all repos — mgba @ 78ef8523ac3c49ccce9108427895dfd49cd829ce

mGBA Game Boy Advance Emulator

src/gba/serialize.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 "serialize.h"
  7
  8#include "gba/audio.h"
  9#include "gba/cheats.h"
 10#include "gba/io.h"
 11#include "gba/rr/rr.h"
 12#include "gba/supervisor/thread.h"
 13#include "gba/video.h"
 14
 15#include "util/memory.h"
 16#include "util/vfs.h"
 17
 18#include <fcntl.h>
 19#include <sys/time.h>
 20
 21#ifdef USE_PNG
 22#include "util/png-io.h"
 23#include <png.h>
 24#include <zlib.h>
 25#endif
 26
 27const uint32_t GBA_SAVESTATE_MAGIC = 0x01000000;
 28
 29struct GBABundledState {
 30	struct GBASerializedState* state;
 31	struct GBAExtdata* extdata;
 32};
 33
 34struct GBAExtdataHeader {
 35	uint32_t tag;
 36	int32_t size;
 37	int64_t offset;
 38};
 39
 40void GBASerialize(struct GBA* gba, struct GBASerializedState* state) {
 41	STORE_32(GBA_SAVESTATE_MAGIC, 0, &state->versionMagic);
 42	STORE_32(gba->biosChecksum, 0, &state->biosChecksum);
 43	STORE_32(gba->romCrc32, 0, &state->romCrc32);
 44
 45	if (gba->memory.rom) {
 46		state->id = ((struct GBACartridge*) gba->memory.rom)->id;
 47		memcpy(state->title, ((struct GBACartridge*) gba->memory.rom)->title, sizeof(state->title));
 48	} else {
 49		state->id = 0;
 50		memset(state->title, 0, sizeof(state->title));
 51	}
 52
 53	int i;
 54	for (i = 0; i < 16; ++i) {
 55		STORE_32(gba->cpu->gprs[i], i * sizeof(state->cpu.gprs[0]), state->cpu.gprs);
 56	}
 57	STORE_32(gba->cpu->cpsr.packed, 0, &state->cpu.cpsr.packed);
 58	STORE_32(gba->cpu->spsr.packed, 0, &state->cpu.spsr.packed);
 59	STORE_32(gba->cpu->cycles, 0, &state->cpu.cycles);
 60	STORE_32(gba->cpu->nextEvent, 0, &state->cpu.nextEvent);
 61	for (i = 0; i < 6; ++i) {
 62		int j;
 63		for (j = 0; j < 7; ++j) {
 64			STORE_32(gba->cpu->bankedRegisters[i][j], (i * 7 + j) * sizeof(gba->cpu->bankedRegisters[0][0]), state->cpu.bankedRegisters);
 65		}
 66		STORE_32(gba->cpu->bankedSPSRs[i], i * sizeof(gba->cpu->bankedSPSRs[0]), state->cpu.bankedSPSRs);
 67	}
 68
 69	state->biosPrefetch = gba->memory.biosPrefetch;
 70	STORE_32(gba->cpu->prefetch[0], 0, state->cpuPrefetch);
 71	STORE_32(gba->cpu->prefetch[1], 4, state->cpuPrefetch);
 72
 73	GBAMemorySerialize(&gba->memory, state);
 74	GBAIOSerialize(gba, state);
 75	GBAVideoSerialize(&gba->video, state);
 76	GBAAudioSerialize(&gba->audio, state);
 77	GBASavedataSerialize(&gba->memory.savedata, state);
 78
 79	struct timeval tv;
 80	if (!gettimeofday(&tv, 0)) {
 81		uint64_t usec = tv.tv_usec;
 82		usec += tv.tv_sec * 1000000LL;
 83		STORE_64(usec, 0, &state->creationUsec);
 84	} else {
 85		state->creationUsec = 0;
 86	}
 87	state->associatedStreamId = 0;
 88	if (gba->rr) {
 89		gba->rr->stateSaved(gba->rr, state);
 90	}
 91}
 92
 93bool GBADeserialize(struct GBA* gba, const struct GBASerializedState* state) {
 94	bool error = false;
 95	int32_t check;
 96	uint32_t ucheck;
 97	LOAD_32(ucheck, 0, &state->versionMagic);
 98	if (ucheck != GBA_SAVESTATE_MAGIC) {
 99		GBALog(gba, GBA_LOG_WARN, "Invalid or too new savestate: expected %08X, got %08X", GBA_SAVESTATE_MAGIC, ucheck);
100		error = true;
101	}
102	LOAD_32(ucheck, 0, &state->biosChecksum);
103	if (ucheck != gba->biosChecksum) {
104		GBALog(gba, GBA_LOG_WARN, "Savestate created using a different version of the BIOS: expected %08X, got %08X", gba->biosChecksum, ucheck);
105		uint32_t pc;
106		LOAD_32(pc, ARM_PC * sizeof(state->cpu.gprs[0]), state->cpu.gprs);
107		if (pc < SIZE_BIOS && pc >= 0x20) {
108			error = true;
109		}
110	}
111	if (gba->memory.rom && (state->id != ((struct GBACartridge*) gba->memory.rom)->id || memcmp(state->title, ((struct GBACartridge*) gba->memory.rom)->title, sizeof(state->title)))) {
112		GBALog(gba, GBA_LOG_WARN, "Savestate is for a different game");
113		error = true;
114	} else if (!gba->memory.rom && state->id != 0) {
115		GBALog(gba, GBA_LOG_WARN, "Savestate is for a game, but no game loaded");
116		error = true;
117	}
118	LOAD_32(ucheck, 0, &state->romCrc32);
119	if (ucheck != gba->romCrc32) {
120		GBALog(gba, GBA_LOG_WARN, "Savestate is for a different version of the game");
121	}
122	LOAD_32(check, 0, &state->cpu.cycles);
123	if (check < 0) {
124		GBALog(gba, GBA_LOG_WARN, "Savestate is corrupted: CPU cycles are negative");
125		error = true;
126	}
127	if (check >= (int32_t) GBA_ARM7TDMI_FREQUENCY) {
128		GBALog(gba, GBA_LOG_WARN, "Savestate is corrupted: CPU cycles are too high");
129		error = true;
130	}
131	LOAD_32(check, 0, &state->video.eventDiff);
132	if (check < 0) {
133		GBALog(gba, GBA_LOG_WARN, "Savestate is corrupted: video eventDiff is negative");
134		error = true;
135	}
136	LOAD_32(check, ARM_PC * sizeof(state->cpu.gprs[0]), state->cpu.gprs);
137	int region = (check >> BASE_OFFSET);
138	if ((region == REGION_CART0 || region == REGION_CART1 || region == REGION_CART2) && ((check - WORD_SIZE_ARM) & SIZE_CART0) >= gba->memory.romSize - WORD_SIZE_ARM) {
139		GBALog(gba, GBA_LOG_WARN, "Savestate created using a differently sized version of the ROM");
140		error = true;
141	}
142	if (error) {
143		return false;
144	}
145	size_t i;
146	for (i = 0; i < 16; ++i) {
147		LOAD_32(gba->cpu->gprs[i], i * sizeof(gba->cpu->gprs[0]), state->cpu.gprs);
148	}
149	LOAD_32(gba->cpu->cpsr.packed, 0, &state->cpu.cpsr.packed);
150	LOAD_32(gba->cpu->spsr.packed, 0, &state->cpu.spsr.packed);
151	LOAD_32(gba->cpu->cycles, 0, &state->cpu.cycles);
152	LOAD_32(gba->cpu->nextEvent, 0, &state->cpu.nextEvent);
153	for (i = 0; i < 6; ++i) {
154		int j;
155		for (j = 0; j < 7; ++j) {
156			LOAD_32(gba->cpu->bankedRegisters[i][j], (i * 7 + j) * sizeof(gba->cpu->bankedRegisters[0][0]), state->cpu.bankedRegisters);
157		}
158		LOAD_32(gba->cpu->bankedSPSRs[i], i * sizeof(gba->cpu->bankedSPSRs[0]), state->cpu.bankedSPSRs);
159	}
160	gba->cpu->privilegeMode = gba->cpu->cpsr.priv;
161	gba->cpu->memory.setActiveRegion(gba->cpu, gba->cpu->gprs[ARM_PC]);
162	if (state->biosPrefetch) {
163		LOAD_32(gba->memory.biosPrefetch, 0, &state->biosPrefetch);
164	}
165	if (gba->cpu->cpsr.t) {
166		gba->cpu->executionMode = MODE_THUMB;
167		if (state->cpuPrefetch[0] && state->cpuPrefetch[1]) {
168			LOAD_32(gba->cpu->prefetch[0], 0, state->cpuPrefetch);
169			LOAD_32(gba->cpu->prefetch[1], 4, state->cpuPrefetch);
170			gba->cpu->prefetch[0] &= 0xFFFF;
171			gba->cpu->prefetch[1] &= 0xFFFF;
172		} else {
173			// Maintain backwards compat
174			LOAD_16(gba->cpu->prefetch[0], (gba->cpu->gprs[ARM_PC] - WORD_SIZE_THUMB) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
175			LOAD_16(gba->cpu->prefetch[1], (gba->cpu->gprs[ARM_PC]) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
176		}
177	} else {
178		gba->cpu->executionMode = MODE_ARM;
179		if (state->cpuPrefetch[0] && state->cpuPrefetch[1]) {
180			LOAD_32(gba->cpu->prefetch[0], 0, state->cpuPrefetch);
181			LOAD_32(gba->cpu->prefetch[1], 4, state->cpuPrefetch);
182		} else {
183			// Maintain backwards compat
184			LOAD_32(gba->cpu->prefetch[0], (gba->cpu->gprs[ARM_PC] - WORD_SIZE_ARM) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
185			LOAD_32(gba->cpu->prefetch[1], (gba->cpu->gprs[ARM_PC]) & gba->cpu->memory.activeMask, gba->cpu->memory.activeRegion);
186		}
187	}
188
189	GBAMemoryDeserialize(&gba->memory, state);
190	GBAIODeserialize(gba, state);
191	GBAVideoDeserialize(&gba->video, state);
192	GBAAudioDeserialize(&gba->audio, state);
193	GBASavedataDeserialize(&gba->memory.savedata, state);
194
195	if (gba->rr) {
196		gba->rr->stateLoaded(gba->rr, state);
197	}
198	return true;
199}
200
201struct VFile* GBAGetState(struct GBA* gba, struct VDir* dir, int slot, bool write) {
202	char basename[PATH_MAX];
203	separatePath(gba->activeFile, 0, basename, 0);
204	char path[PATH_MAX];
205	snprintf(path, sizeof(path), "%s.ss%i", basename, slot);
206	return dir->openFile(dir, path, write ? (O_CREAT | O_TRUNC | O_RDWR) : O_RDONLY);
207}
208
209#ifdef USE_PNG
210static bool _savePNGState(struct GBA* gba, struct VFile* vf, struct GBAExtdata* extdata) {
211	unsigned stride;
212	const void* pixels = 0;
213	gba->video.renderer->getPixels(gba->video.renderer, &stride, &pixels);
214	if (!pixels) {
215		return false;
216	}
217
218	struct GBASerializedState* state = GBAAllocateState();
219	if (!state) {
220		return false;
221	}
222	GBASerialize(gba, state);
223	uLongf len = compressBound(sizeof(*state));
224	void* buffer = malloc(len);
225	if (!buffer) {
226		GBADeallocateState(state);
227		return false;
228	}
229	compress(buffer, &len, (const Bytef*) state, sizeof(*state));
230	GBADeallocateState(state);
231
232	png_structp png = PNGWriteOpen(vf);
233	png_infop info = PNGWriteHeader(png, VIDEO_HORIZONTAL_PIXELS, VIDEO_VERTICAL_PIXELS);
234	if (!png || !info) {
235		PNGWriteClose(png, info);
236		free(buffer);
237		return false;
238	}
239	PNGWritePixels(png, VIDEO_HORIZONTAL_PIXELS, VIDEO_VERTICAL_PIXELS, stride, pixels);
240	PNGWriteCustomChunk(png, "gbAs", len, buffer);
241	if (extdata) {
242		uint32_t i;
243		for (i = 1; i < EXTDATA_MAX; ++i) {
244			if (!extdata->data[i].data) {
245				continue;
246			}
247			uLongf len = compressBound(extdata->data[i].size) + sizeof(uint32_t) * 2;
248			uint32_t* data = malloc(len);
249			if (!data) {
250				continue;
251			}
252			STORE_32(i, 0, data);
253			STORE_32(extdata->data[i].size, sizeof(uint32_t), data);
254			compress((Bytef*) (data + 2), &len, extdata->data[i].data, extdata->data[i].size);
255			PNGWriteCustomChunk(png, "gbAx", len + sizeof(uint32_t) * 2, data);
256			free(data);
257		}
258	}
259	PNGWriteClose(png, info);
260	free(buffer);
261	return true;
262}
263
264static int _loadPNGChunkHandler(png_structp png, png_unknown_chunkp chunk) {
265	struct GBABundledState* bundle = png_get_user_chunk_ptr(png);
266	if (!bundle) {
267		return 0;
268	}
269	if (!strcmp((const char*) chunk->name, "gbAs")) {
270		struct GBASerializedState* state = bundle->state;
271		if (!state) {
272			return 0;
273		}
274		uLongf len = sizeof(*state);
275		uncompress((Bytef*) state, &len, chunk->data, chunk->size);
276		return 1;
277	}
278	if (!strcmp((const char*) chunk->name, "gbAx")) {
279		struct GBAExtdata* extdata = bundle->extdata;
280		if (!extdata) {
281			return 0;
282		}
283		struct GBAExtdataItem item;
284		if (chunk->size < sizeof(uint32_t) * 2) {
285			return 0;
286		}
287		uint32_t tag;
288		LOAD_32(tag, 0, chunk->data);
289		LOAD_32(item.size, sizeof(uint32_t), chunk->data);
290		uLongf len = item.size;
291		if (item.size < 0 || tag == EXTDATA_NONE || tag >= EXTDATA_MAX) {
292			return 0;
293		}
294		item.data = malloc(item.size);
295		item.clean = free;
296		if (!item.data) {
297			return 0;
298		}
299		const uint8_t* data = chunk->data;
300		data += sizeof(uint32_t) * 2;
301		uncompress((Bytef*) item.data, &len, data, chunk->size);
302		item.size = len;
303		GBAExtdataPut(extdata, tag, &item);
304		return 1;
305	}
306	return 0;
307}
308
309static struct GBASerializedState* _loadPNGState(struct VFile* vf, struct GBAExtdata* extdata) {
310	png_structp png = PNGReadOpen(vf, PNG_HEADER_BYTES);
311	png_infop info = png_create_info_struct(png);
312	png_infop end = png_create_info_struct(png);
313	if (!png || !info || !end) {
314		PNGReadClose(png, info, end);
315		return false;
316	}
317	uint32_t* pixels = malloc(VIDEO_HORIZONTAL_PIXELS * VIDEO_VERTICAL_PIXELS * 4);
318	if (!pixels) {
319		PNGReadClose(png, info, end);
320		return false;
321	}
322
323	struct GBASerializedState* state = GBAAllocateState();
324	struct GBABundledState bundle = {
325		.state = state,
326		.extdata = extdata
327	};
328
329	PNGInstallChunkHandler(png, &bundle, _loadPNGChunkHandler, "gbAs gbAx");
330	bool success = PNGReadHeader(png, info);
331	success = success && PNGReadPixels(png, info, pixels, VIDEO_HORIZONTAL_PIXELS, VIDEO_VERTICAL_PIXELS, VIDEO_HORIZONTAL_PIXELS);
332	success = success && PNGReadFooter(png, end);
333	PNGReadClose(png, info, end);
334
335	if (success) {
336		struct GBAExtdataItem item = {
337			.size = VIDEO_HORIZONTAL_PIXELS * VIDEO_VERTICAL_PIXELS * 4,
338			.data = pixels,
339			.clean = free
340		};
341		GBAExtdataPut(extdata, EXTDATA_SCREENSHOT, &item);
342	} else {
343		free(pixels);
344		GBADeallocateState(state);
345		return 0;
346	}
347	return state;
348}
349#endif
350
351bool GBASaveState(struct GBAThread* threadContext, struct VDir* dir, int slot, int flags) {
352	struct VFile* vf = GBAGetState(threadContext->gba, dir, slot, true);
353	if (!vf) {
354		return false;
355	}
356	bool success = GBASaveStateNamed(threadContext->gba, vf, flags);
357	vf->close(vf);
358	if (success) {
359#if SAVESTATE_DEBUG
360		vf = GBAGetState(threadContext->gba, dir, slot, false);
361		if (vf) {
362			struct GBA* backup = anonymousMemoryMap(sizeof(*backup));
363			memcpy(backup, threadContext->gba, sizeof(*backup));
364			memset(threadContext->gba->memory.io, 0, sizeof(threadContext->gba->memory.io));
365			memset(threadContext->gba->timers, 0, sizeof(threadContext->gba->timers));
366			GBALoadStateNamed(threadContext->gba, vf, flags);
367			if (memcmp(backup, threadContext->gba, sizeof(*backup))) {
368				char suffix[16] = { '\0' };
369				struct VFile* vf2;
370				snprintf(suffix, sizeof(suffix), ".dump.0.%d", slot);
371				vf2 = VDirOptionalOpenFile(dir, threadContext->gba->activeFile, "savestate", suffix, write ? (O_CREAT | O_TRUNC | O_RDWR) : O_RDONLY);
372				if (vf2) {
373					vf2->write(vf2, backup, sizeof(*backup));
374					vf2->close(vf2);
375				}
376				snprintf(suffix, sizeof(suffix), ".dump.1.%d", slot);
377				vf2 = VDirOptionalOpenFile(dir, threadContext->gba->activeFile, "savestate", suffix, write ? (O_CREAT | O_TRUNC | O_RDWR) : O_RDONLY);
378				if (vf2) {
379					vf2->write(vf2, threadContext->gba, sizeof(*threadContext->gba));
380					vf2->close(vf2);
381				}
382			}
383			mappedMemoryFree(backup, sizeof(*backup));
384			vf->close(vf);
385		}
386#endif
387		GBALog(threadContext->gba, GBA_LOG_STATUS, "State %i saved", slot);
388	} else {
389		GBALog(threadContext->gba, GBA_LOG_STATUS, "State %i failed to save", slot);
390	}
391
392	return success;
393}
394
395bool GBALoadState(struct GBAThread* threadContext, struct VDir* dir, int slot, int flags) {
396	struct VFile* vf = GBAGetState(threadContext->gba, dir, slot, false);
397	if (!vf) {
398		return false;
399	}
400	threadContext->rewindBufferSize = 0;
401	bool success = GBALoadStateNamed(threadContext->gba, vf, flags);
402	vf->close(vf);
403	if (success) {
404		GBALog(threadContext->gba, GBA_LOG_STATUS, "State %i loaded", slot);
405	} else {
406		GBALog(threadContext->gba, GBA_LOG_STATUS, "State %i failed to load", slot);
407	}
408	return success;
409}
410
411bool GBASaveStateNamed(struct GBA* gba, struct VFile* vf, int flags) {
412	struct GBAExtdata extdata;
413	GBAExtdataInit(&extdata);
414	if (flags & SAVESTATE_SAVEDATA) {
415		// TODO: A better way to do this would be nice
416		void* sram = malloc(SIZE_CART_FLASH1M);
417		struct VFile* svf = VFileFromMemory(sram, SIZE_CART_FLASH1M);
418		if (GBASavedataClone(&gba->memory.savedata, svf)) {
419			struct GBAExtdataItem item = {
420				.size = svf->seek(svf, 0, SEEK_CUR),
421				.data = sram,
422				.clean = free
423			};
424			GBAExtdataPut(&extdata, EXTDATA_SAVEDATA, &item);
425		} else {
426			free(sram);
427		}
428		svf->close(svf);
429	}
430	struct VFile* cheatVf = 0;
431	if (flags & SAVESTATE_CHEATS && gba->cpu->components && gba->cpu->components[GBA_COMPONENT_CHEAT_DEVICE]) {
432		struct GBACheatDevice* device = (struct GBACheatDevice*) gba->cpu->components[GBA_COMPONENT_CHEAT_DEVICE];
433		cheatVf = VFileMemChunk(0, 0);
434		if (cheatVf) {
435			GBACheatSaveFile(device, cheatVf);
436			struct GBAExtdataItem item = {
437				.size = cheatVf->size(cheatVf),
438				.data = cheatVf->map(cheatVf, cheatVf->size(cheatVf), MAP_READ),
439				.clean = 0
440			};
441			GBAExtdataPut(&extdata, EXTDATA_CHEATS, &item);
442		}
443	};
444#ifdef USE_PNG
445	if (!(flags & SAVESTATE_SCREENSHOT)) {
446#else
447	UNUSED(flags);
448#endif
449		vf->truncate(vf, sizeof(struct GBASerializedState));
450		struct GBASerializedState* state = vf->map(vf, sizeof(struct GBASerializedState), MAP_WRITE);
451		if (!state) {
452			GBAExtdataDeinit(&extdata);
453			if (cheatVf) {
454				cheatVf->close(cheatVf);
455			}
456			return false;
457		}
458		GBASerialize(gba, state);
459		vf->unmap(vf, state, sizeof(struct GBASerializedState));
460		vf->seek(vf, sizeof(struct GBASerializedState), SEEK_SET);
461		GBAExtdataSerialize(&extdata, vf);
462		GBAExtdataDeinit(&extdata);
463		if (cheatVf) {
464			cheatVf->close(cheatVf);
465		}
466		return true;
467#ifdef USE_PNG
468	}
469	else {
470		bool success = _savePNGState(gba, vf, &extdata);
471		GBAExtdataDeinit(&extdata);
472		return success;
473	}
474#endif
475	GBAExtdataDeinit(&extdata);
476	return false;
477}
478
479struct GBASerializedState* GBAExtractState(struct VFile* vf, struct GBAExtdata* extdata) {
480#ifdef USE_PNG
481	if (isPNG(vf)) {
482		return _loadPNGState(vf, extdata);
483	}
484#endif
485	vf->seek(vf, 0, SEEK_SET);
486	if (vf->size(vf) < (ssize_t) sizeof(struct GBASerializedState)) {
487		return false;
488	}
489	struct GBASerializedState* state = GBAAllocateState();
490	if (vf->read(vf, state, sizeof(*state)) != sizeof(*state)) {
491		GBADeallocateState(state);
492		return 0;
493	}
494	if (extdata) {
495		GBAExtdataDeserialize(extdata, vf);
496	}
497	return state;
498}
499
500bool GBALoadStateNamed(struct GBA* gba, struct VFile* vf, int flags) {
501	struct GBAExtdata extdata;
502	GBAExtdataInit(&extdata);
503	struct GBASerializedState* state = GBAExtractState(vf, &extdata);
504	if (!state) {
505		return false;
506	}
507	bool success = GBADeserialize(gba, state);
508	GBADeallocateState(state);
509
510	struct GBAExtdataItem item;
511	if (flags & SAVESTATE_SCREENSHOT && GBAExtdataGet(&extdata, EXTDATA_SCREENSHOT, &item)) {
512		if (item.size >= VIDEO_HORIZONTAL_PIXELS * VIDEO_VERTICAL_PIXELS * 4) {
513			gba->video.renderer->putPixels(gba->video.renderer, VIDEO_HORIZONTAL_PIXELS, item.data);
514			GBASyncForceFrame(gba->sync);
515		} else {
516			GBALog(gba, GBA_LOG_WARN, "Savestate includes invalid screenshot");
517		}
518	}
519	if (flags & SAVESTATE_SAVEDATA && GBAExtdataGet(&extdata, EXTDATA_SAVEDATA, &item)) {
520		struct VFile* svf = VFileFromMemory(item.data, item.size);
521		if (svf) {
522			GBASavedataLoad(&gba->memory.savedata, svf);
523			svf->close(svf);
524		}
525	}
526	if (flags & SAVESTATE_CHEATS && gba->cpu->components && gba->cpu->components[GBA_COMPONENT_CHEAT_DEVICE] && GBAExtdataGet(&extdata, EXTDATA_CHEATS, &item)) {
527		if (item.size) {
528			struct GBACheatDevice* device = (struct GBACheatDevice*) gba->cpu->components[GBA_COMPONENT_CHEAT_DEVICE];
529			struct VFile* svf = VFileFromMemory(item.data, item.size);
530			if (svf) {
531				GBACheatDeviceClear(device);
532				GBACheatParseFile(device, svf);
533				svf->close(svf);
534			}
535		}
536	}
537	GBAExtdataDeinit(&extdata);
538	return success;
539}
540
541bool GBAExtdataInit(struct GBAExtdata* extdata) {
542	memset(extdata->data, 0, sizeof(extdata->data));
543	return true;
544}
545
546void GBAExtdataDeinit(struct GBAExtdata* extdata) {
547	size_t i;
548	for (i = 1; i < EXTDATA_MAX; ++i) {
549		if (extdata->data[i].data && extdata->data[i].clean) {
550			extdata->data[i].clean(extdata->data[i].data);
551		}
552	}
553}
554
555void GBAExtdataPut(struct GBAExtdata* extdata, enum GBAExtdataTag tag, struct GBAExtdataItem* item) {
556	if (tag == EXTDATA_NONE || tag >= EXTDATA_MAX) {
557		return;
558	}
559
560	if (extdata->data[tag].data && extdata->data[tag].clean) {
561		extdata->data[tag].clean(extdata->data[tag].data);
562	}
563	extdata->data[tag] = *item;
564}
565
566bool GBAExtdataGet(struct GBAExtdata* extdata, enum GBAExtdataTag tag, struct GBAExtdataItem* item) {
567	if (tag == EXTDATA_NONE || tag >= EXTDATA_MAX) {
568		return false;
569	}
570
571	*item = extdata->data[tag];
572	return true;
573}
574
575bool GBAExtdataSerialize(struct GBAExtdata* extdata, struct VFile* vf) {
576	ssize_t position = vf->seek(vf, 0, SEEK_CUR);
577	ssize_t size = 2;
578	size_t i = 0;
579	for (i = 1; i < EXTDATA_MAX; ++i) {
580		if (extdata->data[i].data) {
581			size += sizeof(uint64_t) * 2;
582		}
583	}
584	if (size == 2) {
585		return true;
586	}
587	struct GBAExtdataHeader* header = malloc(size);
588	position += size;
589
590	size_t j;
591	for (i = 1, j = 0; i < EXTDATA_MAX; ++i) {
592		if (extdata->data[i].data) {
593			STORE_32(i, offsetof(struct GBAExtdataHeader, tag), &header[j]);
594			STORE_32(extdata->data[i].size, offsetof(struct GBAExtdataHeader, size), &header[j]);
595			STORE_64(position, offsetof(struct GBAExtdataHeader, offset), &header[j]);
596			position += extdata->data[i].size;
597			++j;
598		}
599	}
600	header[j].tag = 0;
601	header[j].size = 0;
602	header[j].offset = 0;
603
604	if (vf->write(vf, header, size) != size) {
605		free(header);
606		return false;
607	}
608	free(header);
609
610	for (i = 1; i < EXTDATA_MAX; ++i) {
611		if (extdata->data[i].data) {
612			if (vf->write(vf, extdata->data[i].data, extdata->data[i].size) != extdata->data[i].size) {
613				return false;
614			}
615		}
616	}
617	return true;
618}
619
620bool GBAExtdataDeserialize(struct GBAExtdata* extdata, struct VFile* vf) {
621	while (true) {
622		struct GBAExtdataHeader buffer, header;
623		if (vf->read(vf, &buffer, sizeof(buffer)) != sizeof(buffer)) {
624			return false;
625		}
626		LOAD_32(header.tag, 0, &buffer.tag);
627		LOAD_32(header.size, 0, &buffer.size);
628		LOAD_64(header.offset, 0, &buffer.offset);
629
630		if (header.tag == EXTDATA_NONE) {
631			break;
632		}
633		if (header.tag >= EXTDATA_MAX) {
634			continue;
635		}
636		ssize_t position = vf->seek(vf, 0, SEEK_CUR);
637		if (vf->seek(vf, header.offset, SEEK_SET) < 0) {
638			return false;
639		}
640		struct GBAExtdataItem item = {
641			.data = malloc(header.size),
642			.size = header.size,
643			.clean = free
644		};
645		if (!item.data) {
646			continue;
647		}
648		if (vf->read(vf, item.data, header.size) != header.size) {
649			free(item.data);
650			continue;
651		}
652		GBAExtdataPut(extdata, header.tag, &item);
653		vf->seek(vf, position, SEEK_SET);
654	};
655	return true;
656}
657
658struct GBASerializedState* GBAAllocateState(void) {
659	return anonymousMemoryMap(sizeof(struct GBASerializedState));
660}
661
662void GBADeallocateState(struct GBASerializedState* state) {
663	mappedMemoryFree(state, sizeof(struct GBASerializedState));
664}
665
666void GBARecordFrame(struct GBAThread* thread) {
667	int offset = thread->rewindBufferWriteOffset;
668	struct GBASerializedState* state = thread->rewindBuffer[offset];
669	if (!state) {
670		state = GBAAllocateState();
671		thread->rewindBuffer[offset] = state;
672	}
673	GBASerialize(thread->gba, state);
674
675	if (thread->rewindScreenBuffer) {
676		unsigned stride;
677		const uint8_t* pixels = 0;
678		thread->gba->video.renderer->getPixels(thread->gba->video.renderer, &stride, (const void**) &pixels);
679		if (pixels) {
680			size_t y;
681			for (y = 0; y < VIDEO_VERTICAL_PIXELS; ++y) {
682				memcpy(&thread->rewindScreenBuffer[(offset * VIDEO_VERTICAL_PIXELS + y) * VIDEO_HORIZONTAL_PIXELS * BYTES_PER_PIXEL], &pixels[y * stride * BYTES_PER_PIXEL], VIDEO_HORIZONTAL_PIXELS * BYTES_PER_PIXEL);
683			}
684		}
685	}
686	thread->rewindBufferSize = thread->rewindBufferSize == thread->rewindBufferCapacity ? thread->rewindBufferCapacity : thread->rewindBufferSize + 1;
687	thread->rewindBufferWriteOffset = (offset + 1) % thread->rewindBufferCapacity;
688}
689
690void GBARewindSettingsChanged(struct GBAThread* threadContext, int newCapacity, int newInterval) {
691	if (newCapacity == threadContext->rewindBufferCapacity && newInterval == threadContext->rewindBufferInterval) {
692		return;
693	}
694	threadContext->rewindBufferInterval = newInterval;
695	threadContext->rewindBufferNext = threadContext->rewindBufferInterval;
696	threadContext->rewindBufferSize = 0;
697	if (threadContext->rewindBuffer) {
698		int i;
699		for (i = 0; i < threadContext->rewindBufferCapacity; ++i) {
700			GBADeallocateState(threadContext->rewindBuffer[i]);
701		}
702		free(threadContext->rewindBuffer);
703		free(threadContext->rewindScreenBuffer);
704	}
705	threadContext->rewindBufferCapacity = newCapacity;
706	if (threadContext->rewindBufferCapacity > 0) {
707		threadContext->rewindBuffer = calloc(threadContext->rewindBufferCapacity, sizeof(struct GBASerializedState*));
708		threadContext->rewindScreenBuffer = calloc(threadContext->rewindBufferCapacity, VIDEO_VERTICAL_PIXELS * VIDEO_HORIZONTAL_PIXELS * BYTES_PER_PIXEL);
709	} else {
710		threadContext->rewindBuffer = 0;
711		threadContext->rewindScreenBuffer = 0;
712	}
713}
714
715int GBARewind(struct GBAThread* thread, int nStates) {
716	if (nStates > thread->rewindBufferSize || nStates < 0) {
717		nStates = thread->rewindBufferSize;
718	}
719	if (nStates == 0) {
720		return 0;
721	}
722	int offset = thread->rewindBufferWriteOffset - nStates;
723	if (offset < 0) {
724		offset += thread->rewindBufferCapacity;
725	}
726	struct GBASerializedState* state = thread->rewindBuffer[offset];
727	if (!state) {
728		return 0;
729	}
730	thread->rewindBufferSize -= nStates;
731	thread->rewindBufferWriteOffset = offset;
732	GBADeserialize(thread->gba, state);
733	if (thread->rewindScreenBuffer) {
734		thread->gba->video.renderer->putPixels(thread->gba->video.renderer, VIDEO_HORIZONTAL_PIXELS, &thread->rewindScreenBuffer[offset * VIDEO_HORIZONTAL_PIXELS * VIDEO_VERTICAL_PIXELS * BYTES_PER_PIXEL]);
735	}
736	return nStates;
737}
738
739void GBARewindAll(struct GBAThread* thread) {
740	GBARewind(thread, thread->rewindBufferSize);
741}
742
743void GBATakeScreenshot(struct GBA* gba, struct VDir* dir) {
744#ifdef USE_PNG
745	unsigned stride;
746	const void* pixels = 0;
747	char basename[PATH_MAX];
748	separatePath(gba->activeFile, 0, basename, 0);
749	struct VFile* vf = VDirFindNextAvailable(dir, basename, "-", ".png", O_CREAT | O_TRUNC | O_WRONLY);
750	bool success = false;
751	if (vf) {
752		gba->video.renderer->getPixels(gba->video.renderer, &stride, &pixels);
753		png_structp png = PNGWriteOpen(vf);
754		png_infop info = PNGWriteHeader(png, VIDEO_HORIZONTAL_PIXELS, VIDEO_VERTICAL_PIXELS);
755		success = PNGWritePixels(png, VIDEO_HORIZONTAL_PIXELS, VIDEO_VERTICAL_PIXELS, stride, pixels);
756		PNGWriteClose(png, info);
757		vf->close(vf);
758	}
759	if (success) {
760		GBALog(gba, GBA_LOG_STATUS, "Screenshot saved");
761		return;
762	}
763#else
764	UNUSED(dir);
765#endif
766	GBALog(gba, GBA_LOG_STATUS, "Failed to take screenshot");
767}