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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#include <mgba/internal/gba/rr/rr.h>
 17
 18#include <mgba-util/patch.h>
 19#include <mgba-util/crc32.h>
 20#include <mgba-util/math.h>
 21#include <mgba-util/memory.h>
 22#include <mgba-util/vfs.h>
 23
 24#ifdef USE_ELF
 25#include <mgba-util/elf-read.h>
 26#endif
 27
 28mLOG_DEFINE_CATEGORY(GBA, "GBA", "gba");
 29mLOG_DEFINE_CATEGORY(GBA_DEBUG, "GBA Debug", "gba.debug");
 30
 31const uint32_t GBA_COMPONENT_MAGIC = 0x1000000;
 32
 33static const size_t GBA_ROM_MAGIC_OFFSET = 3;
 34static const uint8_t GBA_ROM_MAGIC[] = { 0xEA };
 35
 36static const size_t GBA_MB_MAGIC_OFFSET = 0xC0;
 37
 38static void GBAInit(void* cpu, struct mCPUComponent* component);
 39static void GBAInterruptHandlerInit(struct ARMInterruptHandler* irqh);
 40static void GBAProcessEvents(struct ARMCore* cpu);
 41static void GBAHitStub(struct ARMCore* cpu, uint32_t opcode);
 42static void GBAIllegal(struct ARMCore* cpu, uint32_t opcode);
 43static void GBABreakpoint(struct ARMCore* cpu, int immediate);
 44
 45static bool _setSoftwareBreakpoint(struct ARMDebugger*, uint32_t address, enum ExecutionMode mode, uint32_t* opcode);
 46static bool _clearSoftwareBreakpoint(struct ARMDebugger*, uint32_t address, enum ExecutionMode mode, uint32_t opcode);
 47
 48
 49#ifdef FIXED_ROM_BUFFER
 50extern uint32_t* romBuffer;
 51extern size_t romBufferSize;
 52#endif
 53
 54void GBACreate(struct GBA* gba) {
 55	gba->d.id = GBA_COMPONENT_MAGIC;
 56	gba->d.init = GBAInit;
 57	gba->d.deinit = 0;
 58}
 59
 60static void GBAInit(void* cpu, struct mCPUComponent* component) {
 61	struct GBA* gba = (struct GBA*) component;
 62	gba->cpu = cpu;
 63	gba->debugger = 0;
 64	gba->sync = 0;
 65
 66	GBAInterruptHandlerInit(&gba->cpu->irqh);
 67	GBAMemoryInit(gba);
 68
 69	gba->memory.savedata.timing = &gba->timing;
 70	GBASavedataInit(&gba->memory.savedata, NULL);
 71
 72	gba->video.p = gba;
 73	GBAVideoInit(&gba->video);
 74
 75	gba->audio.p = gba;
 76	GBAAudioInit(&gba->audio, GBA_AUDIO_SAMPLES);
 77
 78	GBAIOInit(gba);
 79
 80	gba->sio.p = gba;
 81	GBASIOInit(&gba->sio);
 82
 83	GBAHardwareInit(&gba->memory.hw, NULL);
 84
 85	gba->springIRQ = 0;
 86	gba->keySource = 0;
 87	gba->rotationSource = 0;
 88	gba->luminanceSource = 0;
 89	gba->rtcSource = 0;
 90	gba->rumble = 0;
 91	gba->rr = 0;
 92
 93	gba->romVf = 0;
 94	gba->biosVf = 0;
 95
 96	gba->stream = NULL;
 97	gba->keyCallback = NULL;
 98	mCoreCallbacksListInit(&gba->coreCallbacks, 0);
 99
100	gba->biosChecksum = GBAChecksum(gba->memory.bios, SIZE_BIOS);
101
102	gba->idleOptimization = IDLE_LOOP_REMOVE;
103	gba->idleLoop = IDLE_LOOP_NONE;
104
105	gba->realisticTiming = true;
106	gba->hardCrash = true;
107	gba->allowOpposingDirections = true;
108
109	gba->performingDMA = false;
110
111	gba->isPristine = false;
112	gba->pristineRomSize = 0;
113	gba->yankedRomSize = 0;
114
115	mTimingInit(&gba->timing, &gba->cpu->cycles, &gba->cpu->nextEvent);
116}
117
118void GBAUnloadROM(struct GBA* gba) {
119	if (gba->memory.rom && !gba->isPristine) {
120		if (gba->yankedRomSize) {
121			gba->yankedRomSize = 0;
122		}
123		mappedMemoryFree(gba->memory.rom, SIZE_CART0);
124	}
125
126	if (gba->romVf) {
127#ifndef FIXED_ROM_BUFFER
128		gba->romVf->unmap(gba->romVf, gba->memory.rom, gba->pristineRomSize);
129#endif
130		gba->romVf->close(gba->romVf);
131		gba->romVf = NULL;
132	}
133	gba->memory.rom = NULL;
134	gba->isPristine = false;
135
136	GBASavedataDeinit(&gba->memory.savedata);
137	if (gba->memory.savedata.realVf) {
138		gba->memory.savedata.realVf->close(gba->memory.savedata.realVf);
139		gba->memory.savedata.realVf = 0;
140	}
141	gba->idleLoop = IDLE_LOOP_NONE;
142}
143
144void GBADestroy(struct GBA* gba) {
145	GBAUnloadROM(gba);
146
147	if (gba->biosVf) {
148		gba->biosVf->unmap(gba->biosVf, gba->memory.bios, SIZE_BIOS);
149		gba->biosVf->close(gba->biosVf);
150		gba->biosVf = 0;
151	}
152
153	GBAMemoryDeinit(gba);
154	GBAVideoDeinit(&gba->video);
155	GBAAudioDeinit(&gba->audio);
156	GBASIODeinit(&gba->sio);
157	gba->rr = 0;
158	mTimingDeinit(&gba->timing);
159	mCoreCallbacksListDeinit(&gba->coreCallbacks);
160}
161
162void GBAInterruptHandlerInit(struct ARMInterruptHandler* irqh) {
163	irqh->reset = GBAReset;
164	irqh->processEvents = GBAProcessEvents;
165	irqh->swi16 = GBASwi16;
166	irqh->swi32 = GBASwi32;
167	irqh->hitIllegal = GBAIllegal;
168	irqh->readCPSR = GBATestIRQ;
169	irqh->hitStub = GBAHitStub;
170	irqh->bkpt16 = GBABreakpoint;
171	irqh->bkpt32 = GBABreakpoint;
172}
173
174void GBAReset(struct ARMCore* cpu) {
175	ARMSetPrivilegeMode(cpu, MODE_IRQ);
176	cpu->gprs[ARM_SP] = SP_BASE_IRQ;
177	ARMSetPrivilegeMode(cpu, MODE_SUPERVISOR);
178	cpu->gprs[ARM_SP] = SP_BASE_SUPERVISOR;
179	ARMSetPrivilegeMode(cpu, MODE_SYSTEM);
180	cpu->gprs[ARM_SP] = SP_BASE_SYSTEM;
181
182	struct GBA* gba = (struct GBA*) cpu->master;
183	if (!gba->rr || (!gba->rr->isPlaying(gba->rr) && !gba->rr->isRecording(gba->rr))) {
184		GBASavedataUnmask(&gba->memory.savedata);
185	}
186
187	gba->cpuBlocked = false;
188	gba->earlyExit = false;
189	if (gba->yankedRomSize) {
190		gba->memory.romSize = gba->yankedRomSize;
191		gba->memory.romMask = toPow2(gba->memory.romSize) - 1;
192		gba->yankedRomSize = 0;
193	}
194	mTimingClear(&gba->timing);
195	GBAMemoryReset(gba);
196	GBAVideoReset(&gba->video);
197	GBAAudioReset(&gba->audio);
198	GBAIOInit(gba);
199	GBATimerInit(gba);
200
201	GBASIOReset(&gba->sio);
202
203	gba->lastJump = 0;
204	gba->haltPending = false;
205	gba->idleDetectionStep = 0;
206	gba->idleDetectionFailures = 0;
207
208	gba->debug = false;
209	memset(gba->debugString, 0, sizeof(gba->debugString));
210
211	if (!gba->romVf && gba->memory.rom) {
212		GBASkipBIOS(gba);
213	}
214}
215
216void GBASkipBIOS(struct GBA* gba) {
217	struct ARMCore* cpu = gba->cpu;
218	if (cpu->gprs[ARM_PC] == BASE_RESET + WORD_SIZE_ARM) {
219		if (gba->memory.rom) {
220			cpu->gprs[ARM_PC] = BASE_CART0;
221		} else {
222			cpu->gprs[ARM_PC] = BASE_WORKING_RAM;
223		}
224		gba->memory.io[REG_VCOUNT >> 1] = 0x7E;
225		gba->memory.io[REG_POSTFLG >> 1] = 1;
226		int currentCycles = 0;
227		ARM_WRITE_PC;
228	}
229}
230
231static void GBAProcessEvents(struct ARMCore* cpu) {
232	struct GBA* gba = (struct GBA*) cpu->master;
233
234	gba->bus = cpu->prefetch[1];
235	if (cpu->executionMode == MODE_THUMB) {
236		gba->bus |= cpu->prefetch[1] << 16;
237	}
238
239	if (gba->springIRQ && !cpu->cpsr.i) {
240		ARMRaiseIRQ(cpu);
241		gba->springIRQ = 0;
242	}
243
244	int32_t nextEvent = cpu->nextEvent;
245	while (cpu->cycles >= nextEvent) {
246		cpu->nextEvent = INT_MAX;
247		nextEvent = 0;
248		do {
249			int32_t cycles = cpu->cycles;
250			cpu->cycles = 0;
251#ifndef NDEBUG
252			if (cycles < 0) {
253				mLOG(GBA, FATAL, "Negative cycles passed: %i", cycles);
254			}
255#endif
256			nextEvent = mTimingTick(&gba->timing, nextEvent + cycles);
257		} while (gba->cpuBlocked);
258
259		cpu->nextEvent = nextEvent;
260
261		if (gba->earlyExit) {
262			gba->earlyExit = false;
263			break;
264		}
265		if (cpu->halted) {
266			cpu->cycles = nextEvent;
267			if (!gba->memory.io[REG_IME >> 1] || !gba->memory.io[REG_IE >> 1]) {
268				break;
269			}
270		}
271#ifndef NDEBUG
272		else if (nextEvent < 0) {
273			mLOG(GBA, FATAL, "Negative cycles will pass: %i", nextEvent);
274		}
275#endif
276	}
277#ifndef NDEBUG
278	if (gba->cpuBlocked) {
279		mLOG(GBA, FATAL, "CPU is blocked!");
280	}
281#endif
282}
283
284#ifdef USE_DEBUGGERS
285void GBAAttachDebugger(struct GBA* gba, struct mDebugger* debugger) {
286	gba->debugger = (struct ARMDebugger*) debugger->platform;
287	gba->debugger->setSoftwareBreakpoint = _setSoftwareBreakpoint;
288	gba->debugger->clearSoftwareBreakpoint = _clearSoftwareBreakpoint;
289	gba->cpu->components[CPU_COMPONENT_DEBUGGER] = &debugger->d;
290	ARMHotplugAttach(gba->cpu, CPU_COMPONENT_DEBUGGER);
291}
292
293void GBADetachDebugger(struct GBA* gba) {
294	if (gba->debugger) {
295		ARMHotplugDetach(gba->cpu, CPU_COMPONENT_DEBUGGER);
296	}
297	gba->cpu->components[CPU_COMPONENT_DEBUGGER] = NULL;
298	gba->debugger = NULL;
299}
300#endif
301
302bool GBALoadNull(struct GBA* gba) {
303	GBAUnloadROM(gba);
304	gba->romVf = NULL;
305	gba->pristineRomSize = 0;
306#ifndef FIXED_ROM_BUFFER
307	gba->memory.rom = anonymousMemoryMap(SIZE_CART0);
308#else
309	gba->memory.rom = romBuffer;
310#endif
311	gba->isPristine = false;
312	gba->yankedRomSize = 0;
313	gba->memory.romSize = SIZE_CART0;
314	gba->memory.romMask = SIZE_CART0 - 1;
315	gba->memory.mirroring = false;
316	gba->romCrc32 = 0;
317
318	if (gba->cpu) {
319		gba->cpu->memory.setActiveRegion(gba->cpu, gba->cpu->gprs[ARM_PC]);
320	}
321	return true;
322}
323
324bool GBALoadMB(struct GBA* gba, struct VFile* vf) {
325	GBAUnloadROM(gba);
326	gba->romVf = vf;
327	gba->pristineRomSize = vf->size(vf);
328	vf->seek(vf, 0, SEEK_SET);
329	if (gba->pristineRomSize > SIZE_WORKING_RAM) {
330		gba->pristineRomSize = SIZE_WORKING_RAM;
331	}
332	gba->isPristine = true;
333	memset(gba->memory.wram, 0, SIZE_WORKING_RAM);
334	vf->read(vf, gba->memory.wram, gba->pristineRomSize);
335	if (!gba->memory.wram) {
336		mLOG(GBA, WARN, "Couldn't map ROM");
337		return false;
338	}
339	gba->yankedRomSize = 0;
340	gba->memory.romSize = 0;
341	gba->memory.romMask = 0;
342	gba->romCrc32 = doCrc32(gba->memory.wram, gba->pristineRomSize);
343	if (gba->cpu && gba->memory.activeRegion == REGION_WORKING_RAM) {
344		gba->cpu->memory.setActiveRegion(gba->cpu, gba->cpu->gprs[ARM_PC]);
345	}
346	return true;
347}
348
349bool GBALoadROM(struct GBA* gba, struct VFile* vf) {
350	if (!vf) {
351		return false;
352	}
353	GBAUnloadROM(gba);
354	gba->romVf = vf;
355	gba->pristineRomSize = vf->size(vf);
356	vf->seek(vf, 0, SEEK_SET);
357	if (gba->pristineRomSize > SIZE_CART0) {
358		gba->pristineRomSize = SIZE_CART0;
359	}
360	gba->isPristine = true;
361#ifdef FIXED_ROM_BUFFER
362	if (gba->pristineRomSize <= romBufferSize) {
363		gba->memory.rom = romBuffer;
364		vf->read(vf, romBuffer, gba->pristineRomSize);
365	}
366#else
367	gba->memory.rom = vf->map(vf, gba->pristineRomSize, MAP_READ);
368#endif
369	if (!gba->memory.rom) {
370		mLOG(GBA, WARN, "Couldn't map ROM");
371		return false;
372	}
373	gba->yankedRomSize = 0;
374	gba->memory.romSize = gba->pristineRomSize;
375	gba->memory.romMask = toPow2(gba->memory.romSize) - 1;
376	gba->memory.mirroring = false;
377	gba->romCrc32 = doCrc32(gba->memory.rom, gba->memory.romSize);
378	GBAHardwareInit(&gba->memory.hw, &((uint16_t*) gba->memory.rom)[GPIO_REG_DATA >> 1]);
379	GBAVFameDetect(&gba->memory.vfame, gba->memory.rom, gba->memory.romSize);
380	if (popcount32(gba->memory.romSize) != 1) {
381		// This ROM is either a bad dump or homebrew. Emulate flash cart behavior.
382#ifndef FIXED_ROM_BUFFER
383		void* newRom = anonymousMemoryMap(SIZE_CART0);
384		memcpy(newRom, gba->memory.rom, gba->pristineRomSize);
385		gba->memory.rom = newRom;
386#endif
387		gba->memory.romSize = SIZE_CART0;
388		gba->isPristine = false;
389	}
390	if (gba->cpu && gba->memory.activeRegion >= REGION_CART0) {
391		gba->cpu->memory.setActiveRegion(gba->cpu, gba->cpu->gprs[ARM_PC]);
392	}
393	// TODO: error check
394	return true;
395}
396
397bool GBALoadSave(struct GBA* gba, struct VFile* sav) {
398	GBASavedataInit(&gba->memory.savedata, sav);
399	return true;
400}
401
402void GBAYankROM(struct GBA* gba) {
403	gba->yankedRomSize = gba->memory.romSize;
404	gba->memory.romSize = 0;
405	gba->memory.romMask = 0;
406	GBARaiseIRQ(gba, IRQ_GAMEPAK);
407}
408
409void GBALoadBIOS(struct GBA* gba, struct VFile* vf) {
410	gba->biosVf = vf;
411	uint32_t* bios = vf->map(vf, SIZE_BIOS, MAP_READ);
412	if (!bios) {
413		mLOG(GBA, WARN, "Couldn't map BIOS");
414		return;
415	}
416	gba->memory.bios = bios;
417	gba->memory.fullBios = 1;
418	uint32_t checksum = GBAChecksum(gba->memory.bios, SIZE_BIOS);
419	mLOG(GBA, DEBUG, "BIOS Checksum: 0x%X", checksum);
420	if (checksum == GBA_BIOS_CHECKSUM) {
421		mLOG(GBA, INFO, "Official GBA BIOS detected");
422	} else if (checksum == GBA_DS_BIOS_CHECKSUM) {
423		mLOG(GBA, INFO, "Official GBA (DS) BIOS detected");
424	} else {
425		mLOG(GBA, WARN, "BIOS checksum incorrect");
426	}
427	gba->biosChecksum = checksum;
428	if (gba->memory.activeRegion == REGION_BIOS) {
429		gba->cpu->memory.activeRegion = gba->memory.bios;
430	}
431	// TODO: error check
432}
433
434void GBAApplyPatch(struct GBA* gba, struct Patch* patch) {
435	size_t patchedSize = patch->outputSize(patch, gba->memory.romSize);
436	if (!patchedSize || patchedSize > SIZE_CART0) {
437		return;
438	}
439	void* newRom = anonymousMemoryMap(SIZE_CART0);
440	if (!patch->applyPatch(patch, gba->memory.rom, gba->pristineRomSize, newRom, patchedSize)) {
441		mappedMemoryFree(newRom, SIZE_CART0);
442		return;
443	}
444	if (gba->romVf) {
445#ifndef FIXED_ROM_BUFFER
446		gba->romVf->unmap(gba->romVf, gba->memory.rom, gba->pristineRomSize);
447#endif
448		gba->romVf->close(gba->romVf);
449		gba->romVf = NULL;
450	}
451	gba->isPristine = false;
452	gba->memory.rom = newRom;
453	gba->memory.hw.gpioBase = &((uint16_t*) gba->memory.rom)[GPIO_REG_DATA >> 1];
454	gba->memory.romSize = patchedSize;
455	gba->memory.romMask = SIZE_CART0 - 1;
456	gba->romCrc32 = doCrc32(gba->memory.rom, gba->memory.romSize);
457}
458
459void GBAWriteIE(struct GBA* gba, uint16_t value) {
460	if (gba->memory.io[REG_IME >> 1] && value & gba->memory.io[REG_IF >> 1]) {
461		ARMRaiseIRQ(gba->cpu);
462	}
463}
464
465void GBAWriteIME(struct GBA* gba, uint16_t value) {
466	if (value && gba->memory.io[REG_IE >> 1] & gba->memory.io[REG_IF >> 1]) {
467		ARMRaiseIRQ(gba->cpu);
468	}
469}
470
471void GBARaiseIRQ(struct GBA* gba, enum GBAIRQ irq) {
472	gba->memory.io[REG_IF >> 1] |= 1 << irq;
473
474	if (gba->memory.io[REG_IE >> 1] & 1 << irq) {
475		gba->cpu->halted = 0;
476		if (gba->memory.io[REG_IME >> 1]) {
477			ARMRaiseIRQ(gba->cpu);
478		}
479	}
480}
481
482void GBATestIRQ(struct ARMCore* cpu) {
483	struct GBA* gba = (struct GBA*) cpu->master;
484	if (gba->memory.io[REG_IME >> 1] && gba->memory.io[REG_IE >> 1] & gba->memory.io[REG_IF >> 1]) {
485		gba->springIRQ = gba->memory.io[REG_IE >> 1] & gba->memory.io[REG_IF >> 1];
486		gba->cpu->nextEvent = gba->cpu->cycles;
487	}
488}
489
490void GBAHalt(struct GBA* gba) {
491	gba->cpu->nextEvent = gba->cpu->cycles;
492	gba->cpu->halted = 1;
493}
494
495void GBAStop(struct GBA* gba) {
496	size_t c;
497	for (c = 0; c < mCoreCallbacksListSize(&gba->coreCallbacks); ++c) {
498		struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gba->coreCallbacks, c);
499		if (callbacks->sleep) {
500			callbacks->sleep(callbacks->context);
501		}
502	}
503	gba->cpu->nextEvent = gba->cpu->cycles;
504}
505
506void GBADebug(struct GBA* gba, uint16_t flags) {
507	gba->debugFlags = flags;
508	if (GBADebugFlagsIsSend(gba->debugFlags)) {
509		int level = 1 << GBADebugFlagsGetLevel(gba->debugFlags);
510		level &= 0x1F;
511		char oolBuf[0x101];
512		strncpy(oolBuf, gba->debugString, sizeof(gba->debugString));
513		oolBuf[0x100] = '\0';
514		mLog(_mLOG_CAT_GBA_DEBUG(), level, "%s", oolBuf);
515	}
516	gba->debugFlags = GBADebugFlagsClearSend(gba->debugFlags);
517}
518
519bool GBAIsROM(struct VFile* vf) {
520#ifdef USE_ELF
521	struct ELF* elf = ELFOpen(vf);
522	if (elf) {
523		uint32_t entry = ELFEntry(elf);
524		bool isGBA = true;
525		isGBA = isGBA && ELFMachine(elf) == EM_ARM;
526		isGBA = isGBA && (entry == BASE_CART0 || entry == BASE_WORKING_RAM);
527		ELFClose(elf);
528		return isGBA;
529	}
530#endif
531	if (!vf) {
532		return false;
533	}
534	if (vf->seek(vf, GBA_ROM_MAGIC_OFFSET, SEEK_SET) < 0) {
535		return false;
536	}
537	uint8_t signature[sizeof(GBA_ROM_MAGIC)];
538	if (vf->read(vf, &signature, sizeof(signature)) != sizeof(signature)) {
539		return false;
540	}
541	if (GBAIsBIOS(vf)) {
542		return false;
543	}
544	return memcmp(signature, GBA_ROM_MAGIC, sizeof(signature)) == 0;
545}
546
547bool GBAIsMB(struct VFile* vf) {
548	if (!GBAIsROM(vf)) {
549		return false;
550	}
551#ifdef USE_ELF
552	struct ELF* elf = ELFOpen(vf);
553	if (elf) {
554		bool isMB = ELFEntry(elf) == BASE_WORKING_RAM;
555		ELFClose(elf);
556		return isMB;
557	}
558#endif
559	if (vf->size(vf) > SIZE_WORKING_RAM) {
560		return false;
561	}
562	if (vf->seek(vf, GBA_MB_MAGIC_OFFSET, SEEK_SET) < 0) {
563		return false;
564	}
565	uint32_t signature;
566	if (vf->read(vf, &signature, sizeof(signature)) != sizeof(signature)) {
567		return false;
568	}
569	uint32_t opcode;
570	LOAD_32(opcode, 0, &signature);
571	struct ARMInstructionInfo info;
572	ARMDecodeARM(opcode, &info);
573	if (info.branchType == ARM_BRANCH) {
574		if (info.op1.immediate <= 0) {
575			return false;
576		} else if (info.op1.immediate == 28) {
577			// Ancient toolchain that is known to throw MB detection for a loop
578			return false;
579		} else if (info.op1.immediate != 24) {
580			return true;
581		}
582	}
583
584	uint32_t pc = GBA_MB_MAGIC_OFFSET;
585	int i;
586	for (i = 0; i < 80; ++i) {
587		if (vf->read(vf, &signature, sizeof(signature)) != sizeof(signature)) {
588			break;
589		}
590		pc += 4;
591		LOAD_32(opcode, 0, &signature);
592		ARMDecodeARM(opcode, &info);
593		if (info.mnemonic != ARM_MN_LDR) {
594			continue;
595		}
596		if ((info.operandFormat & ARM_OPERAND_MEMORY) && info.memory.baseReg == ARM_PC && info.memory.format & ARM_MEMORY_IMMEDIATE_OFFSET) {
597			uint32_t immediate = info.memory.offset.immediate;
598			if (info.memory.format & ARM_MEMORY_OFFSET_SUBTRACT) {
599				immediate = -immediate;
600			}
601			immediate += pc + 8;
602			if (vf->seek(vf, immediate, SEEK_SET) < 0) {
603				break;
604			}
605			if (vf->read(vf, &signature, sizeof(signature)) != sizeof(signature)) {
606				break;
607			}
608			LOAD_32(immediate, 0, &signature);
609			if (vf->seek(vf, pc, SEEK_SET) < 0) {
610				break;
611			}
612			if ((immediate & ~0x7FF) == BASE_WORKING_RAM) {
613				return true;
614			}
615		}
616	}
617	// Found a libgba-linked cart...these are a bit harder to detect.
618	return false;
619}
620
621bool GBAIsBIOS(struct VFile* vf) {
622	if (vf->seek(vf, 0, SEEK_SET) < 0) {
623		return false;
624	}
625	uint8_t interruptTable[7 * 4];
626	if (vf->read(vf, &interruptTable, sizeof(interruptTable)) != sizeof(interruptTable)) {
627		return false;
628	}
629	int i;
630	for (i = 0; i < 7; ++i) {
631		if (interruptTable[4 * i + 3] != 0xEA || interruptTable[4 * i + 2]) {
632			return false;
633		}
634	}
635	return true;
636}
637
638void GBAGetGameCode(const struct GBA* gba, char* out) {
639	memset(out, 0, 8);
640	if (!gba->memory.rom) {
641		return;
642	}
643
644	memcpy(out, "AGB-", 4);
645	memcpy(&out[4], &((struct GBACartridge*) gba->memory.rom)->id, 4);
646}
647
648void GBAGetGameTitle(const struct GBA* gba, char* out) {
649	if (gba->memory.rom) {
650		memcpy(out, &((struct GBACartridge*) gba->memory.rom)->title, 12);
651		return;
652	}
653	if (gba->isPristine && gba->memory.wram) {
654		memcpy(out, &((struct GBACartridge*) gba->memory.wram)->title, 12);
655		return;
656	}
657	strncpy(out, "(BIOS)", 12);
658}
659
660void GBAHitStub(struct ARMCore* cpu, uint32_t opcode) {
661	struct GBA* gba = (struct GBA*) cpu->master;
662#ifdef USE_DEBUGGERS
663	if (gba->debugger) {
664		struct mDebuggerEntryInfo info = {
665			.address = _ARMPCAddress(cpu),
666			.type.bp.opcode = opcode
667		};
668		mDebuggerEnter(gba->debugger->d.p, DEBUGGER_ENTER_ILLEGAL_OP, &info);
669	}
670#endif
671	// TODO: More sensible category?
672	mLOG(GBA, ERROR, "Stub opcode: %08x", opcode);
673}
674
675void GBAIllegal(struct ARMCore* cpu, uint32_t opcode) {
676	struct GBA* gba = (struct GBA*) cpu->master;
677	if (!gba->yankedRomSize) {
678		// TODO: More sensible category?
679		mLOG(GBA, WARN, "Illegal opcode: %08x", opcode);
680	}
681	if (cpu->executionMode == MODE_THUMB && (opcode & 0xFFC0) == 0xE800) {
682		mLOG(GBA, DEBUG, "Hit Wii U VC opcode: %08x", opcode);
683		return;
684	}
685#ifdef USE_DEBUGGERS
686	if (gba->debugger) {
687		struct mDebuggerEntryInfo info = {
688			.address = _ARMPCAddress(cpu),
689			.type.bp.opcode = opcode
690		};
691		mDebuggerEnter(gba->debugger->d.p, DEBUGGER_ENTER_ILLEGAL_OP, &info);
692	} else
693#endif
694	{
695		ARMRaiseUndefined(cpu);
696	}
697}
698
699void GBABreakpoint(struct ARMCore* cpu, int immediate) {
700	struct GBA* gba = (struct GBA*) cpu->master;
701	if (immediate >= CPU_COMPONENT_MAX) {
702		return;
703	}
704	switch (immediate) {
705#ifdef USE_DEBUGGERS
706	case CPU_COMPONENT_DEBUGGER:
707		if (gba->debugger) {
708			struct mDebuggerEntryInfo info = {
709				.address = _ARMPCAddress(cpu),
710				.type.bp.breakType = BREAKPOINT_SOFTWARE
711			};
712			mDebuggerEnter(gba->debugger->d.p, DEBUGGER_ENTER_BREAKPOINT, &info);
713		}
714		break;
715#endif
716	case CPU_COMPONENT_CHEAT_DEVICE:
717		if (gba->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
718			struct mCheatDevice* device = (struct mCheatDevice*) gba->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
719			struct GBACheatHook* hook = 0;
720			size_t i;
721			for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
722				struct GBACheatSet* cheats = (struct GBACheatSet*) *mCheatSetsGetPointer(&device->cheats, i);
723				if (cheats->hook && cheats->hook->address == _ARMPCAddress(cpu)) {
724					mCheatRefresh(device, &cheats->d);
725					hook = cheats->hook;
726				}
727			}
728			if (hook) {
729				ARMRunFake(cpu, hook->patchedOpcode);
730			}
731		}
732		break;
733	default:
734		break;
735	}
736}
737
738void GBAFrameStarted(struct GBA* gba) {
739	GBATestKeypadIRQ(gba);
740
741	size_t c;
742	for (c = 0; c < mCoreCallbacksListSize(&gba->coreCallbacks); ++c) {
743		struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gba->coreCallbacks, c);
744		if (callbacks->videoFrameStarted) {
745			callbacks->videoFrameStarted(callbacks->context);
746		}
747	}
748}
749
750void GBAFrameEnded(struct GBA* gba) {
751	GBASavedataClean(&gba->memory.savedata, gba->video.frameCounter);
752
753	if (gba->rr) {
754		gba->rr->nextFrame(gba->rr);
755	}
756
757	if (gba->cpu->components && gba->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
758		struct mCheatDevice* device = (struct mCheatDevice*) gba->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
759		size_t i;
760		for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
761			struct GBACheatSet* cheats = (struct GBACheatSet*) *mCheatSetsGetPointer(&device->cheats, i);
762			mCheatRefresh(device, &cheats->d);
763		}
764	}
765
766	if (gba->stream && gba->stream->postVideoFrame) {
767		const color_t* pixels;
768		size_t stride;
769		gba->video.renderer->getPixels(gba->video.renderer, &stride, (const void**) &pixels);
770		gba->stream->postVideoFrame(gba->stream, pixels, stride);
771	}
772
773	if (gba->memory.hw.devices & (HW_GB_PLAYER | HW_GB_PLAYER_DETECTION)) {
774		GBAHardwarePlayerUpdate(gba);
775	}
776
777	size_t c;
778	for (c = 0; c < mCoreCallbacksListSize(&gba->coreCallbacks); ++c) {
779		struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gba->coreCallbacks, c);
780		if (callbacks->videoFrameEnded) {
781			callbacks->videoFrameEnded(callbacks->context);
782		}
783	}
784}
785
786void GBATestKeypadIRQ(struct GBA* gba) {
787	uint16_t keycnt = gba->memory.io[REG_KEYCNT >> 1];
788	if (!(keycnt & 0x4000)) {
789		return;
790	}
791	int isAnd = keycnt & 0x8000;
792	if (!gba->keySource) {
793		// TODO?
794		return;
795	}
796
797	keycnt &= 0x3FF;
798	uint16_t keyInput = *gba->keySource & keycnt;
799
800	if (isAnd && keycnt == keyInput) {
801		GBARaiseIRQ(gba, IRQ_KEYPAD);
802	} else if (!isAnd && keyInput) {
803		GBARaiseIRQ(gba, IRQ_KEYPAD);
804	}
805}
806
807void GBASetBreakpoint(struct GBA* gba, struct mCPUComponent* component, uint32_t address, enum ExecutionMode mode, uint32_t* opcode) {
808	size_t immediate;
809	for (immediate = 0; immediate < gba->cpu->numComponents; ++immediate) {
810		if (gba->cpu->components[immediate] == component) {
811			break;
812		}
813	}
814	if (immediate == gba->cpu->numComponents) {
815		return;
816	}
817	if (mode == MODE_ARM) {
818		int32_t value;
819		int32_t old;
820		value = 0xE1200070;
821		value |= immediate & 0xF;
822		value |= (immediate & 0xFFF0) << 4;
823		GBAPatch32(gba->cpu, address, value, &old);
824		*opcode = old;
825	} else {
826		int16_t value;
827		int16_t old;
828		value = 0xBE00;
829		value |= immediate & 0xFF;
830		GBAPatch16(gba->cpu, address, value, &old);
831		*opcode = (uint16_t) old;
832	}
833}
834
835void GBAClearBreakpoint(struct GBA* gba, uint32_t address, enum ExecutionMode mode, uint32_t opcode) {
836	if (mode == MODE_ARM) {
837		GBAPatch32(gba->cpu, address, opcode, 0);
838	} else {
839		GBAPatch16(gba->cpu, address, opcode, 0);
840	}
841}
842
843static bool _setSoftwareBreakpoint(struct ARMDebugger* debugger, uint32_t address, enum ExecutionMode mode, uint32_t* opcode) {
844	GBASetBreakpoint((struct GBA*) debugger->cpu->master, &debugger->d.p->d, address, mode, opcode);
845	return true;
846}
847
848static bool _clearSoftwareBreakpoint(struct ARMDebugger* debugger, uint32_t address, enum ExecutionMode mode, uint32_t opcode) {
849	GBAClearBreakpoint((struct GBA*) debugger->cpu->master, address, mode, opcode);
850	return true;
851}