all repos — mgba @ 5c15ed7dd536541700014f71f53a7f4cb00240fd

mGBA Game Boy Advance Emulator

src/gba/io.c (view raw)

  1/* Copyright (c) 2013-2015 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 "gba/rr/rr.h"
  9#include "gba/serialize.h"
 10#include "gba/sio.h"
 11#include "gba/video.h"
 12
 13mLOG_DEFINE_CATEGORY(GBA_IO, "GBA I/O");
 14
 15const char* const GBAIORegisterNames[] = {
 16	// Video
 17	"DISPCNT",
 18	0,
 19	"DISPSTAT",
 20	"VCOUNT",
 21	"BG0CNT",
 22	"BG1CNT",
 23	"BG2CNT",
 24	"BG3CNT",
 25	"BG0HOFS",
 26	"BG0VOFS",
 27	"BG1HOFS",
 28	"BG1VOFS",
 29	"BG2HOFS",
 30	"BG2VOFS",
 31	"BG3HOFS",
 32	"BG3VOFS",
 33	"BG2PA",
 34	"BG2PB",
 35	"BG2PC",
 36	"BG2PD",
 37	"BG2X_LO",
 38	"BG2X_HI",
 39	"BG2Y_LO",
 40	"BG2Y_HI",
 41	"BG3PA",
 42	"BG3PB",
 43	"BG3PC",
 44	"BG3PD",
 45	"BG3X_LO",
 46	"BG3X_HI",
 47	"BG3Y_LO",
 48	"BG3Y_HI",
 49	"WIN0H",
 50	"WIN1H",
 51	"WIN0V",
 52	"WIN1V",
 53	"WININ",
 54	"WINOUT",
 55	"MOSAIC",
 56	0,
 57	"BLDCNT",
 58	"BLDALPHA",
 59	"BLDY",
 60	0,
 61	0,
 62	0,
 63	0,
 64	0,
 65
 66	// Sound
 67	"SOUND1CNT_LO",
 68	"SOUND1CNT_HI",
 69	"SOUND1CNT_X",
 70	0,
 71	"SOUND2CNT_LO",
 72	0,
 73	"SOUND2CNT_HI",
 74	0,
 75	"SOUND3CNT_LO",
 76	"SOUND3CNT_HI",
 77	"SOUND3CNT_X",
 78	0,
 79	"SOUND4CNT_LO",
 80	0,
 81	"SOUND4CNT_HI",
 82	0,
 83	"SOUNDCNT_LO",
 84	"SOUNDCNT_HI",
 85	"SOUNDCNT_X",
 86	0,
 87	"SOUNDBIAS",
 88	0,
 89	0,
 90	0,
 91	"WAVE_RAM0_LO",
 92	"WAVE_RAM0_HI",
 93	"WAVE_RAM1_LO",
 94	"WAVE_RAM1_HI",
 95	"WAVE_RAM2_LO",
 96	"WAVE_RAM2_HI",
 97	"WAVE_RAM3_LO",
 98	"WAVE_RAM3_HI",
 99	"FIFO_A_LO",
100	"FIFO_A_HI",
101	"FIFO_B_LO",
102	"FIFO_B_HI",
103	0,
104	0,
105	0,
106	0,
107
108	// DMA
109	"DMA0SAD_LO",
110	"DMA0SAD_HI",
111	"DMA0DAD_LO",
112	"DMA0DAD_HI",
113	"DMA0CNT_LO",
114	"DMA0CNT_HI",
115	"DMA1SAD_LO",
116	"DMA1SAD_HI",
117	"DMA1DAD_LO",
118	"DMA1DAD_HI",
119	"DMA1CNT_LO",
120	"DMA1CNT_HI",
121	"DMA2SAD_LO",
122	"DMA2SAD_HI",
123	"DMA2DAD_LO",
124	"DMA2DAD_HI",
125	"DMA2CNT_LO",
126	"DMA2CNT_HI",
127	"DMA3SAD_LO",
128	"DMA3SAD_HI",
129	"DMA3DAD_LO",
130	"DMA3DAD_HI",
131	"DMA3CNT_LO",
132	"DMA3CNT_HI",
133
134	0, 0, 0, 0, 0, 0, 0, 0,
135	0, 0, 0, 0, 0, 0, 0, 0,
136
137	// Timers
138	"TM0CNT_LO",
139	"TM0CNT_HI",
140	"TM1CNT_LO",
141	"TM1CNT_HI",
142	"TM2CNT_LO",
143	"TM2CNT_HI",
144	"TM3CNT_LO",
145	"TM3CNT_HI",
146
147	0, 0, 0, 0, 0, 0, 0, 0,
148
149	// SIO
150	"SIOMULTI0",
151	"SIOMULTI1",
152	"SIOMULTI2",
153	"SIOMULTI3",
154	"SIOCNT",
155	"SIOMLT_SEND",
156	0,
157	0,
158	"KEYINPUT",
159	"KEYCNT",
160	"RCNT",
161	0,
162	0,
163	0,
164	0,
165	0,
166	"JOYCNT",
167	0,
168	0,
169	0,
170	0,
171	0,
172	0,
173	0,
174	"JOY_RECV_LO",
175	"JOY_RECV_HI",
176	"JOY_TRANS_LO",
177	"JOY_TRANS_HI",
178	"JOYSTAT",
179	0,
180	0,
181	0,
182
183	0, 0, 0, 0, 0, 0, 0, 0,
184	0, 0, 0, 0, 0, 0, 0, 0,
185	0, 0, 0, 0, 0, 0, 0, 0,
186	0, 0, 0, 0, 0, 0, 0, 0,
187	0, 0, 0, 0, 0, 0, 0, 0,
188	0, 0, 0, 0, 0, 0, 0, 0,
189	0, 0, 0, 0, 0, 0, 0, 0,
190	0, 0, 0, 0, 0, 0, 0, 0,
191	0, 0, 0, 0, 0, 0, 0, 0,
192	0, 0, 0, 0, 0, 0, 0, 0,
193
194	// Interrupts, etc
195	"IE",
196	"IF",
197	"WAITCNT",
198	0,
199	"IME"
200};
201
202static const int _isValidRegister[REG_MAX >> 1] = {
203	// Video
204	1, 0, 1, 1, 1, 1, 1, 1,
205	1, 1, 1, 1, 1, 1, 1, 1,
206	1, 1, 1, 1, 1, 1, 1, 1,
207	1, 1, 1, 1, 1, 1, 1, 1,
208	1, 1, 1, 1, 1, 1, 1, 0,
209	1, 1, 1, 0, 0, 0, 0, 0,
210	// Audio
211	1, 1, 1, 0, 1, 0, 1, 0,
212	1, 1, 1, 0, 1, 0, 1, 0,
213	1, 1, 1, 0, 1, 0, 0, 0,
214	1, 1, 1, 1, 1, 1, 1, 1,
215	1, 1, 1, 1, 0, 0, 0, 0,
216	// DMA
217	1, 1, 1, 1, 1, 1, 1, 1,
218	1, 1, 1, 1, 1, 1, 1, 1,
219	1, 1, 1, 1, 1, 1, 1, 1,
220	0, 0, 0, 0, 0, 0, 0, 0,
221	0, 0, 0, 0, 0, 0, 0, 0,
222	// Timers
223	1, 1, 1, 1, 1, 1, 1, 1,
224	0, 0, 0, 0, 0, 0, 0, 0,
225	// SIO
226	1, 1, 1, 1, 1, 0, 0, 0,
227	1, 1, 1, 0, 0, 0, 0, 0,
228	1, 0, 0, 0, 0, 0, 0, 0,
229	1, 0, 1, 0, 1, 0, 0, 0,
230	0, 0, 0, 0, 0, 0, 0, 0,
231	0, 0, 0, 0, 0, 0, 0, 0,
232	0, 0, 0, 0, 0, 0, 0, 0,
233	0, 0, 0, 0, 0, 0, 0, 0,
234	0, 0, 0, 0, 0, 0, 0, 0,
235	0, 0, 0, 0, 0, 0, 0, 0,
236	0, 0, 0, 0, 0, 0, 0, 0,
237	0, 0, 0, 0, 0, 0, 0, 0,
238	0, 0, 0, 0, 0, 0, 0, 0,
239	0, 0, 0, 0, 0, 0, 0, 0,
240	// Interrupts
241	1, 1, 1, 0, 1
242};
243
244static const int _isRSpecialRegister[REG_MAX >> 1] = {
245	// Video
246	0, 0, 1, 1, 0, 0, 0, 0,
247	1, 1, 1, 1, 1, 1, 1, 1,
248	1, 1, 1, 1, 1, 1, 1, 1,
249	1, 1, 1, 1, 1, 1, 1, 1,
250	1, 1, 1, 1, 1, 1, 1, 1,
251	1, 1, 1, 1, 1, 1, 1, 1,
252	// Audio
253	0, 0, 0, 0, 0, 0, 0, 0,
254	0, 0, 0, 0, 0, 0, 0, 0,
255	0, 0, 0, 0, 1, 0, 0, 0,
256	1, 1, 1, 1, 1, 1, 1, 1,
257	1, 1, 1, 1, 0, 0, 0, 0,
258	// DMA
259	1, 1, 1, 1, 1, 1, 1, 1,
260	1, 1, 1, 1, 1, 1, 1, 1,
261	1, 1, 1, 1, 1, 1, 1, 1,
262	0, 0, 0, 0, 0, 0, 0, 0,
263	0, 0, 0, 0, 0, 0, 0, 0,
264	// Timers
265	1, 1, 1, 1, 1, 1, 1, 1,
266	0, 0, 0, 0, 0, 0, 0, 0,
267	// SIO
268	1, 1, 1, 1, 1, 0, 0, 0,
269	1, 1, 1, 0, 0, 0, 0, 0,
270	1, 0, 0, 0, 0, 0, 0, 0,
271	1, 0, 1, 0, 1, 0, 0, 0,
272	0, 0, 0, 0, 0, 0, 0, 0,
273	0, 0, 0, 0, 0, 0, 0, 0,
274	0, 0, 0, 0, 0, 0, 0, 0,
275	0, 0, 0, 0, 0, 0, 0, 0,
276	0, 0, 0, 0, 0, 0, 0, 0,
277	0, 0, 0, 0, 0, 0, 0, 0,
278	0, 0, 0, 0, 0, 0, 0, 0,
279	0, 0, 0, 0, 0, 0, 0, 0,
280	0, 0, 0, 0, 0, 0, 0, 0,
281	0, 0, 0, 0, 0, 0, 0, 0,
282	// Interrupts
283};
284
285static const int _isWSpecialRegister[REG_MAX >> 1] = {
286	// Video
287	0, 0, 1, 1, 0, 0, 0, 0,
288	0, 0, 0, 0, 0, 0, 0, 0,
289	0, 0, 0, 0, 0, 0, 0, 0,
290	0, 0, 0, 0, 0, 0, 0, 0,
291	0, 0, 0, 0, 0, 0, 0, 0,
292	0, 0, 0, 0, 0, 0, 0, 0,
293	// Audio
294	0, 0, 0, 0, 0, 0, 0, 0,
295	0, 0, 0, 0, 0, 0, 0, 0,
296	0, 0, 1, 0, 0, 0, 0, 0,
297	1, 1, 1, 1, 1, 1, 1, 1,
298	1, 1, 1, 1, 0, 0, 0, 0,
299	// DMA
300	0, 0, 0, 0, 0, 1, 0, 0,
301	0, 0, 0, 1, 0, 0, 0, 0,
302	0, 1, 0, 0, 0, 0, 0, 1,
303	0, 0, 0, 0, 0, 0, 0, 0,
304	0, 0, 0, 0, 0, 0, 0, 0,
305	// Timers
306	1, 1, 1, 1, 1, 1, 1, 1,
307	0, 0, 0, 0, 0, 0, 0, 0,
308	// SIO
309	1, 1, 1, 1, 1, 0, 0, 0,
310	1, 1, 1, 0, 0, 0, 0, 0,
311	1, 0, 0, 0, 0, 0, 0, 0,
312	1, 0, 1, 0, 1, 0, 0, 0,
313	0, 0, 0, 0, 0, 0, 0, 0,
314	0, 0, 0, 0, 0, 0, 0, 0,
315	0, 0, 0, 0, 0, 0, 0, 0,
316	0, 0, 0, 0, 0, 0, 0, 0,
317	0, 0, 0, 0, 0, 0, 0, 0,
318	0, 0, 0, 0, 0, 0, 0, 0,
319	0, 0, 0, 0, 0, 0, 0, 0,
320	0, 0, 0, 0, 0, 0, 0, 0,
321	0, 0, 0, 0, 0, 0, 0, 0,
322	0, 0, 0, 0, 0, 0, 0, 0,
323	// Interrupts
324	1, 1, 0, 0, 1
325};
326
327void GBAIOInit(struct GBA* gba) {
328	gba->memory.io[REG_DISPCNT >> 1] = 0x0080;
329	gba->memory.io[REG_RCNT >> 1] = RCNT_INITIAL;
330	gba->memory.io[REG_KEYINPUT >> 1] = 0x3FF;
331	gba->memory.io[REG_SOUNDBIAS >> 1] = 0x200;
332	gba->memory.io[REG_BG2PA >> 1] = 0x100;
333	gba->memory.io[REG_BG2PD >> 1] = 0x100;
334	gba->memory.io[REG_BG3PA >> 1] = 0x100;
335	gba->memory.io[REG_BG3PD >> 1] = 0x100;
336
337	if (!gba->biosVf) {
338		gba->memory.io[REG_VCOUNT >> 1] = 0x7E;
339		gba->memory.io[REG_POSTFLG >> 1] = 1;
340	}
341}
342
343void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value) {
344	if (address < REG_SOUND1CNT_LO && (address > REG_VCOUNT || address == REG_DISPCNT)) {
345		value = gba->video.renderer->writeVideoRegister(gba->video.renderer, address, value);
346	} else {
347		switch (address) {
348		// Video
349		case REG_DISPSTAT:
350			value &= 0xFFF8;
351			GBAVideoWriteDISPSTAT(&gba->video, value);
352			return;
353
354		case REG_VCOUNT:
355			mLOG(GBA_IO, GAME_ERROR, "Write to read-only I/O register: %03X", address);
356			return;
357
358		// Audio
359		case REG_SOUND1CNT_LO:
360			GBAAudioWriteSOUND1CNT_LO(&gba->audio, value);
361			value &= 0x007F;
362			break;
363		case REG_SOUND1CNT_HI:
364			GBAAudioWriteSOUND1CNT_HI(&gba->audio, value);
365			break;
366		case REG_SOUND1CNT_X:
367			GBAAudioWriteSOUND1CNT_X(&gba->audio, value);
368			value &= 0x47FF;
369			break;
370		case REG_SOUND2CNT_LO:
371			GBAAudioWriteSOUND2CNT_LO(&gba->audio, value);
372			break;
373		case REG_SOUND2CNT_HI:
374			GBAAudioWriteSOUND2CNT_HI(&gba->audio, value);
375			value &= 0x47FF;
376			break;
377		case REG_SOUND3CNT_LO:
378			GBAAudioWriteSOUND3CNT_LO(&gba->audio, value);
379			value &= 0x00E0;
380			break;
381		case REG_SOUND3CNT_HI:
382			GBAAudioWriteSOUND3CNT_HI(&gba->audio, value);
383			value &= 0xE03F;
384			break;
385		case REG_SOUND3CNT_X:
386			GBAAudioWriteSOUND3CNT_X(&gba->audio, value);
387			// TODO: The low bits need to not be readable, but still 8-bit writable
388			value &= 0x47FF;
389			break;
390		case REG_SOUND4CNT_LO:
391			GBAAudioWriteSOUND4CNT_LO(&gba->audio, value);
392			value &= 0xFF3F;
393			break;
394		case REG_SOUND4CNT_HI:
395			GBAAudioWriteSOUND4CNT_HI(&gba->audio, value);
396			value &= 0x40FF;
397			break;
398		case REG_SOUNDCNT_LO:
399			GBAAudioWriteSOUNDCNT_LO(&gba->audio, value);
400			value &= 0xFF77;
401			break;
402		case REG_SOUNDCNT_HI:
403			GBAAudioWriteSOUNDCNT_HI(&gba->audio, value);
404			value &= 0x770F;
405			break;
406		case REG_SOUNDCNT_X:
407			GBAAudioWriteSOUNDCNT_X(&gba->audio, value);
408			value &= 0x0080;
409			value |= gba->memory.io[REG_SOUNDCNT_X >> 1] & 0xF;
410			break;
411		case REG_SOUNDBIAS:
412			GBAAudioWriteSOUNDBIAS(&gba->audio, value);
413			break;
414
415		case REG_WAVE_RAM0_LO:
416		case REG_WAVE_RAM1_LO:
417		case REG_WAVE_RAM2_LO:
418		case REG_WAVE_RAM3_LO:
419			GBAIOWrite32(gba, address, (gba->memory.io[(address >> 1) + 1] << 16) | value);
420			break;
421
422		case REG_WAVE_RAM0_HI:
423		case REG_WAVE_RAM1_HI:
424		case REG_WAVE_RAM2_HI:
425		case REG_WAVE_RAM3_HI:
426			GBAIOWrite32(gba, address - 2, gba->memory.io[(address >> 1) - 1] | (value << 16));
427			break;
428
429		case REG_FIFO_A_LO:
430		case REG_FIFO_B_LO:
431			GBAIOWrite32(gba, address, (gba->memory.io[(address >> 1) + 1] << 16) | value);
432			break;
433
434		case REG_FIFO_A_HI:
435		case REG_FIFO_B_HI:
436			GBAIOWrite32(gba, address - 2, gba->memory.io[(address >> 1) - 1] | (value << 16));
437			break;
438
439		// DMA
440		case REG_DMA0SAD_LO:
441		case REG_DMA0DAD_LO:
442		case REG_DMA1SAD_LO:
443		case REG_DMA1DAD_LO:
444		case REG_DMA2SAD_LO:
445		case REG_DMA2DAD_LO:
446		case REG_DMA3SAD_LO:
447		case REG_DMA3DAD_LO:
448			GBAIOWrite32(gba, address, (gba->memory.io[(address >> 1) + 1] << 16) | value);
449			break;
450
451		case REG_DMA0SAD_HI:
452		case REG_DMA0DAD_HI:
453		case REG_DMA1SAD_HI:
454		case REG_DMA1DAD_HI:
455		case REG_DMA2SAD_HI:
456		case REG_DMA2DAD_HI:
457		case REG_DMA3SAD_HI:
458		case REG_DMA3DAD_HI:
459			GBAIOWrite32(gba, address - 2, gba->memory.io[(address >> 1) - 1] | (value << 16));
460			break;
461
462		case REG_DMA0CNT_LO:
463			GBAMemoryWriteDMACNT_LO(gba, 0, value);
464			break;
465		case REG_DMA0CNT_HI:
466			value = GBAMemoryWriteDMACNT_HI(gba, 0, value);
467			break;
468		case REG_DMA1CNT_LO:
469			GBAMemoryWriteDMACNT_LO(gba, 1, value);
470			break;
471		case REG_DMA1CNT_HI:
472			value = GBAMemoryWriteDMACNT_HI(gba, 1, value);
473			break;
474		case REG_DMA2CNT_LO:
475			GBAMemoryWriteDMACNT_LO(gba, 2, value);
476			break;
477		case REG_DMA2CNT_HI:
478			value = GBAMemoryWriteDMACNT_HI(gba, 2, value);
479			break;
480		case REG_DMA3CNT_LO:
481			GBAMemoryWriteDMACNT_LO(gba, 3, value);
482			break;
483		case REG_DMA3CNT_HI:
484			value = GBAMemoryWriteDMACNT_HI(gba, 3, value);
485			break;
486
487		// Timers
488		case REG_TM0CNT_LO:
489			GBATimerWriteTMCNT_LO(gba, 0, value);
490			return;
491		case REG_TM1CNT_LO:
492			GBATimerWriteTMCNT_LO(gba, 1, value);
493			return;
494		case REG_TM2CNT_LO:
495			GBATimerWriteTMCNT_LO(gba, 2, value);
496			return;
497		case REG_TM3CNT_LO:
498			GBATimerWriteTMCNT_LO(gba, 3, value);
499			return;
500
501		case REG_TM0CNT_HI:
502			value &= 0x00C7;
503			GBATimerWriteTMCNT_HI(gba, 0, value);
504			break;
505		case REG_TM1CNT_HI:
506			value &= 0x00C7;
507			GBATimerWriteTMCNT_HI(gba, 1, value);
508			break;
509		case REG_TM2CNT_HI:
510			value &= 0x00C7;
511			GBATimerWriteTMCNT_HI(gba, 2, value);
512			break;
513		case REG_TM3CNT_HI:
514			value &= 0x00C7;
515			GBATimerWriteTMCNT_HI(gba, 3, value);
516			break;
517
518		// SIO
519		case REG_SIOCNT:
520			GBASIOWriteSIOCNT(&gba->sio, value);
521			break;
522		case REG_RCNT:
523			value &= 0xC1FF;
524			GBASIOWriteRCNT(&gba->sio, value);
525			break;
526		case REG_SIOMLT_SEND:
527		case REG_JOYCNT:
528		case REG_JOYSTAT:
529		case REG_JOY_RECV_LO:
530		case REG_JOY_RECV_HI:
531		case REG_JOY_TRANS_LO:
532		case REG_JOY_TRANS_HI:
533			value = GBASIOWriteRegister(&gba->sio, address, value);
534			break;
535
536		// Interrupts and misc
537		case REG_WAITCNT:
538			GBAAdjustWaitstates(gba, value);
539			break;
540		case REG_IE:
541			GBAWriteIE(gba, value);
542			break;
543		case REG_IF:
544			value = gba->memory.io[REG_IF >> 1] & ~value;
545			break;
546		case REG_IME:
547			GBAWriteIME(gba, value);
548			break;
549		case REG_MAX:
550			// Some bad interrupt libraries will write to this
551			break;
552		case REG_DEBUG_ENABLE:
553			gba->debug = value == 0xC0DE;
554			return;
555		case REG_DEBUG_FLAGS:
556			if (gba->debug) {
557				GBADebug(gba, value);
558				return;
559			}
560			// Fall through
561		default:
562			if (address >= REG_DEBUG_STRING && address - REG_DEBUG_STRING < sizeof(gba->debugString)) {
563				STORE_16LE(value, address - REG_DEBUG_STRING, gba->debugString);
564				return;
565			}
566			mLOG(GBA_IO, STUB, "Stub I/O register write: %03X", address);
567			if (address >= REG_MAX) {
568				mLOG(GBA_IO, GAME_ERROR, "Write to unused I/O register: %03X", address);
569				return;
570			}
571			break;
572		}
573	}
574	gba->memory.io[address >> 1] = value;
575}
576
577void GBAIOWrite8(struct GBA* gba, uint32_t address, uint8_t value) {
578	if (address == REG_HALTCNT) {
579		value &= 0x80;
580		if (!value) {
581			GBAHalt(gba);
582		} else {
583			GBAStop(gba);
584		}
585		return;
586	}
587	if (address == REG_POSTFLG) {
588		gba->memory.io[(address & (SIZE_IO - 1)) >> 1] = value;
589		return;
590	}
591	if (address >= REG_DEBUG_STRING && address - REG_DEBUG_STRING < sizeof(gba->debugString)) {
592		gba->debugString[address - REG_DEBUG_STRING] = value;
593		return;
594	}
595	if (address > SIZE_IO) {
596		return;
597	}
598	uint16_t value16 = value << (8 * (address & 1));
599	value16 |= (gba->memory.io[(address & (SIZE_IO - 1)) >> 1]) & ~(0xFF << (8 * (address & 1)));
600	GBAIOWrite(gba, address & 0xFFFFFFFE, value16);
601}
602
603void GBAIOWrite32(struct GBA* gba, uint32_t address, uint32_t value) {
604	switch (address) {
605	case REG_WAVE_RAM0_LO:
606		GBAAudioWriteWaveRAM(&gba->audio, 0, value);
607		break;
608	case REG_WAVE_RAM1_LO:
609		GBAAudioWriteWaveRAM(&gba->audio, 1, value);
610		break;
611	case REG_WAVE_RAM2_LO:
612		GBAAudioWriteWaveRAM(&gba->audio, 2, value);
613		break;
614	case REG_WAVE_RAM3_LO:
615		GBAAudioWriteWaveRAM(&gba->audio, 3, value);
616		break;
617	case REG_FIFO_A_LO:
618	case REG_FIFO_B_LO:
619		GBAAudioWriteFIFO(&gba->audio, address, value);
620		break;
621	case REG_DMA0SAD_LO:
622		value = GBAMemoryWriteDMASAD(gba, 0, value);
623		break;
624	case REG_DMA0DAD_LO:
625		value = GBAMemoryWriteDMADAD(gba, 0, value);
626		break;
627	case REG_DMA1SAD_LO:
628		value = GBAMemoryWriteDMASAD(gba, 1, value);
629		break;
630	case REG_DMA1DAD_LO:
631		value = GBAMemoryWriteDMADAD(gba, 1, value);
632		break;
633	case REG_DMA2SAD_LO:
634		value = GBAMemoryWriteDMASAD(gba, 2, value);
635		break;
636	case REG_DMA2DAD_LO:
637		value = GBAMemoryWriteDMADAD(gba, 2, value);
638		break;
639	case REG_DMA3SAD_LO:
640		value = GBAMemoryWriteDMASAD(gba, 3, value);
641		break;
642	case REG_DMA3DAD_LO:
643		value = GBAMemoryWriteDMADAD(gba, 3, value);
644		break;
645	default:
646		if (address >= REG_DEBUG_STRING && address - REG_DEBUG_STRING < sizeof(gba->debugString)) {
647			STORE_32LE(value, address - REG_DEBUG_STRING, gba->debugString);
648			return;
649		}
650		GBAIOWrite(gba, address, value & 0xFFFF);
651		GBAIOWrite(gba, address | 2, value >> 16);
652		return;
653	}
654	gba->memory.io[address >> 1] = value;
655	gba->memory.io[(address >> 1) + 1] = value >> 16;
656}
657
658bool GBAIOIsReadConstant(uint32_t address) {
659	switch (address) {
660	default:
661		return false;
662	case REG_BG0CNT:
663	case REG_BG1CNT:
664	case REG_BG2CNT:
665	case REG_BG3CNT:
666	case REG_WININ:
667	case REG_WINOUT:
668	case REG_BLDCNT:
669	case REG_BLDALPHA:
670	case REG_SOUND1CNT_LO:
671	case REG_SOUND1CNT_HI:
672	case REG_SOUND1CNT_X:
673	case REG_SOUND2CNT_LO:
674	case REG_SOUND2CNT_HI:
675	case REG_SOUND3CNT_LO:
676	case REG_SOUND3CNT_HI:
677	case REG_SOUND3CNT_X:
678	case REG_SOUND4CNT_LO:
679	case REG_SOUND4CNT_HI:
680	case REG_SOUNDCNT_LO:
681	case REG_SOUNDCNT_HI:
682	case REG_TM0CNT_HI:
683	case REG_TM1CNT_HI:
684	case REG_TM2CNT_HI:
685	case REG_TM3CNT_HI:
686	case REG_KEYINPUT:
687	case REG_IE:
688		return true;
689	}
690}
691
692uint16_t GBAIORead(struct GBA* gba, uint32_t address) {
693	if (!GBAIOIsReadConstant(address)) {
694		// Most IO reads need to disable idle removal
695		gba->haltPending = false;
696	}
697
698	switch (address) {
699	case REG_TM0CNT_LO:
700		GBATimerUpdateRegister(gba, 0);
701		break;
702	case REG_TM1CNT_LO:
703		GBATimerUpdateRegister(gba, 1);
704		break;
705	case REG_TM2CNT_LO:
706		GBATimerUpdateRegister(gba, 2);
707		break;
708	case REG_TM3CNT_LO:
709		GBATimerUpdateRegister(gba, 3);
710		break;
711
712	case REG_KEYINPUT:
713		if (gba->rr && gba->rr->isPlaying(gba->rr)) {
714			return 0x3FF ^ gba->rr->queryInput(gba->rr);
715		} else {
716			uint16_t input = 0x3FF;
717			if (gba->keyCallback) {
718				input = gba->keyCallback->readKeys(gba->keyCallback);
719			} else if (gba->keySource) {
720				input = *gba->keySource;
721			}
722			if (!gba->allowOpposingDirections) {
723				unsigned rl = input & 0x030;
724				unsigned ud = input & 0x0C0;
725				input &= 0x30F;
726				if (rl != 0x030) {
727					input |= rl;
728				}
729				if (ud != 0x0C0) {
730					input |= ud;
731				}
732			}
733			if (gba->rr && gba->rr->isRecording(gba->rr)) {
734				gba->rr->logInput(gba->rr, input);
735			}
736			return 0x3FF ^ input;
737		}
738
739	case REG_SIOCNT:
740		return gba->sio.siocnt;
741	case REG_RCNT:
742		return gba->sio.rcnt;
743
744	case REG_BG0HOFS:
745	case REG_BG0VOFS:
746	case REG_BG1HOFS:
747	case REG_BG1VOFS:
748	case REG_BG2HOFS:
749	case REG_BG2VOFS:
750	case REG_BG3HOFS:
751	case REG_BG3VOFS:
752	case REG_BG2PA:
753	case REG_BG2PB:
754	case REG_BG2PC:
755	case REG_BG2PD:
756	case REG_BG2X_LO:
757	case REG_BG2X_HI:
758	case REG_BG2Y_LO:
759	case REG_BG2Y_HI:
760	case REG_BG3PA:
761	case REG_BG3PB:
762	case REG_BG3PC:
763	case REG_BG3PD:
764	case REG_BG3X_LO:
765	case REG_BG3X_HI:
766	case REG_BG3Y_LO:
767	case REG_BG3Y_HI:
768	case REG_WIN0H:
769	case REG_WIN1H:
770	case REG_WIN0V:
771	case REG_WIN1V:
772	case REG_MOSAIC:
773	case REG_BLDY:
774	case REG_FIFO_A_LO:
775	case REG_FIFO_A_HI:
776	case REG_FIFO_B_LO:
777	case REG_FIFO_B_HI:
778	case REG_DMA0SAD_LO:
779	case REG_DMA0SAD_HI:
780	case REG_DMA0DAD_LO:
781	case REG_DMA0DAD_HI:
782	case REG_DMA1SAD_LO:
783	case REG_DMA1SAD_HI:
784	case REG_DMA1DAD_LO:
785	case REG_DMA1DAD_HI:
786	case REG_DMA2SAD_LO:
787	case REG_DMA2SAD_HI:
788	case REG_DMA2DAD_LO:
789	case REG_DMA2DAD_HI:
790	case REG_DMA3SAD_LO:
791	case REG_DMA3SAD_HI:
792	case REG_DMA3DAD_LO:
793	case REG_DMA3DAD_HI:
794		// Write-only register
795		mLOG(GBA_IO, GAME_ERROR, "Read from write-only I/O register: %03X", address);
796		return GBALoadBad(gba->cpu);
797
798	case REG_DMA0CNT_LO:
799	case REG_DMA1CNT_LO:
800	case REG_DMA2CNT_LO:
801	case REG_DMA3CNT_LO:
802		// Write-only register
803		mLOG(GBA_IO, GAME_ERROR, "Read from write-only I/O register: %03X", address);
804		return 0;
805
806	case REG_SOUNDBIAS:
807	case REG_KEYCNT:
808	case REG_POSTFLG:
809		mLOG(GBA_IO, STUB, "Stub I/O register read: %03x", address);
810		break;
811	case REG_SOUND1CNT_LO:
812	case REG_SOUND1CNT_HI:
813	case REG_SOUND1CNT_X:
814	case REG_SOUND2CNT_LO:
815	case REG_SOUND2CNT_HI:
816	case REG_SOUND3CNT_LO:
817	case REG_SOUND3CNT_HI:
818	case REG_SOUND3CNT_X:
819	case REG_SOUND4CNT_LO:
820	case REG_SOUND4CNT_HI:
821	case REG_SOUNDCNT_LO:
822	case REG_SOUNDCNT_HI:
823		if (!GBAudioEnableIsEnable(gba->memory.io[REG_SOUNDCNT_X >> 1])) {
824			// TODO: Is writing allowed when the circuit is disabled?
825			return 0;
826		}
827		// Fall through
828	case REG_DISPCNT:
829	case REG_DISPSTAT:
830	case REG_VCOUNT:
831	case REG_BG0CNT:
832	case REG_BG1CNT:
833	case REG_BG2CNT:
834	case REG_BG3CNT:
835	case REG_WININ:
836	case REG_WINOUT:
837	case REG_BLDCNT:
838	case REG_BLDALPHA:
839	case REG_SOUNDCNT_X:
840	case REG_WAVE_RAM0_LO:
841	case REG_WAVE_RAM0_HI:
842	case REG_WAVE_RAM1_LO:
843	case REG_WAVE_RAM1_HI:
844	case REG_WAVE_RAM2_LO:
845	case REG_WAVE_RAM2_HI:
846	case REG_WAVE_RAM3_LO:
847	case REG_WAVE_RAM3_HI:
848	case REG_DMA0CNT_HI:
849	case REG_DMA1CNT_HI:
850	case REG_DMA2CNT_HI:
851	case REG_DMA3CNT_HI:
852	case REG_TM0CNT_HI:
853	case REG_TM1CNT_HI:
854	case REG_TM2CNT_HI:
855	case REG_TM3CNT_HI:
856	case REG_SIOMULTI0:
857	case REG_SIOMULTI1:
858	case REG_SIOMULTI2:
859	case REG_SIOMULTI3:
860	case REG_SIOMLT_SEND:
861	case REG_JOYCNT:
862	case REG_JOY_RECV_LO:
863	case REG_JOY_RECV_HI:
864	case REG_JOY_TRANS_LO:
865	case REG_JOY_TRANS_HI:
866	case REG_JOYSTAT:
867	case REG_IE:
868	case REG_IF:
869	case REG_WAITCNT:
870	case REG_IME:
871		// Handled transparently by registers
872		break;
873	case REG_MAX:
874		// Some bad interrupt libraries will read from this
875		break;
876	case 0x66:
877	case 0x6E:
878	case 0x76:
879	case 0x7A:
880	case 0x7E:
881	case 0x86:
882	case 0x8A:
883		mLOG(GBA_IO, GAME_ERROR, "Read from unused I/O register: %03X", address);
884		return 0;
885	case REG_DEBUG_ENABLE:
886		if (gba->debug) {
887			return 0x1DEA;
888		}
889		// Fall through
890	default:
891		mLOG(GBA_IO, GAME_ERROR, "Read from unused I/O register: %03X", address);
892		return GBALoadBad(gba->cpu);
893	}
894	return gba->memory.io[address >> 1];
895}
896
897void GBAIOSerialize(struct GBA* gba, struct GBASerializedState* state) {
898	int i;
899	for (i = 0; i < REG_MAX; i += 2) {
900		if (_isRSpecialRegister[i >> 1]) {
901			STORE_16(gba->memory.io[i >> 1], i, state->io);
902		} else if (_isValidRegister[i >> 1]) {
903			uint16_t reg = GBAIORead(gba, i);
904			STORE_16(reg, i, state->io);
905		}
906	}
907
908	for (i = 0; i < 4; ++i) {
909		STORE_16(gba->memory.io[(REG_DMA0CNT_LO + i * 12) >> 1], (REG_DMA0CNT_LO + i * 12), state->io);
910		STORE_16(gba->timers[i].reload, 0, &state->timers[i].reload);
911		STORE_16(gba->timers[i].oldReload, 0, &state->timers[i].oldReload);
912		STORE_32(gba->timers[i].lastEvent, 0, &state->timers[i].lastEvent);
913		STORE_32(gba->timers[i].nextEvent, 0, &state->timers[i].nextEvent);
914		STORE_32(gba->timers[i].overflowInterval, 0, &state->timers[i].overflowInterval);
915		STORE_32(gba->timers[i].flags, 0, &state->timers[i].flags);
916		STORE_32(gba->memory.dma[i].nextSource, 0, &state->dma[i].nextSource);
917		STORE_32(gba->memory.dma[i].nextDest, 0, &state->dma[i].nextDest);
918		STORE_32(gba->memory.dma[i].nextCount, 0, &state->dma[i].nextCount);
919		STORE_32(gba->memory.dma[i].nextEvent, 0, &state->dma[i].nextEvent);
920	}
921
922	GBAHardwareSerialize(&gba->memory.hw, state);
923}
924
925void GBAIODeserialize(struct GBA* gba, const struct GBASerializedState* state) {
926	int i;
927	for (i = 0; i < REG_MAX; i += 2) {
928		if (_isWSpecialRegister[i >> 1]) {
929			LOAD_16(gba->memory.io[i >> 1], i, state->io);
930		} else if (_isValidRegister[i >> 1]) {
931			uint16_t reg;
932			LOAD_16(reg, i, state->io);
933			GBAIOWrite(gba, i, reg);
934		}
935	}
936
937	gba->timersEnabled = 0;
938	for (i = 0; i < 4; ++i) {
939		LOAD_16(gba->timers[i].reload, 0, &state->timers[i].reload);
940		LOAD_16(gba->timers[i].oldReload, 0, &state->timers[i].oldReload);
941		LOAD_32(gba->timers[i].overflowInterval, 0, &state->timers[i].overflowInterval);
942		LOAD_32(gba->timers[i].flags, 0, &state->timers[i].flags);
943		if (i > 0 && GBATimerFlagsIsCountUp(gba->timers[i].flags)) {
944			// Overwrite invalid values in savestate
945			gba->timers[i].lastEvent = 0;
946			gba->timers[i].nextEvent = INT_MAX;
947		} else {
948			LOAD_32(gba->timers[i].lastEvent, 0, &state->timers[i].lastEvent);
949			LOAD_32(gba->timers[i].nextEvent, 0, &state->timers[i].nextEvent);
950		}
951		LOAD_16(gba->memory.dma[i].reg, (REG_DMA0CNT_HI + i * 12), state->io);
952		LOAD_32(gba->memory.dma[i].nextSource, 0, &state->dma[i].nextSource);
953		LOAD_32(gba->memory.dma[i].nextDest, 0, &state->dma[i].nextDest);
954		LOAD_32(gba->memory.dma[i].nextCount, 0, &state->dma[i].nextCount);
955		LOAD_32(gba->memory.dma[i].nextEvent, 0, &state->dma[i].nextEvent);
956		if (GBADMARegisterGetTiming(gba->memory.dma[i].reg) != DMA_TIMING_NOW) {
957			GBAMemoryScheduleDMA(gba, i, &gba->memory.dma[i]);
958		}
959
960		if (GBATimerFlagsIsEnable(gba->timers[i].flags)) {
961			gba->timersEnabled |= 1 << i;
962		}
963	}
964	GBAAudioWriteSOUNDCNT_X(&gba->audio, gba->memory.io[REG_SOUNDCNT_X >> 1]);
965	GBAMemoryUpdateDMAs(gba, 0);
966	GBAHardwareDeserialize(&gba->memory.hw, state);
967}