all repos — mgba @ 69014400db6b8c299ab5ca6770e5a4e19ae78c0a

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 <mgba/internal/gba/io.h>
  7
  8#include <mgba/internal/arm/macros.h>
  9#include <mgba/internal/gba/dma.h>
 10#include <mgba/internal/gba/gba.h>
 11#include <mgba/internal/gba/rr/rr.h>
 12#include <mgba/internal/gba/serialize.h>
 13
 14mLOG_DEFINE_CATEGORY(GBA_IO, "GBA I/O", "gba.io");
 15
 16const char* const GBAIORegisterNames[] = {
 17	// Video
 18	"DISPCNT",
 19	0,
 20	"DISPSTAT",
 21	"VCOUNT",
 22	"BG0CNT",
 23	"BG1CNT",
 24	"BG2CNT",
 25	"BG3CNT",
 26	"BG0HOFS",
 27	"BG0VOFS",
 28	"BG1HOFS",
 29	"BG1VOFS",
 30	"BG2HOFS",
 31	"BG2VOFS",
 32	"BG3HOFS",
 33	"BG3VOFS",
 34	"BG2PA",
 35	"BG2PB",
 36	"BG2PC",
 37	"BG2PD",
 38	"BG2X_LO",
 39	"BG2X_HI",
 40	"BG2Y_LO",
 41	"BG2Y_HI",
 42	"BG3PA",
 43	"BG3PB",
 44	"BG3PC",
 45	"BG3PD",
 46	"BG3X_LO",
 47	"BG3X_HI",
 48	"BG3Y_LO",
 49	"BG3Y_HI",
 50	"WIN0H",
 51	"WIN1H",
 52	"WIN0V",
 53	"WIN1V",
 54	"WININ",
 55	"WINOUT",
 56	"MOSAIC",
 57	0,
 58	"BLDCNT",
 59	"BLDALPHA",
 60	"BLDY",
 61	0,
 62	0,
 63	0,
 64	0,
 65	0,
 66
 67	// Sound
 68	"SOUND1CNT_LO",
 69	"SOUND1CNT_HI",
 70	"SOUND1CNT_X",
 71	0,
 72	"SOUND2CNT_LO",
 73	0,
 74	"SOUND2CNT_HI",
 75	0,
 76	"SOUND3CNT_LO",
 77	"SOUND3CNT_HI",
 78	"SOUND3CNT_X",
 79	0,
 80	"SOUND4CNT_LO",
 81	0,
 82	"SOUND4CNT_HI",
 83	0,
 84	"SOUNDCNT_LO",
 85	"SOUNDCNT_HI",
 86	"SOUNDCNT_X",
 87	0,
 88	"SOUNDBIAS",
 89	0,
 90	0,
 91	0,
 92	"WAVE_RAM0_LO",
 93	"WAVE_RAM0_HI",
 94	"WAVE_RAM1_LO",
 95	"WAVE_RAM1_HI",
 96	"WAVE_RAM2_LO",
 97	"WAVE_RAM2_HI",
 98	"WAVE_RAM3_LO",
 99	"WAVE_RAM3_HI",
100	"FIFO_A_LO",
101	"FIFO_A_HI",
102	"FIFO_B_LO",
103	"FIFO_B_HI",
104	0,
105	0,
106	0,
107	0,
108
109	// DMA
110	"DMA0SAD_LO",
111	"DMA0SAD_HI",
112	"DMA0DAD_LO",
113	"DMA0DAD_HI",
114	"DMA0CNT_LO",
115	"DMA0CNT_HI",
116	"DMA1SAD_LO",
117	"DMA1SAD_HI",
118	"DMA1DAD_LO",
119	"DMA1DAD_HI",
120	"DMA1CNT_LO",
121	"DMA1CNT_HI",
122	"DMA2SAD_LO",
123	"DMA2SAD_HI",
124	"DMA2DAD_LO",
125	"DMA2DAD_HI",
126	"DMA2CNT_LO",
127	"DMA2CNT_HI",
128	"DMA3SAD_LO",
129	"DMA3SAD_HI",
130	"DMA3DAD_LO",
131	"DMA3DAD_HI",
132	"DMA3CNT_LO",
133	"DMA3CNT_HI",
134
135	0, 0, 0, 0, 0, 0, 0, 0,
136	0, 0, 0, 0, 0, 0, 0, 0,
137
138	// Timers
139	"TM0CNT_LO",
140	"TM0CNT_HI",
141	"TM1CNT_LO",
142	"TM1CNT_HI",
143	"TM2CNT_LO",
144	"TM2CNT_HI",
145	"TM3CNT_LO",
146	"TM3CNT_HI",
147
148	0, 0, 0, 0, 0, 0, 0, 0,
149
150	// SIO
151	"SIOMULTI0",
152	"SIOMULTI1",
153	"SIOMULTI2",
154	"SIOMULTI3",
155	"SIOCNT",
156	"SIOMLT_SEND",
157	0,
158	0,
159	"KEYINPUT",
160	"KEYCNT",
161	"RCNT",
162	0,
163	0,
164	0,
165	0,
166	0,
167	"JOYCNT",
168	0,
169	0,
170	0,
171	0,
172	0,
173	0,
174	0,
175	"JOY_RECV_LO",
176	"JOY_RECV_HI",
177	"JOY_TRANS_LO",
178	"JOY_TRANS_HI",
179	"JOYSTAT",
180	0,
181	0,
182	0,
183
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	0, 0, 0, 0, 0, 0, 0, 0,
194
195	// Interrupts, etc
196	"IE",
197	"IF",
198	"WAITCNT",
199	0,
200	"IME"
201};
202
203static const int _isValidRegister[REG_MAX >> 1] = {
204	// Video
205	1, 0, 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, 1,
209	1, 1, 1, 1, 1, 1, 1, 0,
210	1, 1, 1, 0, 0, 0, 0, 0,
211	// Audio
212	1, 1, 1, 0, 1, 0, 1, 0,
213	1, 1, 1, 0, 1, 0, 1, 0,
214	1, 1, 1, 0, 1, 0, 0, 0,
215	1, 1, 1, 1, 1, 1, 1, 1,
216	1, 1, 1, 1, 0, 0, 0, 0,
217	// DMA
218	1, 1, 1, 1, 1, 1, 1, 1,
219	1, 1, 1, 1, 1, 1, 1, 1,
220	1, 1, 1, 1, 1, 1, 1, 1,
221	0, 0, 0, 0, 0, 0, 0, 0,
222	0, 0, 0, 0, 0, 0, 0, 0,
223	// Timers
224	1, 1, 1, 1, 1, 1, 1, 1,
225	0, 0, 0, 0, 0, 0, 0, 0,
226	// SIO
227	1, 1, 1, 1, 1, 0, 0, 0,
228	1, 1, 1, 0, 0, 0, 0, 0,
229	1, 0, 0, 0, 0, 0, 0, 0,
230	1, 0, 1, 0, 1, 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	0, 0, 0, 0, 0, 0, 0, 0,
241	// Interrupts
242	1, 1, 1, 0, 1
243};
244
245static const int _isRSpecialRegister[REG_MAX >> 1] = {
246	// Video
247	0, 0, 1, 1, 0, 0, 0, 0,
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	1, 1, 1, 1, 1, 1, 1, 1,
253	// Audio
254	0, 0, 1, 0, 0, 0, 1, 0,
255	0, 0, 1, 0, 0, 0, 1, 0,
256	0, 0, 0, 0, 1, 0, 0, 0,
257	1, 1, 1, 1, 1, 1, 1, 1,
258	1, 1, 1, 1, 0, 0, 0, 0,
259	// DMA
260	1, 1, 1, 1, 1, 1, 1, 1,
261	1, 1, 1, 1, 1, 1, 1, 1,
262	1, 1, 1, 1, 1, 1, 1, 1,
263	0, 0, 0, 0, 0, 0, 0, 0,
264	0, 0, 0, 0, 0, 0, 0, 0,
265	// Timers
266	1, 1, 1, 1, 1, 1, 1, 1,
267	0, 0, 0, 0, 0, 0, 0, 0,
268	// SIO
269	1, 1, 1, 1, 1, 0, 0, 0,
270	1, 1, 1, 0, 0, 0, 0, 0,
271	1, 0, 0, 0, 0, 0, 0, 0,
272	1, 0, 1, 0, 1, 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	0, 0, 0, 0, 0, 0, 0, 0,
283	// Interrupts
284};
285
286static const int _isWSpecialRegister[REG_MAX >> 1] = {
287	// Video
288	0, 0, 1, 1, 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	0, 0, 0, 0, 0, 0, 0, 0,
294	// Audio
295	1, 1, 1, 0, 1, 0, 1, 0,
296	1, 0, 1, 0, 1, 0, 1, 0,
297	1, 0, 1, 0, 0, 0, 0, 0,
298	1, 1, 1, 1, 1, 1, 1, 1,
299	1, 1, 1, 1, 0, 0, 0, 0,
300	// DMA
301	0, 0, 0, 0, 0, 1, 0, 0,
302	0, 0, 0, 1, 0, 0, 0, 0,
303	0, 1, 0, 0, 0, 0, 0, 1,
304	0, 0, 0, 0, 0, 0, 0, 0,
305	0, 0, 0, 0, 0, 0, 0, 0,
306	// Timers
307	1, 1, 1, 1, 1, 1, 1, 1,
308	0, 0, 0, 0, 0, 0, 0, 0,
309	// SIO
310	1, 1, 1, 1, 1, 0, 0, 0,
311	1, 1, 1, 0, 0, 0, 0, 0,
312	1, 0, 0, 0, 0, 0, 0, 0,
313	1, 0, 1, 0, 1, 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	0, 0, 0, 0, 0, 0, 0, 0,
324	// Interrupts
325	1, 1, 0, 0, 1
326};
327
328void GBAIOInit(struct GBA* gba) {
329	gba->memory.io[REG_DISPCNT >> 1] = 0x0080;
330	gba->memory.io[REG_RCNT >> 1] = RCNT_INITIAL;
331	gba->memory.io[REG_KEYINPUT >> 1] = 0x3FF;
332	gba->memory.io[REG_SOUNDBIAS >> 1] = 0x200;
333	gba->memory.io[REG_BG2PA >> 1] = 0x100;
334	gba->memory.io[REG_BG2PD >> 1] = 0x100;
335	gba->memory.io[REG_BG3PA >> 1] = 0x100;
336	gba->memory.io[REG_BG3PD >> 1] = 0x100;
337
338	if (!gba->biosVf) {
339		gba->memory.io[REG_VCOUNT >> 1] = 0x7E;
340		gba->memory.io[REG_POSTFLG >> 1] = 1;
341	}
342}
343
344void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value) {
345	if (address < REG_SOUND1CNT_LO && (address > REG_VCOUNT || address == REG_DISPCNT)) {
346		value = gba->video.renderer->writeVideoRegister(gba->video.renderer, address, value);
347	} else {
348		switch (address) {
349		// Video
350		case REG_DISPSTAT:
351			value &= 0xFFF8;
352			GBAVideoWriteDISPSTAT(&gba->video, value);
353			return;
354
355		case REG_VCOUNT:
356			mLOG(GBA_IO, GAME_ERROR, "Write to read-only I/O register: %03X", address);
357			return;
358
359		// Audio
360		case REG_SOUND1CNT_LO:
361			GBAAudioWriteSOUND1CNT_LO(&gba->audio, value);
362			value &= 0x007F;
363			break;
364		case REG_SOUND1CNT_HI:
365			GBAAudioWriteSOUND1CNT_HI(&gba->audio, value);
366			break;
367		case REG_SOUND1CNT_X:
368			GBAAudioWriteSOUND1CNT_X(&gba->audio, value);
369			value &= 0x47FF;
370			break;
371		case REG_SOUND2CNT_LO:
372			GBAAudioWriteSOUND2CNT_LO(&gba->audio, value);
373			break;
374		case REG_SOUND2CNT_HI:
375			GBAAudioWriteSOUND2CNT_HI(&gba->audio, value);
376			value &= 0x47FF;
377			break;
378		case REG_SOUND3CNT_LO:
379			GBAAudioWriteSOUND3CNT_LO(&gba->audio, value);
380			value &= 0x00E0;
381			break;
382		case REG_SOUND3CNT_HI:
383			GBAAudioWriteSOUND3CNT_HI(&gba->audio, value);
384			value &= 0xE03F;
385			break;
386		case REG_SOUND3CNT_X:
387			GBAAudioWriteSOUND3CNT_X(&gba->audio, value);
388			// TODO: The low bits need to not be readable, but still 8-bit writable
389			value &= 0x47FF;
390			break;
391		case REG_SOUND4CNT_LO:
392			GBAAudioWriteSOUND4CNT_LO(&gba->audio, value);
393			value &= 0xFF3F;
394			break;
395		case REG_SOUND4CNT_HI:
396			GBAAudioWriteSOUND4CNT_HI(&gba->audio, value);
397			value &= 0x40FF;
398			break;
399		case REG_SOUNDCNT_LO:
400			GBAAudioWriteSOUNDCNT_LO(&gba->audio, value);
401			value &= 0xFF77;
402			break;
403		case REG_SOUNDCNT_HI:
404			GBAAudioWriteSOUNDCNT_HI(&gba->audio, value);
405			value &= 0x770F;
406			break;
407		case REG_SOUNDCNT_X:
408			GBAAudioWriteSOUNDCNT_X(&gba->audio, value);
409			value &= 0x0080;
410			value |= gba->memory.io[REG_SOUNDCNT_X >> 1] & 0xF;
411			break;
412		case REG_SOUNDBIAS:
413			GBAAudioWriteSOUNDBIAS(&gba->audio, value);
414			break;
415
416		case REG_WAVE_RAM0_LO:
417		case REG_WAVE_RAM1_LO:
418		case REG_WAVE_RAM2_LO:
419		case REG_WAVE_RAM3_LO:
420			GBAIOWrite32(gba, address, (gba->memory.io[(address >> 1) + 1] << 16) | value);
421			break;
422
423		case REG_WAVE_RAM0_HI:
424		case REG_WAVE_RAM1_HI:
425		case REG_WAVE_RAM2_HI:
426		case REG_WAVE_RAM3_HI:
427			GBAIOWrite32(gba, address - 2, gba->memory.io[(address >> 1) - 1] | (value << 16));
428			break;
429
430		case REG_FIFO_A_LO:
431		case REG_FIFO_B_LO:
432			GBAIOWrite32(gba, address, (gba->memory.io[(address >> 1) + 1] << 16) | value);
433			break;
434
435		case REG_FIFO_A_HI:
436		case REG_FIFO_B_HI:
437			GBAIOWrite32(gba, address - 2, gba->memory.io[(address >> 1) - 1] | (value << 16));
438			break;
439
440		// DMA
441		case REG_DMA0SAD_LO:
442		case REG_DMA0DAD_LO:
443		case REG_DMA1SAD_LO:
444		case REG_DMA1DAD_LO:
445		case REG_DMA2SAD_LO:
446		case REG_DMA2DAD_LO:
447		case REG_DMA3SAD_LO:
448		case REG_DMA3DAD_LO:
449			GBAIOWrite32(gba, address, (gba->memory.io[(address >> 1) + 1] << 16) | value);
450			break;
451
452		case REG_DMA0SAD_HI:
453		case REG_DMA0DAD_HI:
454		case REG_DMA1SAD_HI:
455		case REG_DMA1DAD_HI:
456		case REG_DMA2SAD_HI:
457		case REG_DMA2DAD_HI:
458		case REG_DMA3SAD_HI:
459		case REG_DMA3DAD_HI:
460			GBAIOWrite32(gba, address - 2, gba->memory.io[(address >> 1) - 1] | (value << 16));
461			break;
462
463		case REG_DMA0CNT_LO:
464			GBADMAWriteCNT_LO(gba, 0, value);
465			break;
466		case REG_DMA0CNT_HI:
467			value = GBADMAWriteCNT_HI(gba, 0, value);
468			break;
469		case REG_DMA1CNT_LO:
470			GBADMAWriteCNT_LO(gba, 1, value);
471			break;
472		case REG_DMA1CNT_HI:
473			value = GBADMAWriteCNT_HI(gba, 1, value);
474			break;
475		case REG_DMA2CNT_LO:
476			GBADMAWriteCNT_LO(gba, 2, value);
477			break;
478		case REG_DMA2CNT_HI:
479			value = GBADMAWriteCNT_HI(gba, 2, value);
480			break;
481		case REG_DMA3CNT_LO:
482			GBADMAWriteCNT_LO(gba, 3, value);
483			break;
484		case REG_DMA3CNT_HI:
485			value = GBADMAWriteCNT_HI(gba, 3, value);
486			break;
487
488		// Timers
489		case REG_TM0CNT_LO:
490			GBATimerWriteTMCNT_LO(gba, 0, value);
491			return;
492		case REG_TM1CNT_LO:
493			GBATimerWriteTMCNT_LO(gba, 1, value);
494			return;
495		case REG_TM2CNT_LO:
496			GBATimerWriteTMCNT_LO(gba, 2, value);
497			return;
498		case REG_TM3CNT_LO:
499			GBATimerWriteTMCNT_LO(gba, 3, value);
500			return;
501
502		case REG_TM0CNT_HI:
503			value &= 0x00C7;
504			GBATimerWriteTMCNT_HI(gba, 0, value);
505			break;
506		case REG_TM1CNT_HI:
507			value &= 0x00C7;
508			GBATimerWriteTMCNT_HI(gba, 1, value);
509			break;
510		case REG_TM2CNT_HI:
511			value &= 0x00C7;
512			GBATimerWriteTMCNT_HI(gba, 2, value);
513			break;
514		case REG_TM3CNT_HI:
515			value &= 0x00C7;
516			GBATimerWriteTMCNT_HI(gba, 3, value);
517			break;
518
519		// SIO
520		case REG_SIOCNT:
521			GBASIOWriteSIOCNT(&gba->sio, value);
522			break;
523		case REG_RCNT:
524			value &= 0xC1FF;
525			GBASIOWriteRCNT(&gba->sio, value);
526			break;
527		case REG_JOY_TRANS_LO:
528		case REG_JOY_TRANS_HI:
529			gba->memory.io[REG_JOYSTAT >> 1] |= JOYSTAT_TRANS_BIT;
530			// Fall through
531		case REG_SIOMLT_SEND:
532		case REG_JOYCNT:
533		case REG_JOYSTAT:
534		case REG_JOY_RECV_LO:
535		case REG_JOY_RECV_HI:
536			value = GBASIOWriteRegister(&gba->sio, address, value);
537			break;
538
539		// Interrupts and misc
540		case REG_KEYCNT:
541			value &= 0xC3FF;
542			gba->memory.io[address >> 1] = value;
543			GBATestKeypadIRQ(gba);
544			return;
545		case REG_WAITCNT:
546			value &= 0x5FFF;
547			GBAAdjustWaitstates(gba, value);
548			break;
549		case REG_IE:
550			gba->memory.io[REG_IE >> 1] = value;
551			GBATestIRQ(gba->cpu);
552			return;
553		case REG_IF:
554			value = gba->memory.io[REG_IF >> 1] & ~value;
555			gba->memory.io[REG_IF >> 1] = value;
556			GBATestIRQ(gba->cpu);
557			return;
558		case REG_IME:
559			gba->memory.io[REG_IME >> 1] = value;
560			GBATestIRQ(gba->cpu);
561			return;
562		case REG_MAX:
563			// Some bad interrupt libraries will write to this
564			break;
565		case REG_DEBUG_ENABLE:
566			gba->debug = value == 0xC0DE;
567			return;
568		case REG_DEBUG_FLAGS:
569			if (gba->debug) {
570				GBADebug(gba, value);
571				return;
572			}
573			// Fall through
574		default:
575			if (address >= REG_DEBUG_STRING && address - REG_DEBUG_STRING < sizeof(gba->debugString)) {
576				STORE_16LE(value, address - REG_DEBUG_STRING, gba->debugString);
577				return;
578			}
579			mLOG(GBA_IO, STUB, "Stub I/O register write: %03X", address);
580			if (address >= REG_MAX) {
581				mLOG(GBA_IO, GAME_ERROR, "Write to unused I/O register: %03X", address);
582				return;
583			}
584			break;
585		}
586	}
587	gba->memory.io[address >> 1] = value;
588}
589
590void GBAIOWrite8(struct GBA* gba, uint32_t address, uint8_t value) {
591	if (address == REG_HALTCNT) {
592		value &= 0x80;
593		if (!value) {
594			GBAHalt(gba);
595		} else {
596			GBAStop(gba);
597		}
598		return;
599	}
600	if (address == REG_POSTFLG) {
601		gba->memory.io[(address & (SIZE_IO - 1)) >> 1] = value;
602		return;
603	}
604	if (address >= REG_DEBUG_STRING && address - REG_DEBUG_STRING < sizeof(gba->debugString)) {
605		gba->debugString[address - REG_DEBUG_STRING] = value;
606		return;
607	}
608	if (address > SIZE_IO) {
609		return;
610	}
611	uint16_t value16 = value << (8 * (address & 1));
612	value16 |= (gba->memory.io[(address & (SIZE_IO - 1)) >> 1]) & ~(0xFF << (8 * (address & 1)));
613	GBAIOWrite(gba, address & 0xFFFFFFFE, value16);
614}
615
616void GBAIOWrite32(struct GBA* gba, uint32_t address, uint32_t value) {
617	switch (address) {
618	case REG_WAVE_RAM0_LO:
619		GBAAudioWriteWaveRAM(&gba->audio, 0, value);
620		break;
621	case REG_WAVE_RAM1_LO:
622		GBAAudioWriteWaveRAM(&gba->audio, 1, value);
623		break;
624	case REG_WAVE_RAM2_LO:
625		GBAAudioWriteWaveRAM(&gba->audio, 2, value);
626		break;
627	case REG_WAVE_RAM3_LO:
628		GBAAudioWriteWaveRAM(&gba->audio, 3, value);
629		break;
630	case REG_FIFO_A_LO:
631	case REG_FIFO_B_LO:
632		GBAAudioWriteFIFO(&gba->audio, address, value);
633		break;
634	case REG_DMA0SAD_LO:
635		value = GBADMAWriteSAD(gba, 0, value);
636		break;
637	case REG_DMA0DAD_LO:
638		value = GBADMAWriteDAD(gba, 0, value);
639		break;
640	case REG_DMA1SAD_LO:
641		value = GBADMAWriteSAD(gba, 1, value);
642		break;
643	case REG_DMA1DAD_LO:
644		value = GBADMAWriteDAD(gba, 1, value);
645		break;
646	case REG_DMA2SAD_LO:
647		value = GBADMAWriteSAD(gba, 2, value);
648		break;
649	case REG_DMA2DAD_LO:
650		value = GBADMAWriteDAD(gba, 2, value);
651		break;
652	case REG_DMA3SAD_LO:
653		value = GBADMAWriteSAD(gba, 3, value);
654		break;
655	case REG_DMA3DAD_LO:
656		value = GBADMAWriteDAD(gba, 3, value);
657		break;
658	default:
659		if (address >= REG_DEBUG_STRING && address - REG_DEBUG_STRING < sizeof(gba->debugString)) {
660			STORE_32LE(value, address - REG_DEBUG_STRING, gba->debugString);
661			return;
662		}
663		GBAIOWrite(gba, address, value & 0xFFFF);
664		GBAIOWrite(gba, address | 2, value >> 16);
665		return;
666	}
667	gba->memory.io[address >> 1] = value;
668	gba->memory.io[(address >> 1) + 1] = value >> 16;
669}
670
671bool GBAIOIsReadConstant(uint32_t address) {
672	switch (address) {
673	default:
674		return false;
675	case REG_BG0CNT:
676	case REG_BG1CNT:
677	case REG_BG2CNT:
678	case REG_BG3CNT:
679	case REG_WININ:
680	case REG_WINOUT:
681	case REG_BLDCNT:
682	case REG_BLDALPHA:
683	case REG_SOUND1CNT_LO:
684	case REG_SOUND1CNT_HI:
685	case REG_SOUND1CNT_X:
686	case REG_SOUND2CNT_LO:
687	case REG_SOUND2CNT_HI:
688	case REG_SOUND3CNT_LO:
689	case REG_SOUND3CNT_HI:
690	case REG_SOUND3CNT_X:
691	case REG_SOUND4CNT_LO:
692	case REG_SOUND4CNT_HI:
693	case REG_SOUNDCNT_LO:
694	case REG_SOUNDCNT_HI:
695	case REG_TM0CNT_HI:
696	case REG_TM1CNT_HI:
697	case REG_TM2CNT_HI:
698	case REG_TM3CNT_HI:
699	case REG_KEYINPUT:
700	case REG_KEYCNT:
701	case REG_IE:
702		return true;
703	}
704}
705
706uint16_t GBAIORead(struct GBA* gba, uint32_t address) {
707	if (!GBAIOIsReadConstant(address)) {
708		// Most IO reads need to disable idle removal
709		gba->haltPending = false;
710	}
711
712	switch (address) {
713	// Reading this takes two cycles (1N+1I), so let's remove them preemptively
714	case REG_TM0CNT_LO:
715		GBATimerUpdateRegister(gba, 0, 4);
716		break;
717	case REG_TM1CNT_LO:
718		GBATimerUpdateRegister(gba, 1, 4);
719		break;
720	case REG_TM2CNT_LO:
721		GBATimerUpdateRegister(gba, 2, 4);
722		break;
723	case REG_TM3CNT_LO:
724		GBATimerUpdateRegister(gba, 3, 4);
725		break;
726
727	case REG_KEYINPUT:
728		if (gba->rr && gba->rr->isPlaying(gba->rr)) {
729			return 0x3FF ^ gba->rr->queryInput(gba->rr);
730		} else {
731			uint16_t input = 0;
732			if (gba->keyCallback) {
733				input = gba->keyCallback->readKeys(gba->keyCallback);
734				if (gba->keySource) {
735					*gba->keySource = input;
736				}
737			} else if (gba->keySource) {
738				input = *gba->keySource;
739				if (!gba->allowOpposingDirections) {
740					unsigned rl = input & 0x030;
741					unsigned ud = input & 0x0C0;
742					input &= 0x30F;
743					if (rl != 0x030) {
744						input |= rl;
745					}
746					if (ud != 0x0C0) {
747						input |= ud;
748					}
749				}
750			}
751			if (gba->rr && gba->rr->isRecording(gba->rr)) {
752				gba->rr->logInput(gba->rr, input);
753			}
754			return 0x3FF ^ input;
755		}
756
757	case REG_SIOCNT:
758		return gba->sio.siocnt;
759	case REG_RCNT:
760		return gba->sio.rcnt;
761
762	case REG_BG0HOFS:
763	case REG_BG0VOFS:
764	case REG_BG1HOFS:
765	case REG_BG1VOFS:
766	case REG_BG2HOFS:
767	case REG_BG2VOFS:
768	case REG_BG3HOFS:
769	case REG_BG3VOFS:
770	case REG_BG2PA:
771	case REG_BG2PB:
772	case REG_BG2PC:
773	case REG_BG2PD:
774	case REG_BG2X_LO:
775	case REG_BG2X_HI:
776	case REG_BG2Y_LO:
777	case REG_BG2Y_HI:
778	case REG_BG3PA:
779	case REG_BG3PB:
780	case REG_BG3PC:
781	case REG_BG3PD:
782	case REG_BG3X_LO:
783	case REG_BG3X_HI:
784	case REG_BG3Y_LO:
785	case REG_BG3Y_HI:
786	case REG_WIN0H:
787	case REG_WIN1H:
788	case REG_WIN0V:
789	case REG_WIN1V:
790	case REG_MOSAIC:
791	case REG_BLDY:
792	case REG_FIFO_A_LO:
793	case REG_FIFO_A_HI:
794	case REG_FIFO_B_LO:
795	case REG_FIFO_B_HI:
796	case REG_DMA0SAD_LO:
797	case REG_DMA0SAD_HI:
798	case REG_DMA0DAD_LO:
799	case REG_DMA0DAD_HI:
800	case REG_DMA1SAD_LO:
801	case REG_DMA1SAD_HI:
802	case REG_DMA1DAD_LO:
803	case REG_DMA1DAD_HI:
804	case REG_DMA2SAD_LO:
805	case REG_DMA2SAD_HI:
806	case REG_DMA2DAD_LO:
807	case REG_DMA2DAD_HI:
808	case REG_DMA3SAD_LO:
809	case REG_DMA3SAD_HI:
810	case REG_DMA3DAD_LO:
811	case REG_DMA3DAD_HI:
812		// Write-only register
813		mLOG(GBA_IO, GAME_ERROR, "Read from write-only I/O register: %03X", address);
814		return GBALoadBad(gba->cpu);
815
816	case REG_DMA0CNT_LO:
817	case REG_DMA1CNT_LO:
818	case REG_DMA2CNT_LO:
819	case REG_DMA3CNT_LO:
820		// Write-only register
821		mLOG(GBA_IO, GAME_ERROR, "Read from write-only I/O register: %03X", address);
822		return 0;
823
824	case REG_JOY_RECV_LO:
825	case REG_JOY_RECV_HI:
826		gba->memory.io[REG_JOYSTAT >> 1] &= ~JOYSTAT_RECV_BIT;
827		break;
828
829	case REG_SOUNDBIAS:
830	case REG_POSTFLG:
831		mLOG(GBA_IO, STUB, "Stub I/O register read: %03x", address);
832		break;
833	case REG_SOUND1CNT_LO:
834	case REG_SOUND1CNT_HI:
835	case REG_SOUND1CNT_X:
836	case REG_SOUND2CNT_LO:
837	case REG_SOUND2CNT_HI:
838	case REG_SOUND3CNT_LO:
839	case REG_SOUND3CNT_HI:
840	case REG_SOUND3CNT_X:
841	case REG_SOUND4CNT_LO:
842	case REG_SOUND4CNT_HI:
843	case REG_SOUNDCNT_LO:
844		if (!GBAudioEnableIsEnable(gba->memory.io[REG_SOUNDCNT_X >> 1])) {
845			// TODO: Is writing allowed when the circuit is disabled?
846			return 0;
847		}
848		// Fall through
849	case REG_DISPCNT:
850	case REG_DISPSTAT:
851	case REG_VCOUNT:
852	case REG_BG0CNT:
853	case REG_BG1CNT:
854	case REG_BG2CNT:
855	case REG_BG3CNT:
856	case REG_WININ:
857	case REG_WINOUT:
858	case REG_BLDCNT:
859	case REG_BLDALPHA:
860	case REG_SOUNDCNT_HI:
861	case REG_SOUNDCNT_X:
862	case REG_WAVE_RAM0_LO:
863	case REG_WAVE_RAM0_HI:
864	case REG_WAVE_RAM1_LO:
865	case REG_WAVE_RAM1_HI:
866	case REG_WAVE_RAM2_LO:
867	case REG_WAVE_RAM2_HI:
868	case REG_WAVE_RAM3_LO:
869	case REG_WAVE_RAM3_HI:
870	case REG_DMA0CNT_HI:
871	case REG_DMA1CNT_HI:
872	case REG_DMA2CNT_HI:
873	case REG_DMA3CNT_HI:
874	case REG_TM0CNT_HI:
875	case REG_TM1CNT_HI:
876	case REG_TM2CNT_HI:
877	case REG_TM3CNT_HI:
878	case REG_KEYCNT:
879	case REG_SIOMULTI0:
880	case REG_SIOMULTI1:
881	case REG_SIOMULTI2:
882	case REG_SIOMULTI3:
883	case REG_SIOMLT_SEND:
884	case REG_JOYCNT:
885	case REG_JOY_TRANS_LO:
886	case REG_JOY_TRANS_HI:
887	case REG_JOYSTAT:
888	case REG_IE:
889	case REG_IF:
890	case REG_WAITCNT:
891	case REG_IME:
892		// Handled transparently by registers
893		break;
894	case REG_MAX:
895		// Some bad interrupt libraries will read from this
896	case 0x066:
897	case 0x06E:
898	case 0x076:
899	case 0x07A:
900	case 0x07E:
901	case 0x086:
902	case 0x08A:
903	case 0x136:
904	case 0x142:
905	case 0x15A:
906	case 0x206:
907		mLOG(GBA_IO, GAME_ERROR, "Read from unused I/O register: %03X", address);
908		return 0;
909	case REG_DEBUG_ENABLE:
910		if (gba->debug) {
911			return 0x1DEA;
912		}
913		// Fall through
914	default:
915		mLOG(GBA_IO, GAME_ERROR, "Read from unused I/O register: %03X", address);
916		return GBALoadBad(gba->cpu);
917	}
918	return gba->memory.io[address >> 1];
919}
920
921void GBAIOSerialize(struct GBA* gba, struct GBASerializedState* state) {
922	int i;
923	for (i = 0; i < REG_MAX; i += 2) {
924		if (_isRSpecialRegister[i >> 1]) {
925			STORE_16(gba->memory.io[i >> 1], i, state->io);
926		} else if (_isValidRegister[i >> 1]) {
927			uint16_t reg = GBAIORead(gba, i);
928			STORE_16(reg, i, state->io);
929		}
930	}
931
932	for (i = 0; i < 4; ++i) {
933		STORE_16(gba->memory.io[(REG_DMA0CNT_LO + i * 12) >> 1], (REG_DMA0CNT_LO + i * 12), state->io);
934		STORE_16(gba->timers[i].reload, 0, &state->timers[i].reload);
935		STORE_32(gba->timers[i].lastEvent - mTimingCurrentTime(&gba->timing), 0, &state->timers[i].lastEvent);
936		STORE_32(gba->timers[i].event.when - mTimingCurrentTime(&gba->timing), 0, &state->timers[i].nextEvent);
937		STORE_32(gba->timers[i].flags, 0, &state->timers[i].flags);
938		STORE_32(gba->memory.dma[i].nextSource, 0, &state->dma[i].nextSource);
939		STORE_32(gba->memory.dma[i].nextDest, 0, &state->dma[i].nextDest);
940		STORE_32(gba->memory.dma[i].nextCount, 0, &state->dma[i].nextCount);
941		STORE_32(gba->memory.dma[i].when, 0, &state->dma[i].when);
942	}
943
944	state->dmaTransferRegister = gba->memory.dmaTransferRegister;
945
946	GBAHardwareSerialize(&gba->memory.hw, state);
947}
948
949void GBAIODeserialize(struct GBA* gba, const struct GBASerializedState* state) {
950	int i;
951	for (i = 0; i < REG_MAX; i += 2) {
952		if (_isWSpecialRegister[i >> 1]) {
953			LOAD_16(gba->memory.io[i >> 1], i, state->io);
954		} else if (_isValidRegister[i >> 1]) {
955			uint16_t reg;
956			LOAD_16(reg, i, state->io);
957			GBAIOWrite(gba, i, reg);
958		}
959	}
960
961	uint32_t when;
962	for (i = 0; i < 4; ++i) {
963		LOAD_16(gba->timers[i].reload, 0, &state->timers[i].reload);
964		LOAD_32(gba->timers[i].flags, 0, &state->timers[i].flags);
965		if (i > 0 && GBATimerFlagsIsCountUp(gba->timers[i].flags)) {
966			// Overwrite invalid values in savestate
967			gba->timers[i].lastEvent = 0;
968		} else {
969			LOAD_32(when, 0, &state->timers[i].lastEvent);
970			gba->timers[i].lastEvent = when + mTimingCurrentTime(&gba->timing);
971		}
972		LOAD_32(when, 0, &state->timers[i].nextEvent);
973		if (GBATimerFlagsIsEnable(gba->timers[i].flags)) {
974			mTimingSchedule(&gba->timing, &gba->timers[i].event, when);
975		}
976
977		LOAD_16(gba->memory.dma[i].reg, (REG_DMA0CNT_HI + i * 12), state->io);
978		LOAD_32(gba->memory.dma[i].nextSource, 0, &state->dma[i].nextSource);
979		LOAD_32(gba->memory.dma[i].nextDest, 0, &state->dma[i].nextDest);
980		LOAD_32(gba->memory.dma[i].nextCount, 0, &state->dma[i].nextCount);
981		LOAD_32(gba->memory.dma[i].when, 0, &state->dma[i].when);
982		if (GBADMARegisterGetTiming(gba->memory.dma[i].reg) != GBA_DMA_TIMING_NOW) {
983			GBADMASchedule(gba, i, &gba->memory.dma[i]);
984		}
985	}
986	GBAAudioWriteSOUNDCNT_X(&gba->audio, gba->memory.io[REG_SOUNDCNT_X >> 1]);
987	gba->memory.dmaTransferRegister = state->dmaTransferRegister;
988	GBADMAUpdate(gba);
989	GBAHardwareDeserialize(&gba->memory.hw, state);
990}