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 GBMemoryDeinit(gb);
225 GBVideoDeinit(&gb->video);
226 GBSIODeinit(&gb->sio);
227}
228
229void GBInterruptHandlerInit(struct LR35902InterruptHandler* irqh) {
230 irqh->reset = GBReset;
231 irqh->processEvents = GBProcessEvents;
232 irqh->setInterrupts = GBSetInterrupts;
233 irqh->hitIllegal = GBIllegal;
234 irqh->stop = GBStop;
235 irqh->halt = GBHalt;
236}
237
238void GBReset(struct LR35902Core* cpu) {
239 struct GB* gb = (struct GB*) cpu->master;
240
241 if (gb->biosVf) {
242 gb->biosVf->seek(gb->biosVf, 0, SEEK_SET);
243 gb->memory.romBase = malloc(GB_SIZE_CART_BANK0);
244 ssize_t size = gb->biosVf->read(gb->biosVf, gb->memory.romBase, GB_SIZE_CART_BANK0);
245 uint32_t biosCrc = doCrc32(gb->memory.romBase, size);
246 switch (biosCrc) {
247 case 0x59C8598E:
248 gb->model = GB_MODEL_DMG;
249 gb->audio.style = GB_AUDIO_DMG;
250 break;
251 case 0x41884E46:
252 gb->model = GB_MODEL_CGB;
253 gb->audio.style = GB_AUDIO_CGB;
254 break;
255 default:
256 free(gb->memory.romBase);
257 gb->memory.romBase = gb->memory.rom;
258 gb->biosVf = NULL;
259 break;
260 }
261
262 memcpy(&gb->memory.romBase[size], &gb->memory.rom[size], GB_SIZE_CART_BANK0 - size);
263 if (size > 0x100) {
264 memcpy(&gb->memory.romBase[0x100], &gb->memory.rom[0x100], sizeof(struct GBCartridge));
265 }
266
267 cpu->a = 0;
268 cpu->f.packed = 0;
269 cpu->c = 0;
270 cpu->e = 0;
271 cpu->h = 0;
272 cpu->l = 0;
273 cpu->sp = 0;
274 cpu->pc = 0;
275 }
276 if (!gb->biosVf) {
277 const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
278 if (cart->cgb & 0x80) {
279 gb->model = GB_MODEL_CGB;
280 gb->audio.style = GB_AUDIO_CGB;
281 cpu->a = 0x11;
282 cpu->f.packed = 0x80;
283 cpu->c = 0;
284 cpu->e = 0x08;
285 cpu->h = 0;
286 cpu->l = 0x7C;
287 } else {
288 // TODO: SGB
289 gb->model = GB_MODEL_DMG;
290 gb->audio.style = GB_AUDIO_DMG;
291 cpu->a = 1;
292 cpu->f.packed = 0xB0;
293 cpu->c = 0x13;
294 cpu->e = 0xD8;
295 cpu->h = 1;
296 cpu->l = 0x4D;
297 }
298
299 cpu->sp = 0xFFFE;
300 cpu->pc = 0x100;
301 }
302
303 cpu->b = 0;
304 cpu->d = 0;
305
306 gb->eiPending = INT_MAX;
307 gb->doubleSpeed = 0;
308
309 cpu->memory.setActiveRegion(cpu, cpu->pc);
310
311 if (gb->yankedRomSize) {
312 gb->memory.romSize = gb->yankedRomSize;
313 gb->yankedRomSize = 0;
314 }
315 GBMemoryReset(gb);
316 GBVideoReset(&gb->video);
317 GBTimerReset(&gb->timer);
318 GBIOReset(gb);
319 GBAudioReset(&gb->audio);
320 GBSIOReset(&gb->sio);
321
322 GBSavedataUnmask(gb);
323}
324
325void GBUpdateIRQs(struct GB* gb) {
326 int irqs = gb->memory.ie & gb->memory.io[REG_IF];
327 if (!irqs) {
328 return;
329 }
330 gb->cpu->halted = false;
331
332 if (!gb->memory.ime || gb->cpu->irqPending) {
333 return;
334 }
335
336 if (irqs & (1 << GB_IRQ_VBLANK)) {
337 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_VBLANK);
338 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_VBLANK);
339 return;
340 }
341 if (irqs & (1 << GB_IRQ_LCDSTAT)) {
342 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_LCDSTAT);
343 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
344 return;
345 }
346 if (irqs & (1 << GB_IRQ_TIMER)) {
347 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_TIMER);
348 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_TIMER);
349 return;
350 }
351 if (irqs & (1 << GB_IRQ_SIO)) {
352 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_SIO);
353 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_SIO);
354 return;
355 }
356 if (irqs & (1 << GB_IRQ_KEYPAD)) {
357 LR35902RaiseIRQ(gb->cpu, GB_VECTOR_KEYPAD);
358 gb->memory.io[REG_IF] &= ~(1 << GB_IRQ_KEYPAD);
359 }
360}
361
362void GBProcessEvents(struct LR35902Core* cpu) {
363 struct GB* gb = (struct GB*) cpu->master;
364 do {
365 int32_t cycles = cpu->nextEvent;
366 int32_t nextEvent = INT_MAX;
367 int32_t testEvent;
368
369 if (gb->eiPending != INT_MAX) {
370 gb->eiPending -= cycles;
371 if (gb->eiPending <= 0) {
372 gb->memory.ime = true;
373 GBUpdateIRQs(gb);
374 gb->eiPending = INT_MAX;
375 } else {
376 nextEvent = gb->eiPending;
377 }
378 }
379
380 testEvent = GBVideoProcessEvents(&gb->video, cycles >> gb->doubleSpeed);
381 if (testEvent != INT_MAX) {
382 testEvent <<= gb->doubleSpeed;
383 if (testEvent < nextEvent) {
384 nextEvent = testEvent;
385 }
386 }
387
388 testEvent = GBAudioProcessEvents(&gb->audio, cycles >> gb->doubleSpeed);
389 if (testEvent != INT_MAX) {
390 testEvent <<= gb->doubleSpeed;
391 if (testEvent < nextEvent) {
392 nextEvent = testEvent;
393 }
394 }
395
396 testEvent = GBTimerProcessEvents(&gb->timer, cycles);
397 if (testEvent < nextEvent) {
398 nextEvent = testEvent;
399 }
400
401 testEvent = GBSIOProcessEvents(&gb->sio, cycles);
402 if (testEvent < nextEvent) {
403 nextEvent = testEvent;
404 }
405
406 testEvent = GBMemoryProcessEvents(gb, cycles);
407 if (testEvent < nextEvent) {
408 nextEvent = testEvent;
409 }
410
411 cpu->cycles -= cycles;
412 cpu->nextEvent = nextEvent;
413
414 if (cpu->halted) {
415 cpu->cycles = cpu->nextEvent;
416 }
417 } while (cpu->cycles >= cpu->nextEvent);
418}
419
420void GBSetInterrupts(struct LR35902Core* cpu, bool enable) {
421 struct GB* gb = (struct GB*) cpu->master;
422 if (!enable) {
423 gb->memory.ime = enable;
424 gb->eiPending = INT_MAX;
425 GBUpdateIRQs(gb);
426 } else {
427 if (cpu->nextEvent > cpu->cycles + 4) {
428 cpu->nextEvent = cpu->cycles + 4;
429 }
430 gb->eiPending = cpu->cycles + 4;
431 }
432}
433
434void GBHalt(struct LR35902Core* cpu) {
435 if (!cpu->irqPending) {
436 cpu->cycles = cpu->nextEvent;
437 cpu->halted = true;
438 }
439}
440
441void GBStop(struct LR35902Core* cpu) {
442 struct GB* gb = (struct GB*) cpu->master;
443 if (cpu->bus) {
444 mLOG(GB, GAME_ERROR, "Hit illegal stop at address %04X:%02X\n", cpu->pc, cpu->bus);
445 if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
446 struct mDebuggerEntryInfo info = {
447 .address = cpu->pc - 1,
448 .opcode = 0x1000 | cpu->bus
449 };
450 mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
451 }
452 // Hang forever
453 gb->memory.ime = 0;
454 cpu->pc -= 2;
455 } else if (gb->memory.io[REG_KEY1] & 1) {
456 gb->doubleSpeed ^= 1;
457 gb->memory.io[REG_KEY1] &= 1;
458 gb->memory.io[REG_KEY1] |= gb->doubleSpeed << 7;
459 }
460 // TODO: Actually stop
461}
462
463void GBIllegal(struct LR35902Core* cpu) {
464 struct GB* gb = (struct GB*) cpu->master;
465 mLOG(GB, GAME_ERROR, "Hit illegal opcode at address %04X:%02X\n", cpu->pc, cpu->bus);
466 if (cpu->components && cpu->components[CPU_COMPONENT_DEBUGGER]) {
467 struct mDebuggerEntryInfo info = {
468 .address = cpu->pc,
469 .opcode = cpu->bus
470 };
471 mDebuggerEnter((struct mDebugger*) cpu->components[CPU_COMPONENT_DEBUGGER], DEBUGGER_ENTER_ILLEGAL_OP, &info);
472 }
473 // Hang forever
474 gb->memory.ime = 0;
475 --cpu->pc;
476}
477
478bool GBIsROM(struct VFile* vf) {
479 vf->seek(vf, 0x104, SEEK_SET);
480 uint8_t header[4];
481 static const uint8_t knownHeader[4] = { 0xCE, 0xED, 0x66, 0x66};
482
483 if (vf->read(vf, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
484 return false;
485 }
486 if (memcmp(header, knownHeader, sizeof(header))) {
487 return false;
488 }
489 return true;
490}
491
492void GBGetGameTitle(struct GB* gb, char* out) {
493 const struct GBCartridge* cart = NULL;
494 if (gb->memory.rom) {
495 cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
496 }
497 if (gb->pristineRom) {
498 cart = (const struct GBCartridge*) &((uint8_t*) gb->pristineRom)[0x100];
499 }
500 if (!cart) {
501 return;
502 }
503 if (cart->oldLicensee != 0x33) {
504 memcpy(out, cart->titleLong, 16);
505 } else {
506 memcpy(out, cart->titleShort, 11);
507 }
508}
509
510void GBGetGameCode(struct GB* gb, char* out) {
511 memset(out, 0, 8);
512 const struct GBCartridge* cart = NULL;
513 if (gb->memory.rom) {
514 cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
515 }
516 if (gb->pristineRom) {
517 cart = (const struct GBCartridge*) &((uint8_t*) gb->pristineRom)[0x100];
518 }
519 if (!cart) {
520 return;
521 }
522 if (cart->cgb == 0xC0) {
523 memcpy(out, "CGB-????", 8);
524 } else {
525 memcpy(out, "DMG-????", 8);
526 }
527 if (cart->oldLicensee == 0x33) {
528 memcpy(&out[4], cart->maker, 4);
529 }
530}
531
532void GBFrameEnded(struct GB* gb) {
533 if (gb->cpu->components && gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE]) {
534 struct mCheatDevice* device = (struct mCheatDevice*) gb->cpu->components[CPU_COMPONENT_CHEAT_DEVICE];
535 size_t i;
536 for (i = 0; i < mCheatSetsSize(&device->cheats); ++i) {
537 struct mCheatSet* cheats = *mCheatSetsGetPointer(&device->cheats, i);
538 mCheatRefresh(device, cheats);
539 }
540 }
541}