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mGBA Game Boy Advance Emulator

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 <mgba/internal/gb/io.h>
  7
  8#include <mgba/internal/gb/gb.h>
  9#include <mgba/internal/gb/sio.h>
 10#include <mgba/internal/gb/serialize.h>
 11
 12mLOG_DEFINE_CATEGORY(GB_IO, "GB I/O", "gb.io");
 13
 14MGBA_EXPORT const char* const GBIORegisterNames[] = {
 15	[REG_JOYP] = "JOYP",
 16	[REG_SB] = "SB",
 17	[REG_SC] = "SC",
 18	[REG_DIV] = "DIV",
 19	[REG_TIMA] = "TIMA",
 20	[REG_TMA] = "TMA",
 21	[REG_TAC] = "TAC",
 22	[REG_IF] = "IF",
 23	[REG_NR10] = "NR10",
 24	[REG_NR11] = "NR11",
 25	[REG_NR12] = "NR12",
 26	[REG_NR13] = "NR13",
 27	[REG_NR14] = "NR14",
 28	[REG_NR21] = "NR21",
 29	[REG_NR22] = "NR22",
 30	[REG_NR23] = "NR23",
 31	[REG_NR24] = "NR24",
 32	[REG_NR30] = "NR30",
 33	[REG_NR31] = "NR31",
 34	[REG_NR32] = "NR32",
 35	[REG_NR33] = "NR33",
 36	[REG_NR34] = "NR34",
 37	[REG_NR41] = "NR41",
 38	[REG_NR42] = "NR42",
 39	[REG_NR43] = "NR43",
 40	[REG_NR44] = "NR44",
 41	[REG_NR50] = "NR50",
 42	[REG_NR51] = "NR51",
 43	[REG_NR52] = "NR52",
 44	[REG_LCDC] = "LCDC",
 45	[REG_STAT] = "STAT",
 46	[REG_SCY] = "SCY",
 47	[REG_SCX] = "SCX",
 48	[REG_LY] = "LY",
 49	[REG_LYC] = "LYC",
 50	[REG_DMA] = "DMA",
 51	[REG_BGP] = "BGP",
 52	[REG_OBP0] = "OBP0",
 53	[REG_OBP1] = "OBP1",
 54	[REG_WY] = "WY",
 55	[REG_WX] = "WX",
 56	[REG_KEY0] = "KEY0",
 57	[REG_KEY1] = "KEY1",
 58	[REG_VBK] = "VBK",
 59	[REG_HDMA1] = "HDMA1",
 60	[REG_HDMA2] = "HDMA2",
 61	[REG_HDMA3] = "HDMA3",
 62	[REG_HDMA4] = "HDMA4",
 63	[REG_HDMA5] = "HDMA5",
 64	[REG_RP] = "RP",
 65	[REG_BCPS] = "BCPS",
 66	[REG_BCPD] = "BCPD",
 67	[REG_OCPS] = "OCPS",
 68	[REG_OCPD] = "OCPD",
 69	[REG_OPRI] = "OPRI",
 70	[REG_SVBK] = "SVBK",
 71	[REG_IE] = "IE",
 72};
 73
 74static const uint8_t _registerMask[] = {
 75	[REG_SC]   = 0x7E, // TODO: GBC differences
 76	[REG_IF]   = 0xE0,
 77	[REG_TAC]  = 0xF8,
 78	[REG_NR10] = 0x80,
 79	[REG_NR11] = 0x3F,
 80	[REG_NR12] = 0x00,
 81	[REG_NR13] = 0xFF,
 82	[REG_NR14] = 0xBF,
 83	[REG_NR21] = 0x3F,
 84	[REG_NR22] = 0x00,
 85	[REG_NR23] = 0xFF,
 86	[REG_NR24] = 0xBF,
 87	[REG_NR30] = 0x7F,
 88	[REG_NR31] = 0xFF,
 89	[REG_NR32] = 0x9F,
 90	[REG_NR33] = 0xFF,
 91	[REG_NR34] = 0xBF,
 92	[REG_NR41] = 0xFF,
 93	[REG_NR42] = 0x00,
 94	[REG_NR43] = 0x00,
 95	[REG_NR44] = 0xBF,
 96	[REG_NR50] = 0x00,
 97	[REG_NR51] = 0x00,
 98	[REG_NR52] = 0x70,
 99	[REG_STAT] = 0x80,
100	[REG_KEY1] = 0x7E,
101	[REG_VBK] = 0xFE,
102	[REG_OCPS] = 0x40,
103	[REG_BCPS] = 0x40,
104	[REG_OPRI] = 0xFE,
105	[REG_SVBK] = 0xF8,
106	[REG_IE]   = 0xE0,
107};
108
109static uint8_t _readKeys(struct GB* gb);
110static uint8_t _readKeysFiltered(struct GB* gb);
111
112static void _writeSGBBits(struct GB* gb, int bits) {
113	if (!bits) {
114		gb->sgbBit = -1;
115		memset(gb->sgbPacket, 0, sizeof(gb->sgbPacket));
116	}
117	if (bits == gb->currentSgbBits) {
118		return;
119	}
120	switch (bits) {
121	case 0:
122	case 1:
123		if (gb->currentSgbBits & 2) {
124			gb->sgbIncrement = !gb->sgbIncrement;
125		}
126		break;
127	case 3:
128		if (gb->sgbIncrement) {
129			gb->sgbIncrement = false;
130			gb->sgbCurrentController = (gb->sgbCurrentController + 1) & gb->sgbControllers;
131		}
132		break;
133	}
134	gb->currentSgbBits = bits;
135	if (gb->sgbBit == 128 && bits == 2) {
136		GBVideoWriteSGBPacket(&gb->video, gb->sgbPacket);
137		++gb->sgbBit;
138	}
139	if (gb->sgbBit >= 128) {
140		return;
141	}
142	switch (bits) {
143	case 1:
144		if (gb->sgbBit < 0) {
145			return;
146		}
147		gb->sgbPacket[gb->sgbBit >> 3] |= 1 << (gb->sgbBit & 7);
148		break;
149	case 3:
150		++gb->sgbBit;
151	default:
152		break;
153	}
154}
155
156void GBIOInit(struct GB* gb) {
157	memset(gb->memory.io, 0, sizeof(gb->memory.io));
158}
159
160void GBIOReset(struct GB* gb) {
161	memset(gb->memory.io, 0, sizeof(gb->memory.io));
162
163	GBIOWrite(gb, REG_TIMA, 0);
164	GBIOWrite(gb, REG_TMA, 0);
165	GBIOWrite(gb, REG_TAC, 0);
166	GBIOWrite(gb, REG_IF, 1);
167	GBIOWrite(gb, REG_NR52, 0xF1);
168	GBIOWrite(gb, REG_NR14, 0x3F);
169	GBIOWrite(gb, REG_NR10, 0x80);
170	GBIOWrite(gb, REG_NR11, 0xBF);
171	GBIOWrite(gb, REG_NR12, 0xF3);
172	GBIOWrite(gb, REG_NR13, 0xF3);
173	GBIOWrite(gb, REG_NR24, 0x3F);
174	GBIOWrite(gb, REG_NR21, 0x3F);
175	GBIOWrite(gb, REG_NR22, 0x00);
176	GBIOWrite(gb, REG_NR34, 0x3F);
177	GBIOWrite(gb, REG_NR30, 0x7F);
178	GBIOWrite(gb, REG_NR31, 0xFF);
179	GBIOWrite(gb, REG_NR32, 0x9F);
180	GBIOWrite(gb, REG_NR44, 0x3F);
181	GBIOWrite(gb, REG_NR41, 0xFF);
182	GBIOWrite(gb, REG_NR42, 0x00);
183	GBIOWrite(gb, REG_NR43, 0x00);
184	GBIOWrite(gb, REG_NR50, 0x77);
185	GBIOWrite(gb, REG_NR51, 0xF3);
186	if (!gb->biosVf) {
187		GBIOWrite(gb, REG_LCDC, 0x91);
188		gb->memory.io[0x50] = 1;
189	} else {
190		GBIOWrite(gb, REG_LCDC, 0x00);
191		gb->memory.io[0x50] = 0xFF;
192	}
193	GBIOWrite(gb, REG_SCY, 0x00);
194	GBIOWrite(gb, REG_SCX, 0x00);
195	GBIOWrite(gb, REG_LYC, 0x00);
196	GBIOWrite(gb, REG_DMA, 0xFF);
197	GBIOWrite(gb, REG_BGP, 0xFC);
198	if (gb->model < GB_MODEL_CGB) {
199		GBIOWrite(gb, REG_OBP0, 0xFF);
200		GBIOWrite(gb, REG_OBP1, 0xFF);
201	}
202	GBIOWrite(gb, REG_WY, 0x00);
203	GBIOWrite(gb, REG_WX, 0x00);
204	if (gb->model & GB_MODEL_CGB) {
205		GBIOWrite(gb, REG_KEY0, 0);
206		GBIOWrite(gb, REG_JOYP, 0xFF);
207		GBIOWrite(gb, REG_VBK, 0);
208		GBIOWrite(gb, REG_BCPS, 0x80);
209		GBIOWrite(gb, REG_OCPS, 0);
210		GBIOWrite(gb, REG_SVBK, 1);
211		GBIOWrite(gb, REG_HDMA1, 0xFF);
212		GBIOWrite(gb, REG_HDMA2, 0xFF);
213		GBIOWrite(gb, REG_HDMA3, 0xFF);
214		GBIOWrite(gb, REG_HDMA4, 0xFF);
215		gb->memory.io[REG_HDMA5] = 0xFF;
216	} else if (gb->model & GB_MODEL_SGB) {
217		GBIOWrite(gb, REG_JOYP, 0xFF);
218	}
219	GBIOWrite(gb, REG_IE, 0x00);
220}
221
222void GBIOWrite(struct GB* gb, unsigned address, uint8_t value) {
223	switch (address) {
224	case REG_SB:
225		GBSIOWriteSB(&gb->sio, value);
226		break;
227	case REG_SC:
228		GBSIOWriteSC(&gb->sio, value);
229		break;
230	case REG_DIV:
231		GBTimerDivReset(&gb->timer);
232		return;
233	case REG_NR10:
234		if (gb->audio.enable) {
235			GBAudioWriteNR10(&gb->audio, value);
236		} else {
237			value = 0;
238		}
239		break;
240	case REG_NR11:
241		if (gb->audio.enable) {
242			GBAudioWriteNR11(&gb->audio, value);
243		} else {
244			if (gb->audio.style == GB_AUDIO_DMG) {
245				GBAudioWriteNR11(&gb->audio, value & _registerMask[REG_NR11]);
246			}
247			value = 0;
248		}
249		break;
250	case REG_NR12:
251		if (gb->audio.enable) {
252			GBAudioWriteNR12(&gb->audio, value);
253		} else {
254			value = 0;
255		}
256		break;
257	case REG_NR13:
258		if (gb->audio.enable) {
259			GBAudioWriteNR13(&gb->audio, value);
260		} else {
261			value = 0;
262		}
263		break;
264	case REG_NR14:
265		if (gb->audio.enable) {
266			GBAudioWriteNR14(&gb->audio, value);
267		} else {
268			value = 0;
269		}
270		break;
271	case REG_NR21:
272		if (gb->audio.enable) {
273			GBAudioWriteNR21(&gb->audio, value);
274		} else {
275			if (gb->audio.style == GB_AUDIO_DMG) {
276				GBAudioWriteNR21(&gb->audio, value & _registerMask[REG_NR21]);
277			}
278			value = 0;
279		}
280		break;
281	case REG_NR22:
282		if (gb->audio.enable) {
283			GBAudioWriteNR22(&gb->audio, value);
284		} else {
285			value = 0;
286		}
287		break;
288	case REG_NR23:
289		if (gb->audio.enable) {
290			GBAudioWriteNR23(&gb->audio, value);
291		} else {
292			value = 0;
293		}
294		break;
295	case REG_NR24:
296		if (gb->audio.enable) {
297			GBAudioWriteNR24(&gb->audio, value);
298		} else {
299			value = 0;
300		}
301		break;
302	case REG_NR30:
303		if (gb->audio.enable) {
304			GBAudioWriteNR30(&gb->audio, value);
305		} else {
306			value = 0;
307		}
308		break;
309	case REG_NR31:
310		if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
311			GBAudioWriteNR31(&gb->audio, value);
312		} else {
313			value = 0;
314		}
315		break;
316	case REG_NR32:
317		if (gb->audio.enable) {
318			GBAudioWriteNR32(&gb->audio, value);
319		} else {
320			value = 0;
321		}
322		break;
323	case REG_NR33:
324		if (gb->audio.enable) {
325			GBAudioWriteNR33(&gb->audio, value);
326		} else {
327			value = 0;
328		}
329		break;
330	case REG_NR34:
331		if (gb->audio.enable) {
332			GBAudioWriteNR34(&gb->audio, value);
333		} else {
334			value = 0;
335		}
336		break;
337	case REG_NR41:
338		if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
339			GBAudioWriteNR41(&gb->audio, value);
340		} else {
341			value = 0;
342		}
343		break;
344	case REG_NR42:
345		if (gb->audio.enable) {
346			GBAudioWriteNR42(&gb->audio, value);
347		} else {
348			value = 0;
349		}
350		break;
351	case REG_NR43:
352		if (gb->audio.enable) {
353			GBAudioWriteNR43(&gb->audio, value);
354		} else {
355			value = 0;
356		}
357		break;
358	case REG_NR44:
359		if (gb->audio.enable) {
360			GBAudioWriteNR44(&gb->audio, value);
361		} else {
362			value = 0;
363		}
364		break;
365	case REG_NR50:
366		if (gb->audio.enable) {
367			GBAudioWriteNR50(&gb->audio, value);
368		} else {
369			value = 0;
370		}
371		break;
372	case REG_NR51:
373		if (gb->audio.enable) {
374			GBAudioWriteNR51(&gb->audio, value);
375		} else {
376			value = 0;
377		}
378		break;
379	case REG_NR52:
380		GBAudioWriteNR52(&gb->audio, value);
381		value &= 0x80;
382		value |= gb->memory.io[REG_NR52] & 0x0F;
383		break;
384	case REG_WAVE_0:
385	case REG_WAVE_1:
386	case REG_WAVE_2:
387	case REG_WAVE_3:
388	case REG_WAVE_4:
389	case REG_WAVE_5:
390	case REG_WAVE_6:
391	case REG_WAVE_7:
392	case REG_WAVE_8:
393	case REG_WAVE_9:
394	case REG_WAVE_A:
395	case REG_WAVE_B:
396	case REG_WAVE_C:
397	case REG_WAVE_D:
398	case REG_WAVE_E:
399	case REG_WAVE_F:
400		if (!gb->audio.playingCh3 || gb->audio.style != GB_AUDIO_DMG) {
401			gb->audio.ch3.wavedata8[address - REG_WAVE_0] = value;
402		} else if(gb->audio.ch3.readable) {
403			gb->audio.ch3.wavedata8[gb->audio.ch3.window >> 1] = value;
404		}
405		break;
406	case REG_JOYP:
407		gb->memory.io[REG_JOYP] = value | 0x0F;
408		_readKeys(gb);
409		if (gb->model & GB_MODEL_SGB) {
410			_writeSGBBits(gb, (value >> 4) & 3);
411		}
412		return;
413	case REG_TIMA:
414		if (value && mTimingUntil(&gb->timing, &gb->timer.irq) > 1) {
415			mTimingDeschedule(&gb->timing, &gb->timer.irq);
416		}
417		if (mTimingUntil(&gb->timing, &gb->timer.irq) == -1) {
418			return;
419		}
420		break;
421	case REG_TMA:
422		if (mTimingUntil(&gb->timing, &gb->timer.irq) == -1) {
423			gb->memory.io[REG_TIMA] = value;
424		}
425		break;
426	case REG_TAC:
427		value = GBTimerUpdateTAC(&gb->timer, value);
428		break;
429	case REG_IF:
430		gb->memory.io[REG_IF] = value | 0xE0;
431		GBUpdateIRQs(gb);
432		return;
433	case REG_LCDC:
434		// TODO: handle GBC differences
435		GBVideoProcessDots(&gb->video, 0);
436		value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
437		GBVideoWriteLCDC(&gb->video, value);
438		break;
439	case REG_LYC:
440		GBVideoWriteLYC(&gb->video, value);
441		break;
442	case REG_DMA:
443		GBMemoryDMA(gb, value << 8);
444		break;
445	case REG_SCY:
446	case REG_SCX:
447	case REG_WY:
448	case REG_WX:
449		GBVideoProcessDots(&gb->video, 0);
450		value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
451		break;
452	case REG_BGP:
453	case REG_OBP0:
454	case REG_OBP1:
455		GBVideoProcessDots(&gb->video, 0);
456		GBVideoWritePalette(&gb->video, address, value);
457		break;
458	case REG_STAT:
459		GBVideoWriteSTAT(&gb->video, value);
460		value = gb->video.stat;
461		break;
462	case 0x50:
463		if (gb->memory.io[0x50] != 0xFF) {
464			break;
465		}
466		GBUnmapBIOS(gb);
467		if (gb->model >= GB_MODEL_CGB && gb->memory.io[REG_KEY0] < 0x80) {
468			gb->model = GB_MODEL_DMG;
469			GBVideoDisableCGB(&gb->video);
470		}
471		break;
472	case REG_IE:
473		gb->memory.ie = value;
474		GBUpdateIRQs(gb);
475		return;
476	default:
477		if (gb->model >= GB_MODEL_CGB) {
478			switch (address) {
479			case REG_KEY0:
480				break;
481			case REG_KEY1:
482				value &= 0x1;
483				value |= gb->memory.io[address] & 0x80;
484				break;
485			case REG_VBK:
486				GBVideoSwitchBank(&gb->video, value);
487				break;
488			case REG_HDMA1:
489			case REG_HDMA2:
490			case REG_HDMA3:
491			case REG_HDMA4:
492				// Handled transparently by the registers
493				break;
494			case REG_HDMA5:
495				value = GBMemoryWriteHDMA5(gb, value);
496				break;
497			case REG_BCPS:
498				gb->video.bcpIndex = value & 0x3F;
499				gb->video.bcpIncrement = value & 0x80;
500				gb->memory.io[REG_BCPD] = gb->video.palette[gb->video.bcpIndex >> 1] >> (8 * (gb->video.bcpIndex & 1));
501				break;
502			case REG_BCPD:
503				if (gb->video.mode != 3) {
504					GBVideoProcessDots(&gb->video, 0);
505				}
506				GBVideoWritePalette(&gb->video, address, value);
507				return;
508			case REG_OCPS:
509				gb->video.ocpIndex = value & 0x3F;
510				gb->video.ocpIncrement = value & 0x80;
511				gb->memory.io[REG_OCPD] = gb->video.palette[8 * 4 + (gb->video.ocpIndex >> 1)] >> (8 * (gb->video.ocpIndex & 1));
512				break;
513			case REG_OCPD:
514				if (gb->video.mode != 3) {
515					GBVideoProcessDots(&gb->video, 0);
516				}
517				GBVideoWritePalette(&gb->video, address, value);
518				return;
519			case REG_SVBK:
520				GBMemorySwitchWramBank(&gb->memory, value);
521				value = gb->memory.wramCurrentBank;
522				break;
523			default:
524				goto failed;
525			}
526			goto success;
527		}
528		failed:
529		mLOG(GB_IO, STUB, "Writing to unknown register FF%02X:%02X", address, value);
530		if (address >= GB_SIZE_IO) {
531			return;
532		}
533		break;
534	}
535	success:
536	gb->memory.io[address] = value;
537}
538
539static uint8_t _readKeys(struct GB* gb) {
540	uint8_t keys = *gb->keySource;
541	if (gb->sgbCurrentController != 0) {
542		keys = 0;
543	}
544	uint8_t joyp = gb->memory.io[REG_JOYP];
545	switch (joyp & 0x30) {
546	case 0x30:
547		keys = gb->sgbCurrentController;
548		break;
549	case 0x20:
550		keys >>= 4;
551		break;
552	case 0x10:
553		break;
554	case 0x00:
555		keys |= keys >> 4;
556		break;
557	}
558	gb->memory.io[REG_JOYP] = (0xCF | joyp) ^ (keys & 0xF);
559	if (joyp & ~gb->memory.io[REG_JOYP] & 0xF) {
560		gb->memory.io[REG_IF] |= (1 << GB_IRQ_KEYPAD);
561		GBUpdateIRQs(gb);
562	}
563	return gb->memory.io[REG_JOYP];
564}
565
566static uint8_t _readKeysFiltered(struct GB* gb) {
567	uint8_t keys = _readKeys(gb);
568	if (!gb->allowOpposingDirections && (keys & 0x30) == 0x20) {
569		unsigned rl = keys & 0x03;
570		unsigned ud = keys & 0x0C;
571		if (!rl) {
572			keys |= 0x03;
573		}
574		if (!ud) {
575			keys |= 0x0C;
576		}
577	}
578	return keys;
579}
580
581uint8_t GBIORead(struct GB* gb, unsigned address) {
582	switch (address) {
583	case REG_JOYP:
584		{
585			size_t c;
586			for (c = 0; c < mCoreCallbacksListSize(&gb->coreCallbacks); ++c) {
587				struct mCoreCallbacks* callbacks = mCoreCallbacksListGetPointer(&gb->coreCallbacks, c);
588				if (callbacks->keysRead) {
589					callbacks->keysRead(callbacks->context);
590				}
591			}
592		}
593		return _readKeysFiltered(gb);
594	case REG_IE:
595		return gb->memory.ie;
596	case REG_WAVE_0:
597	case REG_WAVE_1:
598	case REG_WAVE_2:
599	case REG_WAVE_3:
600	case REG_WAVE_4:
601	case REG_WAVE_5:
602	case REG_WAVE_6:
603	case REG_WAVE_7:
604	case REG_WAVE_8:
605	case REG_WAVE_9:
606	case REG_WAVE_A:
607	case REG_WAVE_B:
608	case REG_WAVE_C:
609	case REG_WAVE_D:
610	case REG_WAVE_E:
611	case REG_WAVE_F:
612		if (gb->audio.playingCh3) {
613			if (gb->audio.ch3.readable || gb->audio.style != GB_AUDIO_DMG) {
614				return gb->audio.ch3.wavedata8[gb->audio.ch3.window >> 1];
615			} else {
616				return 0xFF;
617			}
618		} else {
619			return gb->audio.ch3.wavedata8[address - REG_WAVE_0];
620		}
621		break;
622	case REG_SB:
623	case REG_SC:
624	case REG_IF:
625	case REG_NR10:
626	case REG_NR11:
627	case REG_NR12:
628	case REG_NR14:
629	case REG_NR21:
630	case REG_NR22:
631	case REG_NR24:
632	case REG_NR30:
633	case REG_NR32:
634	case REG_NR34:
635	case REG_NR41:
636	case REG_NR42:
637	case REG_NR43:
638	case REG_NR44:
639	case REG_NR50:
640	case REG_NR51:
641	case REG_NR52:
642	case REG_DIV:
643	case REG_TIMA:
644	case REG_TMA:
645	case REG_TAC:
646	case REG_STAT:
647	case REG_LCDC:
648	case REG_SCY:
649	case REG_SCX:
650	case REG_LY:
651	case REG_LYC:
652	case REG_DMA:
653	case REG_BGP:
654	case REG_OBP0:
655	case REG_OBP1:
656	case REG_WY:
657	case REG_WX:
658		// Handled transparently by the registers
659		break;
660	default:
661		if (gb->model >= GB_MODEL_CGB) {
662			switch (address) {
663			case REG_KEY1:
664			case REG_VBK:
665			case REG_HDMA1:
666			case REG_HDMA2:
667			case REG_HDMA3:
668			case REG_HDMA4:
669			case REG_HDMA5:
670			case REG_BCPS:
671			case REG_BCPD:
672			case REG_OCPS:
673			case REG_OCPD:
674			case REG_SVBK:
675				// Handled transparently by the registers
676				goto success;
677			default:
678				break;
679			}
680		}
681		mLOG(GB_IO, STUB, "Reading from unknown register FF%02X", address);
682		return 0xFF;
683	}
684	success:
685	return gb->memory.io[address] | _registerMask[address];
686}
687
688void GBTestKeypadIRQ(struct GB* gb) {
689	_readKeys(gb);
690}
691
692struct GBSerializedState;
693void GBIOSerialize(const struct GB* gb, struct GBSerializedState* state) {
694	memcpy(state->io, gb->memory.io, GB_SIZE_IO);
695	state->ie = gb->memory.ie;
696}
697
698void GBIODeserialize(struct GB* gb, const struct GBSerializedState* state) {
699	memcpy(gb->memory.io, state->io, GB_SIZE_IO);
700	gb->memory.ie = state->ie;
701
702	if (GBAudioEnableGetEnable(*gb->audio.nr52)) {
703		GBIOWrite(gb, REG_NR10, gb->memory.io[REG_NR10]);
704		GBIOWrite(gb, REG_NR11, gb->memory.io[REG_NR11]);
705		GBIOWrite(gb, REG_NR12, gb->memory.io[REG_NR12]);
706		GBIOWrite(gb, REG_NR13, gb->memory.io[REG_NR13]);
707		gb->audio.ch1.control.frequency &= 0xFF;
708		gb->audio.ch1.control.frequency |= GBAudioRegisterControlGetFrequency(gb->memory.io[REG_NR14] << 8);
709		gb->audio.ch1.control.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR14] << 8);
710		GBIOWrite(gb, REG_NR21, gb->memory.io[REG_NR21]);
711		GBIOWrite(gb, REG_NR22, gb->memory.io[REG_NR22]);
712		GBIOWrite(gb, REG_NR22, gb->memory.io[REG_NR23]);
713		gb->audio.ch2.control.frequency &= 0xFF;
714		gb->audio.ch2.control.frequency |= GBAudioRegisterControlGetFrequency(gb->memory.io[REG_NR24] << 8);
715		gb->audio.ch2.control.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR24] << 8);
716		GBIOWrite(gb, REG_NR30, gb->memory.io[REG_NR30]);
717		GBIOWrite(gb, REG_NR31, gb->memory.io[REG_NR31]);
718		GBIOWrite(gb, REG_NR32, gb->memory.io[REG_NR32]);
719		GBIOWrite(gb, REG_NR32, gb->memory.io[REG_NR33]);
720		gb->audio.ch3.rate &= 0xFF;
721		gb->audio.ch3.rate |= GBAudioRegisterControlGetRate(gb->memory.io[REG_NR34] << 8);
722		gb->audio.ch3.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR34] << 8);
723		GBIOWrite(gb, REG_NR41, gb->memory.io[REG_NR41]);
724		GBIOWrite(gb, REG_NR42, gb->memory.io[REG_NR42]);
725		GBIOWrite(gb, REG_NR43, gb->memory.io[REG_NR43]);
726		gb->audio.ch4.stop = GBAudioRegisterNoiseControlGetStop(gb->memory.io[REG_NR44]);
727		GBIOWrite(gb, REG_NR50, gb->memory.io[REG_NR50]);
728		GBIOWrite(gb, REG_NR51, gb->memory.io[REG_NR51]);
729	}
730
731	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_LCDC, state->io[REG_LCDC]);
732	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_SCY, state->io[REG_SCY]);
733	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_SCX, state->io[REG_SCX]);
734	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_WY, state->io[REG_WY]);
735	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_WX, state->io[REG_WX]);
736	if (gb->model & GB_MODEL_SGB) {
737		gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_BGP, state->io[REG_BGP]);
738		gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_OBP0, state->io[REG_OBP0]);
739		gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_OBP1, state->io[REG_OBP1]);
740	}
741	gb->video.stat = state->io[REG_STAT];
742}