all repos — mgba @ 98a6510b927d969e22043c5a1caedadc9e7204b4

mGBA Game Boy Advance Emulator

src/gba/gba.c (view raw)

  1/* Copyright (c) 2013-2014 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-io.h"
 10#include "gba-rr.h"
 11#include "gba-sio.h"
 12#include "gba-thread.h"
 13
 14#include "isa-inlines.h"
 15
 16#include "util/crc32.h"
 17#include "util/memory.h"
 18#include "util/patch.h"
 19#include "util/vfs.h"
 20
 21const uint32_t GBA_ARM7TDMI_FREQUENCY = 0x1000000;
 22const uint32_t GBA_COMPONENT_MAGIC = 0x1000000;
 23
 24static const size_t GBA_ROM_MAGIC_OFFSET = 2;
 25static const uint8_t GBA_ROM_MAGIC[] = { 0x00, 0xEA };
 26
 27enum {
 28	SP_BASE_SYSTEM = 0x03FFFF00,
 29	SP_BASE_IRQ = 0x03FFFFA0,
 30	SP_BASE_SUPERVISOR = 0x03FFFFE0
 31};
 32
 33struct GBACartridgeOverride {
 34	const char id[4];
 35	enum SavedataType type;
 36	int gpio;
 37	uint32_t busyLoop;
 38};
 39
 40static const struct GBACartridgeOverride _overrides[] = {
 41	// Boktai: The Sun is in Your Hand
 42	{ "U3IE", SAVEDATA_EEPROM, GPIO_RTC | GPIO_LIGHT_SENSOR, -1 },
 43	{ "U3IP", SAVEDATA_EEPROM, GPIO_RTC | GPIO_LIGHT_SENSOR, -1 },
 44
 45	// Boktai 2: Solar Boy Django
 46	{ "U32E", SAVEDATA_EEPROM, GPIO_RTC | GPIO_LIGHT_SENSOR, -1 },
 47	{ "U32P", SAVEDATA_EEPROM, GPIO_RTC | GPIO_LIGHT_SENSOR, -1 },
 48
 49	// Drill Dozer
 50	{ "V49J", SAVEDATA_SRAM, GPIO_RUMBLE, -1 },
 51	{ "V49E", SAVEDATA_SRAM, GPIO_RUMBLE, -1 },
 52
 53	// Final Fantasy Tactics Advance
 54	{ "AFXE", SAVEDATA_FLASH512, GPIO_NONE, 0x8000418 },
 55
 56	// Koro Koro Puzzle - Happy Panechu!
 57	{ "KHPJ", SAVEDATA_EEPROM, GPIO_TILT, -1 },
 58
 59	// Mega Man Battle Network
 60	{ "AREE", SAVEDATA_SRAM, GPIO_NONE, 0x800032E },
 61
 62	// Pokemon Ruby
 63	{ "AXVJ", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 64	{ "AXVE", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 65	{ "AXVP", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 66	{ "AXVI", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 67	{ "AXVS", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 68	{ "AXVD", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 69	{ "AXVF", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 70
 71	// Pokemon Sapphire
 72	{ "AXPJ", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 73	{ "AXPE", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 74	{ "AXPP", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 75	{ "AXPI", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 76	{ "AXPS", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 77	{ "AXPD", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 78	{ "AXPF", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 79
 80	// Pokemon Emerald
 81	{ "BPEJ", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 82	{ "BPEE", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 83	{ "BPEP", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 84	{ "BPEI", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 85	{ "BPES", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 86	{ "BPED", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 87	{ "BPEF", SAVEDATA_FLASH1M, GPIO_RTC, -1 },
 88
 89	// Pokemon Mystery Dungeon
 90	{ "B24J", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
 91	{ "B24E", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
 92	{ "B24P", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
 93	{ "B24U", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
 94
 95	// Pokemon FireRed
 96	{ "BPRJ", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
 97	{ "BPRE", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
 98	{ "BPRP", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
 99
100	// Pokemon LeafGreen
101	{ "BPGJ", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
102	{ "BPGE", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
103	{ "BPGP", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
104
105	// RockMan EXE 4.5 - Real Operation
106	{ "BR4J", SAVEDATA_FLASH512, GPIO_RTC, -1 },
107
108	// Super Mario Advance 4
109	{ "AX4J", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
110	{ "AX4E", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
111	{ "AX4P", SAVEDATA_FLASH1M, GPIO_NONE, -1 },
112
113	// Wario Ware Twisted
114	{ "RZWJ", SAVEDATA_SRAM, GPIO_RUMBLE | GPIO_GYRO, -1 },
115	{ "RZWE", SAVEDATA_SRAM, GPIO_RUMBLE | GPIO_GYRO, -1 },
116	{ "RZWP", SAVEDATA_SRAM, GPIO_RUMBLE | GPIO_GYRO, -1 },
117
118	// Yoshi's Universal Gravitation
119	{ "KYGJ", SAVEDATA_EEPROM, GPIO_TILT, -1 },
120	{ "KYGE", SAVEDATA_EEPROM, GPIO_TILT, -1 },
121	{ "KYGP", SAVEDATA_EEPROM, GPIO_TILT, -1 },
122
123	{ { 0, 0, 0, 0 }, 0, 0, -1 }
124};
125
126static void GBAInit(struct ARMCore* cpu, struct ARMComponent* component);
127static void GBAInterruptHandlerInit(struct ARMInterruptHandler* irqh);
128static void GBAProcessEvents(struct ARMCore* cpu);
129static int32_t GBATimersProcessEvents(struct GBA* gba, int32_t cycles);
130static void GBAHitStub(struct ARMCore* cpu, uint32_t opcode);
131static void GBAIllegal(struct ARMCore* cpu, uint32_t opcode);
132
133static void _checkOverrides(struct GBA* gba, uint32_t code);
134
135void GBACreate(struct GBA* gba) {
136	gba->d.id = GBA_COMPONENT_MAGIC;
137	gba->d.init = GBAInit;
138	gba->d.deinit = 0;
139}
140
141static void GBAInit(struct ARMCore* cpu, struct ARMComponent* component) {
142	struct GBA* gba = (struct GBA*) component;
143	gba->cpu = cpu;
144	gba->debugger = 0;
145
146	GBAInterruptHandlerInit(&cpu->irqh);
147	GBAMemoryInit(gba);
148	GBASavedataInit(&gba->memory.savedata, 0);
149
150	gba->video.p = gba;
151	GBAVideoInit(&gba->video);
152
153	gba->audio.p = gba;
154	GBAAudioInit(&gba->audio, GBA_AUDIO_SAMPLES);
155
156	GBAIOInit(gba);
157
158	gba->sio.p = gba;
159	GBASIOInit(&gba->sio);
160
161	gba->timersEnabled = 0;
162	memset(gba->timers, 0, sizeof(gba->timers));
163
164	gba->springIRQ = 0;
165	gba->keySource = 0;
166	gba->rotationSource = 0;
167	gba->luminanceSource = 0;
168	gba->rtcSource = 0;
169	gba->rumble = 0;
170	gba->rr = 0;
171
172	gba->romVf = 0;
173	gba->biosVf = 0;
174
175	gba->logLevel = GBA_LOG_INFO | GBA_LOG_WARN | GBA_LOG_ERROR | GBA_LOG_FATAL;
176
177	gba->biosChecksum = GBAChecksum(gba->memory.bios, SIZE_BIOS);
178
179	gba->busyLoop = -1;
180}
181
182void GBADestroy(struct GBA* gba) {
183	if (gba->pristineRom == gba->memory.rom) {
184		gba->memory.rom = 0;
185	}
186
187	if (gba->romVf) {
188		gba->romVf->unmap(gba->romVf, gba->pristineRom, gba->pristineRomSize);
189	}
190
191	if (gba->biosVf) {
192		gba->biosVf->unmap(gba->biosVf, gba->memory.bios, SIZE_BIOS);
193	}
194
195	GBAMemoryDeinit(gba);
196	GBAVideoDeinit(&gba->video);
197	GBAAudioDeinit(&gba->audio);
198	GBARRContextDestroy(gba);
199}
200
201void GBAInterruptHandlerInit(struct ARMInterruptHandler* irqh) {
202	irqh->reset = GBAReset;
203	irqh->processEvents = GBAProcessEvents;
204	irqh->swi16 = GBASwi16;
205	irqh->swi32 = GBASwi32;
206	irqh->hitIllegal = GBAIllegal;
207	irqh->readCPSR = GBATestIRQ;
208	irqh->hitStub = GBAHitStub;
209}
210
211void GBAReset(struct ARMCore* cpu) {
212	ARMSetPrivilegeMode(cpu, MODE_IRQ);
213	cpu->gprs[ARM_SP] = SP_BASE_IRQ;
214	ARMSetPrivilegeMode(cpu, MODE_SUPERVISOR);
215	cpu->gprs[ARM_SP] = SP_BASE_SUPERVISOR;
216	ARMSetPrivilegeMode(cpu, MODE_SYSTEM);
217	cpu->gprs[ARM_SP] = SP_BASE_SYSTEM;
218
219	struct GBA* gba = (struct GBA*) cpu->master;
220	if (!GBARRIsPlaying(gba->rr) && !GBARRIsRecording(gba->rr)) {
221		GBASavedataUnmask(&gba->memory.savedata);
222	}
223	GBAMemoryReset(gba);
224	GBAVideoReset(&gba->video);
225	GBAAudioReset(&gba->audio);
226	GBAIOInit(gba);
227
228	GBASIODeinit(&gba->sio);
229	GBASIOInit(&gba->sio);
230
231	gba->timersEnabled = 0;
232	memset(gba->timers, 0, sizeof(gba->timers));
233}
234
235void GBASkipBIOS(struct ARMCore* cpu) {
236	if (cpu->gprs[ARM_PC] == BASE_RESET + WORD_SIZE_ARM) {
237		cpu->gprs[ARM_PC] = BASE_CART0;
238		int currentCycles = 0;
239		ARM_WRITE_PC;
240	}
241}
242
243static void GBAProcessEvents(struct ARMCore* cpu) {
244	do {
245		struct GBA* gba = (struct GBA*) cpu->master;
246		int32_t cycles = cpu->cycles;
247		int32_t nextEvent = INT_MAX;
248		int32_t testEvent;
249
250		gba->bus = cpu->prefetch[1];
251		if (cpu->executionMode == MODE_THUMB) {
252			gba->bus |= cpu->prefetch[1] << 16;
253		}
254
255		if (gba->springIRQ) {
256			ARMRaiseIRQ(cpu);
257			gba->springIRQ = 0;
258		}
259
260		testEvent = GBAVideoProcessEvents(&gba->video, cycles);
261		if (testEvent < nextEvent) {
262			nextEvent = testEvent;
263		}
264
265		testEvent = GBAAudioProcessEvents(&gba->audio, cycles);
266		if (testEvent < nextEvent) {
267			nextEvent = testEvent;
268		}
269
270		testEvent = GBATimersProcessEvents(gba, cycles);
271		if (testEvent < nextEvent) {
272			nextEvent = testEvent;
273		}
274
275		testEvent = GBAMemoryRunDMAs(gba, cycles);
276		if (testEvent < nextEvent) {
277			nextEvent = testEvent;
278		}
279
280		testEvent = GBASIOProcessEvents(&gba->sio, cycles);
281		if (testEvent < nextEvent) {
282			nextEvent = testEvent;
283		}
284
285		cpu->cycles -= cycles;
286		cpu->nextEvent = nextEvent;
287
288		if (cpu->halted) {
289			cpu->cycles = cpu->nextEvent;
290		}
291	} while (cpu->cycles >= cpu->nextEvent);
292}
293
294static int32_t GBATimersProcessEvents(struct GBA* gba, int32_t cycles) {
295	int32_t nextEvent = INT_MAX;
296	if (gba->timersEnabled) {
297		struct GBATimer* timer;
298		struct GBATimer* nextTimer;
299
300		timer = &gba->timers[0];
301		if (timer->enable) {
302			timer->nextEvent -= cycles;
303			timer->lastEvent -= cycles;
304			if (timer->nextEvent <= 0) {
305				timer->lastEvent = timer->nextEvent;
306				timer->nextEvent += timer->overflowInterval;
307				gba->memory.io[REG_TM0CNT_LO >> 1] = timer->reload;
308				timer->oldReload = timer->reload;
309
310				if (timer->doIrq) {
311					GBARaiseIRQ(gba, IRQ_TIMER0);
312				}
313
314				if (gba->audio.enable) {
315					if ((gba->audio.chALeft || gba->audio.chARight) && gba->audio.chATimer == 0) {
316						GBAAudioSampleFIFO(&gba->audio, 0, timer->lastEvent);
317					}
318
319					if ((gba->audio.chBLeft || gba->audio.chBRight) && gba->audio.chBTimer == 0) {
320						GBAAudioSampleFIFO(&gba->audio, 1, timer->lastEvent);
321					}
322				}
323
324				nextTimer = &gba->timers[1];
325				if (nextTimer->countUp) {
326					++gba->memory.io[REG_TM1CNT_LO >> 1];
327					if (!gba->memory.io[REG_TM1CNT_LO >> 1]) {
328						nextTimer->nextEvent = 0;
329					}
330				}
331			}
332			nextEvent = timer->nextEvent;
333		}
334
335		timer = &gba->timers[1];
336		if (timer->enable) {
337			timer->nextEvent -= cycles;
338			timer->lastEvent -= cycles;
339			if (timer->nextEvent <= 0) {
340				timer->lastEvent = timer->nextEvent;
341				timer->nextEvent += timer->overflowInterval;
342				gba->memory.io[REG_TM1CNT_LO >> 1] = timer->reload;
343				timer->oldReload = timer->reload;
344
345				if (timer->doIrq) {
346					GBARaiseIRQ(gba, IRQ_TIMER1);
347				}
348
349				if (gba->audio.enable) {
350					if ((gba->audio.chALeft || gba->audio.chARight) && gba->audio.chATimer == 1) {
351						GBAAudioSampleFIFO(&gba->audio, 0, timer->lastEvent);
352					}
353
354					if ((gba->audio.chBLeft || gba->audio.chBRight) && gba->audio.chBTimer == 1) {
355						GBAAudioSampleFIFO(&gba->audio, 1, timer->lastEvent);
356					}
357				}
358
359				if (timer->countUp) {
360					timer->nextEvent = INT_MAX;
361				}
362
363				nextTimer = &gba->timers[2];
364				if (nextTimer->countUp) {
365					++gba->memory.io[REG_TM2CNT_LO >> 1];
366					if (!gba->memory.io[REG_TM2CNT_LO >> 1]) {
367						nextTimer->nextEvent = 0;
368					}
369				}
370			}
371			if (timer->nextEvent < nextEvent) {
372				nextEvent = timer->nextEvent;
373			}
374		}
375
376		timer = &gba->timers[2];
377		if (timer->enable) {
378			timer->nextEvent -= cycles;
379			timer->lastEvent -= cycles;
380			nextEvent = timer->nextEvent;
381			if (timer->nextEvent <= 0) {
382				timer->lastEvent = timer->nextEvent;
383				timer->nextEvent += timer->overflowInterval;
384				gba->memory.io[REG_TM2CNT_LO >> 1] = timer->reload;
385				timer->oldReload = timer->reload;
386
387				if (timer->doIrq) {
388					GBARaiseIRQ(gba, IRQ_TIMER2);
389				}
390
391				if (timer->countUp) {
392					timer->nextEvent = INT_MAX;
393				}
394
395				nextTimer = &gba->timers[3];
396				if (nextTimer->countUp) {
397					++gba->memory.io[REG_TM3CNT_LO >> 1];
398					if (!gba->memory.io[REG_TM3CNT_LO >> 1]) {
399						nextTimer->nextEvent = 0;
400					}
401				}
402			}
403			if (timer->nextEvent < nextEvent) {
404				nextEvent = timer->nextEvent;
405			}
406		}
407
408		timer = &gba->timers[3];
409		if (timer->enable) {
410			timer->nextEvent -= cycles;
411			timer->lastEvent -= cycles;
412			nextEvent = timer->nextEvent;
413			if (timer->nextEvent <= 0) {
414				timer->lastEvent = timer->nextEvent;
415				timer->nextEvent += timer->overflowInterval;
416				gba->memory.io[REG_TM3CNT_LO >> 1] = timer->reload;
417				timer->oldReload = timer->reload;
418
419				if (timer->doIrq) {
420					GBARaiseIRQ(gba, IRQ_TIMER3);
421				}
422
423				if (timer->countUp) {
424					timer->nextEvent = INT_MAX;
425				}
426			}
427			if (timer->nextEvent < nextEvent) {
428				nextEvent = timer->nextEvent;
429			}
430		}
431	}
432	return nextEvent;
433}
434
435void GBAAttachDebugger(struct GBA* gba, struct ARMDebugger* debugger) {
436	gba->debugger = debugger;
437}
438
439void GBADetachDebugger(struct GBA* gba) {
440	gba->debugger = 0;
441}
442
443void GBALoadROM(struct GBA* gba, struct VFile* vf, struct VFile* sav, const char* fname) {
444	gba->romVf = vf;
445	gba->pristineRomSize = vf->seek(vf, 0, SEEK_END);
446	vf->seek(vf, 0, SEEK_SET);
447	if (gba->pristineRomSize > SIZE_CART0) {
448		gba->pristineRomSize = SIZE_CART0;
449	}
450	gba->pristineRom = vf->map(vf, gba->pristineRomSize, MAP_READ);
451	if (!gba->pristineRom) {
452		GBALog(gba, GBA_LOG_WARN, "Couldn't map ROM");
453		return;
454	}
455	gba->memory.rom = gba->pristineRom;
456	gba->activeFile = fname;
457	gba->memory.romSize = gba->pristineRomSize;
458	gba->romCrc32 = doCrc32(gba->memory.rom, gba->memory.romSize);
459	GBASavedataInit(&gba->memory.savedata, sav);
460	GBAGPIOInit(&gba->memory.gpio, &((uint16_t*) gba->memory.rom)[GPIO_REG_DATA >> 1]);
461	_checkOverrides(gba, ((struct GBACartridge*) gba->memory.rom)->id);
462	// TODO: error check
463}
464
465void GBALoadBIOS(struct GBA* gba, struct VFile* vf) {
466	gba->biosVf = vf;
467	uint32_t* bios = vf->map(vf, SIZE_BIOS, MAP_READ);
468	if (!bios) {
469		GBALog(gba, GBA_LOG_WARN, "Couldn't map BIOS");
470		return;
471	}
472	gba->memory.bios = bios;
473	gba->memory.fullBios = 1;
474	uint32_t checksum = GBAChecksum(gba->memory.bios, SIZE_BIOS);
475	GBALog(gba, GBA_LOG_DEBUG, "BIOS Checksum: 0x%X", checksum);
476	if (checksum == GBA_BIOS_CHECKSUM) {
477		GBALog(gba, GBA_LOG_INFO, "Official GBA BIOS detected");
478	} else if (checksum == GBA_DS_BIOS_CHECKSUM) {
479		GBALog(gba, GBA_LOG_INFO, "Official GBA (DS) BIOS detected");
480	} else {
481		GBALog(gba, GBA_LOG_WARN, "BIOS checksum incorrect");
482	}
483	gba->biosChecksum = checksum;
484	if (gba->memory.activeRegion == REGION_BIOS) {
485		gba->cpu->memory.activeRegion = gba->memory.bios;
486	}
487	// TODO: error check
488}
489
490void GBAApplyPatch(struct GBA* gba, struct Patch* patch) {
491	size_t patchedSize = patch->outputSize(patch, gba->memory.romSize);
492	if (!patchedSize) {
493		return;
494	}
495	gba->memory.rom = anonymousMemoryMap(patchedSize);
496	memcpy(gba->memory.rom, gba->pristineRom, gba->memory.romSize > patchedSize ? patchedSize : gba->memory.romSize);
497	if (!patch->applyPatch(patch, gba->memory.rom, patchedSize)) {
498		mappedMemoryFree(gba->memory.rom, patchedSize);
499		gba->memory.rom = gba->pristineRom;
500		return;
501	}
502	gba->memory.romSize = patchedSize;
503	gba->romCrc32 = doCrc32(gba->memory.rom, gba->memory.romSize);
504}
505
506void GBATimerUpdateRegister(struct GBA* gba, int timer) {
507	struct GBATimer* currentTimer = &gba->timers[timer];
508	if (currentTimer->enable && !currentTimer->countUp) {
509		gba->memory.io[(REG_TM0CNT_LO + (timer << 2)) >> 1] = currentTimer->oldReload + ((gba->cpu->cycles - currentTimer->lastEvent) >> currentTimer->prescaleBits);
510	}
511}
512
513void GBATimerWriteTMCNT_LO(struct GBA* gba, int timer, uint16_t reload) {
514	gba->timers[timer].reload = reload;
515}
516
517void GBATimerWriteTMCNT_HI(struct GBA* gba, int timer, uint16_t control) {
518	struct GBATimer* currentTimer = &gba->timers[timer];
519	GBATimerUpdateRegister(gba, timer);
520
521	int oldPrescale = currentTimer->prescaleBits;
522	switch (control & 0x0003) {
523	case 0x0000:
524		currentTimer->prescaleBits = 0;
525		break;
526	case 0x0001:
527		currentTimer->prescaleBits = 6;
528		break;
529	case 0x0002:
530		currentTimer->prescaleBits = 8;
531		break;
532	case 0x0003:
533		currentTimer->prescaleBits = 10;
534		break;
535	}
536	currentTimer->countUp = !!(control & 0x0004);
537	currentTimer->doIrq = !!(control & 0x0040);
538	currentTimer->overflowInterval = (0x10000 - currentTimer->reload) << currentTimer->prescaleBits;
539	int wasEnabled = currentTimer->enable;
540	currentTimer->enable = !!(control & 0x0080);
541	if (!wasEnabled && currentTimer->enable) {
542		if (!currentTimer->countUp) {
543			currentTimer->nextEvent = gba->cpu->cycles + currentTimer->overflowInterval;
544		} else {
545			currentTimer->nextEvent = INT_MAX;
546		}
547		gba->memory.io[(REG_TM0CNT_LO + (timer << 2)) >> 1] = currentTimer->reload;
548		currentTimer->oldReload = currentTimer->reload;
549		currentTimer->lastEvent = 0;
550		gba->timersEnabled |= 1 << timer;
551	} else if (wasEnabled && !currentTimer->enable) {
552		if (!currentTimer->countUp) {
553			gba->memory.io[(REG_TM0CNT_LO + (timer << 2)) >> 1] = currentTimer->oldReload + ((gba->cpu->cycles - currentTimer->lastEvent) >> oldPrescale);
554		}
555		gba->timersEnabled &= ~(1 << timer);
556	} else if (currentTimer->prescaleBits != oldPrescale && !currentTimer->countUp) {
557		// FIXME: this might be before present
558		currentTimer->nextEvent = currentTimer->lastEvent + currentTimer->overflowInterval;
559	}
560
561	if (currentTimer->nextEvent < gba->cpu->nextEvent) {
562		gba->cpu->nextEvent = currentTimer->nextEvent;
563	}
564};
565
566void GBAWriteIE(struct GBA* gba, uint16_t value) {
567	if (value & (1 << IRQ_KEYPAD)) {
568		GBALog(gba, GBA_LOG_STUB, "Keypad interrupts not implemented");
569	}
570
571	if (value & (1 << IRQ_GAMEPAK)) {
572		GBALog(gba, GBA_LOG_STUB, "Gamepak interrupts not implemented");
573	}
574
575	if (gba->memory.io[REG_IME >> 1] && value & gba->memory.io[REG_IF >> 1]) {
576		ARMRaiseIRQ(gba->cpu);
577	}
578}
579
580void GBAWriteIME(struct GBA* gba, uint16_t value) {
581	if (value && gba->memory.io[REG_IE >> 1] & gba->memory.io[REG_IF >> 1]) {
582		ARMRaiseIRQ(gba->cpu);
583	}
584}
585
586void GBARaiseIRQ(struct GBA* gba, enum GBAIRQ irq) {
587	gba->memory.io[REG_IF >> 1] |= 1 << irq;
588	gba->cpu->halted = 0;
589
590	if (gba->memory.io[REG_IME >> 1] && (gba->memory.io[REG_IE >> 1] & 1 << irq)) {
591		ARMRaiseIRQ(gba->cpu);
592	}
593}
594
595void GBATestIRQ(struct ARMCore* cpu) {
596	struct GBA* gba = (struct GBA*) cpu->master;
597	if (gba->memory.io[REG_IME >> 1] && gba->memory.io[REG_IE >> 1] & gba->memory.io[REG_IF >> 1]) {
598		gba->springIRQ = 1;
599		gba->cpu->nextEvent = 0;
600	}
601}
602
603void GBAHalt(struct GBA* gba) {
604	gba->cpu->nextEvent = 0;
605	gba->cpu->halted = 1;
606}
607
608static void _GBAVLog(struct GBA* gba, enum GBALogLevel level, const char* format, va_list args) {
609	struct GBAThread* threadContext = GBAThreadGetContext();
610	enum GBALogLevel logLevel = -1;
611
612	if (gba) {
613		logLevel = gba->logLevel;
614	}
615
616	if (threadContext) {
617		logLevel = threadContext->logLevel;
618	}
619
620	if (!(level & logLevel) && level != GBA_LOG_FATAL) {
621		return;
622	}
623
624	if (threadContext && threadContext->logHandler) {
625		threadContext->logHandler(threadContext, level, format, args);
626		return;
627	}
628
629	vprintf(format, args);
630	printf("\n");
631
632	if (level == GBA_LOG_FATAL) {
633		abort();
634	}
635}
636
637void GBALog(struct GBA* gba, enum GBALogLevel level, const char* format, ...) {
638	va_list args;
639	va_start(args, format);
640	_GBAVLog(gba, level, format, args);
641	va_end(args);
642}
643
644void GBADebuggerLogShim(struct ARMDebugger* debugger, enum DebuggerLogLevel level, const char* format, ...) {
645	struct GBA* gba = 0;
646	if (debugger->cpu) {
647		gba = (struct GBA*) debugger->cpu->master;
648	}
649
650	enum GBALogLevel gbaLevel;
651	switch (level) {
652	default: // Avoids compiler warning
653	case DEBUGGER_LOG_DEBUG:
654		gbaLevel = GBA_LOG_DEBUG;
655		break;
656	case DEBUGGER_LOG_INFO:
657		gbaLevel = GBA_LOG_INFO;
658		break;
659	case DEBUGGER_LOG_WARN:
660		gbaLevel = GBA_LOG_WARN;
661		break;
662	case DEBUGGER_LOG_ERROR:
663		gbaLevel = GBA_LOG_ERROR;
664		break;
665	}
666	va_list args;
667	va_start(args, format);
668	_GBAVLog(gba, gbaLevel, format, args);
669	va_end(args);
670}
671
672bool GBAIsROM(struct VFile* vf) {
673	if (vf->seek(vf, GBA_ROM_MAGIC_OFFSET, SEEK_SET) < 0) {
674		return false;
675	}
676	uint8_t signature[sizeof(GBA_ROM_MAGIC)];
677	if (vf->read(vf, &signature, sizeof(signature)) != sizeof(signature)) {
678		return false;
679	}
680	return memcmp(signature, GBA_ROM_MAGIC, sizeof(signature)) == 0;
681}
682
683void GBAGetGameCode(struct GBA* gba, char* out) {
684	memcpy(out, &((struct GBACartridge*) gba->memory.rom)->id, 4);
685}
686
687void GBAGetGameTitle(struct GBA* gba, char* out) {
688	memcpy(out, &((struct GBACartridge*) gba->memory.rom)->title, 12);
689}
690
691void GBAHitStub(struct ARMCore* cpu, uint32_t opcode) {
692	struct GBA* gba = (struct GBA*) cpu->master;
693	enum GBALogLevel level = GBA_LOG_FATAL;
694	if (gba->debugger) {
695		level = GBA_LOG_STUB;
696		ARMDebuggerEnter(gba->debugger, DEBUGGER_ENTER_ILLEGAL_OP);
697	}
698	GBALog(gba, level, "Stub opcode: %08x", opcode);
699}
700
701void GBAIllegal(struct ARMCore* cpu, uint32_t opcode) {
702	struct GBA* gba = (struct GBA*) cpu->master;
703	GBALog(gba, GBA_LOG_WARN, "Illegal opcode: %08x", opcode);
704	if (gba->debugger) {
705		ARMDebuggerEnter(gba->debugger, DEBUGGER_ENTER_ILLEGAL_OP);
706	}
707}
708
709void _checkOverrides(struct GBA* gba, uint32_t id) {
710	int i;
711	gba->busyLoop = -1;
712	if ((id & 0xFF) == 'F') {
713		GBALog(gba, GBA_LOG_DEBUG, "Found Classic NES Series game, using EEPROM saves");
714		GBASavedataInitEEPROM(&gba->memory.savedata);
715		return;
716	}
717	for (i = 0; _overrides[i].id[0]; ++i) {
718		const uint32_t* overrideId = (const uint32_t*) _overrides[i].id;
719		if (*overrideId == id) {
720			GBALog(gba, GBA_LOG_DEBUG, "Found override for game %s!", _overrides[i].id);
721			GBASavedataForceType(&gba->memory.savedata, _overrides[i].type);
722
723			if (_overrides[i].gpio & GPIO_RTC) {
724				GBAGPIOInitRTC(&gba->memory.gpio);
725			}
726
727			if (_overrides[i].gpio & GPIO_GYRO) {
728				GBAGPIOInitGyro(&gba->memory.gpio);
729			}
730
731			if (_overrides[i].gpio & GPIO_RUMBLE) {
732				GBAGPIOInitRumble(&gba->memory.gpio);
733			}
734
735			if (_overrides[i].gpio & GPIO_LIGHT_SENSOR) {
736				GBAGPIOInitLightSensor(&gba->memory.gpio);
737			}
738
739			if (_overrides[i].gpio & GPIO_TILT) {
740				GBAGPIOInitTilt(&gba->memory.gpio);
741			}
742
743			gba->busyLoop = _overrides[i].busyLoop;
744			return;
745		}
746	}
747}