all repos — mgba @ 67905d281bfecbb06f51f2ca5ac939df378734a5

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/serialize.h"
  12
  13#include "util/memory.h"
  14
  15#include <time.h>
  16
  17mLOG_DEFINE_CATEGORY(GB_MBC, "GB MBC");
  18mLOG_DEFINE_CATEGORY(GB_MEM, "GB Memory");
  19
  20static void _pristineCow(struct GB* gba);
  21
  22static void _GBMBCNone(struct GBMemory* memory, uint16_t address, uint8_t value) {
  23	UNUSED(memory);
  24	UNUSED(address);
  25	UNUSED(value);
  26
  27	mLOG(GB_MBC, GAME_ERROR, "Wrote to invalid MBC");
  28}
  29
  30static void _GBMBC1(struct GBMemory*, uint16_t address, uint8_t value);
  31static void _GBMBC2(struct GBMemory*, uint16_t address, uint8_t value);
  32static void _GBMBC3(struct GBMemory*, uint16_t address, uint8_t value);
  33static void _GBMBC5(struct GBMemory*, uint16_t address, uint8_t value);
  34static void _GBMBC6(struct GBMemory*, uint16_t address, uint8_t value);
  35static void _GBMBC7(struct GBMemory*, uint16_t address, uint8_t value);
  36static uint8_t _GBMBC7Read(struct GBMemory*, uint16_t address);
  37static void _GBMBC7Write(struct GBMemory*, uint16_t address, uint8_t value);
  38static void _GBHuC3(struct GBMemory*, uint16_t address, uint8_t value);
  39
  40static uint8_t GBFastLoad8(struct LR35902Core* cpu, uint16_t address) {
  41	if (UNLIKELY(address > cpu->memory.activeRegionEnd)) {
  42		cpu->memory.setActiveRegion(cpu, address);
  43		return cpu->memory.cpuLoad8(cpu, address);
  44	}
  45	return cpu->memory.activeRegion[address & cpu->memory.activeMask];
  46}
  47
  48static void GBSetActiveRegion(struct LR35902Core* cpu, uint16_t address) {
  49	struct GB* gb = (struct GB*) cpu->master;
  50	struct GBMemory* memory = &gb->memory;
  51	switch (address >> 12) {
  52	case GB_REGION_CART_BANK0:
  53	case GB_REGION_CART_BANK0 + 1:
  54	case GB_REGION_CART_BANK0 + 2:
  55	case GB_REGION_CART_BANK0 + 3:
  56		cpu->memory.cpuLoad8 = GBFastLoad8;
  57		cpu->memory.activeRegion = memory->romBase;
  58		cpu->memory.activeRegionEnd = GB_BASE_CART_BANK1;
  59		cpu->memory.activeMask = GB_SIZE_CART_BANK0 - 1;
  60		break;
  61	case GB_REGION_CART_BANK1:
  62	case GB_REGION_CART_BANK1 + 1:
  63	case GB_REGION_CART_BANK1 + 2:
  64	case GB_REGION_CART_BANK1 + 3:
  65		cpu->memory.cpuLoad8 = GBFastLoad8;
  66		cpu->memory.activeRegion = memory->romBank;
  67		cpu->memory.activeRegionEnd = GB_BASE_VRAM;
  68		cpu->memory.activeMask = GB_SIZE_CART_BANK0 - 1;
  69		break;
  70	default:
  71		cpu->memory.cpuLoad8 = GBLoad8;
  72		break;
  73	}
  74}
  75
  76static void _GBMemoryDMAService(struct GB* gb);
  77static void _GBMemoryHDMAService(struct GB* gb);
  78
  79void GBMemoryInit(struct GB* gb) {
  80	struct LR35902Core* cpu = gb->cpu;
  81	cpu->memory.cpuLoad8 = GBLoad8;
  82	cpu->memory.load8 = GBLoad8;
  83	cpu->memory.store8 = GBStore8;
  84	cpu->memory.setActiveRegion = GBSetActiveRegion;
  85
  86	gb->memory.wram = 0;
  87	gb->memory.wramBank = 0;
  88	gb->memory.rom = 0;
  89	gb->memory.romBank = 0;
  90	gb->memory.romSize = 0;
  91	gb->memory.sram = 0;
  92	gb->memory.mbcType = GB_MBC_NONE;
  93	gb->memory.mbc = 0;
  94
  95	gb->memory.rtc = NULL;
  96
  97	GBIOInit(gb);
  98}
  99
 100void GBMemoryDeinit(struct GB* gb) {
 101	mappedMemoryFree(gb->memory.wram, GB_SIZE_WORKING_RAM);
 102	if (gb->memory.rom) {
 103		mappedMemoryFree(gb->memory.rom, gb->memory.romSize);
 104	}
 105}
 106
 107void GBMemoryReset(struct GB* gb) {
 108	if (gb->memory.wram) {
 109		mappedMemoryFree(gb->memory.wram, GB_SIZE_WORKING_RAM);
 110	}
 111	gb->memory.wram = anonymousMemoryMap(GB_SIZE_WORKING_RAM);
 112	GBMemorySwitchWramBank(&gb->memory, 1);
 113	gb->memory.romBank = &gb->memory.rom[GB_SIZE_CART_BANK0];
 114	gb->memory.currentBank = 1;
 115	if (!gb->memory.sram) {
 116		gb->memory.sram = anonymousMemoryMap(0x20000);
 117	}
 118	gb->memory.sramCurrentBank = 0;
 119	gb->memory.sramBank = gb->memory.sram;
 120
 121	gb->memory.ime = false;
 122	gb->memory.ie = 0;
 123
 124	gb->memory.dmaNext = INT_MAX;
 125	gb->memory.dmaRemaining = 0;
 126	gb->memory.dmaSource = 0;
 127	gb->memory.dmaDest = 0;
 128	gb->memory.hdmaNext = INT_MAX;
 129	gb->memory.hdmaRemaining = 0;
 130	gb->memory.hdmaSource = 0;
 131	gb->memory.hdmaDest = 0;
 132	gb->memory.isHdma = false;
 133
 134	gb->memory.sramAccess = false;
 135	gb->memory.rtcAccess = false;
 136	gb->memory.activeRtcReg = 0;
 137	gb->memory.rtcLatched = false;
 138	memset(&gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
 139
 140	memset(&gb->memory.hram, 0, sizeof(gb->memory.hram));
 141	memset(&gb->memory.mbcState, 0, sizeof(gb->memory.mbcState));
 142
 143	const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
 144	switch (cart->type) {
 145	case 0:
 146	case 8:
 147	case 9:
 148		gb->memory.mbc = _GBMBCNone;
 149		gb->memory.mbcType = GB_MBC_NONE;
 150		break;
 151	case 1:
 152	case 2:
 153	case 3:
 154		gb->memory.mbc = _GBMBC1;
 155		gb->memory.mbcType = GB_MBC1;
 156		break;
 157	case 5:
 158	case 6:
 159		gb->memory.mbc = _GBMBC2;
 160		gb->memory.mbcType = GB_MBC2;
 161		break;
 162	case 0x0F:
 163	case 0x10:
 164	case 0x11:
 165	case 0x12:
 166	case 0x13:
 167		gb->memory.mbc = _GBMBC3;
 168		gb->memory.mbcType = GB_MBC3;
 169		break;
 170	default:
 171		mLOG(GB_MBC, WARN, "Unknown MBC type: %02X", cart->type);
 172	case 0x19:
 173	case 0x1A:
 174	case 0x1B:
 175		gb->memory.mbc = _GBMBC5;
 176		gb->memory.mbcType = GB_MBC5;
 177		break;
 178	case 0x1C:
 179	case 0x1D:
 180	case 0x1E:
 181		gb->memory.mbc = _GBMBC5;
 182		gb->memory.mbcType = GB_MBC5_RUMBLE;
 183		break;
 184	case 0x20:
 185		gb->memory.mbc = _GBMBC6;
 186		gb->memory.mbcType = GB_MBC6;
 187		break;
 188	case 0x22:
 189		gb->memory.mbc = _GBMBC7;
 190		gb->memory.mbcType = GB_MBC7;
 191		break;
 192	case 0xFE:
 193		gb->memory.mbc = _GBHuC3;
 194		gb->memory.mbcType = GB_HuC3;
 195		break;
 196	}
 197
 198	if (!gb->memory.wram) {
 199		GBMemoryDeinit(gb);
 200	}
 201}
 202
 203void GBMemorySwitchWramBank(struct GBMemory* memory, int bank) {
 204	bank &= 7;
 205	if (!bank) {
 206		bank = 1;
 207	}
 208	memory->wramBank = &memory->wram[GB_SIZE_WORKING_RAM_BANK0 * bank];
 209	memory->wramCurrentBank = bank;
 210}
 211
 212uint8_t GBLoad8(struct LR35902Core* cpu, uint16_t address) {
 213	struct GB* gb = (struct GB*) cpu->master;
 214	struct GBMemory* memory = &gb->memory;
 215	switch (address >> 12) {
 216	case GB_REGION_CART_BANK0:
 217	case GB_REGION_CART_BANK0 + 1:
 218	case GB_REGION_CART_BANK0 + 2:
 219	case GB_REGION_CART_BANK0 + 3:
 220		return memory->romBase[address & (GB_SIZE_CART_BANK0 - 1)];
 221	case GB_REGION_CART_BANK1:
 222	case GB_REGION_CART_BANK1 + 1:
 223	case GB_REGION_CART_BANK1 + 2:
 224	case GB_REGION_CART_BANK1 + 3:
 225		return memory->romBank[address & (GB_SIZE_CART_BANK0 - 1)];
 226	case GB_REGION_VRAM:
 227	case GB_REGION_VRAM + 1:
 228		return gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)];
 229	case GB_REGION_EXTERNAL_RAM:
 230	case GB_REGION_EXTERNAL_RAM + 1:
 231		if (memory->rtcAccess) {
 232			return gb->memory.rtcRegs[memory->activeRtcReg];
 233		} else if (memory->sramAccess) {
 234			return gb->memory.sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)];
 235		} else if (memory->mbcType == GB_MBC7) {
 236			return _GBMBC7Read(memory, address);
 237		} else if (memory->mbcType == GB_HuC3) {
 238			return 0x01; // TODO: Is this supposed to be the current SRAM bank?
 239		}
 240		return 0xFF;
 241	case GB_REGION_WORKING_RAM_BANK0:
 242	case GB_REGION_WORKING_RAM_BANK0 + 2:
 243		return memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
 244	case GB_REGION_WORKING_RAM_BANK1:
 245		return memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
 246	default:
 247		if (address < GB_BASE_OAM) {
 248			return memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)];
 249		}
 250		if (address < GB_BASE_UNUSABLE) {
 251			if (gb->video.mode < 2) {
 252				return gb->video.oam.raw[address & 0xFF];
 253			}
 254			return 0xFF;
 255		}
 256		if (address < GB_BASE_IO) {
 257			mLOG(GB_MEM, GAME_ERROR, "Attempt to read from unusable memory: %04X", address);
 258			return 0xFF;
 259		}
 260		if (address < GB_BASE_HRAM) {
 261			return GBIORead(gb, address & (GB_SIZE_IO - 1));
 262		}
 263		if (address < GB_BASE_IE) {
 264			return memory->hram[address & GB_SIZE_HRAM];
 265		}
 266		return GBIORead(gb, REG_IE);
 267	}
 268}
 269
 270void GBStore8(struct LR35902Core* cpu, uint16_t address, int8_t value) {
 271	struct GB* gb = (struct GB*) cpu->master;
 272	struct GBMemory* memory = &gb->memory;
 273	switch (address >> 12) {
 274	case GB_REGION_CART_BANK0:
 275	case GB_REGION_CART_BANK0 + 1:
 276	case GB_REGION_CART_BANK0 + 2:
 277	case GB_REGION_CART_BANK0 + 3:
 278	case GB_REGION_CART_BANK1:
 279	case GB_REGION_CART_BANK1 + 1:
 280	case GB_REGION_CART_BANK1 + 2:
 281	case GB_REGION_CART_BANK1 + 3:
 282		memory->mbc(memory, address, value);
 283		cpu->memory.setActiveRegion(cpu, cpu->pc);
 284		return;
 285	case GB_REGION_VRAM:
 286	case GB_REGION_VRAM + 1:
 287		// TODO: Block access in wrong modes
 288		gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)] = value;
 289		return;
 290	case GB_REGION_EXTERNAL_RAM:
 291	case GB_REGION_EXTERNAL_RAM + 1:
 292		if (memory->rtcAccess) {
 293			gb->memory.rtcRegs[memory->activeRtcReg] = value;
 294		} else if (memory->sramAccess) {
 295			gb->memory.sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)] = value;
 296		} else if (gb->memory.mbcType == GB_MBC7) {
 297			_GBMBC7Write(&gb->memory, address, value);
 298		}
 299		return;
 300	case GB_REGION_WORKING_RAM_BANK0:
 301	case GB_REGION_WORKING_RAM_BANK0 + 2:
 302		memory->wram[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
 303		return;
 304	case GB_REGION_WORKING_RAM_BANK1:
 305		memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
 306		return;
 307	default:
 308		if (address < GB_BASE_OAM) {
 309			memory->wramBank[address & (GB_SIZE_WORKING_RAM_BANK0 - 1)] = value;
 310		} else if (address < GB_BASE_UNUSABLE) {
 311			if (gb->video.mode < 2) {
 312				gb->video.oam.raw[address & 0xFF] = value;
 313			}
 314		} else if (address < GB_BASE_IO) {
 315			mLOG(GB_MEM, GAME_ERROR, "Attempt to write to unusable memory: %04X:%02X", address, value);
 316		} else if (address < GB_BASE_HRAM) {
 317			GBIOWrite(gb, address & (GB_SIZE_IO - 1), value);
 318		} else if (address < GB_BASE_IE) {
 319			memory->hram[address & GB_SIZE_HRAM] = value;
 320		} else {
 321			GBIOWrite(gb, REG_IE, value);
 322		}
 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
 543static void _switchBank(struct GBMemory* memory, int bank) {
 544	size_t bankStart = bank * GB_SIZE_CART_BANK0;
 545	if (bankStart + GB_SIZE_CART_BANK0 > memory->romSize) {
 546		mLOG(GB_MBC, GAME_ERROR, "Attempting to switch to an invalid ROM bank: %0X", bank);
 547		bankStart &= (memory->romSize - 1);
 548		bank = bankStart / GB_SIZE_CART_BANK0;
 549	}
 550	memory->romBank = &memory->rom[bankStart];
 551	memory->currentBank = bank;
 552}
 553
 554static void _switchSramBank(struct GBMemory* memory, int bank) {
 555	size_t bankStart = bank * GB_SIZE_EXTERNAL_RAM;
 556	memory->sramBank = &memory->sram[bankStart];
 557	memory->sramCurrentBank = bank;
 558}
 559
 560static void _latchRtc(struct GBMemory* memory) {
 561	time_t t;
 562	struct mRTCSource* rtc = memory->rtc;
 563	if (rtc) {
 564		if (rtc->sample) {
 565			rtc->sample(rtc);
 566		}
 567		t = rtc->unixTime(rtc);
 568	} else {
 569		t = time(0);
 570	}
 571	struct tm date;
 572	localtime_r(&t, &date);
 573	memory->rtcRegs[0] = date.tm_sec;
 574	memory->rtcRegs[1] = date.tm_min;
 575	memory->rtcRegs[2] = date.tm_hour;
 576	memory->rtcRegs[3] = date.tm_yday; // TODO: Persist day counter
 577	memory->rtcRegs[4] &= 0xF0;
 578	memory->rtcRegs[4] |= date.tm_yday >> 8;
 579}
 580
 581void _GBMBC1(struct GBMemory* memory, uint16_t address, uint8_t value) {
 582	int bank = value & 0x1F;
 583	switch (address >> 13) {
 584	case 0x0:
 585		switch (value) {
 586		case 0:
 587			memory->sramAccess = false;
 588			break;
 589		case 0xA:
 590			memory->sramAccess = true;
 591			_switchSramBank(memory, memory->sramCurrentBank);
 592			break;
 593		default:
 594			// TODO
 595			mLOG(GB_MBC, STUB, "MBC1 unknown value %02X", value);
 596			break;
 597		}
 598		break;
 599	case 0x1:
 600		if (!bank) {
 601			++bank;
 602		}
 603		_switchBank(memory, bank | (memory->currentBank & 0x60));
 604		break;
 605	case 0x2:
 606		bank &= 3;
 607		if (!memory->mbcState.mbc1.mode) {
 608			_switchBank(memory, (bank << 5) | (memory->currentBank & 0x1F));
 609		} else {
 610			_switchSramBank(memory, bank);
 611		}
 612		break;
 613	case 0x3:
 614		memory->mbcState.mbc1.mode = value & 1;
 615		if (memory->mbcState.mbc1.mode) {
 616			_switchBank(memory, memory->currentBank & 0x1F);
 617		} else {
 618			_switchSramBank(memory, 0);
 619		}
 620		break;
 621	default:
 622		// TODO
 623		mLOG(GB_MBC, STUB, "MBC1 unknown address: %04X:%02X", address, value);
 624		break;
 625	}
 626}
 627
 628void _GBMBC2(struct GBMemory* memory, uint16_t address, uint8_t value) {
 629	int bank = value & 0xF;
 630	switch (address >> 13) {
 631	case 0x0:
 632		switch (value) {
 633		case 0:
 634			memory->sramAccess = false;
 635			break;
 636		case 0xA:
 637			memory->sramAccess = true;
 638			_switchSramBank(memory, memory->sramCurrentBank);
 639			break;
 640		default:
 641			// TODO
 642			mLOG(GB_MBC, STUB, "MBC1 unknown value %02X", value);
 643			break;
 644		}
 645		break;
 646	case 0x1:
 647		if (!bank) {
 648			++bank;
 649		}
 650		_switchBank(memory, bank);
 651		break;
 652	default:
 653		// TODO
 654		mLOG(GB_MBC, STUB, "MBC2 unknown address: %04X:%02X", address, value);
 655		break;
 656	}}
 657
 658void _GBMBC3(struct GBMemory* memory, uint16_t address, uint8_t value) {
 659	int bank = value & 0x7F;
 660	switch (address >> 13) {
 661	case 0x0:
 662		switch (value) {
 663		case 0:
 664			memory->sramAccess = false;
 665			break;
 666		case 0xA:
 667			memory->sramAccess = true;
 668			_switchSramBank(memory, memory->sramCurrentBank);
 669			break;
 670		default:
 671			// TODO
 672			mLOG(GB_MBC, STUB, "MBC3 unknown value %02X", value);
 673			break;
 674		}
 675		break;
 676	case 0x1:
 677		if (!bank) {
 678			++bank;
 679		}
 680		_switchBank(memory, bank);
 681		break;
 682	case 0x2:
 683		if (value < 4) {
 684			_switchSramBank(memory, value);
 685			memory->rtcAccess = false;
 686		} else if (value >= 8 && value <= 0xC) {
 687			memory->activeRtcReg = value - 8;
 688			memory->rtcAccess = true;
 689		}
 690		break;
 691	case 0x3:
 692		if (memory->rtcLatched && value == 0) {
 693			memory->rtcLatched = false;
 694		} else if (!memory->rtcLatched && value == 1) {
 695			_latchRtc(memory);
 696			memory->rtcLatched = true;
 697		}
 698		break;
 699	}
 700}
 701
 702void _GBMBC5(struct GBMemory* memory, uint16_t address, uint8_t value) {
 703	int bank;
 704	switch (address >> 12) {
 705	case 0x0:
 706	case 0x1:
 707		switch (value) {
 708		case 0:
 709			memory->sramAccess = false;
 710			break;
 711		case 0xA:
 712			memory->sramAccess = true;
 713			_switchSramBank(memory, memory->sramCurrentBank);
 714			break;
 715		default:
 716			// TODO
 717			mLOG(GB_MBC, STUB, "MBC5 unknown value %02X", value);
 718			break;
 719		}
 720		break;
 721	case 0x2:
 722		bank = (memory->currentBank & 0x100) | value;
 723		_switchBank(memory, bank);
 724		break;
 725	case 0x3:
 726		bank = (memory->currentBank & 0xFF) | ((value & 1) << 8);
 727		_switchBank(memory, bank);
 728		break;
 729	case 0x4:
 730	case 0x5:
 731		if (memory->mbcType == GB_MBC5_RUMBLE && memory->rumble) {
 732			memory->rumble->setRumble(memory->rumble, (value >> 3) & 1);
 733			value &= ~8;
 734		}
 735		_switchSramBank(memory, value & 0xF);
 736		break;
 737	default:
 738		// TODO
 739		mLOG(GB_MBC, STUB, "MBC5 unknown address: %04X:%02X", address, value);
 740		break;
 741	}
 742}
 743
 744void _GBMBC6(struct GBMemory* memory, uint16_t address, uint8_t value) {
 745	// TODO
 746	mLOG(GB_MBC, STUB, "MBC6 unimplemented");
 747}
 748
 749void _GBMBC7(struct GBMemory* memory, uint16_t address, uint8_t value) {
 750	int bank = value & 0x7F;
 751	switch (address >> 13) {
 752	case 0x1:
 753		_switchBank(memory, bank);
 754		break;
 755	case 0x2:
 756		if (value < 0x10) {
 757			_switchSramBank(memory, value);
 758		}
 759		break;
 760	default:
 761		// TODO
 762		mLOG(GB_MBC, STUB, "MBC7 unknown address: %04X:%02X", address, value);
 763		break;
 764	}
 765}
 766
 767uint8_t _GBMBC7Read(struct GBMemory* memory, uint16_t address) {
 768	struct GBMBC7State* mbc7 = &memory->mbcState.mbc7;
 769	switch (address & 0xF0) {
 770	case 0x00:
 771	case 0x10:
 772	case 0x60:
 773	case 0x70:
 774		return 0;
 775	case 0x20:
 776		if (memory->rotation && memory->rotation->readTiltX) {
 777			int32_t x = -memory->rotation->readTiltX(memory->rotation);
 778			x >>= 21;
 779			x += 2047;
 780			return x;
 781		}
 782		return 0xFF;
 783	case 0x30:
 784		if (memory->rotation && memory->rotation->readTiltX) {
 785			int32_t x = -memory->rotation->readTiltX(memory->rotation);
 786			x >>= 21;
 787			x += 2047;
 788			return x >> 8;
 789		}
 790		return 7;
 791	case 0x40:
 792		if (memory->rotation && memory->rotation->readTiltY) {
 793			int32_t y = -memory->rotation->readTiltY(memory->rotation);
 794			y >>= 21;
 795			y += 2047;
 796			return y;
 797		}
 798		return 0xFF;
 799	case 0x50:
 800		if (memory->rotation && memory->rotation->readTiltY) {
 801			int32_t y = -memory->rotation->readTiltY(memory->rotation);
 802			y >>= 21;
 803			y += 2047;
 804			return y >> 8;
 805		}
 806		return 7;
 807	case 0x80:
 808		return (mbc7->sr >> 16) & 1;
 809	default:
 810		return 0xFF;
 811	}
 812}
 813
 814void _GBMBC7Write(struct GBMemory* memory, uint16_t address, uint8_t value) {
 815	if ((address & 0xF0) != 0x80) {
 816		return;
 817	}
 818	struct GBMBC7State* mbc7 = &memory->mbcState.mbc7;
 819	GBMBC7Field old = memory->mbcState.mbc7.field;
 820	mbc7->field = GBMBC7FieldClearIO(value);
 821	if (!GBMBC7FieldIsCS(old) && GBMBC7FieldIsCS(value)) {
 822		if (mbc7->state == GBMBC7_STATE_WRITE) {
 823			if (mbc7->writable) {
 824				memory->sramBank[mbc7->address * 2] = mbc7->sr >> 8;
 825				memory->sramBank[mbc7->address * 2 + 1] = mbc7->sr;
 826			}
 827			mbc7->sr = 0x1FFFF;
 828			mbc7->state = GBMBC7_STATE_NULL;
 829		} else {
 830			mbc7->state = GBMBC7_STATE_IDLE;
 831		}
 832	}
 833	if (!GBMBC7FieldIsSK(old) && GBMBC7FieldIsSK(value)) {
 834		if (mbc7->state > GBMBC7_STATE_IDLE && mbc7->state != GBMBC7_STATE_READ) {
 835			mbc7->sr <<= 1;
 836			mbc7->sr |= GBMBC7FieldGetIO(value);
 837			++mbc7->srBits;
 838		}
 839		switch (mbc7->state) {
 840		case GBMBC7_STATE_IDLE:
 841			if (GBMBC7FieldIsIO(value)) {
 842				mbc7->state = GBMBC7_STATE_READ_COMMAND;
 843				mbc7->srBits = 0;
 844				mbc7->sr = 0;
 845			}
 846			break;
 847		case GBMBC7_STATE_READ_COMMAND:
 848			if (mbc7->srBits == 2) {
 849				mbc7->state = GBMBC7_STATE_READ_ADDRESS;
 850				mbc7->srBits = 0;
 851				mbc7->command = mbc7->sr;
 852			}
 853			break;
 854		case GBMBC7_STATE_READ_ADDRESS:
 855			if (mbc7->srBits == 8) {
 856				mbc7->state = GBMBC7_STATE_COMMAND_0 + mbc7->command;
 857				mbc7->srBits = 0;
 858				mbc7->address = mbc7->sr;
 859				if (mbc7->state == GBMBC7_STATE_COMMAND_0) {
 860					switch (mbc7->address >> 6) {
 861					case 0:
 862						mbc7->writable = false;
 863						mbc7->state = GBMBC7_STATE_NULL;
 864						break;
 865					case 3:
 866						mbc7->writable = true;
 867						mbc7->state = GBMBC7_STATE_NULL;
 868						break;
 869					}
 870				}
 871			}
 872			break;
 873		case GBMBC7_STATE_COMMAND_0:
 874			if (mbc7->srBits == 16) {
 875				switch (mbc7->address >> 6) {
 876				case 0:
 877					mbc7->writable = false;
 878					mbc7->state = GBMBC7_STATE_NULL;
 879					break;
 880				case 1:
 881					mbc7->state = GBMBC7_STATE_WRITE;
 882					if (mbc7->writable) {
 883						int i;
 884						for (i = 0; i < 256; ++i) {
 885							memory->sramBank[i * 2] = mbc7->sr >> 8;
 886							memory->sramBank[i * 2 + 1] = mbc7->sr;
 887						}
 888					}
 889					break;
 890				case 2:
 891					mbc7->state = GBMBC7_STATE_WRITE;
 892					if (mbc7->writable) {
 893						int i;
 894						for (i = 0; i < 256; ++i) {
 895							memory->sramBank[i * 2] = 0xFF;
 896							memory->sramBank[i * 2 + 1] = 0xFF;
 897						}
 898					}
 899					break;
 900				case 3:
 901					mbc7->writable = true;
 902					mbc7->state = GBMBC7_STATE_NULL;
 903					break;
 904				}
 905			}
 906			break;
 907		case GBMBC7_STATE_COMMAND_SR_WRITE:
 908			if (mbc7->srBits == 16) {
 909				mbc7->srBits = 0;
 910				mbc7->state = GBMBC7_STATE_WRITE;
 911			}
 912			break;
 913		case GBMBC7_STATE_COMMAND_SR_READ:
 914			if (mbc7->srBits == 1) {
 915				mbc7->sr = memory->sramBank[mbc7->address * 2] << 8;
 916				mbc7->sr |= memory->sramBank[mbc7->address * 2 + 1];
 917				mbc7->srBits = 0;
 918				mbc7->state = GBMBC7_STATE_READ;
 919			}
 920			break;
 921		case GBMBC7_STATE_COMMAND_SR_FILL:
 922			if (mbc7->srBits == 16) {
 923				mbc7->sr = 0xFFFF;
 924				mbc7->srBits = 0;
 925				mbc7->state = GBMBC7_STATE_WRITE;
 926			}
 927			break;
 928		default:
 929			break;
 930		}
 931	} else if (GBMBC7FieldIsSK(old) && !GBMBC7FieldIsSK(value)) {
 932		if (mbc7->state == GBMBC7_STATE_READ) {
 933			mbc7->sr <<= 1;
 934			++mbc7->srBits;
 935			if (mbc7->srBits == 16) {
 936				mbc7->srBits = 0;
 937				mbc7->state = GBMBC7_STATE_NULL;
 938			}
 939		}
 940	}
 941}
 942
 943void _GBHuC3(struct GBMemory* memory, uint16_t address, uint8_t value) {
 944	int bank = value & 0x3F;
 945	if (address & 0x1FFF) {
 946		mLOG(GB_MBC, STUB, "HuC-3 unknown value %04X:%02X", address, value);
 947	}
 948
 949	switch (address >> 13) {
 950	case 0x0:
 951		switch (value) {
 952		case 0xA:
 953			memory->sramAccess = true;
 954			_switchSramBank(memory, memory->sramCurrentBank);
 955			break;
 956		default:
 957			memory->sramAccess = false;
 958			break;
 959		}
 960		break;
 961	case 0x1:
 962		_switchBank(memory, bank);
 963		break;
 964	case 0x2:
 965		_switchSramBank(memory, bank);
 966		break;
 967	default:
 968		// TODO
 969		mLOG(GB_MBC, STUB, "HuC-3 unknown address: %04X:%02X", address, value);
 970		break;
 971	}
 972}
 973
 974void GBMemorySerialize(const struct GBMemory* memory, struct GBSerializedState* state) {
 975	memcpy(state->wram, memory->wram, GB_SIZE_WORKING_RAM);
 976	memcpy(state->hram, memory->hram, GB_SIZE_HRAM);
 977	STORE_16LE(memory->currentBank, 0, &state->memory.currentBank);
 978	state->memory.wramCurrentBank = memory->wramCurrentBank;
 979	state->memory.sramCurrentBank = memory->sramCurrentBank;
 980
 981	STORE_32LE(memory->dmaNext, 0, &state->memory.dmaNext);
 982	STORE_16LE(memory->dmaSource, 0, &state->memory.dmaSource);
 983	STORE_16LE(memory->dmaDest, 0, &state->memory.dmaDest);
 984
 985	STORE_32LE(memory->hdmaNext, 0, &state->memory.hdmaNext);
 986	STORE_16LE(memory->hdmaSource, 0, &state->memory.hdmaSource);
 987	STORE_16LE(memory->hdmaDest, 0, &state->memory.hdmaDest);
 988
 989	STORE_16LE(memory->hdmaRemaining, 0, &state->memory.hdmaRemaining);
 990	state->memory.dmaRemaining = memory->dmaRemaining;
 991	memcpy(state->memory.rtcRegs, memory->rtcRegs, sizeof(state->memory.rtcRegs));
 992
 993	GBSerializedMemoryFlags flags = 0;
 994	flags = GBSerializedMemoryFlagsSetSramAccess(flags, memory->sramAccess);
 995	flags = GBSerializedMemoryFlagsSetRtcAccess(flags, memory->rtcAccess);
 996	flags = GBSerializedMemoryFlagsSetRtcLatched(flags, memory->rtcLatched);
 997	flags = GBSerializedMemoryFlagsSetIme(flags, memory->ime);
 998	flags = GBSerializedMemoryFlagsSetIsHdma(flags, memory->isHdma);
 999	flags = GBSerializedMemoryFlagsSetActiveRtcReg(flags, memory->activeRtcReg);
1000	STORE_16LE(flags, 0, &state->memory.flags);
1001}
1002
1003void GBMemoryDeserialize(struct GBMemory* memory, const struct GBSerializedState* state) {
1004	memcpy(memory->wram, state->wram, GB_SIZE_WORKING_RAM);
1005	memcpy(memory->hram, state->hram, GB_SIZE_HRAM);
1006	LOAD_16LE(memory->currentBank, 0, &state->memory.currentBank);
1007	memory->wramCurrentBank = state->memory.wramCurrentBank;
1008	memory->sramCurrentBank = state->memory.sramCurrentBank;
1009
1010	_switchBank(memory, memory->currentBank);
1011	GBMemorySwitchWramBank(memory, memory->wramCurrentBank);
1012	_switchSramBank(memory, memory->sramCurrentBank);
1013
1014	LOAD_32LE(memory->dmaNext, 0, &state->memory.dmaNext);
1015	LOAD_16LE(memory->dmaSource, 0, &state->memory.dmaSource);
1016	LOAD_16LE(memory->dmaDest, 0, &state->memory.dmaDest);
1017
1018	LOAD_32LE(memory->hdmaNext, 0, &state->memory.hdmaNext);
1019	LOAD_16LE(memory->hdmaSource, 0, &state->memory.hdmaSource);
1020	LOAD_16LE(memory->hdmaDest, 0, &state->memory.hdmaDest);
1021
1022	LOAD_16LE(memory->hdmaRemaining, 0, &state->memory.hdmaRemaining);
1023	memory->dmaRemaining = state->memory.dmaRemaining;
1024	memcpy(memory->rtcRegs, state->memory.rtcRegs, sizeof(state->memory.rtcRegs));
1025
1026	GBSerializedMemoryFlags flags;
1027	LOAD_16LE(flags, 0, &state->memory.flags);
1028	memory->sramAccess = GBSerializedMemoryFlagsGetSramAccess(flags);
1029	memory->rtcAccess = GBSerializedMemoryFlagsGetRtcAccess(flags);
1030	memory->rtcLatched = GBSerializedMemoryFlagsGetRtcLatched(flags);
1031	memory->ime = GBSerializedMemoryFlagsGetIme(flags);
1032	memory->isHdma = GBSerializedMemoryFlagsGetIsHdma(flags);
1033	memory->activeRtcReg = GBSerializedMemoryFlagsGetActiveRtcReg(flags);
1034}
1035
1036void _pristineCow(struct GB* gb) {
1037	if (gb->memory.rom != gb->pristineRom) {
1038		return;
1039	}
1040	gb->memory.rom = anonymousMemoryMap(GB_SIZE_CART_MAX);
1041	memcpy(gb->memory.rom, gb->pristineRom, gb->memory.romSize);
1042	memset(((uint8_t*) gb->memory.rom) + gb->memory.romSize, 0xFF, GB_SIZE_CART_MAX - gb->memory.romSize);
1043	_switchBank(&gb->memory, gb->memory.currentBank);
1044}