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
10#include "core/core.h"
11#include "core/cheats.h"
12#include "util/crc32.h"
13#include "util/memory.h"
14#include "util/math.h"
15#include "util/patch.h"
16#include "util/vfs.h"
17
18const uint32_t CGB_LR35902_FREQUENCY = 0x800000;
19const uint32_t SGB_LR35902_FREQUENCY = 0x418B1E;
20
21const uint32_t GB_COMPONENT_MAGIC = 0x400000;
22
23mLOG_DEFINE_CATEGORY(GB, "GB");
24
25static void GBInit(void* cpu, struct mCPUComponent* component);
26static void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh);
27static void GBProcessEvents(struct LR35902Core* cpu);
28static void GBSetInterrupts(struct LR35902Core* cpu, bool enable);
29static void GBIllegal(struct LR35902Core* cpu);
30static void GBStop(struct LR35902Core* cpu);
31
32#ifdef _3DS
33extern uint32_t* romBuffer;
34extern size_t romBufferSize;
35#endif
36
37void GBCreate(struct GB* gb) {
38 gb->d.id = GB_COMPONENT_MAGIC;
39 gb->d.init = GBInit;
40 gb->d.deinit = 0;
41}
42
43static void GBInit(void* cpu, struct mCPUComponent* component) {
44 struct GB* gb = (struct GB*) component;
45 gb->cpu = cpu;
46 gb->sync = NULL;
47
48 GBInterruptHandlerInit(&gb->cpu->irqh);
49 GBMemoryInit(gb);
50
51 gb->video.p = gb;
52 GBVideoInit(&gb->video);
53
54 gb->audio.p = gb;
55 GBAudioInit(&gb->audio, 2048, &gb->memory.io[REG_NR52], GB_AUDIO_DMG); // TODO: Remove magic constant
56
57 gb->sio.p = gb;
58 GBSIOInit(&gb->sio);
59
60 gb->timer.p = gb;
61
62 gb->biosVf = 0;
63 gb->romVf = 0;
64 gb->sramVf = 0;
65
66 gb->pristineRom = 0;
67 gb->pristineRomSize = 0;
68 gb->yankedRomSize = 0;
69
70 gb->stream = NULL;
71}
72
73bool GBLoadROM(struct GB* gb, struct VFile* vf) {
74 GBUnloadROM(gb);
75 gb->romVf = vf;
76 gb->pristineRomSize = vf->size(vf);
77 vf->seek(vf, 0, SEEK_SET);
78#ifdef _3DS
79 gb->pristineRom = 0;
80 if (gb->pristineRomSize <= romBufferSize) {
81 gb->pristineRom = romBuffer;
82 vf->read(vf, romBuffer, gb->pristineRomSize);
83 }
84#else
85 gb->pristineRom = vf->map(vf, gb->pristineRomSize, MAP_READ);
86#endif
87 if (!gb->pristineRom) {
88 return false;
89 }
90 gb->yankedRomSize = 0;
91 gb->memory.rom = gb->pristineRom;
92 gb->memory.romBase = gb->memory.rom;
93 gb->memory.romSize = gb->pristineRomSize;
94 gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
95
96 // TODO: error check
97 return true;
98}
99
100bool GBLoadSave(struct GB* gb, struct VFile* vf) {
101 gb->sramVf = vf;
102 gb->sramRealVf = vf;
103 return vf;
104}
105
106static void GBSramDeinit(struct GB* gb) {
107 if (gb->sramVf) {
108 gb->sramVf->unmap(gb->sramVf, gb->memory.sram, gb->sramSize);
109 gb->sramVf = 0;
110 } else if (gb->memory.sram) {
111 mappedMemoryFree(gb->memory.sram, gb->sramSize);
112 }
113 gb->memory.sram = 0;
114}
115
116void GBResizeSram(struct GB* gb, size_t size) {
117 struct VFile* vf = gb->sramVf;
118 if (vf) {
119 if (vf == gb->sramRealVf) {
120 if (vf->size(vf) >= 0 && (size_t) vf->size(vf) < size) {
121 uint8_t extdataBuffer[0x100];
122 if (vf->size(vf) & 0xFF) {
123 // Copy over appended data, e.g. RTC data
124 memcpy(extdataBuffer, &gb->memory.sram[gb->sramSize - (vf->size(vf) & 0xFF)], vf->size(vf) & 0xFF);
125 }
126 vf->unmap(vf, gb->memory.sram, gb->sramSize);
127 vf->truncate(vf, size);
128 gb->memory.sram = vf->map(vf, size, MAP_WRITE);
129 memset(&gb->memory.sram[gb->sramSize], 0xFF, size - gb->sramSize);
130 if (size & 0xFF) {
131 memcpy(&gb->memory.sram[gb->sramSize - (size & 0xFF)], extdataBuffer, size & 0xFF);
132 }
133 } else {
134 vf->unmap(vf, gb->memory.sram, gb->sramSize);
135 gb->memory.sram = vf->map(vf, size, MAP_WRITE);
136 }
137 } else {
138 vf->unmap(vf, gb->memory.sram, gb->sramSize);
139 gb->memory.sram = vf->map(vf, size, MAP_READ);
140 }
141 } else {
142 uint8_t* newSram = anonymousMemoryMap(size);
143 if (gb->memory.sram) {
144 if (size > gb->sramSize) {
145 memcpy(newSram, gb->memory.sram, gb->sramSize);
146 memset(&newSram[gb->sramSize], 0xFF, size - gb->sramSize);
147 } else {
148 memcpy(newSram, gb->memory.sram, size);
149 }
150 mappedMemoryFree(gb->memory.sram, gb->sramSize);
151 } else {
152 memset(newSram, 0xFF, size);
153 }
154 gb->memory.sram = newSram;
155 }
156 gb->sramSize = size;
157}
158
159void GBSavedataMask(struct GB* gb, struct VFile* vf) {
160 GBSramDeinit(gb);
161 gb->sramVf = vf;
162 gb->memory.sram = vf->map(vf, gb->sramSize, MAP_READ);
163}
164
165void GBSavedataUnmask(struct GB* gb) {
166 if (gb->sramVf == gb->sramRealVf) {
167 return;
168 }
169 GBSramDeinit(gb);
170 gb->sramVf = gb->sramRealVf;
171 gb->memory.sram = gb->sramVf->map(gb->sramVf, gb->sramSize, MAP_WRITE);
172}
173
174void GBUnloadROM(struct GB* gb) {
175 // TODO: Share with GBAUnloadROM
176 if (gb->memory.rom && gb->memory.romBase != gb->memory.rom) {
177 free(gb->memory.romBase);
178 }
179 if (gb->memory.rom && gb->pristineRom != gb->memory.rom) {
180 if (gb->yankedRomSize) {
181 gb->yankedRomSize = 0;
182 }
183 mappedMemoryFree(gb->memory.rom, GB_SIZE_CART_MAX);
184 }
185 gb->memory.rom = 0;
186
187 if (gb->romVf) {
188#ifndef _3DS
189 gb->romVf->unmap(gb->romVf, gb->pristineRom, gb->pristineRomSize);
190#endif
191 gb->romVf->close(gb->romVf);
192 gb->pristineRom = 0;
193 gb->romVf = 0;
194 }
195
196 GBSramDeinit(gb);
197}
198
199void GBLoadBIOS(struct GB* gb, struct VFile* vf) {
200 gb->biosVf = vf;
201}
202
203void GBApplyPatch(struct GB* gb, struct Patch* patch) {
204 size_t patchedSize = patch->outputSize(patch, gb->memory.romSize);
205 if (!patchedSize) {
206 return;
207 }
208 if (patchedSize > GB_SIZE_CART_MAX) {
209 patchedSize = GB_SIZE_CART_MAX;
210 }
211 gb->memory.rom = anonymousMemoryMap(GB_SIZE_CART_MAX);
212 if (!patch->applyPatch(patch, gb->pristineRom, gb->pristineRomSize, gb->memory.rom, patchedSize)) {
213 mappedMemoryFree(gb->memory.rom, patchedSize);
214 gb->memory.rom = gb->pristineRom;
215 return;
216 }
217 gb->memory.romSize = patchedSize;
218 gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
219}
220
221void GBDestroy(struct GB* gb) {
222 GBUnloadROM(gb);
223
224 if (gb->biosVf) {
225 gb->biosVf->close(gb->biosVf);
226 gb->biosVf = 0;
227 }
228
229 GBMemoryDeinit(gb);
230 GBVideoDeinit(&gb->video);
231 GBSIODeinit(&gb->sio);
232}
233
234void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh) {
235 irqh->reset = GBReset;
236 irqh->processEvents = GBProcessEvents;
237 irqh->setInterrupts = GBSetInterrupts;
238 irqh->hitIllegal = GBIllegal;
239 irqh->stop = GBStop;
240 irqh->halt = GBHalt;
241}
242
243void GBReset(struct LR35902Core* cpu) {
244 struct GB* gb = (struct GB*) cpu->master;
245
246 if (gb->biosVf) {
247 gb->biosVf->seek(gb->biosVf, 0, SEEK_SET);
248 gb->memory.romBase = malloc(GB_SIZE_CART_BANK0);
249 ssize_t size = gb->biosVf->read(gb->biosVf, gb->memory.romBase, GB_SIZE_CART_BANK0);
250 uint32_t biosCrc = doCrc32(gb->memory.romBase, size);
251 switch (biosCrc) {
252 case 0x59C8598E:
253 gb->model = GB_MODEL_DMG;
254 gb->audio.style = GB_AUDIO_DMG;
255 break;
256 case 0x41884E46:
257 gb->model = GB_MODEL_CGB;
258 gb->audio.style = GB_AUDIO_CGB;
259 break;
260 default:
261 free(gb->memory.romBase);
262 gb->memory.romBase = gb->memory.rom;
263 gb->biosVf = NULL;
264 break;
265 }
266
267 memcpy(&gb->memory.romBase[size], &gb->memory.rom[size], GB_SIZE_CART_BANK0 - size);
268 if (size > 0x100) {
269 memcpy(&gb->memory.romBase[0x100], &gb->memory.rom[0x100], sizeof(struct GBCartridge));
270 }
271
272 cpu->a = 0;
273 cpu->f.packed = 0;
274 cpu->c = 0;
275 cpu->e = 0;
276 cpu->h = 0;
277 cpu->l = 0;
278 cpu->sp = 0;
279 cpu->pc = 0;
280 }
281 if (!gb->biosVf) {
282 const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
283 if (cart->cgb & 0x80) {
284 gb->model = GB_MODEL_CGB;
285 gb->audio.style = GB_AUDIO_CGB;
286 cpu->a = 0x11;
287 cpu->f.packed = 0x80;
288 cpu->c = 0;
289 cpu->e = 0x08;
290 cpu->h = 0;
291 cpu->l = 0x7C;
292 } else {
293 // TODO: SGB
294 gb->model = GB_MODEL_DMG;
295 gb->audio.style = GB_AUDIO_DMG;
296 cpu->a = 1;
297 cpu->f.packed = 0xB0;
298 cpu->c = 0x13;
299 cpu->e = 0xD8;
300 cpu->h = 1;
301 cpu->l = 0x4D;
302 }
303
304 cpu->sp = 0xFFFE;
305 cpu->pc = 0x100;
306 }
307
308 cpu->b = 0;
309 cpu->d = 0;
310
311 gb->eiPending = INT_MAX;
312 gb->doubleSpeed = 0;
313
314 cpu->memory.setActiveRegion(cpu, cpu->pc);
315
316 if (gb->yankedRomSize) {
317 gb->memory.romSize = gb->yankedRomSize;
318 gb->yankedRomSize = 0;
319 }
320 GBMemoryReset(gb);
321 GBVideoReset(&gb->video);
322 GBTimerReset(&gb->timer);
323 GBIOReset(gb);
324 GBAudioReset(&gb->audio);
325 GBSIOReset(&gb->sio);
326
327 GBSavedataUnmask(gb);
328}
329
330void GBUpdateIRQs(struct GB* gb) {
331 int irqs = gb->memory.ie & gb->memory.io[REG_IF];
332 if (!irqs) {
333 return;
334 }
335 gb->cpu->halted = false;
336
337 if (!gb->memory.ime || gb->cpu->irqPending) {
338 return;
339 }
340
341 if (irqs & (1 << GB_IRQ_VBLANK)) {
342 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_VBLANK);
343 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_VBLANK);
344 return;
345 }
346 if (irqs & (1 << GB_IRQ_LCDSTAT)) {
347 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_LCDSTAT);
348 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
349 return;
350 }
351 if (irqs & (1 << GB_IRQ_TIMER)) {
352 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_TIMER);
353 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_TIMER);
354 return;
355 }
356 if (irqs & (1 << GB_IRQ_SIO)) {
357 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_SIO);
358 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_SIO);
359 return;
360 }
361 if (irqs & (1 << GB_IRQ_KEYPAD)) {
362 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_KEYPAD);
363 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_KEYPAD);
364 }
365}
366
367void GBProcessEvents(struct LR35902Core* cpu) {
368 struct GB* gb = (struct GB*) cpu->master;
369 do {
370 int32_t cycles = cpu->nextEvent;
371 int32_t nextEvent = INT_MAX;
372 int32_t testEvent;
373
374 if (gb->eiPending != INT_MAX) {
375 gb->eiPending -= cycles;
376 if (gb->eiPending <= 0) {
377 gb->memory.ime = true;
378 GBUpdateIRQs(gb);
379 gb->eiPending = INT_MAX;
380 } else {
381 nextEvent = gb->eiPending;
382 }
383 }
384
385 testEvent = GBVideoProcessEvents(&gb->video, cycles >> gb->doubleSpeed);
386 if (testEvent != INT_MAX) {
387 testEvent <<= gb->doubleSpeed;
388 if (testEvent < nextEvent) {
389 nextEvent = testEvent;
390 }
391 }
392
393 testEvent = GBAudioProcessEvents(&gb->audio, cycles >> gb->doubleSpeed);
394 if (testEvent != INT_MAX) {
395 testEvent <<= gb->doubleSpeed;
396 if (testEvent < nextEvent) {
397 nextEvent = testEvent;
398 }
399 }
400
401 testEvent = GBTimerProcessEvents(&gb->timer, cycles);
402 if (testEvent < nextEvent) {
403 nextEvent = testEvent;
404 }
405
406 testEvent = GBSIOProcessEvents(&gb->sio, cycles);
407 if (testEvent < nextEvent) {
408 nextEvent = testEvent;
409 }
410
411 testEvent = GBMemoryProcessEvents(gb, cycles);
412 if (testEvent < nextEvent) {
413 nextEvent = testEvent;
414 }
415
416 cpu->cycles -= cycles;
417 cpu->nextEvent = nextEvent;
418
419 if (cpu->halted) {
420 cpu->cycles = cpu->nextEvent;
421 }
422 } while (cpu->cycles >= cpu->nextEvent);
423}
424
425void GBSetInterrupts(struct LR35902Core* cpu, bool enable) {
426 struct GB* gb = (struct GB*) cpu->master;
427 if (!enable) {
428 gb->memory.ime = enable;
429 gb->eiPending = INT_MAX;
430 GBUpdateIRQs(gb);
431 } else {
432 if (cpu->nextEvent > cpu->cycles + 4) {
433 cpu->nextEvent = cpu->cycles + 4;
434 }
435 gb->eiPending = cpu->cycles + 4;
436 }
437}
438
439void GBHalt(struct LR35902Core* cpu) {
440 if (!cpu->irqPending) {
441 cpu->cycles = cpu->nextEvent;
442 cpu->halted = true;
443 }
444}
445
446void GBStop(struct LR35902Core* cpu) {
447 struct GB* gb = (struct GB*) cpu->master;
448 if (cpu->bus) {
449 mLOG(GB, GAME_ERROR, "Hit illegal stop at address %04X:%02X\n", cpu->pc, cpu->bus);
450 if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
451 struct mDebuggerEntryInfo info = {
452 .address = cpu->pc - 1,
453 .opcode = 0x1000 | cpu->bus
454 };
455 mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
456 }
457 // Hang forever
458 gb->memory.ime = 0;
459 cpu->pc -= 2;
460 } else if (gb->memory.io[REG_KEY1] & 1) {
461 gb->doubleSpeed ^= 1;
462 gb->memory.io[REG_KEY1] &= 1;
463 gb->memory.io[REG_KEY1] |= gb->doubleSpeed << 7;
464 }
465 // TODO: Actually stop
466}
467
468void GBIllegal(struct LR35902Core* cpu) {
469 struct GB* gb = (struct GB*) cpu->master;
470 mLOG(GB, GAME_ERROR, "Hit illegal opcode at address %04X:%02X\n", cpu->pc, cpu->bus);
471 if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
472 struct mDebuggerEntryInfo info = {
473 .address = cpu->pc,
474 .opcode = cpu->bus
475 };
476 mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
477 }
478 // Hang forever
479 gb->memory.ime = 0;
480 --cpu->pc;
481}
482
483bool GBIsROM(struct VFile* vf) {
484 vf->seek(vf, 0x104, SEEK_SET);
485 uint8_t header[4];
486 static const uint8_t knownHeader[4] = { 0xCE, 0xED, 0x66, 0x66};
487
488 if (vf->read(vf, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
489 return false;
490 }
491 if (memcmp(header, knownHeader, sizeof(header))) {
492 return false;
493 }
494 return true;
495}
496
497void GBGetGameTitle(struct GB* gb, char* out) {
498 const struct GBCartridge* cart = NULL;
499 if (gb->memory.rom) {
500 cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
501 }
502 if (gb->pristineRom) {
503 cart = (const struct GBCartridge*) &((uint8_t*) gb->pristineRom)[0x100];
504 }
505 if (!cart) {
506 return;
507 }
508 if (cart->oldLicensee != 0x33) {
509 memcpy(out, cart->titleLong, 16);
510 } else {
511 memcpy(out, cart->titleShort, 11);
512 }
513}
514
515void GBGetGameCode(struct GB* gb, char* out) {
516 memset(out, 0, 8);
517 const struct GBCartridge* cart = NULL;
518 if (gb->memory.rom) {
519 cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
520 }
521 if (gb->pristineRom) {
522 cart = (const struct GBCartridge*) &((uint8_t*) gb->pristineRom)[0x100];
523 }
524 if (!cart) {
525 return;
526 }
527 if (cart->cgb == 0xC0) {
528 memcpy(out, "CGB-????", 8);
529 } else {
530 memcpy(out, "DMG-????", 8);
531 }
532 if (cart->oldLicensee == 0x33) {
533 memcpy(&out[4], cart->maker, 4);
534 }
535}
536
537void GBFrameEnded(struct GB* gb) {
538 if (gb->cpu->components && gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
539 struct mCheatDevice* device = (struct mCheatDevice*) gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
540 size_t i;
541 for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
542 struct mCheatSet* cheats = *mCheatSetsGetPointer(&device->cheats, i);
543 mCheatRefresh(device, cheats);
544 }
545 }
546}