
623	}
624	uint32_t signature;
625	if (vf->read(vf, &signature, sizeof(signature)) != sizeof(signature)) {
626		return false;
627	}
628	uint32_t opcode;
629	LOAD_32(opcode, 0, &signature);
630	struct ARMInstructionInfo info;
631	ARMDecodeARM(opcode, &info);
632	if (info.branchType == ARM_BRANCH) {
633		if (info.op1.immediate <= 0) {
634			return false;
635		} else if (info.op1.immediate == 28) {
636			// Ancient toolchain that is known to throw MB detection for a loop
637			return false;
638		} else if (info.op1.immediate != 24) {
639			return true;
640		}
641	}
642
643	uint32_t pc = GBA_MB_MAGIC_OFFSET;
644	int i;
645	for (i = 0; i < 80; ++i) {
646		if (vf->read(vf, &signature, sizeof(signature)) != sizeof(signature)) {
647			break;
648		}
649		pc += 4;
650		LOAD_32(opcode, 0, &signature);
651		ARMDecodeARM(opcode, &info);
652		if (info.mnemonic != ARM_MN_LDR) {
653			continue;
654		}
655		if ((info.operandFormat & ARM_OPERAND_MEMORY) && info.memory.baseReg == ARM_PC && info.memory.format & ARM_MEMORY_IMMEDIATE_OFFSET) {
656			uint32_t immediate = info.memory.offset.immediate;
657			if (info.memory.format & ARM_MEMORY_OFFSET_SUBTRACT) {
658				immediate = -immediate;
659			}
660			immediate += pc + 8;
661			if (vf->seek(vf, immediate, SEEK_SET) < 0) {
662				break;
663			}
664			if (vf->read(vf, &signature, sizeof(signature)) != sizeof(signature)) {
665				break;
666			}
667			LOAD_32(immediate, 0, &signature);
668			if (vf->seek(vf, pc, SEEK_SET) < 0) {
669				break;
670			}
671			if ((immediate & ~0x7FF) == BASE_WORKING_RAM) {
672				return true;
673			}
674		}
675	}
676	// Found a libgba-linked cart...these are a bit harder to detect.
677	return false;
678}
679
680bool GBAIsBIOS(struct VFile* vf) {
681	if (vf->seek(vf, 0, SEEK_SET) < 0) {
682		return false;
683	}
684	uint8_t interruptTable[7 * 4];
685	if (vf->read(vf, &interruptTable, sizeof(interruptTable)) != sizeof(interruptTable)) {
686		return false;
687	}
688	int i;
689	for (i = 0; i < 7; ++i) {
690		if (interruptTable[4 * i + 3] != 0xEA || interruptTable[4 * i + 2]) {
691			return false;
692		}
693	}
694	return true;
695}
696
697void GBAGetGameCode(const struct GBA* gba, char* out) {
698	memset(out, 0, 8);
699	if (!gba->memory.rom) {
700		return;
701	}
702
703	memcpy(out, "AGB-", 4);
704	memcpy(&out[4], &((struct GBACartridge*) gba->memory.rom)->id, 4);
705}
706
707void GBAGetGameTitle(const struct GBA* gba, char* out) {
708	if (gba->memory.rom) {
709		memcpy(out, &((struct GBACartridge*) gba->memory.rom)->title, 12);
710		return;
711	}
712	if (gba->isPristine && gba->memory.wram) {
713		memcpy(out, &((struct GBACartridge*) gba->memory.wram)->title, 12);
714		return;
715	}
716	strncpy(out, "(BIOS)", 12);
717}
718
719void GBAHitStub(struct ARMCore* cpu, uint32_t opcode) {
720	struct GBA* gba = (struct GBA*) cpu->master;
721	UNUSED(gba);
722#ifdef USE_DEBUGGERS
723	if (gba->debugger) {
724		struct mDebuggerEntryInfo info = {
725			.address = _ARMPCAddress(cpu),
726			.type.bp.opcode = opcode
727		};
728		mDebuggerEnter(gba->debugger->d.p, DEBUGGER_ENTER_ILLEGAL_OP, &info);
729	}
730#endif
731	// TODO: More sensible category?
732	mLOG(GBA, ERROR, "Stub opcode: %08x", opcode);
733}
734
735void GBAIllegal(struct ARMCore* cpu, uint32_t opcode) {
736	struct GBA* gba = (struct GBA*) cpu->master;
737	if (cpu->executionMode == MODE_THUMB && (opcode & 0xFFC0) == 0xE800) {
738		mLOG(GBA, INFO, "Hit Wii U VC opcode: %08x", opcode);
739		return;
740	}
741	if (!gba->yankedRomSize) {
742		// TODO: More sensible category?
743		mLOG(GBA, WARN, "Illegal opcode: %08x", opcode);
744	}
745#ifdef USE_DEBUGGERS
746	if (gba->debugger) {
747		struct mDebuggerEntryInfo info = {
748			.address = _ARMPCAddress(cpu),
749			.type.bp.opcode = opcode
750		};
751		mDebuggerEnter(gba->debugger->d.p, DEBUGGER_ENTER_ILLEGAL_OP, &info);
752	}
753#endif
754	ARMRaiseUndefined(cpu);
755}
756
757void GBABreakpoint(struct ARMCore* cpu, int immediate) {
758	struct GBA* gba = (struct GBA*) cpu->master;
759	if (immediate >= CPU_COMPONENT_MAX) {
760		return;
761	}
762	switch (immediate) {
763#ifdef USE_DEBUGGERS
764	case CPU_COMPONENT_DEBUGGER:
765		if (gba->debugger) {
766			struct mDebuggerEntryInfo info = {
767				.address = _ARMPCAddress(cpu),
768				.type.bp.breakType = BREAKPOINT_SOFTWARE,
769				.pointId = -1
770			};
771			mDebuggerEnter(gba->debugger->d.p, DEBUGGER_ENTER_BREAKPOINT, &info);
772		}
773		break;
774#endif
775	case CPU_COMPONENT_CHEAT_DEVICE:
776		if (gba->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
777			struct mCheatDevice* device = (struct mCheatDevice*) gba->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
778			struct GBACheatHook* hook = 0;
779			size_t i;
780			for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
781				struct GBACheatSet* cheats = (struct GBACheatSet*) *mCheatSetsGetPointer(&device->cheats, i);
782				if (cheats->hook && cheats->hook->address == _ARMPCAddress(cpu)) {
783					mCheatRefresh(device, &cheats->d);
784					hook = cheats->hook;
785				}
786			}
787			if (hook) {
788				ARMRunFake(cpu, hook->patchedOpcode);
789			}
790		}
791		break;
792	default:
793		break;
794	}
795}
796
797void GBAFrameStarted(struct GBA* gba) {
798	GBATestKeypadIRQ(gba);
799
800	if (gba->audio.mixer) {
801		gba->audio.mixer->vblank(gba->audio.mixer);
802	}
803
804	size_t c;
805	for (c = 0; c < mCoreCallbacksListSize(&gba->coreCallbacks); ++c) {
806		struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gba->coreCallbacks, c);
807		if (callbacks->videoFrameStarted) {
808			callbacks->videoFrameStarted(callbacks->context);
809		}
810	}
811}
812
813void GBAFrameEnded(struct GBA* gba) {
814	GBASavedataClean(&gba->memory.savedata, gba->video.frameCounter);
815
816	if (gba->cpu->components && gba->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
817		struct mCheatDevice* device = (struct mCheatDevice*) gba->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
818		size_t i;
819		for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
820			struct GBACheatSet* cheats = (struct GBACheatSet*) *mCheatSetsGetPointer(&device->cheats, i);
821			if (!cheats->hook) {
822				mCheatRefresh(device, &cheats->d);
823			}
824		}
825	}
826
827	if (gba->stream && gba->stream->postVideoFrame) {
828		const color_t* pixels;
829		size_t stride;
830		gba->video.renderer->getPixels(gba->video.renderer, &stride, (const void**) &pixels);
831		gba->stream->postVideoFrame(gba->stream, pixels, stride);
832	}
833
834	if (gba->memory.hw.devices & (HW_GB_PLAYER | HW_GB_PLAYER_DETECTION)) {
835		GBAHardwarePlayerUpdate(gba);
836	}
837
838	size_t c;
839	for (c = 0; c < mCoreCallbacksListSize(&gba->coreCallbacks); ++c) {
840		struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gba->coreCallbacks, c);
841		if (callbacks->videoFrameEnded) {
842			callbacks->videoFrameEnded(callbacks->context);
843		}
844	}
845}
846
847void GBATestKeypadIRQ(struct GBA* gba) {
848	uint16_t keycnt = gba->memory.io[REG_KEYCNT >> 1];
849	if (!(keycnt & 0x4000)) {
850		return;
851	}
852	int isAnd = keycnt & 0x8000;
853	if (!gba->keySource) {
854		// TODO?
855		return;
856	}
857
858	keycnt &= 0x3FF;
859	uint16_t keyInput = *gba->keySource & keycnt;
860
861	if (isAnd && keycnt == keyInput) {
862		GBARaiseIRQ(gba, IRQ_KEYPAD, 0);
863	} else if (!isAnd && keyInput) {
864		GBARaiseIRQ(gba, IRQ_KEYPAD, 0);
865	}
866}
867
868static void _triggerIRQ(struct mTiming* timing, void* user, uint32_t cyclesLate) {
869	UNUSED(timing);
870	UNUSED(cyclesLate);
871	struct GBA* gba = user;
872	gba->cpu->halted = 0;
873	if (!(gba->memory.io[REG_IE >> 1] & gba->memory.io[REG_IF >> 1])) {
874		return;
875	}
876
877	if (gba->memory.io[REG_IME >> 1] && !gba->cpu->cpsr.i) {
878		ARMRaiseIRQ(gba->cpu);
879	}
880}
881
882void GBASetBreakpoint(struct GBA* gba, struct mCPUComponent* component, uint32_t address, enum ExecutionMode mode, uint32_t* opcode) {
883	size_t immediate;
884	for (immediate = 0; immediate < gba->cpu->numComponents; ++immediate) {
885		if (gba->cpu->components[immediate] == component) {
886			break;
887		}
888	}
889	if (immediate == gba->cpu->numComponents) {
890		return;
891	}
892	if (mode == MODE_ARM) {
893		int32_t value;
894		int32_t old;
895		value = 0xE1200070;
896		value |= immediate & 0xF;
897		value |= (immediate & 0xFFF0) << 4;
898		GBAPatch32(gba->cpu, address, value, &old);
899		*opcode = old;
900	} else {
901		int16_t value;
902		int16_t old;
903		value = 0xBE00;
904		value |= immediate & 0xFF;
905		GBAPatch16(gba->cpu, address, value, &old);
906		*opcode = (uint16_t) old;
907	}
908}
909
910void GBAClearBreakpoint(struct GBA* gba, uint32_t address, enum ExecutionMode mode, uint32_t opcode) {
911	if (mode == MODE_ARM) {
912		GBAPatch32(gba->cpu, address, opcode, 0);
913	} else {
914		GBAPatch16(gba->cpu, address, opcode, 0);
915	}
916}
917
918#ifdef USE_DEBUGGERS
919static bool _setSoftwareBreakpoint(struct ARMDebugger* debugger, uint32_t address, enum ExecutionMode mode, uint32_t* opcode) {
920	GBASetBreakpoint((struct GBA*) debugger->cpu->master, &debugger->d.p->d, address, mode, opcode);
921	return true;
922}
923
924static void _clearSoftwareBreakpoint(struct ARMDebugger* debugger, const struct ARMDebugBreakpoint* breakpoint) {
925	GBAClearBreakpoint((struct GBA*) debugger->cpu->master, breakpoint->d.address, breakpoint->sw.mode, breakpoint->sw.opcode);
926}
927#endif