all repos — mgba @ 87d4dad893d5df04fac5575c12a1c7b82fc07a7b

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 "memory.h"
  7
  8#include "core/interface.h"
  9#include "gb/gb.h"
 10#include "gb/io.h"
 11#include "gb/mbc.h"
 12#include "gb/serialize.h"
 13
 14#include "util/memory.h"
 15
 16mLOG_DEFINE_CATEGORY(GB_MEM, "GB Memory");
 17
 18static void _pristineCow(struct GB* gba);
 19
 20static uint8_t GBFastLoad8(struct LR35902Core* cpu, uint16_t address) {
 21	if (UNLIKELY(address > cpu->memory.activeRegionEnd)) {
 22		cpu->memory.setActiveRegion(cpu, address);
 23		return cpu->memory.cpuLoad8(cpu, address);
 24	}
 25	return cpu->memory.activeRegion[address & cpu->memory.activeMask];
 26}
 27
 28static void GBSetActiveRegion(struct LR35902Core* cpu, uint16_t address) {
 29	struct GB* gb = (struct GB*) cpu->master;
 30	struct GBMemory* memory = &gb->memory;
 31	switch (address >> 12) {
 32	case GB_REGION_CART_BANK0:
 33	case GB_REGION_CART_BANK0 + 1:
 34	case GB_REGION_CART_BANK0 + 2:
 35	case GB_REGION_CART_BANK0 + 3:
 36		cpu->memory.cpuLoad8 = GBFastLoad8;
 37		cpu->memory.activeRegion = memory->romBase;
 38		cpu->memory.activeRegionEnd = GB_BASE_CART_BANK1;
 39		cpu->memory.activeMask = GB_SIZE_CART_BANK0 - 1;
 40		break;
 41	case GB_REGION_CART_BANK1:
 42	case GB_REGION_CART_BANK1 + 1:
 43	case GB_REGION_CART_BANK1 + 2:
 44	case GB_REGION_CART_BANK1 + 3:
 45		cpu->memory.cpuLoad8 = GBFastLoad8;
 46		cpu->memory.activeRegion = memory->romBank;
 47		cpu->memory.activeRegionEnd = GB_BASE_VRAM;
 48		cpu->memory.activeMask = GB_SIZE_CART_BANK0 - 1;
 49		break;
 50	default:
 51		cpu->memory.cpuLoad8 = GBLoad8;
 52		break;
 53	}
 54}
 55
 56static void _GBMemoryDMAService(struct GB* gb);
 57static void _GBMemoryHDMAService(struct GB* gb);
 58
 59void GBMemoryInit(struct GB* gb) {
 60	struct LR35902Core* cpu = gb->cpu;
 61	cpu->memory.cpuLoad8 = GBLoad8;
 62	cpu->memory.load8 = GBLoad8;
 63	cpu->memory.store8 = GBStore8;
 64	cpu->memory.setActiveRegion = GBSetActiveRegion;
 65
 66	gb->memory.wram = 0;
 67	gb->memory.wramBank = 0;
 68	gb->memory.rom = 0;
 69	gb->memory.romBank = 0;
 70	gb->memory.romSize = 0;
 71	gb->memory.sram = 0;
 72	gb->memory.mbcType = GB_MBC_NONE;
 73	gb->memory.mbc = 0;
 74
 75	gb->memory.rtc = NULL;
 76
 77	GBIOInit(gb);
 78}
 79
 80void GBMemoryDeinit(struct GB* gb) {
 81	mappedMemoryFree(gb->memory.wram, GB_SIZE_WORKING_RAM);
 82	if (gb->memory.rom) {
 83		mappedMemoryFree(gb->memory.rom, gb->memory.romSize);
 84	}
 85}
 86
 87void GBMemoryReset(struct GB* gb) {
 88	if (gb->memory.wram) {
 89		mappedMemoryFree(gb->memory.wram, GB_SIZE_WORKING_RAM);
 90	}
 91	gb->memory.wram = anonymousMemoryMap(GB_SIZE_WORKING_RAM);
 92	GBMemorySwitchWramBank(&gb->memory, 1);
 93	gb->memory.romBank = &gb->memory.rom[GB_SIZE_CART_BANK0];
 94	gb->memory.currentBank = 1;
 95	gb->memory.sramCurrentBank = 0;
 96
 97	gb->memory.ime = false;
 98	gb->memory.ie = 0;
 99
100	gb->memory.dmaNext = INT_MAX;
101	gb->memory.dmaRemaining = 0;
102	gb->memory.dmaSource = 0;
103	gb->memory.dmaDest = 0;
104	gb->memory.hdmaNext = INT_MAX;
105	gb->memory.hdmaRemaining = 0;
106	gb->memory.hdmaSource = 0;
107	gb->memory.hdmaDest = 0;
108	gb->memory.isHdma = false;
109
110	gb->memory.sramAccess = false;
111	gb->memory.rtcAccess = false;
112	gb->memory.activeRtcReg = 0;
113	gb->memory.rtcLatched = false;
114	memset(&gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
115
116	memset(&gb->memory.hram, 0, sizeof(gb->memory.hram));
117	memset(&gb->memory.mbcState, 0, sizeof(gb->memory.mbcState));
118
119	GBMBCInit(gb);
120	gb->memory.sramBank = gb->memory.sram;
121
122	if (!gb->memory.wram) {
123		GBMemoryDeinit(gb);
124	}
125}
126
127void GBMemorySwitchWramBank(struct GBMemory* memory, int bank) {
128	bank &= 7;
129	if (!bank) {
130		bank = 1;
131	}
132	memory->wramBank = &memory->wram[GB_SIZE_WORKING_RAM_BANK0 * bank];
133	memory->wramCurrentBank = bank;
134}
135
136uint8_t GBLoad8(struct LR35902Core* cpu, uint16_t address) {
137	struct GB* gb = (struct GB*) cpu->master;
138	struct GBMemory* memory = &gb->memory;
139	switch (address >> 12) {
140	case GB_REGION_CART_BANK0:
141	case GB_REGION_CART_BANK0 + 1:
142	case GB_REGION_CART_BANK0 + 2:
143	case GB_REGION_CART_BANK0 + 3:
144		return memory->romBase[address & (GB_SIZE_CART_BANK0 - 1)];
145	case GB_REGION_CART_BANK1:
146	case GB_REGION_CART_BANK1 + 1:
147	case GB_REGION_CART_BANK1 + 2:
148	case GB_REGION_CART_BANK1 + 3:
149		return memory->romBank[address & (GB_SIZE_CART_BANK0 - 1)];
150	case GB_REGION_VRAM:
151	case GB_REGION_VRAM + 1:
152		return gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)];
153	case GB_REGION_EXTERNAL_RAM:
154	case GB_REGION_EXTERNAL_RAM + 1:
155		if (memory->rtcAccess) {
156			return memory->rtcRegs[memory->activeRtcReg];
157		} else if (memory->sramAccess) {
158			return memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)];
159		} else if (memory->mbcType == GB_MBC7) {
160			return GBMBC7Read(memory, address);
161		} else if (memory->mbcType == GB_HuC3) {
162			return 0x01; // TODO: Is this supposed to be the current SRAM bank?
163		}
164		return 0xFF;
165	case GB_REGION_WORKING_RAM_BANK0:
166	case GB_REGION_WORKING_RAM_BANK0 + 2:
167		return memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
168	case GB_REGION_WORKING_RAM_BANK1:
169		return memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
170	default:
171		if (address < GB_BASE_OAM) {
172			return memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
173		}
174		if (address < GB_BASE_UNUSABLE) {
175			if (gb->video.mode < 2) {
176				return gb->video.oam.raw[address & 0xFF];
177			}
178			return 0xFF;
179		}
180		if (address < GB_BASE_IO) {
181			mLOG(GB_MEM, GAME_ERROR, "Attempt to read from unusable memory: %04X", address);
182			return 0xFF;
183		}
184		if (address < GB_BASE_HRAM) {
185			return GBIORead(gb, address & (GB_SIZE_IO - 1));
186		}
187		if (address < GB_BASE_IE) {
188			return memory->hram[address & GB_SIZE_HRAM];
189		}
190		return GBIORead(gb, REG_IE);
191	}
192}
193
194void GBStore8(struct LR35902Core* cpu, uint16_t address, int8_t value) {
195	struct GB* gb = (struct GB*) cpu->master;
196	struct GBMemory* memory = &gb->memory;
197	switch (address >> 12) {
198	case GB_REGION_CART_BANK0:
199	case GB_REGION_CART_BANK0 + 1:
200	case GB_REGION_CART_BANK0 + 2:
201	case GB_REGION_CART_BANK0 + 3:
202	case GB_REGION_CART_BANK1:
203	case GB_REGION_CART_BANK1 + 1:
204	case GB_REGION_CART_BANK1 + 2:
205	case GB_REGION_CART_BANK1 + 3:
206		memory->mbc(gb, address, value);
207		cpu->memory.setActiveRegion(cpu, cpu->pc);
208		return;
209	case GB_REGION_VRAM:
210	case GB_REGION_VRAM + 1:
211		// TODO: Block access in wrong modes
212		gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)] = value;
213		return;
214	case GB_REGION_EXTERNAL_RAM:
215	case GB_REGION_EXTERNAL_RAM + 1:
216		if (memory->rtcAccess) {
217			memory->rtcRegs[memory->activeRtcReg] = value;
218		} else if (memory->sramAccess) {
219			memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)] = value;
220		} else if (memory->mbcType == GB_MBC7) {
221			GBMBC7Write(memory, address, value);
222		}
223		return;
224	case GB_REGION_WORKING_RAM_BANK0:
225	case GB_REGION_WORKING_RAM_BANK0 + 2:
226		memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
227		return;
228	case GB_REGION_WORKING_RAM_BANK1:
229		memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
230		return;
231	default:
232		if (address < GB_BASE_OAM) {
233			memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
234		} else if (address < GB_BASE_UNUSABLE) {
235			if (gb->video.mode < 2) {
236				gb->video.oam.raw[address & 0xFF] = value;
237			}
238		} else if (address < GB_BASE_IO) {
239			mLOG(GB_MEM, GAME_ERROR, "Attempt to write to unusable memory: %04X:%02X", address, value);
240		} else if (address < GB_BASE_HRAM) {
241			GBIOWrite(gb, address & (GB_SIZE_IO - 1), value);
242		} else if (address < GB_BASE_IE) {
243			memory->hram[address & GB_SIZE_HRAM] = value;
244		} else {
245			GBIOWrite(gb, REG_IE, value);
246		}
247	}
248}
249uint8_t GBView8(struct LR35902Core* cpu, uint16_t address, int segment) {
250	struct GB* gb = (struct GB*) cpu->master;
251	struct GBMemory* memory = &gb->memory;
252	switch (address >> 12) {
253	case GB_REGION_CART_BANK0:
254	case GB_REGION_CART_BANK0 + 1:
255	case GB_REGION_CART_BANK0 + 2:
256	case GB_REGION_CART_BANK0 + 3:
257		return memory->romBase[address & (GB_SIZE_CART_BANK0 - 1)];
258	case GB_REGION_CART_BANK1:
259	case GB_REGION_CART_BANK1 + 1:
260	case GB_REGION_CART_BANK1 + 2:
261	case GB_REGION_CART_BANK1 + 3:
262		if (segment < 0) {
263			return memory->romBank[address & (GB_SIZE_CART_BANK0 - 1)];
264		} else {
265			if ((size_t) segment * GB_SIZE_CART_BANK0 > memory->romSize) {
266				return 0xFF;
267			}
268			return memory->rom[(address & (GB_SIZE_CART_BANK0 - 1)) + segment * GB_SIZE_CART_BANK0];
269		}
270	case GB_REGION_VRAM:
271	case GB_REGION_VRAM + 1:
272		if (segment < 0) {
273			return gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)];
274		} else {
275			return gb->video.vram[(address & (GB_SIZE_VRAM_BANK0 - 1)) + segment *GB_SIZE_VRAM_BANK0];
276		}
277	case GB_REGION_EXTERNAL_RAM:
278	case GB_REGION_EXTERNAL_RAM + 1:
279		if (memory->rtcAccess) {
280			return memory->rtcRegs[memory->activeRtcReg];
281		} else if (memory->sramAccess) {
282			if (segment < 0) {
283				return memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)];
284			} else {
285				return memory->sram[(address & (GB_SIZE_EXTERNAL_RAM - 1)) + segment *GB_SIZE_EXTERNAL_RAM];
286			}
287		} else if (memory->mbcType == GB_MBC7) {
288			return GBMBC7Read(memory, address);
289		} else if (memory->mbcType == GB_HuC3) {
290			return 0x01; // TODO: Is this supposed to be the current SRAM bank?
291		}
292		return 0xFF;
293	case GB_REGION_WORKING_RAM_BANK0:
294	case GB_REGION_WORKING_RAM_BANK0 + 2:
295		return memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
296	case GB_REGION_WORKING_RAM_BANK1:
297		if (segment < 0) {
298			return memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
299		} else {
300			return memory->wram[(address & (GB_SIZE_WORKING_RAM_BANK0 - 1)) + segment *GB_SIZE_WORKING_RAM_BANK0];
301		}
302	default:
303		if (address < GB_BASE_OAM) {
304			return memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
305		}
306		if (address < GB_BASE_UNUSABLE) {
307			if (gb->video.mode < 2) {
308				return gb->video.oam.raw[address & 0xFF];
309			}
310			return 0xFF;
311		}
312		if (address < GB_BASE_IO) {
313			mLOG(GB_MEM, GAME_ERROR, "Attempt to read from unusable memory: %04X", address);
314			return 0xFF;
315		}
316		if (address < GB_BASE_HRAM) {
317			return GBIORead(gb, address & (GB_SIZE_IO - 1));
318		}
319		if (address < GB_BASE_IE) {
320			return memory->hram[address & GB_SIZE_HRAM];
321		}
322		return GBIORead(gb, REG_IE);
323	}
324}
325
326int32_t GBMemoryProcessEvents(struct GB* gb, int32_t cycles) {
327	int nextEvent = INT_MAX;
328	if (gb->memory.dmaRemaining) {
329		gb->memory.dmaNext -= cycles;
330		if (gb->memory.dmaNext <= 0) {
331			_GBMemoryDMAService(gb);
332		}
333		nextEvent = gb->memory.dmaNext;
334	}
335	if (gb->memory.hdmaRemaining) {
336		gb->memory.hdmaNext -= cycles;
337		if (gb->memory.hdmaNext <= 0) {
338			_GBMemoryHDMAService(gb);
339		}
340		if (gb->memory.hdmaNext < nextEvent) {
341			nextEvent = gb->memory.hdmaNext;
342		}
343	}
344	return nextEvent;
345}
346
347void GBMemoryDMA(struct GB* gb, uint16_t base) {
348	if (base > 0xF100) {
349		return;
350	}
351	gb->cpu->memory.store8 = GBDMAStore8;
352	gb->cpu->memory.load8 = GBDMALoad8;
353	gb->cpu->memory.cpuLoad8 = GBDMALoad8;
354	gb->memory.dmaNext = gb->cpu->cycles + 8;
355	if (gb->memory.dmaNext < gb->cpu->nextEvent) {
356		gb->cpu->nextEvent = gb->memory.dmaNext;
357	}
358	gb->memory.dmaSource = base;
359	gb->memory.dmaDest = 0;
360	gb->memory.dmaRemaining = 0xA0;
361}
362
363void GBMemoryWriteHDMA5(struct GB* gb, uint8_t value) {
364	gb->memory.hdmaSource = gb->memory.io[REG_HDMA1] << 8;
365	gb->memory.hdmaSource |= gb->memory.io[REG_HDMA2];
366	gb->memory.hdmaDest = gb->memory.io[REG_HDMA3] << 8;
367	gb->memory.hdmaDest |= gb->memory.io[REG_HDMA4];
368	gb->memory.hdmaSource &= 0xFFF0;
369	if (gb->memory.hdmaSource >= 0x8000 && gb->memory.hdmaSource < 0xA000) {
370		mLOG(GB_MEM, GAME_ERROR, "Invalid HDMA source: %04X", gb->memory.hdmaSource);
371		return;
372	}
373	gb->memory.hdmaDest &= 0x1FF0;
374	gb->memory.hdmaDest |= 0x8000;
375	bool wasHdma = gb->memory.isHdma;
376	gb->memory.isHdma = value & 0x80;
377	if (!wasHdma && !gb->memory.isHdma) {
378		gb->memory.hdmaRemaining = ((value & 0x7F) + 1) * 0x10;
379		gb->memory.hdmaNext = gb->cpu->cycles;
380		gb->cpu->nextEvent = gb->cpu->cycles;
381	}
382}
383
384void _GBMemoryDMAService(struct GB* gb) {
385	uint8_t b = GBLoad8(gb->cpu, gb->memory.dmaSource);
386	// TODO: Can DMA write OAM during modes 2-3?
387	gb->video.oam.raw[gb->memory.dmaDest] = b;
388	++gb->memory.dmaSource;
389	++gb->memory.dmaDest;
390	--gb->memory.dmaRemaining;
391	if (gb->memory.dmaRemaining) {
392		gb->memory.dmaNext += 4;
393	} else {
394		gb->memory.dmaNext = INT_MAX;
395		gb->cpu->memory.store8 = GBStore8;
396		gb->cpu->memory.load8 = GBLoad8;
397	}
398}
399
400void _GBMemoryHDMAService(struct GB* gb) {
401	uint8_t b = gb->cpu->memory.load8(gb->cpu, gb->memory.hdmaSource);
402	gb->cpu->memory.store8(gb->cpu, gb->memory.hdmaDest, b);
403	++gb->memory.hdmaSource;
404	++gb->memory.hdmaDest;
405	--gb->memory.hdmaRemaining;
406	gb->cpu->cycles += 2;
407	if (gb->memory.hdmaRemaining) {
408		gb->memory.hdmaNext += 2;
409	} else {
410		gb->memory.io[REG_HDMA1] = gb->memory.hdmaSource >> 8;
411		gb->memory.io[REG_HDMA2] = gb->memory.hdmaSource;
412		gb->memory.io[REG_HDMA3] = gb->memory.hdmaDest >> 8;
413		gb->memory.io[REG_HDMA4] = gb->memory.hdmaDest;
414		if (gb->memory.isHdma) {
415			--gb->memory.io[REG_HDMA5];
416			if (gb->memory.io[REG_HDMA5] == 0xFF) {
417				gb->memory.isHdma = false;
418			}
419		} else {
420			gb->memory.io[REG_HDMA5] |= 0x80;
421		}
422	}
423}
424
425struct OAMBlock {
426	uint16_t low;
427	uint16_t high;
428};
429
430static const struct OAMBlock _oamBlockDMG[] = {
431	{ 0xA000, 0xFE00 },
432	{ 0xA000, 0xFE00 },
433	{ 0xA000, 0xFE00 },
434	{ 0xA000, 0xFE00 },
435	{ 0x8000, 0xA000 },
436	{ 0xA000, 0xFE00 },
437	{ 0xA000, 0xFE00 },
438	{ 0xA000, 0xFE00 },
439};
440
441static const struct OAMBlock _oamBlockCGB[] = {
442	{ 0xA000, 0xC000 },
443	{ 0xA000, 0xC000 },
444	{ 0xA000, 0xC000 },
445	{ 0xA000, 0xC000 },
446	{ 0x8000, 0xA000 },
447	{ 0xA000, 0xC000 },
448	{ 0xC000, 0xFE00 },
449	{ 0xA000, 0xC000 },
450};
451
452uint8_t GBDMALoad8(struct LR35902Core* cpu, uint16_t address) {
453	struct GB* gb = (struct GB*) cpu->master;
454	struct GBMemory* memory = &gb->memory;
455	const struct OAMBlock* block = gb->model < GB_MODEL_CGB ? _oamBlockDMG : _oamBlockCGB;
456	block = &block[memory->dmaSource >> 13];
457	if (address >= block->low && address < block->high) {
458		return 0xFF;
459	}
460	if (address >= GB_BASE_OAM && address < GB_BASE_UNUSABLE) {
461		return 0xFF;
462	}
463	return GBLoad8(cpu, address);
464}
465
466void GBDMAStore8(struct LR35902Core* cpu, uint16_t address, int8_t value) {
467	struct GB* gb = (struct GB*) cpu->master;
468	struct GBMemory* memory = &gb->memory;
469	const struct OAMBlock* block = gb->model < GB_MODEL_CGB ? _oamBlockDMG : _oamBlockCGB;
470	block = &block[memory->dmaSource >> 13];
471	if (address >= block->low && address < block->high) {
472		return;
473	}
474	if (address >= GB_BASE_OAM && address < GB_BASE_UNUSABLE) {
475		return;
476	}
477	GBStore8(cpu, address, value);
478}
479
480void GBPatch8(struct LR35902Core* cpu, uint16_t address, int8_t value, int8_t* old) {
481	struct GB* gb = (struct GB*) cpu->master;
482	struct GBMemory* memory = &gb->memory;
483	int8_t oldValue = -1;
484
485	switch (address >> 12) {
486	case GB_REGION_CART_BANK0:
487	case GB_REGION_CART_BANK0 + 1:
488	case GB_REGION_CART_BANK0 + 2:
489	case GB_REGION_CART_BANK0 + 3:
490		_pristineCow(gb);
491		oldValue = memory->rom[address & (GB_SIZE_CART_BANK0 - 1)];
492		memory->rom[address & (GB_SIZE_CART_BANK0 - 1)] =  value;
493		break;
494	case GB_REGION_CART_BANK1:
495	case GB_REGION_CART_BANK1 + 1:
496	case GB_REGION_CART_BANK1 + 2:
497	case GB_REGION_CART_BANK1 + 3:
498		_pristineCow(gb);
499		oldValue = memory->romBank[address & (GB_SIZE_CART_BANK0 - 1)];
500		memory->romBank[address & (GB_SIZE_CART_BANK0 - 1)] =  value;
501		break;
502	case GB_REGION_VRAM:
503	case GB_REGION_VRAM + 1:
504		oldValue = gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)];
505		gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)] = value;
506		break;
507	case GB_REGION_EXTERNAL_RAM:
508	case GB_REGION_EXTERNAL_RAM + 1:
509		mLOG(GB_MEM, STUB, "Unimplemented memory Patch8: 0x%08X", address);
510		return;
511	case GB_REGION_WORKING_RAM_BANK0:
512	case GB_REGION_WORKING_RAM_BANK0 + 2:
513		oldValue = memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
514		memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
515		break;
516	case GB_REGION_WORKING_RAM_BANK1:
517		oldValue = memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
518		memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
519		break;
520	default:
521		if (address < GB_BASE_OAM) {
522			oldValue = memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
523			memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
524		} else if (address < GB_BASE_UNUSABLE) {
525			oldValue = gb->video.oam.raw[address & 0xFF];
526			gb->video.oam.raw[address & 0xFF] = value;
527		} else if (address < GB_BASE_HRAM) {
528			mLOG(GB_MEM, STUB, "Unimplemented memory Patch8: 0x%08X", address);
529			return;
530		} else if (address < GB_BASE_IE) {
531			oldValue = memory->hram[address & GB_SIZE_HRAM];
532			memory->hram[address & GB_SIZE_HRAM] = value;
533		} else {
534			mLOG(GB_MEM, STUB, "Unimplemented memory Patch8: 0x%08X", address);
535			return;
536		}
537	}
538	if (old) {
539		*old = oldValue;
540	}
541}
542
543void GBMemorySerialize(const struct GB* gb, struct GBSerializedState* state) {
544	const struct GBMemory* memory = &gb->memory;
545	memcpy(state->wram, memory->wram, GB_SIZE_WORKING_RAM);
546	memcpy(state->hram, memory->hram, GB_SIZE_HRAM);
547	STORE_16LE(memory->currentBank, 0, &state->memory.currentBank);
548	state->memory.wramCurrentBank = memory->wramCurrentBank;
549	state->memory.sramCurrentBank = memory->sramCurrentBank;
550
551	STORE_32LE(memory->dmaNext, 0, &state->memory.dmaNext);
552	STORE_16LE(memory->dmaSource, 0, &state->memory.dmaSource);
553	STORE_16LE(memory->dmaDest, 0, &state->memory.dmaDest);
554
555	STORE_32LE(memory->hdmaNext, 0, &state->memory.hdmaNext);
556	STORE_16LE(memory->hdmaSource, 0, &state->memory.hdmaSource);
557	STORE_16LE(memory->hdmaDest, 0, &state->memory.hdmaDest);
558
559	STORE_16LE(memory->hdmaRemaining, 0, &state->memory.hdmaRemaining);
560	state->memory.dmaRemaining = memory->dmaRemaining;
561	memcpy(state->memory.rtcRegs, memory->rtcRegs, sizeof(state->memory.rtcRegs));
562
563	GBSerializedMemoryFlags flags = 0;
564	flags = GBSerializedMemoryFlagsSetSramAccess(flags, memory->sramAccess);
565	flags = GBSerializedMemoryFlagsSetRtcAccess(flags, memory->rtcAccess);
566	flags = GBSerializedMemoryFlagsSetRtcLatched(flags, memory->rtcLatched);
567	flags = GBSerializedMemoryFlagsSetIme(flags, memory->ime);
568	flags = GBSerializedMemoryFlagsSetIsHdma(flags, memory->isHdma);
569	flags = GBSerializedMemoryFlagsSetActiveRtcReg(flags, memory->activeRtcReg);
570	STORE_16LE(flags, 0, &state->memory.flags);
571}
572
573void GBMemoryDeserialize(struct GB* gb, const struct GBSerializedState* state) {
574	struct GBMemory* memory = &gb->memory;
575	memcpy(memory->wram, state->wram, GB_SIZE_WORKING_RAM);
576	memcpy(memory->hram, state->hram, GB_SIZE_HRAM);
577	LOAD_16LE(memory->currentBank, 0, &state->memory.currentBank);
578	memory->wramCurrentBank = state->memory.wramCurrentBank;
579	memory->sramCurrentBank = state->memory.sramCurrentBank;
580
581	GBMBCSwitchBank(memory, memory->currentBank);
582	GBMemorySwitchWramBank(memory, memory->wramCurrentBank);
583	GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
584
585	LOAD_32LE(memory->dmaNext, 0, &state->memory.dmaNext);
586	LOAD_16LE(memory->dmaSource, 0, &state->memory.dmaSource);
587	LOAD_16LE(memory->dmaDest, 0, &state->memory.dmaDest);
588
589	LOAD_32LE(memory->hdmaNext, 0, &state->memory.hdmaNext);
590	LOAD_16LE(memory->hdmaSource, 0, &state->memory.hdmaSource);
591	LOAD_16LE(memory->hdmaDest, 0, &state->memory.hdmaDest);
592
593	LOAD_16LE(memory->hdmaRemaining, 0, &state->memory.hdmaRemaining);
594	memory->dmaRemaining = state->memory.dmaRemaining;
595	memcpy(memory->rtcRegs, state->memory.rtcRegs, sizeof(state->memory.rtcRegs));
596
597	GBSerializedMemoryFlags flags;
598	LOAD_16LE(flags, 0, &state->memory.flags);
599	memory->sramAccess = GBSerializedMemoryFlagsGetSramAccess(flags);
600	memory->rtcAccess = GBSerializedMemoryFlagsGetRtcAccess(flags);
601	memory->rtcLatched = GBSerializedMemoryFlagsGetRtcLatched(flags);
602	memory->ime = GBSerializedMemoryFlagsGetIme(flags);
603	memory->isHdma = GBSerializedMemoryFlagsGetIsHdma(flags);
604	memory->activeRtcReg = GBSerializedMemoryFlagsGetActiveRtcReg(flags);
605}
606
607void _pristineCow(struct GB* gb) {
608	if (gb->memory.rom != gb->pristineRom) {
609		return;
610	}
611	gb->memory.rom = anonymousMemoryMap(GB_SIZE_CART_MAX);
612	memcpy(gb->memory.rom, gb->pristineRom, gb->memory.romSize);
613	memset(((uint8_t*) gb->memory.rom) + gb->memory.romSize, 0xFF, GB_SIZE_CART_MAX - gb->memory.romSize);
614	GBMBCSwitchBank(&gb->memory, gb->memory.currentBank);
615}