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mGBA Game Boy Advance Emulator

src/gb/mbc.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/mbc.h>
   7
   8#include <mgba/core/interface.h>
   9#include <mgba/internal/lr35902/lr35902.h>
  10#include <mgba/internal/gb/gb.h>
  11#include <mgba/internal/gb/memory.h>
  12#include <mgba-util/vfs.h>
  13
  14mLOG_DEFINE_CATEGORY(GB_MBC, "GB MBC", "gb.mbc");
  15
  16static void _GBMBCNone(struct GB* gb, uint16_t address, uint8_t value) {
  17	UNUSED(gb);
  18	UNUSED(address);
  19	UNUSED(value);
  20
  21	mLOG(GB_MBC, GAME_ERROR, "Wrote to invalid MBC");
  22}
  23
  24static void _GBMBC1(struct GB*, uint16_t address, uint8_t value);
  25static void _GBMBC2(struct GB*, uint16_t address, uint8_t value);
  26static void _GBMBC3(struct GB*, uint16_t address, uint8_t value);
  27static void _GBMBC5(struct GB*, uint16_t address, uint8_t value);
  28static void _GBMBC6(struct GB*, uint16_t address, uint8_t value);
  29static void _GBMBC7(struct GB*, uint16_t address, uint8_t value);
  30static void _GBHuC3(struct GB*, uint16_t address, uint8_t value);
  31static void _GBPocketCam(struct GB* gb, uint16_t address, uint8_t value);
  32static void _GBTAMA5(struct GB* gb, uint16_t address, uint8_t value);
  33
  34static uint8_t _GBMBC7Read(struct GBMemory*, uint16_t address);
  35static void _GBMBC7Write(struct GBMemory* memory, uint16_t address, uint8_t value);
  36
  37static uint8_t _GBTAMA5Read(struct GBMemory*, uint16_t address);
  38
  39static uint8_t _GBPocketCamRead(struct GBMemory*, uint16_t address);
  40static void _GBPocketCamCapture(struct GBMemory*);
  41
  42void GBMBCSwitchBank(struct GB* gb, int bank) {
  43	size_t bankStart = bank * GB_SIZE_CART_BANK0;
  44	if (bankStart + GB_SIZE_CART_BANK0 > gb->memory.romSize) {
  45		mLOG(GB_MBC, GAME_ERROR, "Attempting to switch to an invalid ROM bank: %0X", bank);
  46		bankStart &= (gb->memory.romSize - 1);
  47		bank = bankStart / GB_SIZE_CART_BANK0;
  48		if (!bank) {
  49			++bank;
  50		}
  51	}
  52	gb->memory.romBank = &gb->memory.rom[bankStart];
  53	gb->memory.currentBank = bank;
  54	if (gb->cpu->pc < GB_BASE_VRAM) {
  55		gb->cpu->memory.setActiveRegion(gb->cpu, gb->cpu->pc);
  56	}
  57}
  58
  59void GBMBCSwitchBank0(struct GB* gb, int bank) {
  60	size_t bankStart = bank * GB_SIZE_CART_BANK0 << gb->memory.mbcState.mbc1.multicartStride;
  61	if (bankStart + GB_SIZE_CART_BANK0 > gb->memory.romSize) {
  62		mLOG(GB_MBC, GAME_ERROR, "Attempting to switch to an invalid ROM bank: %0X", bank);
  63		bankStart &= (gb->memory.romSize - 1);
  64	}
  65	gb->memory.romBase = &gb->memory.rom[bankStart];
  66	if (gb->cpu->pc < GB_SIZE_CART_BANK0) {
  67		gb->cpu->memory.setActiveRegion(gb->cpu, gb->cpu->pc);
  68	}
  69}
  70
  71static bool _isMulticart(const uint8_t* mem) {
  72	bool success = true;
  73	struct VFile* vf;
  74
  75	vf = VFileFromConstMemory(&mem[GB_SIZE_CART_BANK0 * 0x10], 1024);
  76	success = success && GBIsROM(vf);
  77	vf->close(vf);
  78
  79	vf = VFileFromConstMemory(&mem[GB_SIZE_CART_BANK0 * 0x20], 1024);
  80	success = success && GBIsROM(vf);
  81	vf->close(vf);
  82
  83	return success;
  84}
  85
  86void GBMBCSwitchSramBank(struct GB* gb, int bank) {
  87	size_t bankStart = bank * GB_SIZE_EXTERNAL_RAM;
  88	if (bankStart + GB_SIZE_EXTERNAL_RAM > gb->sramSize) {
  89		mLOG(GB_MBC, GAME_ERROR, "Attempting to switch to an invalid RAM bank: %0X", bank);
  90		bankStart &= (gb->sramSize - 1);
  91		bank = bankStart / GB_SIZE_EXTERNAL_RAM;
  92	}
  93	gb->memory.sramBank = &gb->memory.sram[bankStart];
  94	gb->memory.sramCurrentBank = bank;
  95}
  96
  97void GBMBCInit(struct GB* gb) {
  98	const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
  99	if (gb->memory.rom) {
 100		switch (cart->ramSize) {
 101		case 0:
 102			gb->sramSize = 0;
 103			break;
 104		case 1:
 105			gb->sramSize = 0x800;
 106			break;
 107		default:
 108		case 2:
 109			gb->sramSize = 0x2000;
 110			break;
 111		case 3:
 112			gb->sramSize = 0x8000;
 113			break;
 114		case 4:
 115			gb->sramSize = 0x20000;
 116			break;
 117		case 5:
 118			gb->sramSize = 0x10000;
 119			break;
 120		}
 121
 122		if (gb->memory.mbcType == GB_MBC_AUTODETECT) {
 123			switch (cart->type) {
 124			case 0:
 125			case 8:
 126			case 9:
 127				gb->memory.mbcType = GB_MBC_NONE;
 128				break;
 129			case 1:
 130			case 2:
 131			case 3:
 132				gb->memory.mbcType = GB_MBC1;
 133				if (gb->memory.romSize >= GB_SIZE_CART_BANK0 * 0x31 && _isMulticart(gb->memory.rom)) {
 134					gb->memory.mbcState.mbc1.multicartStride = 4;
 135				} else {
 136					gb->memory.mbcState.mbc1.multicartStride = 5;
 137				}
 138				break;
 139			case 5:
 140			case 6:
 141				gb->memory.mbcType = GB_MBC2;
 142				break;
 143			case 0x0F:
 144			case 0x10:
 145				gb->memory.mbcType = GB_MBC3_RTC;
 146				break;
 147			case 0x11:
 148			case 0x12:
 149			case 0x13:
 150				gb->memory.mbcType = GB_MBC3;
 151				break;
 152			default:
 153				mLOG(GB_MBC, WARN, "Unknown MBC type: %02X", cart->type);
 154				// Fall through
 155			case 0x19:
 156			case 0x1A:
 157			case 0x1B:
 158				gb->memory.mbcType = GB_MBC5;
 159				break;
 160			case 0x1C:
 161			case 0x1D:
 162			case 0x1E:
 163				gb->memory.mbcType = GB_MBC5_RUMBLE;
 164				break;
 165			case 0x20:
 166				gb->memory.mbcType = GB_MBC6;
 167				break;
 168			case 0x22:
 169				gb->memory.mbcType = GB_MBC7;
 170				break;
 171			case 0xFC:
 172				gb->memory.mbcType = GB_POCKETCAM;
 173				break;
 174			case 0xFD:
 175				gb->memory.mbcType = GB_TAMA5;
 176				break;
 177			case 0xFE:
 178				gb->memory.mbcType = GB_HuC3;
 179				break;
 180			case 0xFF:
 181				gb->memory.mbcType = GB_HuC1;
 182				break;
 183			}
 184		}
 185	} else {
 186		gb->memory.mbcType = GB_MBC_NONE;
 187	}
 188	gb->memory.mbcRead = NULL;
 189	switch (gb->memory.mbcType) {
 190	case GB_MBC_NONE:
 191		gb->memory.mbcWrite = _GBMBCNone;
 192		break;
 193	case GB_MBC1:
 194		gb->memory.mbcWrite = _GBMBC1;
 195		break;
 196	case GB_MBC2:
 197		gb->memory.mbcWrite = _GBMBC2;
 198		gb->sramSize = 0x200;
 199		break;
 200	case GB_MBC3:
 201		gb->memory.mbcWrite = _GBMBC3;
 202		break;
 203	default:
 204		mLOG(GB_MBC, WARN, "Unknown MBC type: %02X", cart->type);
 205		// Fall through
 206	case GB_MBC5:
 207		gb->memory.mbcWrite = _GBMBC5;
 208		break;
 209	case GB_MBC6:
 210		mLOG(GB_MBC, WARN, "unimplemented MBC: MBC6");
 211		gb->memory.mbcWrite = _GBMBC6;
 212		break;
 213	case GB_MBC7:
 214		gb->memory.mbcWrite = _GBMBC7;
 215		gb->memory.mbcRead = _GBMBC7Read;
 216		gb->sramSize = 0x100;
 217		break;
 218	case GB_MMM01:
 219		mLOG(GB_MBC, WARN, "unimplemented MBC: MMM01");
 220		gb->memory.mbcWrite = _GBMBC1;
 221		break;
 222	case GB_HuC1:
 223		mLOG(GB_MBC, WARN, "unimplemented MBC: HuC-1");
 224		gb->memory.mbcWrite = _GBMBC1;
 225		break;
 226	case GB_HuC3:
 227		gb->memory.mbcWrite = _GBHuC3;
 228		break;
 229	case GB_TAMA5:
 230		mLOG(GB_MBC, WARN, "unimplemented MBC: TAMA5");
 231		memset(gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
 232		gb->memory.mbcWrite = _GBTAMA5;
 233		gb->memory.mbcRead = _GBTAMA5Read;
 234		gb->sramSize = 0x20;
 235		break;
 236	case GB_MBC3_RTC:
 237		memset(gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
 238		gb->memory.mbcWrite = _GBMBC3;
 239		break;
 240	case GB_MBC5_RUMBLE:
 241		gb->memory.mbcWrite = _GBMBC5;
 242		break;
 243	case GB_POCKETCAM:
 244		gb->memory.mbcWrite = _GBPocketCam;
 245		gb->memory.mbcRead = _GBPocketCamRead;
 246		if (gb->memory.cam && gb->memory.cam->startRequestImage) {
 247			gb->memory.cam->startRequestImage(gb->memory.cam, GBCAM_WIDTH, GBCAM_HEIGHT, mCOLOR_ANY);
 248		}
 249		break;
 250	}
 251
 252	gb->memory.currentBank = 1;
 253	gb->memory.sramCurrentBank = 0;
 254	gb->memory.sramAccess = false;
 255	gb->memory.rtcAccess = false;
 256	gb->memory.activeRtcReg = 0;
 257	gb->memory.rtcLatched = false;
 258	gb->memory.rtcLastLatch = 0;
 259	if (gb->memory.rtc) {
 260		if (gb->memory.rtc->sample) {
 261			gb->memory.rtc->sample(gb->memory.rtc);
 262		}
 263		gb->memory.rtcLastLatch = gb->memory.rtc->unixTime(gb->memory.rtc);
 264	} else {
 265		gb->memory.rtcLastLatch = time(0);
 266	}
 267	memset(&gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
 268
 269	GBResizeSram(gb, gb->sramSize);
 270
 271	if (gb->memory.mbcType == GB_MBC3_RTC) {
 272		GBMBCRTCRead(gb);
 273	}
 274}
 275
 276static void _latchRtc(struct mRTCSource* rtc, uint8_t* rtcRegs, time_t* rtcLastLatch) {
 277	time_t t;
 278	if (rtc) {
 279		if (rtc->sample) {
 280			rtc->sample(rtc);
 281		}
 282		t = rtc->unixTime(rtc);
 283	} else {
 284		t = time(0);
 285	}
 286	time_t currentLatch = t;
 287	t -= *rtcLastLatch;
 288	*rtcLastLatch = currentLatch;
 289
 290	int64_t diff;
 291	diff = rtcRegs[0] + t % 60;
 292	if (diff < 0) {
 293		diff += 60;
 294		t -= 60;
 295	}
 296	rtcRegs[0] = diff % 60;
 297	t /= 60;
 298	t += diff / 60;
 299
 300	diff = rtcRegs[1] + t % 60;
 301	if (diff < 0) {
 302		diff += 60;
 303		t -= 60;
 304	}
 305	rtcRegs[1] = diff % 60;
 306	t /= 60;
 307	t += diff / 60;
 308
 309	diff = rtcRegs[2] + t % 24;
 310	if (diff < 0) {
 311		diff += 24;
 312		t -= 24;
 313	}
 314	rtcRegs[2] = diff % 24;
 315	t /= 24;
 316	t += diff / 24;
 317
 318	diff = rtcRegs[3] + ((rtcRegs[4] & 1) << 8) + (t & 0x1FF);
 319	rtcRegs[3] = diff;
 320	rtcRegs[4] &= 0xFE;
 321	rtcRegs[4] |= (diff >> 8) & 1;
 322	if (diff & 0x200) {
 323		rtcRegs[4] |= 0x80;
 324	}
 325}
 326
 327void _GBMBC1(struct GB* gb, uint16_t address, uint8_t value) {
 328	struct GBMemory* memory = &gb->memory;
 329	int bank = value & 0x1F;
 330	int stride = 1 << memory->mbcState.mbc1.multicartStride;
 331	switch (address >> 13) {
 332	case 0x0:
 333		switch (value) {
 334		case 0:
 335			memory->sramAccess = false;
 336			break;
 337		case 0xA:
 338			memory->sramAccess = true;
 339			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 340			break;
 341		default:
 342			// TODO
 343			mLOG(GB_MBC, STUB, "MBC1 unknown value %02X", value);
 344			break;
 345		}
 346		break;
 347	case 0x1:
 348		if (!bank) {
 349			++bank;
 350		}
 351		bank &= stride - 1;
 352		GBMBCSwitchBank(gb, bank | (memory->currentBank & (3 * stride)));
 353		break;
 354	case 0x2:
 355		bank &= 3;
 356		if (memory->mbcState.mbc1.mode) {
 357			GBMBCSwitchBank0(gb, bank);
 358			GBMBCSwitchSramBank(gb, bank);
 359		}
 360		GBMBCSwitchBank(gb, (bank << memory->mbcState.mbc1.multicartStride) | (memory->currentBank & (stride - 1)));
 361		break;
 362	case 0x3:
 363		memory->mbcState.mbc1.mode = value & 1;
 364		if (memory->mbcState.mbc1.mode) {
 365			GBMBCSwitchBank0(gb, memory->currentBank >> memory->mbcState.mbc1.multicartStride);
 366		} else {
 367			GBMBCSwitchBank0(gb, 0);
 368			GBMBCSwitchSramBank(gb, 0);
 369		}
 370		break;
 371	default:
 372		// TODO
 373		mLOG(GB_MBC, STUB, "MBC1 unknown address: %04X:%02X", address, value);
 374		break;
 375	}
 376}
 377
 378void _GBMBC2(struct GB* gb, uint16_t address, uint8_t value) {
 379	struct GBMemory* memory = &gb->memory;
 380	int bank = value & 0xF;
 381	switch (address >> 13) {
 382	case 0x0:
 383		switch (value) {
 384		case 0:
 385			memory->sramAccess = false;
 386			break;
 387		case 0xA:
 388			memory->sramAccess = true;
 389			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 390			break;
 391		default:
 392			// TODO
 393			mLOG(GB_MBC, STUB, "MBC1 unknown value %02X", value);
 394			break;
 395		}
 396		break;
 397	case 0x1:
 398		if (!bank) {
 399			++bank;
 400		}
 401		GBMBCSwitchBank(gb, bank);
 402		break;
 403	default:
 404		// TODO
 405		mLOG(GB_MBC, STUB, "MBC2 unknown address: %04X:%02X", address, value);
 406		break;
 407	}
 408}
 409
 410void _GBMBC3(struct GB* gb, uint16_t address, uint8_t value) {
 411	struct GBMemory* memory = &gb->memory;
 412	int bank = value & 0x7F;
 413	switch (address >> 13) {
 414	case 0x0:
 415		switch (value) {
 416		case 0:
 417			memory->sramAccess = false;
 418			break;
 419		case 0xA:
 420			memory->sramAccess = true;
 421			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 422			break;
 423		default:
 424			// TODO
 425			mLOG(GB_MBC, STUB, "MBC3 unknown value %02X", value);
 426			break;
 427		}
 428		break;
 429	case 0x1:
 430		if (!bank) {
 431			++bank;
 432		}
 433		GBMBCSwitchBank(gb, bank);
 434		break;
 435	case 0x2:
 436		if (value < 4) {
 437			GBMBCSwitchSramBank(gb, value);
 438			memory->rtcAccess = false;
 439		} else if (value >= 8 && value <= 0xC) {
 440			memory->activeRtcReg = value - 8;
 441			memory->rtcAccess = true;
 442		}
 443		break;
 444	case 0x3:
 445		if (memory->rtcLatched && value == 0) {
 446			memory->rtcLatched = false;
 447		} else if (!memory->rtcLatched && value == 1) {
 448			_latchRtc(gb->memory.rtc, gb->memory.rtcRegs, &gb->memory.rtcLastLatch);
 449			memory->rtcLatched = true;
 450		}
 451		break;
 452	}
 453}
 454
 455void _GBMBC5(struct GB* gb, uint16_t address, uint8_t value) {
 456	struct GBMemory* memory = &gb->memory;
 457	int bank;
 458	switch (address >> 12) {
 459	case 0x0:
 460	case 0x1:
 461		switch (value) {
 462		case 0:
 463			memory->sramAccess = false;
 464			break;
 465		case 0xA:
 466			memory->sramAccess = true;
 467			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 468			break;
 469		default:
 470			// TODO
 471			mLOG(GB_MBC, STUB, "MBC5 unknown value %02X", value);
 472			break;
 473		}
 474		break;
 475	case 0x2:
 476		bank = (memory->currentBank & 0x100) | value;
 477		GBMBCSwitchBank(gb, bank);
 478		break;
 479	case 0x3:
 480		bank = (memory->currentBank & 0xFF) | ((value & 1) << 8);
 481		GBMBCSwitchBank(gb, bank);
 482		break;
 483	case 0x4:
 484	case 0x5:
 485		if (memory->mbcType == GB_MBC5_RUMBLE && memory->rumble) {
 486			memory->rumble->setRumble(memory->rumble, (value >> 3) & 1);
 487			value &= ~8;
 488		}
 489		GBMBCSwitchSramBank(gb, value & 0xF);
 490		break;
 491	default:
 492		// TODO
 493		mLOG(GB_MBC, STUB, "MBC5 unknown address: %04X:%02X", address, value);
 494		break;
 495	}
 496}
 497
 498void _GBMBC6(struct GB* gb, uint16_t address, uint8_t value) {
 499	// TODO
 500	mLOG(GB_MBC, STUB, "MBC6 unimplemented");
 501	UNUSED(gb);
 502	UNUSED(address);
 503	UNUSED(value);
 504}
 505
 506void _GBMBC7(struct GB* gb, uint16_t address, uint8_t value) {
 507	int bank = value & 0x7F;
 508	switch (address >> 13) {
 509	case 0x0:
 510		switch (value) {
 511		default:
 512		case 0:
 513			gb->memory.mbcState.mbc7.access = 0;
 514			break;
 515		case 0xA:
 516			gb->memory.mbcState.mbc7.access |= 1;
 517			break;
 518		}
 519		break;
 520	case 0x1:
 521		GBMBCSwitchBank(gb, bank);
 522		break;
 523	case 0x2:
 524		if (value == 0x40) {
 525			gb->memory.mbcState.mbc7.access |= 2;
 526		} else {
 527			gb->memory.mbcState.mbc7.access &= ~2;
 528		}
 529		break;
 530	case 0x5:
 531		_GBMBC7Write(&gb->memory, address, value);
 532	default:
 533		// TODO
 534		mLOG(GB_MBC, STUB, "MBC7 unknown address: %04X:%02X", address, value);
 535		break;
 536	}
 537}
 538
 539uint8_t _GBMBC7Read(struct GBMemory* memory, uint16_t address) {
 540	struct GBMBC7State* mbc7 = &memory->mbcState.mbc7;
 541	if (mbc7->access != 3) {
 542		return 0xFF;
 543	}
 544	switch (address & 0xF0) {
 545	case 0x20:
 546		if (memory->rotation && memory->rotation->readTiltX) {
 547			int32_t x = -memory->rotation->readTiltX(memory->rotation);
 548			x >>= 21;
 549			x += 0x81D0;
 550			return x;
 551		}
 552		return 0xFF;
 553	case 0x30:
 554		if (memory->rotation && memory->rotation->readTiltX) {
 555			int32_t x = -memory->rotation->readTiltX(memory->rotation);
 556			x >>= 21;
 557			x += 0x81D0;
 558			return x >> 8;
 559		}
 560		return 7;
 561	case 0x40:
 562		if (memory->rotation && memory->rotation->readTiltY) {
 563			int32_t y = -memory->rotation->readTiltY(memory->rotation);
 564			y >>= 21;
 565			y += 0x81D0;
 566			return y;
 567		}
 568		return 0xFF;
 569	case 0x50:
 570		if (memory->rotation && memory->rotation->readTiltY) {
 571			int32_t y = -memory->rotation->readTiltY(memory->rotation);
 572			y >>= 21;
 573			y += 0x81D0;
 574			return y >> 8;
 575		}
 576		return 7;
 577	case 0x60:
 578		return 0;
 579	case 0x80:
 580		return mbc7->eeprom;
 581	default:
 582		return 0xFF;
 583	}
 584}
 585
 586static void _GBMBC7Write(struct GBMemory* memory, uint16_t address, uint8_t value) {
 587	struct GBMBC7State* mbc7 = &memory->mbcState.mbc7;
 588	if (mbc7->access != 3) {
 589		return;
 590	}
 591	switch (address & 0xF0) {
 592	case 0x00:
 593		mbc7->latch = (value & 0x55) == 0x55;
 594		return;
 595	case 0x10:
 596		mbc7->latch |= (value & 0xAA);
 597		if (mbc7->latch == 0xAB && memory->rotation && memory->rotation->sample) {
 598			memory->rotation->sample(memory->rotation);
 599		}
 600		mbc7->latch = 0;
 601		return;
 602	default:
 603		mLOG(GB_MBC, STUB, "MBC7 unknown register: %04X:%02X", address, value);
 604		return;
 605	case 0x80:
 606		break;
 607	}
 608	GBMBC7Field old = memory->mbcState.mbc7.eeprom;
 609	value = GBMBC7FieldFillDO(value); // Hi-Z
 610	if (!GBMBC7FieldIsCS(old) && GBMBC7FieldIsCS(value)) {
 611		mbc7->state = GBMBC7_STATE_IDLE;
 612	}
 613	if (!GBMBC7FieldIsCLK(old) && GBMBC7FieldIsCLK(value)) {
 614		if (mbc7->state == GBMBC7_STATE_READ_COMMAND || mbc7->state == GBMBC7_STATE_EEPROM_WRITE || mbc7->state == GBMBC7_STATE_EEPROM_WRAL) {
 615			mbc7->sr <<= 1;
 616			mbc7->sr |= GBMBC7FieldGetDI(value);
 617			++mbc7->srBits;
 618		}
 619		switch (mbc7->state) {
 620		case GBMBC7_STATE_IDLE:
 621			if (GBMBC7FieldIsDI(value)) {
 622				mbc7->state = GBMBC7_STATE_READ_COMMAND;
 623				mbc7->srBits = 0;
 624				mbc7->sr = 0;
 625			}
 626			break;
 627		case GBMBC7_STATE_READ_COMMAND:
 628			if (mbc7->srBits == 10) {
 629				mbc7->state = 0x10 | (mbc7->sr >> 6);
 630				if (mbc7->state & 0xC) {
 631					mbc7->state &= ~0x3;
 632				}
 633				mbc7->srBits = 0;
 634				mbc7->address = mbc7->sr & 0x7F;
 635			}
 636			break;
 637		case GBMBC7_STATE_DO:
 638			value = GBMBC7FieldSetDO(value, mbc7->sr >> 15);
 639			mbc7->sr <<= 1;
 640			--mbc7->srBits;
 641			if (!mbc7->srBits) {
 642				mbc7->state = GBMBC7_STATE_IDLE;
 643			}
 644			break;
 645		default:
 646			break;
 647		}
 648		switch (mbc7->state) {
 649		case GBMBC7_STATE_EEPROM_EWEN:
 650			mbc7->writable = true;
 651			mbc7->state = GBMBC7_STATE_IDLE;
 652			break;
 653		case GBMBC7_STATE_EEPROM_EWDS:
 654			mbc7->writable = false;
 655			mbc7->state = GBMBC7_STATE_IDLE;
 656			break;
 657		case GBMBC7_STATE_EEPROM_WRITE:
 658			if (mbc7->srBits == 16) {
 659				if (mbc7->writable) {
 660					memory->sram[mbc7->address * 2] = mbc7->sr >> 8;
 661					memory->sram[mbc7->address * 2 + 1] = mbc7->sr;
 662				}
 663				mbc7->state = GBMBC7_STATE_IDLE;
 664			}
 665			break;
 666		case GBMBC7_STATE_EEPROM_ERASE:
 667			if (mbc7->writable) {
 668				memory->sram[mbc7->address * 2] = 0xFF;
 669				memory->sram[mbc7->address * 2 + 1] = 0xFF;
 670			}
 671			mbc7->state = GBMBC7_STATE_IDLE;
 672			break;
 673		case GBMBC7_STATE_EEPROM_READ:
 674			mbc7->srBits = 16;
 675			mbc7->sr = memory->sram[mbc7->address * 2] << 8;
 676			mbc7->sr |= memory->sram[mbc7->address * 2 + 1];
 677			mbc7->state = GBMBC7_STATE_DO;
 678			value = GBMBC7FieldClearDO(value);
 679			break;
 680		case GBMBC7_STATE_EEPROM_WRAL:
 681			if (mbc7->srBits == 16) {
 682				if (mbc7->writable) {
 683					int i;
 684					for (i = 0; i < 128; ++i) {
 685						memory->sram[i * 2] = mbc7->sr >> 8;
 686						memory->sram[i * 2 + 1] = mbc7->sr;
 687					}
 688				}
 689				mbc7->state = GBMBC7_STATE_IDLE;
 690			}
 691			break;
 692		case GBMBC7_STATE_EEPROM_ERAL:
 693			if (mbc7->writable) {
 694				int i;
 695				for (i = 0; i < 128; ++i) {
 696					memory->sram[i * 2] = 0xFF;
 697					memory->sram[i * 2 + 1] = 0xFF;
 698				}
 699			}
 700			mbc7->state = GBMBC7_STATE_IDLE;
 701			break;
 702		default:
 703			break;
 704		}
 705	} else if (GBMBC7FieldIsCS(value) && GBMBC7FieldIsCLK(old) && !GBMBC7FieldIsCLK(value)) {
 706		value = GBMBC7FieldSetDO(value, GBMBC7FieldGetDO(old));
 707	}
 708	mbc7->eeprom = value;
 709}
 710
 711void _GBHuC3(struct GB* gb, uint16_t address, uint8_t value) {
 712	struct GBMemory* memory = &gb->memory;
 713	int bank = value & 0x3F;
 714	if (address & 0x1FFF) {
 715		mLOG(GB_MBC, STUB, "HuC-3 unknown value %04X:%02X", address, value);
 716	}
 717
 718	switch (address >> 13) {
 719	case 0x0:
 720		switch (value) {
 721		case 0xA:
 722			memory->sramAccess = true;
 723			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 724			break;
 725		default:
 726			memory->sramAccess = false;
 727			break;
 728		}
 729		break;
 730	case 0x1:
 731		GBMBCSwitchBank(gb, bank);
 732		break;
 733	case 0x2:
 734		GBMBCSwitchSramBank(gb, bank);
 735		break;
 736	default:
 737		// TODO
 738		mLOG(GB_MBC, STUB, "HuC-3 unknown address: %04X:%02X", address, value);
 739		break;
 740	}
 741}
 742
 743void _GBPocketCam(struct GB* gb, uint16_t address, uint8_t value) {
 744	struct GBMemory* memory = &gb->memory;
 745	int bank = value & 0x3F;
 746	switch (address >> 13) {
 747	case 0x0:
 748		switch (value) {
 749		case 0:
 750			memory->sramAccess = false;
 751			break;
 752		case 0xA:
 753			memory->sramAccess = true;
 754			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 755			break;
 756		default:
 757			// TODO
 758			mLOG(GB_MBC, STUB, "Pocket Cam unknown value %02X", value);
 759			break;
 760		}
 761		break;
 762	case 0x1:
 763		GBMBCSwitchBank(gb, bank);
 764		break;
 765	case 0x2:
 766		if (value < 0x10) {
 767			GBMBCSwitchSramBank(gb, value);
 768			memory->mbcState.pocketCam.registersActive = false;
 769		} else {
 770			memory->mbcState.pocketCam.registersActive = true;
 771		}
 772		break;
 773	case 0x5:
 774		address &= 0x7F;
 775		if (address == 0 && value & 1) {
 776			value &= 6; // TODO: Timing
 777			_GBPocketCamCapture(memory);
 778		}
 779		if (address < sizeof(memory->mbcState.pocketCam.registers)) {
 780			memory->mbcState.pocketCam.registers[address] = value;
 781		}
 782		break;
 783	default:
 784		mLOG(GB_MBC, STUB, "Pocket Cam unknown address: %04X:%02X", address, value);
 785		break;
 786	}
 787}
 788
 789uint8_t _GBPocketCamRead(struct GBMemory* memory, uint16_t address) {
 790	if (memory->mbcState.pocketCam.registersActive) {
 791		if ((address & 0x7F) == 0) {
 792			return memory->mbcState.pocketCam.registers[0];
 793		}
 794		return 0;
 795	}
 796	return memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)];
 797}
 798
 799void _GBPocketCamCapture(struct GBMemory* memory) {
 800	if (!memory->cam) {
 801		return;
 802	}
 803	const void* image = NULL;
 804	size_t stride;
 805	enum mColorFormat format;
 806	memory->cam->requestImage(memory->cam, &image, &stride, &format);
 807	if (!image) {
 808		return;
 809	}
 810	memset(&memory->sram[0x100], 0, GBCAM_HEIGHT * GBCAM_WIDTH / 4);
 811	struct GBPocketCamState* pocketCam = &memory->mbcState.pocketCam;
 812	size_t x, y;
 813	for (y = 0; y < GBCAM_HEIGHT; ++y) {
 814		for (x = 0; x < GBCAM_WIDTH; ++x) {
 815			uint32_t gray;
 816			uint32_t color;
 817			switch (format) {
 818			case mCOLOR_XBGR8:
 819			case mCOLOR_XRGB8:
 820			case mCOLOR_ARGB8:
 821			case mCOLOR_ABGR8:
 822				color = ((const uint32_t*) image)[y * stride + x];
 823				gray = (color & 0xFF) + ((color >> 8) & 0xFF) + ((color >> 16) & 0xFF);
 824				break;
 825			case mCOLOR_BGRX8:
 826			case mCOLOR_RGBX8:
 827			case mCOLOR_RGBA8:
 828			case mCOLOR_BGRA8:
 829				color = ((const uint32_t*) image)[y * stride + x];
 830				gray = ((color >> 8) & 0xFF) + ((color >> 16) & 0xFF) + ((color >> 24) & 0xFF);
 831				break;
 832			case mCOLOR_BGR5:
 833			case mCOLOR_RGB5:
 834			case mCOLOR_ARGB5:
 835			case mCOLOR_ABGR5:
 836				color = ((const uint16_t*) image)[y * stride + x];
 837				gray = ((color << 3) & 0xF8) + ((color >> 2) & 0xF8) + ((color >> 7) & 0xF8);
 838				break;
 839			case mCOLOR_BGR565:
 840			case mCOLOR_RGB565:
 841				color = ((const uint16_t*) image)[y * stride + x];
 842				gray = ((color << 3) & 0xF8) + ((color >> 3) & 0xFC) + ((color >> 8) & 0xF8);
 843				break;
 844			case mCOLOR_BGRA5:
 845			case mCOLOR_RGBA5:
 846				color = ((const uint16_t*) image)[y * stride + x];
 847				gray = ((color << 2) & 0xF8) + ((color >> 3) & 0xF8) + ((color >> 8) & 0xF8);
 848				break;
 849			default:
 850				mLOG(GB_MBC, WARN, "Unsupported pixel format: %X", format);
 851				return;
 852			}
 853			uint16_t exposure = (pocketCam->registers[2] << 8) | (pocketCam->registers[3]);
 854			gray = (gray + 1) * exposure / 0x300;
 855			// TODO: Additional processing
 856			int matrixEntry = 3 * ((x & 3) + 4 * (y & 3));
 857			if (gray < pocketCam->registers[matrixEntry + 6]) {
 858				gray = 0x101;
 859			} else if (gray < pocketCam->registers[matrixEntry + 7]) {
 860				gray = 0x100;
 861			} else if (gray < pocketCam->registers[matrixEntry + 8]) {
 862				gray = 0x001;
 863			} else {
 864				gray = 0;
 865			}
 866			int coord = (((x >> 3) & 0xF) * 8 + (y & 0x7)) * 2 + (y & ~0x7) * 0x20;
 867			uint16_t existing;
 868			LOAD_16LE(existing, coord + 0x100, memory->sram);
 869			existing |= gray << (7 - (x & 7));
 870			STORE_16LE(existing, coord + 0x100, memory->sram);
 871		}
 872	}
 873}
 874
 875void _GBTAMA5(struct GB* gb, uint16_t address, uint8_t value) {
 876	struct GBMemory* memory = &gb->memory;
 877	struct GBTAMA5State* tama5 = &memory->mbcState.tama5;
 878	switch (address >> 13) {
 879	case 0x5:
 880		if (address & 1) {
 881			tama5->reg = value;
 882		} else {
 883			value &= 0xF;
 884			if (tama5->reg < GBTAMA5_MAX) {
 885				tama5->registers[tama5->reg] = value;
 886				uint8_t address = ((tama5->registers[GBTAMA5_CS] << 4) & 0x10) | tama5->registers[GBTAMA5_ADDR_LO];
 887				uint8_t out = (tama5->registers[GBTAMA5_WRITE_HI] << 4) | tama5->registers[GBTAMA5_WRITE_LO];
 888				switch (tama5->reg) {
 889				case GBTAMA5_BANK_LO:
 890				case GBTAMA5_BANK_HI:
 891					GBMBCSwitchBank(gb, tama5->registers[GBTAMA5_BANK_LO] | (tama5->registers[GBTAMA5_BANK_HI] << 4));
 892					break;
 893				case GBTAMA5_WRITE_LO:
 894				case GBTAMA5_WRITE_HI:
 895				case GBTAMA5_CS:
 896					break;
 897				case GBTAMA5_ADDR_LO:
 898					switch (tama5->registers[GBTAMA5_CS] >> 1) {
 899					case 0x0: // RAM write
 900						memory->sram[address] = out;
 901						break;
 902					case 0x1: // RAM read
 903						break;
 904					default:
 905						mLOG(GB_MBC, STUB, "TAMA5 unknown address: %X-%02X:%02X", tama5->registers[GBTAMA5_CS] >> 1, address, out);
 906					}
 907					break;
 908				default:
 909					mLOG(GB_MBC, STUB, "TAMA5 unknown write: %02X:%X", tama5->reg, value);
 910					break;
 911				}
 912			} else {
 913				mLOG(GB_MBC, STUB, "TAMA5 unknown write: %02X", tama5->reg);
 914			}
 915		}
 916		break;
 917	default:
 918		mLOG(GB_MBC, STUB, "TAMA5 unknown address: %04X:%02X", address, value);
 919	}
 920}
 921
 922uint8_t _GBTAMA5Read(struct GBMemory* memory, uint16_t address) {
 923	struct GBTAMA5State* tama5 = &memory->mbcState.tama5;
 924	if ((address & 0x1FFF) > 1) {
 925		mLOG(GB_MBC, STUB, "TAMA5 unknown address: %04X", address);
 926	}
 927	if (address & 1) {
 928		return 0xFF;
 929	} else {
 930		uint8_t value = 0xF0;
 931		uint8_t address = ((tama5->registers[GBTAMA5_CS] << 4) & 0x10) | tama5->registers[GBTAMA5_ADDR_LO];
 932		switch (tama5->reg) {
 933		case GBTAMA5_ACTIVE:
 934			return 0xF1;
 935		case GBTAMA5_READ_LO:
 936		case GBTAMA5_READ_HI:
 937			switch (tama5->registers[GBTAMA5_CS] >> 1) {
 938			case 1:
 939				value = memory->sram[address];
 940				break;
 941			default:
 942				mLOG(GB_MBC, STUB, "TAMA5 unknown read: %02X", tama5->reg);
 943				break;
 944			}
 945			if (tama5->reg == GBTAMA5_READ_HI) {
 946				value >>= 4;
 947			}
 948			value |= 0xF0;
 949			return value;
 950		default:
 951			mLOG(GB_MBC, STUB, "TAMA5 unknown read: %02X", tama5->reg);
 952			return 0xF1;
 953		}
 954	}
 955}
 956
 957void GBMBCRTCRead(struct GB* gb) {
 958	struct GBMBCRTCSaveBuffer rtcBuffer;
 959	struct VFile* vf = gb->sramVf;
 960	if (!vf) {
 961		return;
 962	}
 963	vf->seek(vf, gb->sramSize, SEEK_SET);
 964	if (vf->read(vf, &rtcBuffer, sizeof(rtcBuffer)) < (ssize_t) sizeof(rtcBuffer) - 4) {
 965		return;
 966	}
 967
 968	LOAD_32LE(gb->memory.rtcRegs[0], 0, &rtcBuffer.latchedSec);
 969	LOAD_32LE(gb->memory.rtcRegs[1], 0, &rtcBuffer.latchedMin);
 970	LOAD_32LE(gb->memory.rtcRegs[2], 0, &rtcBuffer.latchedHour);
 971	LOAD_32LE(gb->memory.rtcRegs[3], 0, &rtcBuffer.latchedDays);
 972	LOAD_32LE(gb->memory.rtcRegs[4], 0, &rtcBuffer.latchedDaysHi);
 973	LOAD_64LE(gb->memory.rtcLastLatch, 0, &rtcBuffer.unixTime);
 974}
 975
 976void GBMBCRTCWrite(struct GB* gb) {
 977	struct VFile* vf = gb->sramVf;
 978	if (!vf) {
 979		return;
 980	}
 981
 982	uint8_t rtcRegs[5];
 983	memcpy(rtcRegs, gb->memory.rtcRegs, sizeof(rtcRegs));
 984	time_t rtcLastLatch = gb->memory.rtcLastLatch;
 985	_latchRtc(gb->memory.rtc, rtcRegs, &rtcLastLatch);
 986
 987	struct GBMBCRTCSaveBuffer rtcBuffer;
 988	STORE_32LE(rtcRegs[0], 0, &rtcBuffer.sec);
 989	STORE_32LE(rtcRegs[1], 0, &rtcBuffer.min);
 990	STORE_32LE(rtcRegs[2], 0, &rtcBuffer.hour);
 991	STORE_32LE(rtcRegs[3], 0, &rtcBuffer.days);
 992	STORE_32LE(rtcRegs[4], 0, &rtcBuffer.daysHi);
 993	STORE_32LE(gb->memory.rtcRegs[0], 0, &rtcBuffer.latchedSec);
 994	STORE_32LE(gb->memory.rtcRegs[1], 0, &rtcBuffer.latchedMin);
 995	STORE_32LE(gb->memory.rtcRegs[2], 0, &rtcBuffer.latchedHour);
 996	STORE_32LE(gb->memory.rtcRegs[3], 0, &rtcBuffer.latchedDays);
 997	STORE_32LE(gb->memory.rtcRegs[4], 0, &rtcBuffer.latchedDaysHi);
 998	STORE_64LE(gb->memory.rtcLastLatch, 0, &rtcBuffer.unixTime);
 999
1000	if ((size_t) vf->size(vf) < gb->sramSize + sizeof(rtcBuffer)) {
1001		// Writing past the end of the file can invalidate the file mapping
1002		vf->unmap(vf, gb->memory.sram, gb->sramSize);
1003		gb->memory.sram = NULL;
1004	}
1005	vf->seek(vf, gb->sramSize, SEEK_SET);
1006	vf->write(vf, &rtcBuffer, sizeof(rtcBuffer));
1007	if (!gb->memory.sram) {
1008		gb->memory.sram = vf->map(vf, gb->sramSize, MAP_WRITE);
1009		GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
1010	}
1011}