src/gb/io.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 "io.h"
7
8#include "gb/gb.h"
9#include "gb/serialize.h"
10
11mLOG_DEFINE_CATEGORY(GB_IO, "GB I/O");
12
13const char* const GBIORegisterNames[] = {
14 [REG_JOYP] = "JOYP",
15 [REG_SB] = "SB",
16 [REG_SC] = "SC",
17 [REG_DIV] = "DIV",
18 [REG_TIMA] = "TIMA",
19 [REG_TMA] = "TMA",
20 [REG_TAC] = "TAC",
21 [REG_IF] = "IF",
22 [REG_NR10] = "NR10",
23 [REG_NR11] = "NR11",
24 [REG_NR12] = "NR12",
25 [REG_NR13] = "NR13",
26 [REG_NR14] = "NR14",
27 [REG_NR21] = "NR21",
28 [REG_NR22] = "NR22",
29 [REG_NR23] = "NR23",
30 [REG_NR24] = "NR24",
31 [REG_NR30] = "NR30",
32 [REG_NR31] = "NR31",
33 [REG_NR32] = "NR32",
34 [REG_NR33] = "NR33",
35 [REG_NR34] = "NR34",
36 [REG_NR41] = "NR41",
37 [REG_NR42] = "NR42",
38 [REG_NR43] = "NR43",
39 [REG_NR44] = "NR44",
40 [REG_NR50] = "NR50",
41 [REG_NR51] = "NR51",
42 [REG_NR52] = "NR52",
43 [REG_LCDC] = "LCDC",
44 [REG_STAT] = "STAT",
45 [REG_SCY] = "SCY",
46 [REG_SCX] = "SCX",
47 [REG_LY] = "LY",
48 [REG_LYC] = "LYC",
49 [REG_DMA] = "DMA",
50 [REG_BGP] = "BGP",
51 [REG_OBP0] = "OBP0",
52 [REG_OBP1] = "OBP1",
53 [REG_WY] = "WY",
54 [REG_WX] = "WX",
55 [REG_KEY1] = "KEY1",
56 [REG_VBK] = "VBK",
57 [REG_HDMA1] = "HDMA1",
58 [REG_HDMA2] = "HDMA2",
59 [REG_HDMA3] = "HDMA3",
60 [REG_HDMA4] = "HDMA4",
61 [REG_HDMA5] = "HDMA5",
62 [REG_RP] = "RP",
63 [REG_BCPS] = "BCPS",
64 [REG_BCPD] = "BCPD",
65 [REG_OCPS] = "OCPS",
66 [REG_OCPD] = "OCPD",
67 [REG_SVBK] = "SVBK",
68 [REG_IE] = "IE",
69};
70
71static const uint8_t _registerMask[] = {
72 [REG_SC] = 0x7E, // TODO: GBC differences
73 [REG_IF] = 0xE0,
74 [REG_TAC] = 0xF8,
75 [REG_NR10] = 0x80,
76 [REG_NR11] = 0x3F,
77 [REG_NR12] = 0x00,
78 [REG_NR13] = 0xFF,
79 [REG_NR14] = 0xBF,
80 [REG_NR21] = 0x3F,
81 [REG_NR22] = 0x00,
82 [REG_NR23] = 0xFF,
83 [REG_NR24] = 0xBF,
84 [REG_NR30] = 0x7F,
85 [REG_NR31] = 0xFF,
86 [REG_NR32] = 0x9F,
87 [REG_NR33] = 0xFF,
88 [REG_NR34] = 0xBF,
89 [REG_NR41] = 0xFF,
90 [REG_NR42] = 0x00,
91 [REG_NR43] = 0x00,
92 [REG_NR44] = 0xBF,
93 [REG_NR50] = 0x00,
94 [REG_NR51] = 0x00,
95 [REG_NR52] = 0x70,
96 [REG_STAT] = 0x80,
97 [REG_KEY1] = 0x7E,
98 [REG_VBK] = 0xFE,
99 [REG_OCPS] = 0x40,
100 [REG_BCPS] = 0x40,
101 [REG_UNK6C] = 0xFE,
102 [REG_SVBK] = 0xF8,
103 [REG_UNK75] = 0x8F,
104 [REG_IE] = 0xE0,
105};
106
107void GBIOInit(struct GB* gb) {
108 memset(gb->memory.io, 0, sizeof(gb->memory.io));
109}
110
111void GBIOReset(struct GB* gb) {
112 memset(gb->memory.io, 0, sizeof(gb->memory.io));
113
114 GBIOWrite(gb, REG_TIMA, 0);
115 GBIOWrite(gb, REG_TMA, 0);
116 GBIOWrite(gb, REG_TAC, 0);
117 GBIOWrite(gb, REG_IF, 1);
118 GBIOWrite(gb, REG_NR52, 0xF1);
119 GBIOWrite(gb, REG_NR10, 0x80);
120 GBIOWrite(gb, REG_NR11, 0xBF);
121 GBIOWrite(gb, REG_NR12, 0xF3);
122 GBIOWrite(gb, REG_NR13, 0xF3);
123 GBIOWrite(gb, REG_NR14, 0xBF);
124 GBIOWrite(gb, REG_NR21, 0x3F);
125 GBIOWrite(gb, REG_NR22, 0x00);
126 GBIOWrite(gb, REG_NR24, 0xBF);
127 GBIOWrite(gb, REG_NR30, 0x7F);
128 GBIOWrite(gb, REG_NR31, 0xFF);
129 GBIOWrite(gb, REG_NR32, 0x9F);
130 GBIOWrite(gb, REG_NR34, 0xBF);
131 GBIOWrite(gb, REG_NR41, 0xFF);
132 GBIOWrite(gb, REG_NR42, 0x00);
133 GBIOWrite(gb, REG_NR43, 0x00);
134 GBIOWrite(gb, REG_NR44, 0xBF);
135 GBIOWrite(gb, REG_NR50, 0x77);
136 GBIOWrite(gb, REG_NR51, 0xF3);
137 GBIOWrite(gb, REG_LCDC, 0x91);
138 GBIOWrite(gb, REG_SCY, 0x00);
139 GBIOWrite(gb, REG_SCX, 0x00);
140 GBIOWrite(gb, REG_LYC, 0x00);
141 GBIOWrite(gb, REG_BGP, 0xFC);
142 GBIOWrite(gb, REG_OBP0, 0xFF);
143 GBIOWrite(gb, REG_OBP1, 0xFF);
144 GBIOWrite(gb, REG_WY, 0x00);
145 GBIOWrite(gb, REG_WX, 0x00);
146 GBIOWrite(gb, REG_VBK, 0);
147 GBIOWrite(gb, REG_BCPS, 0);
148 GBIOWrite(gb, REG_OCPS, 0);
149 GBIOWrite(gb, REG_SVBK, 1);
150 GBIOWrite(gb, REG_HDMA1, 0xFF);
151 GBIOWrite(gb, REG_HDMA2, 0xFF);
152 GBIOWrite(gb, REG_HDMA3, 0xFF);
153 GBIOWrite(gb, REG_HDMA4, 0xFF);
154 gb->memory.io[REG_HDMA5] = 0xFF;
155 GBIOWrite(gb, REG_IE, 0x00);
156}
157
158void GBIOWrite(struct GB* gb, unsigned address, uint8_t value) {
159 switch (address) {
160 case REG_DIV:
161 GBTimerDivReset(&gb->timer);
162 return;
163 case REG_NR10:
164 if (gb->audio.enable) {
165 GBAudioWriteNR10(&gb->audio, value);
166 } else {
167 value = 0;
168 }
169 break;
170 case REG_NR11:
171 if (gb->audio.enable) {
172 GBAudioWriteNR11(&gb->audio, value);
173 } else {
174 if (gb->audio.style == GB_AUDIO_DMG) {
175 GBAudioWriteNR11(&gb->audio, value & _registerMask[REG_NR11]);
176 }
177 value = 0;
178 }
179 break;
180 case REG_NR12:
181 if (gb->audio.enable) {
182 GBAudioWriteNR12(&gb->audio, value);
183 } else {
184 value = 0;
185 }
186 break;
187 case REG_NR13:
188 if (gb->audio.enable) {
189 GBAudioWriteNR13(&gb->audio, value);
190 } else {
191 value = 0;
192 }
193 break;
194 case REG_NR14:
195 if (gb->audio.enable) {
196 GBAudioWriteNR14(&gb->audio, value);
197 } else {
198 value = 0;
199 }
200 break;
201 case REG_NR21:
202 if (gb->audio.enable) {
203 GBAudioWriteNR21(&gb->audio, value);
204 } else {
205 if (gb->audio.style == GB_AUDIO_DMG) {
206 GBAudioWriteNR21(&gb->audio, value & _registerMask[REG_NR21]);
207 }
208 value = 0;
209 }
210 break;
211 case REG_NR22:
212 if (gb->audio.enable) {
213 GBAudioWriteNR22(&gb->audio, value);
214 } else {
215 value = 0;
216 }
217 break;
218 case REG_NR23:
219 if (gb->audio.enable) {
220 GBAudioWriteNR23(&gb->audio, value);
221 } else {
222 value = 0;
223 }
224 break;
225 case REG_NR24:
226 if (gb->audio.enable) {
227 GBAudioWriteNR24(&gb->audio, value);
228 } else {
229 value = 0;
230 }
231 break;
232 case REG_NR30:
233 if (gb->audio.enable) {
234 GBAudioWriteNR30(&gb->audio, value);
235 } else {
236 value = 0;
237 }
238 break;
239 case REG_NR31:
240 if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
241 GBAudioWriteNR31(&gb->audio, value);
242 } else {
243 value = 0;
244 }
245 break;
246 case REG_NR32:
247 if (gb->audio.enable) {
248 GBAudioWriteNR32(&gb->audio, value);
249 } else {
250 value = 0;
251 }
252 break;
253 case REG_NR33:
254 if (gb->audio.enable) {
255 GBAudioWriteNR33(&gb->audio, value);
256 } else {
257 value = 0;
258 }
259 break;
260 case REG_NR34:
261 if (gb->audio.enable) {
262 GBAudioWriteNR34(&gb->audio, value);
263 } else {
264 value = 0;
265 }
266 break;
267 case REG_NR41:
268 if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
269 GBAudioWriteNR41(&gb->audio, value);
270 } else {
271 value = 0;
272 }
273 break;
274 case REG_NR42:
275 if (gb->audio.enable) {
276 GBAudioWriteNR42(&gb->audio, value);
277 } else {
278 value = 0;
279 }
280 break;
281 case REG_NR43:
282 if (gb->audio.enable) {
283 GBAudioWriteNR43(&gb->audio, value);
284 } else {
285 value = 0;
286 }
287 break;
288 case REG_NR44:
289 if (gb->audio.enable) {
290 GBAudioWriteNR44(&gb->audio, value);
291 } else {
292 value = 0;
293 }
294 break;
295 case REG_NR50:
296 if (gb->audio.enable) {
297 GBAudioWriteNR50(&gb->audio, value);
298 } else {
299 value = 0;
300 }
301 break;
302 case REG_NR51:
303 if (gb->audio.enable) {
304 GBAudioWriteNR51(&gb->audio, value);
305 } else {
306 value = 0;
307 }
308 break;
309 case REG_NR52:
310 GBAudioWriteNR52(&gb->audio, value);
311 value &= 0x80;
312 value |= gb->memory.io[REG_NR52] & 0x0F;
313 break;
314 case REG_WAVE_0:
315 case REG_WAVE_1:
316 case REG_WAVE_2:
317 case REG_WAVE_3:
318 case REG_WAVE_4:
319 case REG_WAVE_5:
320 case REG_WAVE_6:
321 case REG_WAVE_7:
322 case REG_WAVE_8:
323 case REG_WAVE_9:
324 case REG_WAVE_A:
325 case REG_WAVE_B:
326 case REG_WAVE_C:
327 case REG_WAVE_D:
328 case REG_WAVE_E:
329 case REG_WAVE_F:
330 if (!gb->audio.playingCh3 || gb->audio.style != GB_AUDIO_DMG) {
331 gb->audio.ch3.wavedata8[address - REG_WAVE_0] = value;
332 } else if(gb->audio.ch3.readable) {
333 gb->audio.ch3.wavedata8[gb->audio.ch3.window >> 1] = value;
334 }
335 break;
336 case REG_JOYP:
337 case REG_TIMA:
338 case REG_TMA:
339 case REG_LYC:
340 // Handled transparently by the registers
341 break;
342 case REG_TAC:
343 value = GBTimerUpdateTAC(&gb->timer, value);
344 break;
345 case REG_IF:
346 gb->memory.io[REG_IF] = value | 0xE0;
347 GBUpdateIRQs(gb);
348 return;
349 case REG_LCDC:
350 // TODO: handle GBC differences
351 value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
352 GBVideoWriteLCDC(&gb->video, value);
353 break;
354 case REG_DMA:
355 GBMemoryDMA(gb, value << 8);
356 break;
357 case REG_SCY:
358 case REG_SCX:
359 case REG_WY:
360 case REG_WX:
361 GBVideoProcessDots(&gb->video);
362 value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
363 break;
364 case REG_BGP:
365 case REG_OBP0:
366 case REG_OBP1:
367 GBVideoProcessDots(&gb->video);
368 GBVideoWritePalette(&gb->video, address, value);
369 break;
370 case REG_STAT:
371 GBVideoWriteSTAT(&gb->video, value);
372 break;
373 case 0x50:
374 if (gb->memory.romBase != gb->memory.rom) {
375 free(gb->memory.romBase);
376 gb->memory.romBase = gb->memory.rom;
377 }
378 break;
379 case REG_IE:
380 gb->memory.ie = value;
381 GBUpdateIRQs(gb);
382 return;
383 default:
384 if (gb->model >= GB_MODEL_CGB) {
385 switch (address) {
386 case REG_KEY1:
387 value &= 0x1;
388 value |= gb->memory.io[address] & 0x80;
389 break;
390 case REG_VBK:
391 GBVideoSwitchBank(&gb->video, value);
392 break;
393 case REG_HDMA1:
394 case REG_HDMA2:
395 case REG_HDMA3:
396 case REG_HDMA4:
397 // Handled transparently by the registers
398 break;
399 case REG_HDMA5:
400 GBMemoryWriteHDMA5(gb, value);
401 value &= 0x7F;
402 break;
403 case REG_BCPS:
404 gb->video.bcpIndex = value & 0x3F;
405 gb->video.bcpIncrement = value & 0x80;
406 gb->memory.io[REG_BCPD] = gb->video.palette[gb->video.bcpIndex >> 1] >> (8 * (gb->video.bcpIndex & 1));
407 break;
408 case REG_BCPD:
409 GBVideoProcessDots(&gb->video);
410 GBVideoWritePalette(&gb->video, address, value);
411 break;
412 case REG_OCPS:
413 gb->video.ocpIndex = value & 0x3F;
414 gb->video.ocpIncrement = value & 0x80;
415 gb->memory.io[REG_OCPD] = gb->video.palette[8 * 4 + (gb->video.ocpIndex >> 1)] >> (8 * (gb->video.ocpIndex & 1));
416 break;
417 case REG_OCPD:
418 GBVideoProcessDots(&gb->video);
419 GBVideoWritePalette(&gb->video, address, value);
420 break;
421 case REG_SVBK:
422 GBMemorySwitchWramBank(&gb->memory, value);
423 value = gb->memory.wramCurrentBank;
424 break;
425 default:
426 goto failed;
427 }
428 goto success;
429 }
430 failed:
431 mLOG(GB_IO, STUB, "Writing to unknown register FF%02X:%02X", address, value);
432 if (address >= GB_SIZE_IO) {
433 return;
434 }
435 break;
436 }
437 success:
438 gb->memory.io[address] = value;
439}
440
441static uint8_t _readKeys(struct GB* gb) {
442 uint8_t keys = *gb->keySource;
443 switch (gb->memory.io[REG_JOYP] & 0x30) {
444 case 0x30:
445 keys = 0;
446 break;
447 case 0x20:
448 keys >>= 4;
449 break;
450 case 0x10:
451 break;
452 case 0x00:
453 keys |= keys >> 4;
454 break;
455 }
456 return (0xC0 | (gb->memory.io[REG_JOYP] | 0xF)) ^ (keys & 0xF);
457}
458
459uint8_t GBIORead(struct GB* gb, unsigned address) {
460 switch (address) {
461 case REG_JOYP:
462 return _readKeys(gb);
463 case REG_SB:
464 case REG_SC:
465 // TODO
466 break;
467 case REG_IE:
468 return gb->memory.ie;
469 case REG_WAVE_0:
470 case REG_WAVE_1:
471 case REG_WAVE_2:
472 case REG_WAVE_3:
473 case REG_WAVE_4:
474 case REG_WAVE_5:
475 case REG_WAVE_6:
476 case REG_WAVE_7:
477 case REG_WAVE_8:
478 case REG_WAVE_9:
479 case REG_WAVE_A:
480 case REG_WAVE_B:
481 case REG_WAVE_C:
482 case REG_WAVE_D:
483 case REG_WAVE_E:
484 case REG_WAVE_F:
485 if (gb->audio.playingCh3) {
486 if (gb->audio.ch3.readable || gb->audio.style != GB_AUDIO_DMG) {
487 return gb->audio.ch3.wavedata8[gb->audio.ch3.window >> 1];
488 } else {
489 return 0xFF;
490 }
491 } else {
492 return gb->audio.ch3.wavedata8[address - REG_WAVE_0];
493 }
494 break;
495 case REG_IF:
496 case REG_NR10:
497 case REG_NR11:
498 case REG_NR12:
499 case REG_NR14:
500 case REG_NR21:
501 case REG_NR22:
502 case REG_NR24:
503 case REG_NR30:
504 case REG_NR32:
505 case REG_NR34:
506 case REG_NR41:
507 case REG_NR42:
508 case REG_NR43:
509 case REG_NR44:
510 case REG_NR50:
511 case REG_NR51:
512 case REG_NR52:
513 case REG_DIV:
514 case REG_TIMA:
515 case REG_TMA:
516 case REG_TAC:
517 case REG_STAT:
518 case REG_LCDC:
519 case REG_SCY:
520 case REG_SCX:
521 case REG_LY:
522 case REG_LYC:
523 case REG_BGP:
524 case REG_OBP0:
525 case REG_OBP1:
526 case REG_WY:
527 case REG_WX:
528 // Handled transparently by the registers
529 break;
530 default:
531 if (gb->model >= GB_MODEL_CGB) {
532 switch (address) {
533 case REG_KEY1:
534 case REG_VBK:
535 case REG_HDMA1:
536 case REG_HDMA2:
537 case REG_HDMA3:
538 case REG_HDMA4:
539 case REG_HDMA5:
540 case REG_BCPD:
541 case REG_OCPD:
542 case REG_SVBK:
543 // Handled transparently by the registers
544 goto success;
545 default:
546 break;
547 }
548 }
549 mLOG(GB_IO, STUB, "Reading from unknown register FF%02X", address);
550 return 0xFF;
551 }
552 success:
553 return gb->memory.io[address] | _registerMask[address];
554}
555
556struct GBSerializedState;
557void GBIOSerialize(const struct GB* gb, struct GBSerializedState* state) {
558 memcpy(state->io, gb->memory.io, GB_SIZE_IO);
559 state->ie = gb->memory.ie;
560}
561
562void GBIODeserialize(struct GB* gb, const struct GBSerializedState* state) {
563 memcpy(gb->memory.io, state->io, GB_SIZE_IO);
564 gb->memory.ie = state->ie;
565 gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_LCDC, state->io[REG_LCDC]);
566 gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_SCY, state->io[REG_SCY]);
567 gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_SCX, state->io[REG_SCX]);
568 gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_WY, state->io[REG_WY]);
569 gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_WX, state->io[REG_WX]);
570}