src/gb/gb.c (view raw)
1/* Copyright (c) 2013-2016 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 "gb.h"
7
8#include "gb/io.h"
9#include "gb/mbc.h"
10
11#include "core/core.h"
12#include "core/cheats.h"
13#include "util/crc32.h"
14#include "util/memory.h"
15#include "util/math.h"
16#include "util/patch.h"
17#include "util/vfs.h"
18
19#define CLEANUP_THRESHOLD 15
20
21const uint32_t CGB_LR35902_FREQUENCY = 0x800000;
22const uint32_t SGB_LR35902_FREQUENCY = 0x418B1E;
23
24const uint32_t GB_COMPONENT_MAGIC = 0x400000;
25
26static const uint8_t _knownHeader[4] = { 0xCE, 0xED, 0x66, 0x66};
27
28#define DMG_BIOS_CHECKSUM 0xC2F5CC97
29#define DMG_2_BIOS_CHECKSUM 0x59C8598E
30#define CGB_BIOS_CHECKSUM 0x41884E46
31
32mLOG_DEFINE_CATEGORY(GB, "GB");
33
34static void GBInit(void* cpu, struct mCPUComponent* component);
35static void GBDeinit(struct mCPUComponent* component);
36static void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh);
37static void GBProcessEvents(struct LR35902Core* cpu);
38static void GBSetInterrupts(struct LR35902Core* cpu, bool enable);
39static void GBIllegal(struct LR35902Core* cpu);
40static void GBStop(struct LR35902Core* cpu);
41
42#ifdef _3DS
43extern uint32_t* romBuffer;
44extern size_t romBufferSize;
45#endif
46
47void GBCreate(struct GB* gb) {
48 gb->d.id = GB_COMPONENT_MAGIC;
49 gb->d.init = GBInit;
50 gb->d.deinit = GBDeinit;
51}
52
53static void GBInit(void* cpu, struct mCPUComponent* component) {
54 struct GB* gb = (struct GB*) component;
55 gb->cpu = cpu;
56 gb->sync = NULL;
57
58 GBInterruptHandlerInit(&gb->cpu->irqh);
59 GBMemoryInit(gb);
60
61 gb->video.p = gb;
62 GBVideoInit(&gb->video);
63
64 gb->audio.p = gb;
65 GBAudioInit(&gb->audio, 2048, &gb->memory.io[REG_NR52], GB_AUDIO_DMG); // TODO: Remove magic constant
66
67 gb->sio.p = gb;
68 GBSIOInit(&gb->sio);
69
70 gb->timer.p = gb;
71
72 gb->model = GB_MODEL_AUTODETECT;
73
74 gb->biosVf = NULL;
75 gb->romVf = NULL;
76 gb->sramVf = NULL;
77 gb->sramRealVf = NULL;
78
79 gb->pristineRom = 0;
80 gb->pristineRomSize = 0;
81 gb->yankedRomSize = 0;
82
83 gb->coreCallbacks = NULL;
84 gb->stream = NULL;
85
86 mTimingInit(&gb->timing);
87}
88
89static void GBDeinit(struct mCPUComponent* component) {
90 struct GB* gb = (struct GB*) component;
91 mTimingDeinit(&gb->timing);
92}
93
94bool GBLoadROM(struct GB* gb, struct VFile* vf) {
95 if (!vf) {
96 return false;
97 }
98 GBUnloadROM(gb);
99 gb->romVf = vf;
100 gb->pristineRomSize = vf->size(vf);
101 vf->seek(vf, 0, SEEK_SET);
102#ifdef _3DS
103 gb->pristineRom = 0;
104 if (gb->pristineRomSize <= romBufferSize) {
105 gb->pristineRom = romBuffer;
106 vf->read(vf, romBuffer, gb->pristineRomSize);
107 }
108#else
109 gb->pristineRom = vf->map(vf, gb->pristineRomSize, MAP_READ);
110#endif
111 if (!gb->pristineRom) {
112 return false;
113 }
114 gb->yankedRomSize = 0;
115 gb->memory.rom = gb->pristineRom;
116 gb->memory.romBase = gb->memory.rom;
117 gb->memory.romSize = gb->pristineRomSize;
118 gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
119 GBMBCSwitchBank(&gb->memory, gb->memory.currentBank);
120
121 if (gb->cpu) {
122 struct LR35902Core* cpu = gb->cpu;
123 cpu->memory.setActiveRegion(cpu, cpu->pc);
124 }
125
126 // TODO: error check
127 return true;
128}
129
130bool GBLoadSave(struct GB* gb, struct VFile* vf) {
131 gb->sramVf = vf;
132 gb->sramRealVf = vf;
133 return vf;
134}
135
136static void GBSramDeinit(struct GB* gb) {
137 if (gb->sramVf) {
138 gb->sramVf->unmap(gb->sramVf, gb->memory.sram, gb->sramSize);
139 if (gb->memory.mbcType == GB_MBC3_RTC && gb->sramVf == gb->sramRealVf) {
140 GBMBCRTCWrite(gb);
141 }
142 gb->sramVf = NULL;
143 } else if (gb->memory.sram) {
144 mappedMemoryFree(gb->memory.sram, gb->sramSize);
145 }
146 gb->memory.sram = 0;
147}
148
149void GBResizeSram(struct GB* gb, size_t size) {
150 if (gb->memory.sram && size <= gb->sramSize) {
151 return;
152 }
153 mLOG(GB, INFO, "Resizing SRAM to %"PRIz"u bytes", size);
154 struct VFile* vf = gb->sramVf;
155 if (vf) {
156 if (vf == gb->sramRealVf) {
157 ssize_t vfSize = vf->size(vf);
158 if (vfSize >= 0 && (size_t) vfSize < size) {
159 uint8_t extdataBuffer[0x100];
160 if (vfSize & 0xFF) {
161 vf->seek(vf, -(vfSize & 0xFF), SEEK_END);
162 vf->read(vf, extdataBuffer, vfSize & 0xFF);
163 }
164 if (gb->memory.sram) {
165 vf->unmap(vf, gb->memory.sram, gb->sramSize);
166 }
167 vf->truncate(vf, size + (vfSize & 0xFF));
168 if (vfSize & 0xFF) {
169 vf->seek(vf, size, SEEK_SET);
170 vf->write(vf, extdataBuffer, vfSize & 0xFF);
171 }
172 gb->memory.sram = vf->map(vf, size, MAP_WRITE);
173 memset(&gb->memory.sram[gb->sramSize], 0xFF, size - gb->sramSize);
174 } else if (size > gb->sramSize || !gb->memory.sram) {
175 if (gb->memory.sram) {
176 vf->unmap(vf, gb->memory.sram, gb->sramSize);
177 }
178 gb->memory.sram = vf->map(vf, size, MAP_WRITE);
179 }
180 } else {
181 if (gb->memory.sram) {
182 vf->unmap(vf, gb->memory.sram, gb->sramSize);
183 }
184 gb->memory.sram = vf->map(vf, size, MAP_READ);
185 }
186 if (gb->memory.sram == (void*) -1) {
187 gb->memory.sram = NULL;
188 }
189 } else {
190 uint8_t* newSram = anonymousMemoryMap(size);
191 if (gb->memory.sram) {
192 if (size > gb->sramSize) {
193 memcpy(newSram, gb->memory.sram, gb->sramSize);
194 memset(&newSram[gb->sramSize], 0xFF, size - gb->sramSize);
195 } else {
196 memcpy(newSram, gb->memory.sram, size);
197 }
198 mappedMemoryFree(gb->memory.sram, gb->sramSize);
199 } else {
200 memset(newSram, 0xFF, size);
201 }
202 gb->memory.sram = newSram;
203 }
204 if (gb->sramSize < size) {
205 gb->sramSize = size;
206 }
207}
208
209void GBSramClean(struct GB* gb, uint32_t frameCount) {
210 // TODO: Share with GBASavedataClean
211 if (!gb->sramVf || gb->sramVf != gb->sramRealVf) {
212 return;
213 }
214 if (gb->sramDirty & GB_SRAM_DIRT_NEW) {
215 gb->sramDirtAge = frameCount;
216 gb->sramDirty &= ~GB_SRAM_DIRT_NEW;
217 if (!(gb->sramDirty & GB_SRAM_DIRT_SEEN)) {
218 gb->sramDirty |= GB_SRAM_DIRT_SEEN;
219 }
220 } else if ((gb->sramDirty & GB_SRAM_DIRT_SEEN) && frameCount - gb->sramDirtAge > CLEANUP_THRESHOLD) {
221 if (gb->memory.mbcType == GB_MBC3_RTC) {
222 GBMBCRTCWrite(gb);
223 }
224 gb->sramDirty = 0;
225 if (gb->memory.sram && gb->sramVf->sync(gb->sramVf, gb->memory.sram, gb->sramSize)) {
226 mLOG(GB_MEM, INFO, "Savedata synced");
227 } else {
228 mLOG(GB_MEM, INFO, "Savedata failed to sync!");
229 }
230 }
231}
232
233void GBSavedataMask(struct GB* gb, struct VFile* vf, bool writeback) {
234 GBSramDeinit(gb);
235 gb->sramVf = vf;
236 gb->sramMaskWriteback = writeback;
237 gb->memory.sram = vf->map(vf, gb->sramSize, MAP_READ);
238 GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
239}
240
241void GBSavedataUnmask(struct GB* gb) {
242 if (gb->sramVf == gb->sramRealVf) {
243 return;
244 }
245 struct VFile* vf = gb->sramVf;
246 GBSramDeinit(gb);
247 gb->sramVf = gb->sramRealVf;
248 gb->memory.sram = gb->sramVf->map(gb->sramVf, gb->sramSize, MAP_WRITE);
249 if (gb->sramMaskWriteback) {
250 vf->read(vf, gb->memory.sram, gb->sramSize);
251 }
252 vf->close(vf);
253}
254
255void GBUnloadROM(struct GB* gb) {
256 // TODO: Share with GBAUnloadROM
257 if (gb->memory.rom && gb->memory.romBase != gb->memory.rom && gb->memory.romBase != gb->pristineRom) {
258 free(gb->memory.romBase);
259 }
260 if (gb->memory.rom && gb->pristineRom != gb->memory.rom) {
261 if (gb->yankedRomSize) {
262 gb->yankedRomSize = 0;
263 }
264 mappedMemoryFree(gb->memory.rom, GB_SIZE_CART_MAX);
265 gb->memory.rom = gb->pristineRom;
266 }
267 gb->memory.rom = 0;
268
269 if (gb->romVf) {
270#ifndef _3DS
271 gb->romVf->unmap(gb->romVf, gb->pristineRom, gb->pristineRomSize);
272#endif
273 gb->romVf->close(gb->romVf);
274 gb->romVf = 0;
275 }
276 gb->pristineRom = 0;
277
278 GBSavedataUnmask(gb);
279 GBSramDeinit(gb);
280 if (gb->sramRealVf) {
281 gb->sramRealVf->close(gb->sramRealVf);
282 }
283 gb->sramRealVf = NULL;
284 gb->sramVf = NULL;
285}
286
287void GBSynthesizeROM(struct VFile* vf) {
288 if (!vf) {
289 return;
290 }
291 const struct GBCartridge cart = {
292 .logo = { _knownHeader[0], _knownHeader[1], _knownHeader[2], _knownHeader[3]}
293 };
294
295 vf->seek(vf, 0x100, SEEK_SET);
296 vf->write(vf, &cart, sizeof(cart));
297}
298
299void GBLoadBIOS(struct GB* gb, struct VFile* vf) {
300 gb->biosVf = vf;
301}
302
303void GBApplyPatch(struct GB* gb, struct Patch* patch) {
304 size_t patchedSize = patch->outputSize(patch, gb->memory.romSize);
305 if (!patchedSize) {
306 return;
307 }
308 if (patchedSize > GB_SIZE_CART_MAX) {
309 patchedSize = GB_SIZE_CART_MAX;
310 }
311 gb->memory.rom = anonymousMemoryMap(GB_SIZE_CART_MAX);
312 if (!patch->applyPatch(patch, gb->pristineRom, gb->pristineRomSize, gb->memory.rom, patchedSize)) {
313 mappedMemoryFree(gb->memory.rom, patchedSize);
314 gb->memory.rom = gb->pristineRom;
315 return;
316 }
317 gb->memory.romSize = patchedSize;
318 gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
319}
320
321void GBDestroy(struct GB* gb) {
322 GBUnloadROM(gb);
323
324 if (gb->biosVf) {
325 gb->biosVf->close(gb->biosVf);
326 gb->biosVf = 0;
327 }
328
329 GBMemoryDeinit(gb);
330 GBAudioDeinit(&gb->audio);
331 GBVideoDeinit(&gb->video);
332 GBSIODeinit(&gb->sio);
333}
334
335void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh) {
336 irqh->reset = GBReset;
337 irqh->processEvents = GBProcessEvents;
338 irqh->setInterrupts = GBSetInterrupts;
339 irqh->hitIllegal = GBIllegal;
340 irqh->stop = GBStop;
341 irqh->halt = GBHalt;
342}
343
344static uint32_t _GBBiosCRC32(struct VFile* vf) {
345 ssize_t size = vf->size(vf);
346 if (size <= 0 || size > GB_SIZE_CART_BANK0) {
347 return 0;
348 }
349 void* bios = vf->map(vf, size, MAP_READ);
350 uint32_t biosCrc = doCrc32(bios, size);
351 vf->unmap(vf, bios, size);
352 return biosCrc;
353}
354
355bool GBIsBIOS(struct VFile* vf) {
356 switch (_GBBiosCRC32(vf)) {
357 case DMG_BIOS_CHECKSUM:
358 case DMG_2_BIOS_CHECKSUM:
359 case CGB_BIOS_CHECKSUM:
360 return true;
361 default:
362 return false;
363 }
364}
365
366void GBReset(struct LR35902Core* cpu) {
367 struct GB* gb = (struct GB*) cpu->master;
368 GBDetectModel(gb);
369 if (gb->biosVf) {
370 if (!GBIsBIOS(gb->biosVf)) {
371 gb->biosVf->close(gb->biosVf);
372 gb->biosVf = NULL;
373 } else {
374 gb->biosVf->seek(gb->biosVf, 0, SEEK_SET);
375 gb->memory.romBase = malloc(GB_SIZE_CART_BANK0);
376 ssize_t size = gb->biosVf->read(gb->biosVf, gb->memory.romBase, GB_SIZE_CART_BANK0);
377 memcpy(&gb->memory.romBase[size], &gb->memory.rom[size], GB_SIZE_CART_BANK0 - size);
378 if (size > 0x100) {
379 memcpy(&gb->memory.romBase[0x100], &gb->memory.rom[0x100], sizeof(struct GBCartridge));
380 }
381
382 cpu->a = 0;
383 cpu->f.packed = 0;
384 cpu->c = 0;
385 cpu->e = 0;
386 cpu->h = 0;
387 cpu->l = 0;
388 cpu->sp = 0;
389 cpu->pc = 0;
390 }
391 }
392
393 cpu->b = 0;
394 cpu->d = 0;
395
396 if (!gb->biosVf) {
397 switch (gb->model) {
398 case GB_MODEL_DMG:
399 // TODO: SGB
400 case GB_MODEL_SGB:
401 case GB_MODEL_AUTODETECT: // Silence warnings
402 gb->model = GB_MODEL_DMG;
403 cpu->a = 1;
404 cpu->f.packed = 0xB0;
405 cpu->c = 0x13;
406 cpu->e = 0xD8;
407 cpu->h = 1;
408 cpu->l = 0x4D;
409 break;
410 case GB_MODEL_AGB:
411 cpu->b = 1;
412 // Fall through
413 case GB_MODEL_CGB:
414 cpu->a = 0x11;
415 cpu->f.packed = 0x80;
416 cpu->c = 0;
417 cpu->e = 0x08;
418 cpu->h = 0;
419 cpu->l = 0x7C;
420 break;
421 }
422
423 cpu->sp = 0xFFFE;
424 cpu->pc = 0x100;
425 }
426
427 gb->eiPending = INT_MAX;
428 gb->doubleSpeed = 0;
429
430 cpu->memory.setActiveRegion(cpu, cpu->pc);
431
432 if (gb->yankedRomSize) {
433 gb->memory.romSize = gb->yankedRomSize;
434 gb->yankedRomSize = 0;
435 }
436
437 mTimingClear(&gb->timing);
438
439 GBMemoryReset(gb);
440 GBVideoReset(&gb->video);
441 GBTimerReset(&gb->timer);
442 mTimingSchedule(&gb->timing, &gb->timer.event, GB_DMG_DIV_PERIOD);
443
444 GBAudioReset(&gb->audio);
445 GBIOReset(gb);
446 GBSIOReset(&gb->sio);
447
448 GBSavedataUnmask(gb);
449}
450
451void GBDetectModel(struct GB* gb) {
452 if (gb->model != GB_MODEL_AUTODETECT) {
453 return;
454 }
455 if (gb->biosVf) {
456 switch (_GBBiosCRC32(gb->biosVf)) {
457 case DMG_BIOS_CHECKSUM:
458 case DMG_2_BIOS_CHECKSUM:
459 gb->model = GB_MODEL_DMG;
460 break;
461 case CGB_BIOS_CHECKSUM:
462 gb->model = GB_MODEL_CGB;
463 break;
464 default:
465 gb->biosVf->close(gb->biosVf);
466 gb->biosVf = NULL;
467 }
468 }
469 if (gb->model == GB_MODEL_AUTODETECT && gb->memory.rom) {
470 const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
471 if (cart->cgb & 0x80) {
472 gb->model = GB_MODEL_CGB;
473 } else {
474 gb->model = GB_MODEL_DMG;
475 }
476 }
477
478 switch (gb->model) {
479 case GB_MODEL_DMG:
480 case GB_MODEL_SGB:
481 case GB_MODEL_AUTODETECT: //Silence warnings
482 gb->audio.style = GB_AUDIO_DMG;
483 break;
484 case GB_MODEL_AGB:
485 case GB_MODEL_CGB:
486 gb->audio.style = GB_AUDIO_CGB;
487 break;
488 }
489}
490
491void GBUpdateIRQs(struct GB* gb) {
492 int irqs = gb->memory.ie & gb->memory.io[REG_IF];
493 if (!irqs) {
494 return;
495 }
496 gb->cpu->halted = false;
497
498 if (!gb->memory.ime || gb->cpu->irqPending) {
499 return;
500 }
501
502 if (irqs & (1 << GB_IRQ_VBLANK)) {
503 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_VBLANK);
504 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_VBLANK);
505 return;
506 }
507 if (irqs & (1 << GB_IRQ_LCDSTAT)) {
508 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_LCDSTAT);
509 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
510 return;
511 }
512 if (irqs & (1 << GB_IRQ_TIMER)) {
513 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_TIMER);
514 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_TIMER);
515 return;
516 }
517 if (irqs & (1 << GB_IRQ_SIO)) {
518 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_SIO);
519 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_SIO);
520 return;
521 }
522 if (irqs & (1 << GB_IRQ_KEYPAD)) {
523 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_KEYPAD);
524 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_KEYPAD);
525 }
526}
527
528void GBProcessEvents(struct LR35902Core* cpu) {
529 struct GB* gb = (struct GB*) cpu->master;
530 do {
531 int32_t cycles = cpu->nextEvent;
532 int32_t nextEvent = INT_MAX;
533 int32_t testEvent;
534
535 if (gb->eiPending != INT_MAX) {
536 gb->eiPending -= cycles;
537 if (gb->eiPending <= 0) {
538 gb->memory.ime = true;
539 GBUpdateIRQs(gb);
540 gb->eiPending = INT_MAX;
541 } else {
542 nextEvent = gb->eiPending;
543 }
544 }
545
546 mTimingTick(&gb->timing, cycles);
547 testEvent = mTimingNextEvent(&gb->timing);
548 if (testEvent < nextEvent) {
549 nextEvent = testEvent;
550 }
551
552 testEvent = GBVideoProcessEvents(&gb->video, cycles >> gb->doubleSpeed);
553 if (testEvent != INT_MAX) {
554 testEvent <<= gb->doubleSpeed;
555 if (testEvent < nextEvent) {
556 nextEvent = testEvent;
557 }
558 }
559
560 testEvent = GBAudioProcessEvents(&gb->audio, cycles >> gb->doubleSpeed);
561 if (testEvent != INT_MAX) {
562 testEvent <<= gb->doubleSpeed;
563 if (testEvent < nextEvent) {
564 nextEvent = testEvent;
565 }
566 }
567
568 cpu->cycles -= cycles;
569 cpu->nextEvent = nextEvent;
570
571 if (cpu->halted) {
572 cpu->cycles = cpu->nextEvent;
573 if (!gb->memory.ie || !gb->memory.ime) {
574 break;
575 }
576 }
577 } while (cpu->cycles >= cpu->nextEvent);
578}
579
580void GBSetInterrupts(struct LR35902Core* cpu, bool enable) {
581 struct GB* gb = (struct GB*) cpu->master;
582 if (!enable) {
583 gb->memory.ime = enable;
584 gb->eiPending = INT_MAX;
585 GBUpdateIRQs(gb);
586 } else {
587 if (cpu->nextEvent > cpu->cycles + 4) {
588 cpu->nextEvent = cpu->cycles + 4;
589 }
590 gb->eiPending = cpu->cycles + 4;
591 }
592}
593
594void GBHalt(struct LR35902Core* cpu) {
595 if (!cpu->irqPending) {
596 cpu->cycles = cpu->nextEvent;
597 cpu->halted = true;
598 }
599}
600
601void GBStop(struct LR35902Core* cpu) {
602 struct GB* gb = (struct GB*) cpu->master;
603 if (cpu->bus) {
604 mLOG(GB, GAME_ERROR, "Hit illegal stop at address %04X:%02X\n", cpu->pc, cpu->bus);
605 }
606 if (gb->memory.io[REG_KEY1] & 1) {
607 gb->doubleSpeed ^= 1;
608 gb->memory.io[REG_KEY1] = 0;
609 gb->memory.io[REG_KEY1] |= gb->doubleSpeed << 7;
610 } else if (cpu->bus) {
611#ifdef USE_DEBUGGERS
612 if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
613 struct mDebuggerEntryInfo info = {
614 .address = cpu->pc - 1,
615 .opcode = 0x1000 | cpu->bus
616 };
617 mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
618 }
619#endif
620 // Hang forever
621 gb->memory.ime = 0;
622 cpu->pc -= 2;
623 }
624 // TODO: Actually stop
625}
626
627void GBIllegal(struct LR35902Core* cpu) {
628 struct GB* gb = (struct GB*) cpu->master;
629 mLOG(GB, GAME_ERROR, "Hit illegal opcode at address %04X:%02X\n", cpu->pc, cpu->bus);
630#ifdef USE_DEBUGGERS
631 if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
632 struct mDebuggerEntryInfo info = {
633 .address = cpu->pc,
634 .opcode = cpu->bus
635 };
636 mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
637 }
638#endif
639 // Hang forever
640 gb->memory.ime = 0;
641 --cpu->pc;
642}
643
644bool GBIsROM(struct VFile* vf) {
645 vf->seek(vf, 0x104, SEEK_SET);
646 uint8_t header[4];
647
648 if (vf->read(vf, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
649 return false;
650 }
651 if (memcmp(header, _knownHeader, sizeof(header))) {
652 return false;
653 }
654 return true;
655}
656
657void GBGetGameTitle(const struct GB* gb, char* out) {
658 const struct GBCartridge* cart = NULL;
659 if (gb->memory.rom) {
660 cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
661 }
662 if (gb->pristineRom) {
663 cart = (const struct GBCartridge*) &((uint8_t*) gb->pristineRom)[0x100];
664 }
665 if (!cart) {
666 return;
667 }
668 if (cart->oldLicensee != 0x33) {
669 memcpy(out, cart->titleLong, 16);
670 } else {
671 memcpy(out, cart->titleShort, 11);
672 }
673}
674
675void GBGetGameCode(const struct GB* gb, char* out) {
676 memset(out, 0, 8);
677 const struct GBCartridge* cart = NULL;
678 if (gb->memory.rom) {
679 cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
680 }
681 if (gb->pristineRom) {
682 cart = (const struct GBCartridge*) &((uint8_t*) gb->pristineRom)[0x100];
683 }
684 if (!cart) {
685 return;
686 }
687 if (cart->cgb == 0xC0) {
688 memcpy(out, "CGB-????", 8);
689 } else {
690 memcpy(out, "DMG-????", 8);
691 }
692 if (cart->oldLicensee == 0x33) {
693 memcpy(&out[4], cart->maker, 4);
694 }
695}
696
697void GBFrameEnded(struct GB* gb) {
698 GBSramClean(gb, gb->video.frameCounter);
699
700 if (gb->cpu->components && gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
701 struct mCheatDevice* device = (struct mCheatDevice*) gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
702 size_t i;
703 for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
704 struct mCheatSet* cheats = *mCheatSetsGetPointer(&device->cheats, i);
705 mCheatRefresh(device, cheats);
706 }
707 }
708}