all repos — mgba @ 1b6531e32044481feeb0c631ef01bc61d5ccecc6

mGBA Game Boy Advance Emulator

src/gb/memory.c (view raw)

  1/* Copyright (c) 2013-2016 Jeffrey Pfau
  2 *
  3 * This Source Code Form is subject to the terms of the Mozilla Public
  4 * License, v. 2.0. If a copy of the MPL was not distributed with this
  5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
  6#include <mgba/internal/gb/memory.h>
  7
  8#include <mgba/core/interface.h>
  9#include <mgba/internal/gb/gb.h>
 10#include <mgba/internal/gb/io.h>
 11#include <mgba/internal/gb/mbc.h>
 12#include <mgba/internal/gb/serialize.h>
 13#include <mgba/internal/lr35902/lr35902.h>
 14
 15#include <mgba-util/memory.h>
 16
 17mLOG_DEFINE_CATEGORY(GB_MEM, "GB Memory", "gb.memory");
 18
 19static void _pristineCow(struct GB* gba);
 20
 21static uint8_t GBFastLoad8(struct LR35902Core* cpu, uint16_t address) {
 22	if (UNLIKELY(address >= cpu->memory.activeRegionEnd)) {
 23		cpu->memory.setActiveRegion(cpu, address);
 24		return cpu->memory.cpuLoad8(cpu, address);
 25	}
 26	return cpu->memory.activeRegion[address & cpu->memory.activeMask];
 27}
 28
 29static void GBSetActiveRegion(struct LR35902Core* cpu, uint16_t address) {
 30	struct GB* gb = (struct GB*) cpu->master;
 31	struct GBMemory* memory = &gb->memory;
 32	switch (address >> 12) {
 33	case GB_REGION_CART_BANK0:
 34	case GB_REGION_CART_BANK0 + 1:
 35	case GB_REGION_CART_BANK0 + 2:
 36	case GB_REGION_CART_BANK0 + 3:
 37		cpu->memory.cpuLoad8 = GBFastLoad8;
 38		cpu->memory.activeRegion = memory->romBase;
 39		cpu->memory.activeRegionEnd = GB_BASE_CART_BANK1;
 40		cpu->memory.activeMask = GB_SIZE_CART_BANK0 - 1;
 41		break;
 42	case GB_REGION_CART_BANK1:
 43	case GB_REGION_CART_BANK1 + 1:
 44	case GB_REGION_CART_BANK1 + 2:
 45	case GB_REGION_CART_BANK1 + 3:
 46		cpu->memory.cpuLoad8 = GBFastLoad8;
 47		cpu->memory.activeRegion = memory->romBank;
 48		cpu->memory.activeRegionEnd = GB_BASE_VRAM;
 49		cpu->memory.activeMask = GB_SIZE_CART_BANK0 - 1;
 50		break;
 51	default:
 52		cpu->memory.cpuLoad8 = GBLoad8;
 53		break;
 54	}
 55}
 56
 57static void _GBMemoryDMAService(struct mTiming* timing, void* context, uint32_t cyclesLate);
 58static void _GBMemoryHDMAService(struct mTiming* timing, void* context, uint32_t cyclesLate);
 59
 60void GBMemoryInit(struct GB* gb) {
 61	struct LR35902Core* cpu = gb->cpu;
 62	cpu->memory.cpuLoad8 = GBLoad8;
 63	cpu->memory.load8 = GBLoad8;
 64	cpu->memory.store8 = GBStore8;
 65	cpu->memory.setActiveRegion = GBSetActiveRegion;
 66
 67	gb->memory.wram = 0;
 68	gb->memory.wramBank = 0;
 69	gb->memory.rom = 0;
 70	gb->memory.romBank = 0;
 71	gb->memory.romSize = 0;
 72	gb->memory.sram = 0;
 73	gb->memory.mbcType = GB_MBC_AUTODETECT;
 74	gb->memory.mbc = 0;
 75
 76	gb->memory.rtc = NULL;
 77
 78	GBIOInit(gb);
 79}
 80
 81void GBMemoryDeinit(struct GB* gb) {
 82	mappedMemoryFree(gb->memory.wram, GB_SIZE_WORKING_RAM);
 83	if (gb->memory.rom) {
 84		mappedMemoryFree(gb->memory.rom, gb->memory.romSize);
 85	}
 86}
 87
 88void GBMemoryReset(struct GB* gb) {
 89	if (gb->memory.wram) {
 90		mappedMemoryFree(gb->memory.wram, GB_SIZE_WORKING_RAM);
 91	}
 92	gb->memory.wram = anonymousMemoryMap(GB_SIZE_WORKING_RAM);
 93	if (gb->model >= GB_MODEL_CGB) {
 94		uint32_t* base = (uint32_t*) gb->memory.wram;
 95		size_t i;
 96		uint32_t pattern = 0;
 97		for (i = 0; i < GB_SIZE_WORKING_RAM / 4; i += 4) {
 98			if ((i & 0x1FF) == 0) {
 99				pattern = ~pattern;
100			}
101			base[i + 0] = pattern;
102			base[i + 1] = pattern;
103			base[i + 2] = ~pattern;
104			base[i + 3] = ~pattern;
105		}
106	}
107	GBMemorySwitchWramBank(&gb->memory, 1);
108	gb->memory.romBank = &gb->memory.rom[GB_SIZE_CART_BANK0];
109	gb->memory.currentBank = 1;
110	gb->memory.sramCurrentBank = 0;
111
112	gb->memory.ime = false;
113	gb->memory.ie = 0;
114
115	gb->memory.dmaRemaining = 0;
116	gb->memory.dmaSource = 0;
117	gb->memory.dmaDest = 0;
118	gb->memory.hdmaRemaining = 0;
119	gb->memory.hdmaSource = 0;
120	gb->memory.hdmaDest = 0;
121	gb->memory.isHdma = false;
122
123
124	gb->memory.dmaEvent.context = gb;
125	gb->memory.dmaEvent.name = "GB DMA";
126	gb->memory.dmaEvent.callback = _GBMemoryDMAService;
127	gb->memory.dmaEvent.priority = 0x40;
128	gb->memory.hdmaEvent.context = gb;
129	gb->memory.hdmaEvent.name = "GB HDMA";
130	gb->memory.hdmaEvent.callback = _GBMemoryHDMAService;
131	gb->memory.hdmaEvent.priority = 0x41;
132
133	gb->memory.sramAccess = false;
134	gb->memory.rtcAccess = false;
135	gb->memory.activeRtcReg = 0;
136	gb->memory.rtcLatched = false;
137	memset(&gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
138
139	memset(&gb->memory.hram, 0, sizeof(gb->memory.hram));
140	memset(&gb->memory.mbcState, 0, sizeof(gb->memory.mbcState));
141
142	GBMBCInit(gb);
143	gb->memory.sramBank = gb->memory.sram;
144
145	if (!gb->memory.wram) {
146		GBMemoryDeinit(gb);
147	}
148}
149
150void GBMemorySwitchWramBank(struct GBMemory* memory, int bank) {
151	bank &= 7;
152	if (!bank) {
153		bank = 1;
154	}
155	memory->wramBank = &memory->wram[GB_SIZE_WORKING_RAM_BANK0 * bank];
156	memory->wramCurrentBank = bank;
157}
158
159uint8_t GBLoad8(struct LR35902Core* cpu, uint16_t address) {
160	struct GB* gb = (struct GB*) cpu->master;
161	struct GBMemory* memory = &gb->memory;
162	switch (address >> 12) {
163	case GB_REGION_CART_BANK0:
164	case GB_REGION_CART_BANK0 + 1:
165	case GB_REGION_CART_BANK0 + 2:
166	case GB_REGION_CART_BANK0 + 3:
167		return memory->romBase[address & (GB_SIZE_CART_BANK0 - 1)];
168	case GB_REGION_CART_BANK1:
169	case GB_REGION_CART_BANK1 + 1:
170	case GB_REGION_CART_BANK1 + 2:
171	case GB_REGION_CART_BANK1 + 3:
172		return memory->romBank[address & (GB_SIZE_CART_BANK0 - 1)];
173	case GB_REGION_VRAM:
174	case GB_REGION_VRAM + 1:
175		return gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)];
176	case GB_REGION_EXTERNAL_RAM:
177	case GB_REGION_EXTERNAL_RAM + 1:
178		if (memory->rtcAccess) {
179			return memory->rtcRegs[memory->activeRtcReg];
180		} else if (memory->sramAccess) {
181			return memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)];
182		} else if (memory->mbcType == GB_MBC7) {
183			return GBMBC7Read(memory, address);
184		} else if (memory->mbcType == GB_HuC3) {
185			return 0x01; // TODO: Is this supposed to be the current SRAM bank?
186		}
187		return 0xFF;
188	case GB_REGION_WORKING_RAM_BANK0:
189	case GB_REGION_WORKING_RAM_BANK0 + 2:
190		return memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
191	case GB_REGION_WORKING_RAM_BANK1:
192		return memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
193	default:
194		if (address < GB_BASE_OAM) {
195			return memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
196		}
197		if (address < GB_BASE_UNUSABLE) {
198			if (gb->video.mode < 2) {
199				return gb->video.oam.raw[address & 0xFF];
200			}
201			return 0xFF;
202		}
203		if (address < GB_BASE_IO) {
204			mLOG(GB_MEM, GAME_ERROR, "Attempt to read from unusable memory: %04X", address);
205			return 0xFF;
206		}
207		if (address < GB_BASE_HRAM) {
208			return GBIORead(gb, address & (GB_SIZE_IO - 1));
209		}
210		if (address < GB_BASE_IE) {
211			return memory->hram[address & GB_SIZE_HRAM];
212		}
213		return GBIORead(gb, REG_IE);
214	}
215}
216
217void GBStore8(struct LR35902Core* cpu, uint16_t address, int8_t value) {
218	struct GB* gb = (struct GB*) cpu->master;
219	struct GBMemory* memory = &gb->memory;
220	switch (address >> 12) {
221	case GB_REGION_CART_BANK0:
222	case GB_REGION_CART_BANK0 + 1:
223	case GB_REGION_CART_BANK0 + 2:
224	case GB_REGION_CART_BANK0 + 3:
225	case GB_REGION_CART_BANK1:
226	case GB_REGION_CART_BANK1 + 1:
227	case GB_REGION_CART_BANK1 + 2:
228	case GB_REGION_CART_BANK1 + 3:
229		memory->mbc(gb, address, value);
230		cpu->memory.setActiveRegion(cpu, cpu->pc);
231		return;
232	case GB_REGION_VRAM:
233	case GB_REGION_VRAM + 1:
234		gb->video.renderer->writeVRAM(gb->video.renderer, (address & (GB_SIZE_VRAM_BANK0 - 1)) | (GB_SIZE_VRAM_BANK0 * gb->video.vramCurrentBank));
235		gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)] = value;
236		return;
237	case GB_REGION_EXTERNAL_RAM:
238	case GB_REGION_EXTERNAL_RAM + 1:
239		if (memory->rtcAccess) {
240			memory->rtcRegs[memory->activeRtcReg] = value;
241		} else if (memory->sramAccess) {
242			memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)] = value;
243		} else if (memory->mbcType == GB_MBC7) {
244			GBMBC7Write(memory, address, value);
245		}
246		gb->sramDirty |= GB_SRAM_DIRT_NEW;
247		return;
248	case GB_REGION_WORKING_RAM_BANK0:
249	case GB_REGION_WORKING_RAM_BANK0 + 2:
250		memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
251		return;
252	case GB_REGION_WORKING_RAM_BANK1:
253		memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
254		return;
255	default:
256		if (address < GB_BASE_OAM) {
257			memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
258		} else if (address < GB_BASE_UNUSABLE) {
259			if (gb->video.mode < 2) {
260				gb->video.oam.raw[address & 0xFF] = value;
261			}
262		} else if (address < GB_BASE_IO) {
263			mLOG(GB_MEM, GAME_ERROR, "Attempt to write to unusable memory: %04X:%02X", address, value);
264		} else if (address < GB_BASE_HRAM) {
265			GBIOWrite(gb, address & (GB_SIZE_IO - 1), value);
266		} else if (address < GB_BASE_IE) {
267			memory->hram[address & GB_SIZE_HRAM] = value;
268		} else {
269			GBIOWrite(gb, REG_IE, value);
270		}
271	}
272}
273uint8_t GBView8(struct LR35902Core* cpu, uint16_t address, int segment) {
274	struct GB* gb = (struct GB*) cpu->master;
275	struct GBMemory* memory = &gb->memory;
276	switch (address >> 12) {
277	case GB_REGION_CART_BANK0:
278	case GB_REGION_CART_BANK0 + 1:
279	case GB_REGION_CART_BANK0 + 2:
280	case GB_REGION_CART_BANK0 + 3:
281		return memory->romBase[address & (GB_SIZE_CART_BANK0 - 1)];
282	case GB_REGION_CART_BANK1:
283	case GB_REGION_CART_BANK1 + 1:
284	case GB_REGION_CART_BANK1 + 2:
285	case GB_REGION_CART_BANK1 + 3:
286		if (segment < 0) {
287			return memory->romBank[address & (GB_SIZE_CART_BANK0 - 1)];
288		} else if ((size_t) segment * GB_SIZE_CART_BANK0 < memory->romSize) {
289			return memory->rom[(address & (GB_SIZE_CART_BANK0 - 1)) + segment * GB_SIZE_CART_BANK0];
290		} else {
291			return 0xFF;
292		}
293	case GB_REGION_VRAM:
294	case GB_REGION_VRAM + 1:
295		if (segment < 0) {
296			return gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)];
297		} else if (segment < 2) {
298			return gb->video.vram[(address & (GB_SIZE_VRAM_BANK0 - 1)) + segment *GB_SIZE_VRAM_BANK0];
299		} else {
300			return 0xFF;
301		}
302	case GB_REGION_EXTERNAL_RAM:
303	case GB_REGION_EXTERNAL_RAM + 1:
304		if (memory->rtcAccess) {
305			return memory->rtcRegs[memory->activeRtcReg];
306		} else if (memory->sramAccess) {
307			if (segment < 0) {
308				return memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)];
309			} else if ((size_t) segment * GB_SIZE_EXTERNAL_RAM < gb->sramSize) {
310				return memory->sram[(address & (GB_SIZE_EXTERNAL_RAM - 1)) + segment *GB_SIZE_EXTERNAL_RAM];
311			} else {
312				return 0xFF;
313			}
314		} else if (memory->mbcType == GB_MBC7) {
315			return GBMBC7Read(memory, address);
316		} else if (memory->mbcType == GB_HuC3) {
317			return 0x01; // TODO: Is this supposed to be the current SRAM bank?
318		}
319		return 0xFF;
320	case GB_REGION_WORKING_RAM_BANK0:
321	case GB_REGION_WORKING_RAM_BANK0 + 2:
322		return memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
323	case GB_REGION_WORKING_RAM_BANK1:
324		if (segment < 0) {
325			return memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
326		} else if (segment < 8) {
327			return memory->wram[(address & (GB_SIZE_WORKING_RAM_BANK0 - 1)) + segment *GB_SIZE_WORKING_RAM_BANK0];
328		} else {
329			return 0xFF;
330		}
331	default:
332		if (address < GB_BASE_OAM) {
333			return memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
334		}
335		if (address < GB_BASE_UNUSABLE) {
336			if (gb->video.mode < 2) {
337				return gb->video.oam.raw[address & 0xFF];
338			}
339			return 0xFF;
340		}
341		if (address < GB_BASE_IO) {
342			mLOG(GB_MEM, GAME_ERROR, "Attempt to read from unusable memory: %04X", address);
343			return 0xFF;
344		}
345		if (address < GB_BASE_HRAM) {
346			return GBIORead(gb, address & (GB_SIZE_IO - 1));
347		}
348		if (address < GB_BASE_IE) {
349			return memory->hram[address & GB_SIZE_HRAM];
350		}
351		return GBIORead(gb, REG_IE);
352	}
353}
354
355void GBMemoryDMA(struct GB* gb, uint16_t base) {
356	if (base > 0xF100) {
357		return;
358	}
359	gb->cpu->memory.store8 = GBDMAStore8;
360	gb->cpu->memory.load8 = GBDMALoad8;
361	gb->cpu->memory.cpuLoad8 = GBDMALoad8;
362	mTimingSchedule(&gb->timing, &gb->memory.dmaEvent, 8);
363	if (gb->cpu->cycles + 8 < gb->cpu->nextEvent) {
364		gb->cpu->nextEvent = gb->cpu->cycles + 8;
365	}
366	gb->memory.dmaSource = base;
367	gb->memory.dmaDest = 0;
368	gb->memory.dmaRemaining = 0xA0;
369}
370
371void GBMemoryWriteHDMA5(struct GB* gb, uint8_t value) {
372	gb->memory.hdmaSource = gb->memory.io[REG_HDMA1] << 8;
373	gb->memory.hdmaSource |= gb->memory.io[REG_HDMA2];
374	gb->memory.hdmaDest = gb->memory.io[REG_HDMA3] << 8;
375	gb->memory.hdmaDest |= gb->memory.io[REG_HDMA4];
376	gb->memory.hdmaSource &= 0xFFF0;
377	if (gb->memory.hdmaSource >= 0x8000 && gb->memory.hdmaSource < 0xA000) {
378		mLOG(GB_MEM, GAME_ERROR, "Invalid HDMA source: %04X", gb->memory.hdmaSource);
379		return;
380	}
381	gb->memory.hdmaDest &= 0x1FF0;
382	gb->memory.hdmaDest |= 0x8000;
383	bool wasHdma = gb->memory.isHdma;
384	gb->memory.isHdma = value & 0x80;
385	if ((!wasHdma && !gb->memory.isHdma) || gb->video.mode == 0) {
386		gb->memory.hdmaRemaining = ((value & 0x7F) + 1) * 0x10;
387		gb->cpuBlocked = true;
388		mTimingSchedule(&gb->timing, &gb->memory.hdmaEvent, 0);
389		gb->cpu->nextEvent = gb->cpu->cycles;
390	}
391}
392
393void _GBMemoryDMAService(struct mTiming* timing, void* context, uint32_t cyclesLate) {
394	struct GB* gb = context;
395	uint8_t b = GBLoad8(gb->cpu, gb->memory.dmaSource);
396	// TODO: Can DMA write OAM during modes 2-3?
397	gb->video.oam.raw[gb->memory.dmaDest] = b;
398	++gb->memory.dmaSource;
399	++gb->memory.dmaDest;
400	--gb->memory.dmaRemaining;
401	if (gb->memory.dmaRemaining) {
402		mTimingSchedule(timing, &gb->memory.dmaEvent, 4 - cyclesLate);
403	} else {
404		gb->cpu->memory.store8 = GBStore8;
405		gb->cpu->memory.load8 = GBLoad8;
406	}
407}
408
409void _GBMemoryHDMAService(struct mTiming* timing, void* context, uint32_t cyclesLate) {
410	struct GB* gb = context;
411	gb->cpuBlocked = true;
412	uint8_t b = gb->cpu->memory.load8(gb->cpu, gb->memory.hdmaSource);
413	gb->cpu->memory.store8(gb->cpu, gb->memory.hdmaDest, b);
414	++gb->memory.hdmaSource;
415	++gb->memory.hdmaDest;
416	--gb->memory.hdmaRemaining;
417	if (gb->memory.hdmaRemaining) {
418		mTimingDeschedule(timing, &gb->memory.hdmaEvent);
419		mTimingSchedule(timing, &gb->memory.hdmaEvent, 2 - cyclesLate);
420	} else {
421		gb->cpuBlocked = false;
422		gb->memory.io[REG_HDMA1] = gb->memory.hdmaSource >> 8;
423		gb->memory.io[REG_HDMA2] = gb->memory.hdmaSource;
424		gb->memory.io[REG_HDMA3] = gb->memory.hdmaDest >> 8;
425		gb->memory.io[REG_HDMA4] = gb->memory.hdmaDest;
426		if (gb->memory.isHdma) {
427			--gb->memory.io[REG_HDMA5];
428			if (gb->memory.io[REG_HDMA5] == 0xFF) {
429				gb->memory.isHdma = false;
430			}
431		} else {
432			gb->memory.io[REG_HDMA5] = 0xFF;
433		}
434	}
435}
436
437struct OAMBlock {
438	uint16_t low;
439	uint16_t high;
440};
441
442static const struct OAMBlock _oamBlockDMG[] = {
443	{ 0xA000, 0xFE00 },
444	{ 0xA000, 0xFE00 },
445	{ 0xA000, 0xFE00 },
446	{ 0xA000, 0xFE00 },
447	{ 0x8000, 0xA000 },
448	{ 0xA000, 0xFE00 },
449	{ 0xA000, 0xFE00 },
450	{ 0xA000, 0xFE00 },
451};
452
453static const struct OAMBlock _oamBlockCGB[] = {
454	{ 0xA000, 0xC000 },
455	{ 0xA000, 0xC000 },
456	{ 0xA000, 0xC000 },
457	{ 0xA000, 0xC000 },
458	{ 0x8000, 0xA000 },
459	{ 0xA000, 0xC000 },
460	{ 0xC000, 0xFE00 },
461	{ 0xA000, 0xC000 },
462};
463
464uint8_t GBDMALoad8(struct LR35902Core* cpu, uint16_t address) {
465	struct GB* gb = (struct GB*) cpu->master;
466	struct GBMemory* memory = &gb->memory;
467	const struct OAMBlock* block = gb->model < GB_MODEL_CGB ? _oamBlockDMG : _oamBlockCGB;
468	block = &block[memory->dmaSource >> 13];
469	if (address >= block->low && address < block->high) {
470		return 0xFF;
471	}
472	if (address >= GB_BASE_OAM && address < GB_BASE_UNUSABLE) {
473		return 0xFF;
474	}
475	return GBLoad8(cpu, address);
476}
477
478void GBDMAStore8(struct LR35902Core* cpu, uint16_t address, int8_t value) {
479	struct GB* gb = (struct GB*) cpu->master;
480	struct GBMemory* memory = &gb->memory;
481	const struct OAMBlock* block = gb->model < GB_MODEL_CGB ? _oamBlockDMG : _oamBlockCGB;
482	block = &block[memory->dmaSource >> 13];
483	if (address >= block->low && address < block->high) {
484		return;
485	}
486	if (address >= GB_BASE_OAM && address < GB_BASE_UNUSABLE) {
487		return;
488	}
489	GBStore8(cpu, address, value);
490}
491
492void GBPatch8(struct LR35902Core* cpu, uint16_t address, int8_t value, int8_t* old, int segment) {
493	struct GB* gb = (struct GB*) cpu->master;
494	struct GBMemory* memory = &gb->memory;
495	int8_t oldValue = -1;
496
497	switch (address >> 12) {
498	case GB_REGION_CART_BANK0:
499	case GB_REGION_CART_BANK0 + 1:
500	case GB_REGION_CART_BANK0 + 2:
501	case GB_REGION_CART_BANK0 + 3:
502		_pristineCow(gb);
503		oldValue = memory->romBase[address & (GB_SIZE_CART_BANK0 - 1)];
504		memory->romBase[address & (GB_SIZE_CART_BANK0 - 1)] =  value;
505		break;
506	case GB_REGION_CART_BANK1:
507	case GB_REGION_CART_BANK1 + 1:
508	case GB_REGION_CART_BANK1 + 2:
509	case GB_REGION_CART_BANK1 + 3:
510		_pristineCow(gb);
511		if (segment < 0) {
512			oldValue = memory->romBank[address & (GB_SIZE_CART_BANK0 - 1)];
513			memory->romBank[address & (GB_SIZE_CART_BANK0 - 1)] = value;
514		} else if ((size_t) segment * GB_SIZE_CART_BANK0 < memory->romSize) {
515			oldValue = memory->rom[(address & (GB_SIZE_CART_BANK0 - 1)) + segment * GB_SIZE_CART_BANK0];
516			memory->rom[(address & (GB_SIZE_CART_BANK0 - 1)) + segment * GB_SIZE_CART_BANK0] = value;
517		} else {
518			return;
519		}
520		break;
521	case GB_REGION_VRAM:
522	case GB_REGION_VRAM + 1:
523		if (segment < 0) {
524			oldValue = gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)];
525			gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)] = value;
526			gb->video.renderer->writeVRAM(gb->video.renderer, (address & (GB_SIZE_VRAM_BANK0 - 1)) + GB_SIZE_VRAM_BANK0 * gb->video.vramCurrentBank);
527		} else if (segment < 2) {
528			oldValue = gb->video.vram[(address & (GB_SIZE_VRAM_BANK0 - 1)) + segment * GB_SIZE_VRAM_BANK0];
529			gb->video.vramBank[(address & (GB_SIZE_VRAM_BANK0 - 1)) + segment * GB_SIZE_VRAM_BANK0] = value;
530			gb->video.renderer->writeVRAM(gb->video.renderer, (address & (GB_SIZE_VRAM_BANK0 - 1)) + segment * GB_SIZE_VRAM_BANK0);
531		} else {
532			return;
533		}
534		break;
535	case GB_REGION_EXTERNAL_RAM:
536	case GB_REGION_EXTERNAL_RAM + 1:
537		mLOG(GB_MEM, STUB, "Unimplemented memory Patch8: 0x%08X", address);
538		return;
539	case GB_REGION_WORKING_RAM_BANK0:
540	case GB_REGION_WORKING_RAM_BANK0 + 2:
541		oldValue = memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
542		memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
543		break;
544	case GB_REGION_WORKING_RAM_BANK1:
545		if (segment < 0) {
546			oldValue = memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
547			memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
548		} else if (segment < 8) {
549			oldValue = memory->wram[(address & (GB_SIZE_WORKING_RAM_BANK0 - 1)) + segment * GB_SIZE_WORKING_RAM_BANK0];
550			memory->wram[(address & (GB_SIZE_WORKING_RAM_BANK0 - 1)) + segment * GB_SIZE_WORKING_RAM_BANK0] = value;
551		} else {
552			return;
553		}
554		break;
555	default:
556		if (address < GB_BASE_OAM) {
557			oldValue = memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
558			memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
559		} else if (address < GB_BASE_UNUSABLE) {
560			oldValue = gb->video.oam.raw[address & 0xFF];
561			gb->video.oam.raw[address & 0xFF] = value;
562		} else if (address < GB_BASE_HRAM) {
563			mLOG(GB_MEM, STUB, "Unimplemented memory Patch8: 0x%08X", address);
564			return;
565		} else if (address < GB_BASE_IE) {
566			oldValue = memory->hram[address & GB_SIZE_HRAM];
567			memory->hram[address & GB_SIZE_HRAM] = value;
568		} else {
569			mLOG(GB_MEM, STUB, "Unimplemented memory Patch8: 0x%08X", address);
570			return;
571		}
572	}
573	if (old) {
574		*old = oldValue;
575	}
576}
577
578void GBMemorySerialize(const struct GB* gb, struct GBSerializedState* state) {
579	const struct GBMemory* memory = &gb->memory;
580	memcpy(state->wram, memory->wram, GB_SIZE_WORKING_RAM);
581	memcpy(state->hram, memory->hram, GB_SIZE_HRAM);
582	STORE_16LE(memory->currentBank, 0, &state->memory.currentBank);
583	state->memory.wramCurrentBank = memory->wramCurrentBank;
584	state->memory.sramCurrentBank = memory->sramCurrentBank;
585
586	STORE_16LE(memory->dmaSource, 0, &state->memory.dmaSource);
587	STORE_16LE(memory->dmaDest, 0, &state->memory.dmaDest);
588
589	STORE_16LE(memory->hdmaSource, 0, &state->memory.hdmaSource);
590	STORE_16LE(memory->hdmaDest, 0, &state->memory.hdmaDest);
591
592	STORE_16LE(memory->hdmaRemaining, 0, &state->memory.hdmaRemaining);
593	state->memory.dmaRemaining = memory->dmaRemaining;
594	memcpy(state->memory.rtcRegs, memory->rtcRegs, sizeof(state->memory.rtcRegs));
595
596	STORE_32LE(memory->dmaEvent.when - mTimingCurrentTime(&gb->timing), 0, &state->memory.dmaNext);
597	STORE_32LE(memory->hdmaEvent.when - mTimingCurrentTime(&gb->timing), 0, &state->memory.hdmaNext);
598
599	GBSerializedMemoryFlags flags = 0;
600	flags = GBSerializedMemoryFlagsSetSramAccess(flags, memory->sramAccess);
601	flags = GBSerializedMemoryFlagsSetRtcAccess(flags, memory->rtcAccess);
602	flags = GBSerializedMemoryFlagsSetRtcLatched(flags, memory->rtcLatched);
603	flags = GBSerializedMemoryFlagsSetIme(flags, memory->ime);
604	flags = GBSerializedMemoryFlagsSetIsHdma(flags, memory->isHdma);
605	flags = GBSerializedMemoryFlagsSetActiveRtcReg(flags, memory->activeRtcReg);
606	STORE_16LE(flags, 0, &state->memory.flags);
607}
608
609void GBMemoryDeserialize(struct GB* gb, const struct GBSerializedState* state) {
610	struct GBMemory* memory = &gb->memory;
611	memcpy(memory->wram, state->wram, GB_SIZE_WORKING_RAM);
612	memcpy(memory->hram, state->hram, GB_SIZE_HRAM);
613	LOAD_16LE(memory->currentBank, 0, &state->memory.currentBank);
614	memory->wramCurrentBank = state->memory.wramCurrentBank;
615	memory->sramCurrentBank = state->memory.sramCurrentBank;
616
617	GBMBCSwitchBank(gb, memory->currentBank);
618	GBMemorySwitchWramBank(memory, memory->wramCurrentBank);
619	GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
620
621	LOAD_16LE(memory->dmaSource, 0, &state->memory.dmaSource);
622	LOAD_16LE(memory->dmaDest, 0, &state->memory.dmaDest);
623
624	LOAD_16LE(memory->hdmaSource, 0, &state->memory.hdmaSource);
625	LOAD_16LE(memory->hdmaDest, 0, &state->memory.hdmaDest);
626
627	LOAD_16LE(memory->hdmaRemaining, 0, &state->memory.hdmaRemaining);
628	memory->dmaRemaining = state->memory.dmaRemaining;
629	memcpy(memory->rtcRegs, state->memory.rtcRegs, sizeof(state->memory.rtcRegs));
630
631	uint32_t when;
632	LOAD_32LE(when, 0, &state->memory.dmaNext);
633	if (memory->dmaRemaining) {
634		mTimingSchedule(&gb->timing, &memory->dmaEvent, when);
635	}
636	LOAD_32LE(when, 0, &state->memory.hdmaNext);
637	if (memory->hdmaRemaining) {
638		mTimingSchedule(&gb->timing, &memory->hdmaEvent, when);
639	}
640
641	GBSerializedMemoryFlags flags;
642	LOAD_16LE(flags, 0, &state->memory.flags);
643	memory->sramAccess = GBSerializedMemoryFlagsGetSramAccess(flags);
644	memory->rtcAccess = GBSerializedMemoryFlagsGetRtcAccess(flags);
645	memory->rtcLatched = GBSerializedMemoryFlagsGetRtcLatched(flags);
646	memory->ime = GBSerializedMemoryFlagsGetIme(flags);
647	memory->isHdma = GBSerializedMemoryFlagsGetIsHdma(flags);
648	memory->activeRtcReg = GBSerializedMemoryFlagsGetActiveRtcReg(flags);
649}
650
651void _pristineCow(struct GB* gb) {
652	if (!gb->isPristine) {
653		return;
654	}
655	void* newRom = anonymousMemoryMap(GB_SIZE_CART_MAX);
656	memcpy(newRom, gb->memory.rom, gb->memory.romSize);
657	memset(((uint8_t*) newRom) + gb->memory.romSize, 0xFF, GB_SIZE_CART_MAX - gb->memory.romSize);
658	if (gb->memory.rom == gb->memory.romBase) {
659		gb->memory.romBase = newRom;
660	}
661	gb->memory.rom = newRom;
662	GBMBCSwitchBank(gb, gb->memory.currentBank);
663}