all repos — mgba @ a506f6cd9d6fd025410f62e3b663b0aaea3f0b82

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			value &= 0x5FFF;
539			GBAAdjustWaitstates(gba, value);
540			break;
541		case REG_IE:
542			GBAWriteIE(gba, value);
543			break;
544		case REG_IF:
545			gba->springIRQ &= ~value;
546			value = gba->memory.io[REG_IF >> 1] & ~value;
547			break;
548		case REG_IME:
549			GBAWriteIME(gba, value);
550			break;
551		case REG_MAX:
552			// Some bad interrupt libraries will write to this
553			break;
554		case REG_DEBUG_ENABLE:
555			gba->debug = value == 0xC0DE;
556			return;
557		case REG_DEBUG_FLAGS:
558			if (gba->debug) {
559				GBADebug(gba, value);
560				return;
561			}
562			// Fall through
563		default:
564			if (address >= REG_DEBUG_STRING && address - REG_DEBUG_STRING < sizeof(gba->debugString)) {
565				STORE_16LE(value, address - REG_DEBUG_STRING, gba->debugString);
566				return;
567			}
568			mLOG(GBA_IO, STUB, "Stub I/O register write: %03X", address);
569			if (address >= REG_MAX) {
570				mLOG(GBA_IO, GAME_ERROR, "Write to unused I/O register: %03X", address);
571				return;
572			}
573			break;
574		}
575	}
576	gba->memory.io[address >> 1] = value;
577}
578
579void GBAIOWrite8(struct GBA* gba, uint32_t address, uint8_t value) {
580	if (address == REG_HALTCNT) {
581		value &= 0x80;
582		if (!value) {
583			GBAHalt(gba);
584		} else {
585			GBAStop(gba);
586		}
587		return;
588	}
589	if (address == REG_POSTFLG) {
590		gba->memory.io[(address & (SIZE_IO - 1)) >> 1] = value;
591		return;
592	}
593	if (address >= REG_DEBUG_STRING && address - REG_DEBUG_STRING < sizeof(gba->debugString)) {
594		gba->debugString[address - REG_DEBUG_STRING] = value;
595		return;
596	}
597	if (address > SIZE_IO) {
598		return;
599	}
600	uint16_t value16 = value << (8 * (address & 1));
601	value16 |= (gba->memory.io[(address & (SIZE_IO - 1)) >> 1]) & ~(0xFF << (8 * (address & 1)));
602	GBAIOWrite(gba, address & 0xFFFFFFFE, value16);
603}
604
605void GBAIOWrite32(struct GBA* gba, uint32_t address, uint32_t value) {
606	switch (address) {
607	case REG_WAVE_RAM0_LO:
608		GBAAudioWriteWaveRAM(&gba->audio, 0, value);
609		break;
610	case REG_WAVE_RAM1_LO:
611		GBAAudioWriteWaveRAM(&gba->audio, 1, value);
612		break;
613	case REG_WAVE_RAM2_LO:
614		GBAAudioWriteWaveRAM(&gba->audio, 2, value);
615		break;
616	case REG_WAVE_RAM3_LO:
617		GBAAudioWriteWaveRAM(&gba->audio, 3, value);
618		break;
619	case REG_FIFO_A_LO:
620	case REG_FIFO_B_LO:
621		GBAAudioWriteFIFO(&gba->audio, address, value);
622		break;
623	case REG_DMA0SAD_LO:
624		value = GBAMemoryWriteDMASAD(gba, 0, value);
625		break;
626	case REG_DMA0DAD_LO:
627		value = GBAMemoryWriteDMADAD(gba, 0, value);
628		break;
629	case REG_DMA1SAD_LO:
630		value = GBAMemoryWriteDMASAD(gba, 1, value);
631		break;
632	case REG_DMA1DAD_LO:
633		value = GBAMemoryWriteDMADAD(gba, 1, value);
634		break;
635	case REG_DMA2SAD_LO:
636		value = GBAMemoryWriteDMASAD(gba, 2, value);
637		break;
638	case REG_DMA2DAD_LO:
639		value = GBAMemoryWriteDMADAD(gba, 2, value);
640		break;
641	case REG_DMA3SAD_LO:
642		value = GBAMemoryWriteDMASAD(gba, 3, value);
643		break;
644	case REG_DMA3DAD_LO:
645		value = GBAMemoryWriteDMADAD(gba, 3, value);
646		break;
647	default:
648		if (address >= REG_DEBUG_STRING && address - REG_DEBUG_STRING < sizeof(gba->debugString)) {
649			STORE_32LE(value, address - REG_DEBUG_STRING, gba->debugString);
650			return;
651		}
652		GBAIOWrite(gba, address, value & 0xFFFF);
653		GBAIOWrite(gba, address | 2, value >> 16);
654		return;
655	}
656	gba->memory.io[address >> 1] = value;
657	gba->memory.io[(address >> 1) + 1] = value >> 16;
658}
659
660bool GBAIOIsReadConstant(uint32_t address) {
661	switch (address) {
662	default:
663		return false;
664	case REG_BG0CNT:
665	case REG_BG1CNT:
666	case REG_BG2CNT:
667	case REG_BG3CNT:
668	case REG_WININ:
669	case REG_WINOUT:
670	case REG_BLDCNT:
671	case REG_BLDALPHA:
672	case REG_SOUND1CNT_LO:
673	case REG_SOUND1CNT_HI:
674	case REG_SOUND1CNT_X:
675	case REG_SOUND2CNT_LO:
676	case REG_SOUND2CNT_HI:
677	case REG_SOUND3CNT_LO:
678	case REG_SOUND3CNT_HI:
679	case REG_SOUND3CNT_X:
680	case REG_SOUND4CNT_LO:
681	case REG_SOUND4CNT_HI:
682	case REG_SOUNDCNT_LO:
683	case REG_SOUNDCNT_HI:
684	case REG_TM0CNT_HI:
685	case REG_TM1CNT_HI:
686	case REG_TM2CNT_HI:
687	case REG_TM3CNT_HI:
688	case REG_KEYINPUT:
689	case REG_IE:
690		return true;
691	}
692}
693
694uint16_t GBAIORead(struct GBA* gba, uint32_t address) {
695	if (!GBAIOIsReadConstant(address)) {
696		// Most IO reads need to disable idle removal
697		gba->haltPending = false;
698	}
699
700	switch (address) {
701	case REG_TM0CNT_LO:
702		GBATimerUpdateRegister(gba, 0);
703		break;
704	case REG_TM1CNT_LO:
705		GBATimerUpdateRegister(gba, 1);
706		break;
707	case REG_TM2CNT_LO:
708		GBATimerUpdateRegister(gba, 2);
709		break;
710	case REG_TM3CNT_LO:
711		GBATimerUpdateRegister(gba, 3);
712		break;
713
714	case REG_KEYINPUT:
715		if (gba->rr && gba->rr->isPlaying(gba->rr)) {
716			return 0x3FF ^ gba->rr->queryInput(gba->rr);
717		} else {
718			uint16_t input = 0x3FF;
719			if (gba->keyCallback) {
720				input = gba->keyCallback->readKeys(gba->keyCallback);
721			} else if (gba->keySource) {
722				input = *gba->keySource;
723			}
724			if (!gba->allowOpposingDirections) {
725				unsigned rl = input & 0x030;
726				unsigned ud = input & 0x0C0;
727				input &= 0x30F;
728				if (rl != 0x030) {
729					input |= rl;
730				}
731				if (ud != 0x0C0) {
732					input |= ud;
733				}
734			}
735			if (gba->rr && gba->rr->isRecording(gba->rr)) {
736				gba->rr->logInput(gba->rr, input);
737			}
738			return 0x3FF ^ input;
739		}
740
741	case REG_SIOCNT:
742		return gba->sio.siocnt;
743	case REG_RCNT:
744		return gba->sio.rcnt;
745
746	case REG_BG0HOFS:
747	case REG_BG0VOFS:
748	case REG_BG1HOFS:
749	case REG_BG1VOFS:
750	case REG_BG2HOFS:
751	case REG_BG2VOFS:
752	case REG_BG3HOFS:
753	case REG_BG3VOFS:
754	case REG_BG2PA:
755	case REG_BG2PB:
756	case REG_BG2PC:
757	case REG_BG2PD:
758	case REG_BG2X_LO:
759	case REG_BG2X_HI:
760	case REG_BG2Y_LO:
761	case REG_BG2Y_HI:
762	case REG_BG3PA:
763	case REG_BG3PB:
764	case REG_BG3PC:
765	case REG_BG3PD:
766	case REG_BG3X_LO:
767	case REG_BG3X_HI:
768	case REG_BG3Y_LO:
769	case REG_BG3Y_HI:
770	case REG_WIN0H:
771	case REG_WIN1H:
772	case REG_WIN0V:
773	case REG_WIN1V:
774	case REG_MOSAIC:
775	case REG_BLDY:
776	case REG_FIFO_A_LO:
777	case REG_FIFO_A_HI:
778	case REG_FIFO_B_LO:
779	case REG_FIFO_B_HI:
780	case REG_DMA0SAD_LO:
781	case REG_DMA0SAD_HI:
782	case REG_DMA0DAD_LO:
783	case REG_DMA0DAD_HI:
784	case REG_DMA1SAD_LO:
785	case REG_DMA1SAD_HI:
786	case REG_DMA1DAD_LO:
787	case REG_DMA1DAD_HI:
788	case REG_DMA2SAD_LO:
789	case REG_DMA2SAD_HI:
790	case REG_DMA2DAD_LO:
791	case REG_DMA2DAD_HI:
792	case REG_DMA3SAD_LO:
793	case REG_DMA3SAD_HI:
794	case REG_DMA3DAD_LO:
795	case REG_DMA3DAD_HI:
796		// Write-only register
797		mLOG(GBA_IO, GAME_ERROR, "Read from write-only I/O register: %03X", address);
798		return GBALoadBad(gba->cpu);
799
800	case REG_DMA0CNT_LO:
801	case REG_DMA1CNT_LO:
802	case REG_DMA2CNT_LO:
803	case REG_DMA3CNT_LO:
804		// Write-only register
805		mLOG(GBA_IO, GAME_ERROR, "Read from write-only I/O register: %03X", address);
806		return 0;
807
808	case REG_SOUNDBIAS:
809	case REG_KEYCNT:
810	case REG_POSTFLG:
811		mLOG(GBA_IO, STUB, "Stub I/O register read: %03x", address);
812		break;
813	case REG_SOUND1CNT_LO:
814	case REG_SOUND1CNT_HI:
815	case REG_SOUND1CNT_X:
816	case REG_SOUND2CNT_LO:
817	case REG_SOUND2CNT_HI:
818	case REG_SOUND3CNT_LO:
819	case REG_SOUND3CNT_HI:
820	case REG_SOUND3CNT_X:
821	case REG_SOUND4CNT_LO:
822	case REG_SOUND4CNT_HI:
823	case REG_SOUNDCNT_LO:
824	case REG_SOUNDCNT_HI:
825		if (!GBAudioEnableIsEnable(gba->memory.io[REG_SOUNDCNT_X >> 1])) {
826			// TODO: Is writing allowed when the circuit is disabled?
827			return 0;
828		}
829		// Fall through
830	case REG_DISPCNT:
831	case REG_DISPSTAT:
832	case REG_VCOUNT:
833	case REG_BG0CNT:
834	case REG_BG1CNT:
835	case REG_BG2CNT:
836	case REG_BG3CNT:
837	case REG_WININ:
838	case REG_WINOUT:
839	case REG_BLDCNT:
840	case REG_BLDALPHA:
841	case REG_SOUNDCNT_X:
842	case REG_WAVE_RAM0_LO:
843	case REG_WAVE_RAM0_HI:
844	case REG_WAVE_RAM1_LO:
845	case REG_WAVE_RAM1_HI:
846	case REG_WAVE_RAM2_LO:
847	case REG_WAVE_RAM2_HI:
848	case REG_WAVE_RAM3_LO:
849	case REG_WAVE_RAM3_HI:
850	case REG_DMA0CNT_HI:
851	case REG_DMA1CNT_HI:
852	case REG_DMA2CNT_HI:
853	case REG_DMA3CNT_HI:
854	case REG_TM0CNT_HI:
855	case REG_TM1CNT_HI:
856	case REG_TM2CNT_HI:
857	case REG_TM3CNT_HI:
858	case REG_SIOMULTI0:
859	case REG_SIOMULTI1:
860	case REG_SIOMULTI2:
861	case REG_SIOMULTI3:
862	case REG_SIOMLT_SEND:
863	case REG_JOYCNT:
864	case REG_JOY_RECV_LO:
865	case REG_JOY_RECV_HI:
866	case REG_JOY_TRANS_LO:
867	case REG_JOY_TRANS_HI:
868	case REG_JOYSTAT:
869	case REG_IE:
870	case REG_IF:
871	case REG_WAITCNT:
872	case REG_IME:
873		// Handled transparently by registers
874		break;
875	case REG_MAX:
876		// Some bad interrupt libraries will read from this
877		break;
878	case 0x66:
879	case 0x6E:
880	case 0x76:
881	case 0x7A:
882	case 0x7E:
883	case 0x86:
884	case 0x8A:
885		mLOG(GBA_IO, GAME_ERROR, "Read from unused I/O register: %03X", address);
886		return 0;
887	case REG_DEBUG_ENABLE:
888		if (gba->debug) {
889			return 0x1DEA;
890		}
891		// Fall through
892	default:
893		mLOG(GBA_IO, GAME_ERROR, "Read from unused I/O register: %03X", address);
894		return GBALoadBad(gba->cpu);
895	}
896	return gba->memory.io[address >> 1];
897}
898
899void GBAIOSerialize(struct GBA* gba, struct GBASerializedState* state) {
900	int i;
901	for (i = 0; i < REG_MAX; i += 2) {
902		if (_isRSpecialRegister[i >> 1]) {
903			STORE_16(gba->memory.io[i >> 1], i, state->io);
904		} else if (_isValidRegister[i >> 1]) {
905			uint16_t reg = GBAIORead(gba, i);
906			STORE_16(reg, i, state->io);
907		}
908	}
909
910	for (i = 0; i < 4; ++i) {
911		STORE_16(gba->memory.io[(REG_DMA0CNT_LO + i * 12) >> 1], (REG_DMA0CNT_LO + i * 12), state->io);
912		STORE_16(gba->timers[i].reload, 0, &state->timers[i].reload);
913		STORE_16(gba->timers[i].oldReload, 0, &state->timers[i].oldReload);
914		STORE_32(gba->timers[i].lastEvent, 0, &state->timers[i].lastEvent);
915		STORE_32(gba->timers[i].overflowInterval, 0, &state->timers[i].overflowInterval);
916		STORE_32(gba->timers[i].flags, 0, &state->timers[i].flags);
917		STORE_32(gba->memory.dma[i].nextSource, 0, &state->dma[i].nextSource);
918		STORE_32(gba->memory.dma[i].nextDest, 0, &state->dma[i].nextDest);
919		STORE_32(gba->memory.dma[i].nextCount, 0, &state->dma[i].nextCount);
920		STORE_32(gba->memory.dma[i].nextEvent, 0, &state->dma[i].nextEvent);
921	}
922
923	GBAHardwareSerialize(&gba->memory.hw, state);
924}
925
926void GBAIODeserialize(struct GBA* gba, const struct GBASerializedState* state) {
927	int i;
928	for (i = 0; i < REG_MAX; i += 2) {
929		if (_isWSpecialRegister[i >> 1]) {
930			LOAD_16(gba->memory.io[i >> 1], i, state->io);
931		} else if (_isValidRegister[i >> 1]) {
932			uint16_t reg;
933			LOAD_16(reg, i, state->io);
934			GBAIOWrite(gba, i, reg);
935		}
936	}
937
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		} else {
947			LOAD_32(gba->timers[i].lastEvent, 0, &state->timers[i].lastEvent);
948		}
949		LOAD_16(gba->memory.dma[i].reg, (REG_DMA0CNT_HI + i * 12), state->io);
950		LOAD_32(gba->memory.dma[i].nextSource, 0, &state->dma[i].nextSource);
951		LOAD_32(gba->memory.dma[i].nextDest, 0, &state->dma[i].nextDest);
952		LOAD_32(gba->memory.dma[i].nextCount, 0, &state->dma[i].nextCount);
953		LOAD_32(gba->memory.dma[i].nextEvent, 0, &state->dma[i].nextEvent);
954		if (GBADMARegisterGetTiming(gba->memory.dma[i].reg) != DMA_TIMING_NOW) {
955			GBAMemoryScheduleDMA(gba, i, &gba->memory.dma[i]);
956		}
957	}
958	GBAAudioWriteSOUNDCNT_X(&gba->audio, gba->memory.io[REG_SOUNDCNT_X >> 1]);
959	GBAMemoryUpdateDMAs(gba, 0);
960	GBAHardwareDeserialize(&gba->memory.hw, state);
961}