all repos — mgba @ 1a6d5ad7e3f28e01e747f634384e3775c562e119

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