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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 _GBHuC1(struct GB*, uint16_t address, uint8_t value);
  31static void _GBHuC3(struct GB*, uint16_t address, uint8_t value);
  32static void _GBPocketCam(struct GB* gb, uint16_t address, uint8_t value);
  33static void _GBTAMA5(struct GB* gb, uint16_t address, uint8_t value);
  34
  35static uint8_t _GBMBC2Read(struct GBMemory*, uint16_t address);
  36static uint8_t _GBMBC6Read(struct GBMemory*, uint16_t address);
  37static uint8_t _GBMBC7Read(struct GBMemory*, uint16_t address);
  38static void _GBMBC7Write(struct GBMemory* memory, uint16_t address, uint8_t value);
  39
  40static uint8_t _GBTAMA5Read(struct GBMemory*, uint16_t address);
  41
  42static uint8_t _GBPocketCamRead(struct GBMemory*, uint16_t address);
  43static void _GBPocketCamCapture(struct GBMemory*);
  44
  45void GBMBCSwitchBank(struct GB* gb, int bank) {
  46	size_t bankStart = bank * GB_SIZE_CART_BANK0;
  47	if (bankStart + GB_SIZE_CART_BANK0 > gb->memory.romSize) {
  48		mLOG(GB_MBC, GAME_ERROR, "Attempting to switch to an invalid ROM bank: %0X", bank);
  49		bankStart &= (gb->memory.romSize - 1);
  50		bank = bankStart / GB_SIZE_CART_BANK0;
  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
  71void GBMBCSwitchHalfBank(struct GB* gb, int half, int bank) {
  72	size_t bankStart = bank * GB_SIZE_CART_HALFBANK;
  73	if (bankStart + GB_SIZE_CART_HALFBANK > gb->memory.romSize) {
  74		mLOG(GB_MBC, GAME_ERROR, "Attempting to switch to an invalid ROM bank: %0X", bank);
  75		bankStart &= (gb->memory.romSize - 1);
  76		bank = bankStart / GB_SIZE_CART_HALFBANK;
  77		if (!bank) {
  78			++bank;
  79		}
  80	}
  81	if (!half) {
  82		gb->memory.romBank = &gb->memory.rom[bankStart];
  83		gb->memory.currentBank = bank;
  84	} else {
  85		gb->memory.mbcState.mbc6.romBank1 = &gb->memory.rom[bankStart];
  86		gb->memory.mbcState.mbc6.currentBank1 = bank;
  87	}
  88	if (gb->cpu->pc < GB_BASE_VRAM) {
  89		gb->cpu->memory.setActiveRegion(gb->cpu, gb->cpu->pc);
  90	}
  91}
  92
  93static bool _isMulticart(const uint8_t* mem) {
  94	bool success = true;
  95	struct VFile* vf;
  96
  97	vf = VFileFromConstMemory(&mem[GB_SIZE_CART_BANK0 * 0x10], 1024);
  98	success = success && GBIsROM(vf);
  99	vf->close(vf);
 100
 101	vf = VFileFromConstMemory(&mem[GB_SIZE_CART_BANK0 * 0x20], 1024);
 102	success = success && GBIsROM(vf);
 103	vf->close(vf);
 104
 105	return success;
 106}
 107
 108void GBMBCSwitchSramBank(struct GB* gb, int bank) {
 109	size_t bankStart = bank * GB_SIZE_EXTERNAL_RAM;
 110	if (bankStart + GB_SIZE_EXTERNAL_RAM > gb->sramSize) {
 111		mLOG(GB_MBC, GAME_ERROR, "Attempting to switch to an invalid RAM bank: %0X", bank);
 112		bankStart &= (gb->sramSize - 1);
 113		bank = bankStart / GB_SIZE_EXTERNAL_RAM;
 114	}
 115	gb->memory.sramBank = &gb->memory.sram[bankStart];
 116	gb->memory.sramCurrentBank = bank;
 117}
 118
 119void GBMBCSwitchSramHalfBank(struct GB* gb, int half, int bank) {
 120	size_t bankStart = bank * GB_SIZE_EXTERNAL_RAM_HALFBANK;
 121	if (bankStart + GB_SIZE_EXTERNAL_RAM_HALFBANK > gb->sramSize) {
 122		mLOG(GB_MBC, GAME_ERROR, "Attempting to switch to an invalid RAM bank: %0X", bank);
 123		bankStart &= (gb->sramSize - 1);
 124		bank = bankStart / GB_SIZE_EXTERNAL_RAM_HALFBANK;
 125	}
 126	if (!half) {
 127		gb->memory.sramBank = &gb->memory.sram[bankStart];
 128		gb->memory.sramCurrentBank = bank;
 129	} else {
 130		gb->memory.mbcState.mbc6.sramBank1 = &gb->memory.sram[bankStart];
 131		gb->memory.mbcState.mbc6.currentSramBank1 = bank;
 132	}
 133}
 134
 135void GBMBCInit(struct GB* gb) {
 136	const struct GBCartridge* cart = (const struct GBCartridge*) &gb->memory.rom[0x100];
 137	if (gb->memory.rom) {
 138		switch (cart->ramSize) {
 139		case 0:
 140			gb->sramSize = 0;
 141			break;
 142		case 1:
 143			gb->sramSize = 0x800;
 144			break;
 145		default:
 146		case 2:
 147			gb->sramSize = 0x2000;
 148			break;
 149		case 3:
 150			gb->sramSize = 0x8000;
 151			break;
 152		case 4:
 153			gb->sramSize = 0x20000;
 154			break;
 155		case 5:
 156			gb->sramSize = 0x10000;
 157			break;
 158		}
 159
 160		if (gb->memory.mbcType == GB_MBC_AUTODETECT) {
 161			switch (cart->type) {
 162			case 0:
 163			case 8:
 164			case 9:
 165				gb->memory.mbcType = GB_MBC_NONE;
 166				break;
 167			case 1:
 168			case 2:
 169			case 3:
 170				gb->memory.mbcType = GB_MBC1;
 171				if (gb->memory.romSize >= GB_SIZE_CART_BANK0 * 0x31 && _isMulticart(gb->memory.rom)) {
 172					gb->memory.mbcState.mbc1.multicartStride = 4;
 173				} else {
 174					gb->memory.mbcState.mbc1.multicartStride = 5;
 175				}
 176				break;
 177			case 5:
 178			case 6:
 179				gb->memory.mbcType = GB_MBC2;
 180				break;
 181			case 0x0F:
 182			case 0x10:
 183				gb->memory.mbcType = GB_MBC3_RTC;
 184				break;
 185			case 0x11:
 186			case 0x12:
 187			case 0x13:
 188				gb->memory.mbcType = GB_MBC3;
 189				break;
 190			default:
 191				mLOG(GB_MBC, WARN, "Unknown MBC type: %02X", cart->type);
 192				// Fall through
 193			case 0x19:
 194			case 0x1A:
 195			case 0x1B:
 196				gb->memory.mbcType = GB_MBC5;
 197				break;
 198			case 0x1C:
 199			case 0x1D:
 200			case 0x1E:
 201				gb->memory.mbcType = GB_MBC5_RUMBLE;
 202				break;
 203			case 0x20:
 204				gb->memory.mbcType = GB_MBC6;
 205				break;
 206			case 0x22:
 207				gb->memory.mbcType = GB_MBC7;
 208				break;
 209			case 0xFC:
 210				gb->memory.mbcType = GB_POCKETCAM;
 211				break;
 212			case 0xFD:
 213				gb->memory.mbcType = GB_TAMA5;
 214				break;
 215			case 0xFE:
 216				gb->memory.mbcType = GB_HuC3;
 217				break;
 218			case 0xFF:
 219				gb->memory.mbcType = GB_HuC1;
 220				break;
 221			}
 222		}
 223	} else {
 224		gb->memory.mbcType = GB_MBC_NONE;
 225	}
 226	gb->memory.mbcRead = NULL;
 227	switch (gb->memory.mbcType) {
 228	case GB_MBC_NONE:
 229		gb->memory.mbcWrite = _GBMBCNone;
 230		break;
 231	case GB_MBC1:
 232		gb->memory.mbcWrite = _GBMBC1;
 233		break;
 234	case GB_MBC2:
 235		gb->memory.mbcWrite = _GBMBC2;
 236		gb->memory.mbcRead = _GBMBC2Read;
 237		gb->sramSize = 0x100;
 238		break;
 239	case GB_MBC3:
 240		gb->memory.mbcWrite = _GBMBC3;
 241		break;
 242	default:
 243		mLOG(GB_MBC, WARN, "Unknown MBC type: %02X", cart->type);
 244		// Fall through
 245	case GB_MBC5:
 246		gb->memory.mbcWrite = _GBMBC5;
 247		break;
 248	case GB_MBC6:
 249		mLOG(GB_MBC, WARN, "unimplemented MBC: MBC6");
 250		gb->memory.mbcWrite = _GBMBC6;
 251		gb->memory.mbcRead = _GBMBC6Read;
 252		break;
 253	case GB_MBC7:
 254		gb->memory.mbcWrite = _GBMBC7;
 255		gb->memory.mbcRead = _GBMBC7Read;
 256		gb->sramSize = 0x100;
 257		break;
 258	case GB_MMM01:
 259		mLOG(GB_MBC, WARN, "unimplemented MBC: MMM01");
 260		gb->memory.mbcWrite = _GBMBC1;
 261		break;
 262	case GB_HuC1:
 263		gb->memory.mbcWrite = _GBHuC1;
 264		break;
 265	case GB_HuC3:
 266		gb->memory.mbcWrite = _GBHuC3;
 267		break;
 268	case GB_TAMA5:
 269		mLOG(GB_MBC, WARN, "unimplemented MBC: TAMA5");
 270		memset(gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
 271		gb->memory.mbcWrite = _GBTAMA5;
 272		gb->memory.mbcRead = _GBTAMA5Read;
 273		gb->sramSize = 0x20;
 274		break;
 275	case GB_MBC3_RTC:
 276		memset(gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
 277		gb->memory.mbcWrite = _GBMBC3;
 278		break;
 279	case GB_MBC5_RUMBLE:
 280		gb->memory.mbcWrite = _GBMBC5;
 281		break;
 282	case GB_POCKETCAM:
 283		gb->memory.mbcWrite = _GBPocketCam;
 284		gb->memory.mbcRead = _GBPocketCamRead;
 285		if (gb->memory.cam && gb->memory.cam->startRequestImage) {
 286			gb->memory.cam->startRequestImage(gb->memory.cam, GBCAM_WIDTH, GBCAM_HEIGHT, mCOLOR_ANY);
 287		}
 288		break;
 289	}
 290
 291	gb->memory.currentBank = 1;
 292	gb->memory.sramCurrentBank = 0;
 293	gb->memory.sramAccess = false;
 294	gb->memory.rtcAccess = false;
 295	gb->memory.activeRtcReg = 0;
 296	gb->memory.rtcLatched = false;
 297	gb->memory.rtcLastLatch = 0;
 298	if (gb->memory.rtc) {
 299		if (gb->memory.rtc->sample) {
 300			gb->memory.rtc->sample(gb->memory.rtc);
 301		}
 302		gb->memory.rtcLastLatch = gb->memory.rtc->unixTime(gb->memory.rtc);
 303	} else {
 304		gb->memory.rtcLastLatch = time(0);
 305	}
 306	memset(&gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
 307
 308	GBResizeSram(gb, gb->sramSize);
 309
 310	if (gb->memory.mbcType == GB_MBC3_RTC) {
 311		GBMBCRTCRead(gb);
 312	}
 313}
 314
 315static void _latchRtc(struct mRTCSource* rtc, uint8_t* rtcRegs, time_t* rtcLastLatch) {
 316	time_t t;
 317	if (rtc) {
 318		if (rtc->sample) {
 319			rtc->sample(rtc);
 320		}
 321		t = rtc->unixTime(rtc);
 322	} else {
 323		t = time(0);
 324	}
 325	time_t currentLatch = t;
 326	t -= *rtcLastLatch;
 327	*rtcLastLatch = currentLatch;
 328
 329	int64_t diff;
 330	diff = rtcRegs[0] + t % 60;
 331	if (diff < 0) {
 332		diff += 60;
 333		t -= 60;
 334	}
 335	rtcRegs[0] = diff % 60;
 336	t /= 60;
 337	t += diff / 60;
 338
 339	diff = rtcRegs[1] + t % 60;
 340	if (diff < 0) {
 341		diff += 60;
 342		t -= 60;
 343	}
 344	rtcRegs[1] = diff % 60;
 345	t /= 60;
 346	t += diff / 60;
 347
 348	diff = rtcRegs[2] + t % 24;
 349	if (diff < 0) {
 350		diff += 24;
 351		t -= 24;
 352	}
 353	rtcRegs[2] = diff % 24;
 354	t /= 24;
 355	t += diff / 24;
 356
 357	diff = rtcRegs[3] + ((rtcRegs[4] & 1) << 8) + (t & 0x1FF);
 358	rtcRegs[3] = diff;
 359	rtcRegs[4] &= 0xFE;
 360	rtcRegs[4] |= (diff >> 8) & 1;
 361	if (diff & 0x200) {
 362		rtcRegs[4] |= 0x80;
 363	}
 364}
 365
 366void _GBMBC1(struct GB* gb, uint16_t address, uint8_t value) {
 367	struct GBMemory* memory = &gb->memory;
 368	int bank = value & 0x1F;
 369	int stride = 1 << memory->mbcState.mbc1.multicartStride;
 370	switch (address >> 13) {
 371	case 0x0:
 372		switch (value) {
 373		case 0:
 374			memory->sramAccess = false;
 375			break;
 376		case 0xA:
 377			memory->sramAccess = true;
 378			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 379			break;
 380		default:
 381			// TODO
 382			mLOG(GB_MBC, STUB, "MBC1 unknown value %02X", value);
 383			break;
 384		}
 385		break;
 386	case 0x1:
 387		if (!bank) {
 388			++bank;
 389		}
 390		bank &= stride - 1;
 391		GBMBCSwitchBank(gb, bank | (memory->currentBank & (3 * stride)));
 392		break;
 393	case 0x2:
 394		bank &= 3;
 395		if (memory->mbcState.mbc1.mode) {
 396			GBMBCSwitchBank0(gb, bank);
 397			GBMBCSwitchSramBank(gb, bank);
 398		}
 399		GBMBCSwitchBank(gb, (bank << memory->mbcState.mbc1.multicartStride) | (memory->currentBank & (stride - 1)));
 400		break;
 401	case 0x3:
 402		memory->mbcState.mbc1.mode = value & 1;
 403		if (memory->mbcState.mbc1.mode) {
 404			GBMBCSwitchBank0(gb, memory->currentBank >> memory->mbcState.mbc1.multicartStride);
 405		} else {
 406			GBMBCSwitchBank0(gb, 0);
 407			GBMBCSwitchSramBank(gb, 0);
 408		}
 409		break;
 410	default:
 411		// TODO
 412		mLOG(GB_MBC, STUB, "MBC1 unknown address: %04X:%02X", address, value);
 413		break;
 414	}
 415}
 416
 417void _GBMBC2(struct GB* gb, uint16_t address, uint8_t value) {
 418	struct GBMemory* memory = &gb->memory;
 419	int shift = (address & 1) * 4;
 420	int bank = value & 0xF;
 421	switch (address >> 13) {
 422	case 0x0:
 423		switch (value) {
 424		case 0:
 425			memory->sramAccess = false;
 426			break;
 427		case 0xA:
 428			memory->sramAccess = true;
 429			break;
 430		default:
 431			// TODO
 432			mLOG(GB_MBC, STUB, "MBC1 unknown value %02X", value);
 433			break;
 434		}
 435		break;
 436	case 0x1:
 437		if (!bank) {
 438			++bank;
 439		}
 440		GBMBCSwitchBank(gb, bank);
 441		break;
 442	case 0x5:
 443		if (!memory->sramAccess) {
 444			return;
 445		}
 446		address &= 0x1FF;
 447		memory->sramBank[(address >> 1)] &= 0xF0 >> shift;
 448		memory->sramBank[(address >> 1)] |= (value & 0xF) << shift;
 449		break;
 450	default:
 451		// TODO
 452		mLOG(GB_MBC, STUB, "MBC2 unknown address: %04X:%02X", address, value);
 453		break;
 454	}
 455}
 456
 457static uint8_t _GBMBC2Read(struct GBMemory* memory, uint16_t address) {
 458	address &= 0x1FF;
 459	int shift = (address & 1) * 4;
 460	return (memory->sramBank[(address >> 1)] >> shift) | 0xF0;
 461}
 462
 463void _GBMBC3(struct GB* gb, uint16_t address, uint8_t value) {
 464	struct GBMemory* memory = &gb->memory;
 465	int bank = value & 0x7F;
 466	switch (address >> 13) {
 467	case 0x0:
 468		switch (value) {
 469		case 0:
 470			memory->sramAccess = false;
 471			break;
 472		case 0xA:
 473			memory->sramAccess = true;
 474			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 475			break;
 476		default:
 477			// TODO
 478			mLOG(GB_MBC, STUB, "MBC3 unknown value %02X", value);
 479			break;
 480		}
 481		break;
 482	case 0x1:
 483		if (!bank) {
 484			++bank;
 485		}
 486		GBMBCSwitchBank(gb, bank);
 487		break;
 488	case 0x2:
 489		if (value < 4) {
 490			GBMBCSwitchSramBank(gb, value);
 491			memory->rtcAccess = false;
 492		} else if (value >= 8 && value <= 0xC) {
 493			memory->activeRtcReg = value - 8;
 494			memory->rtcAccess = true;
 495		}
 496		break;
 497	case 0x3:
 498		if (memory->rtcLatched && value == 0) {
 499			memory->rtcLatched = false;
 500		} else if (!memory->rtcLatched && value == 1) {
 501			_latchRtc(gb->memory.rtc, gb->memory.rtcRegs, &gb->memory.rtcLastLatch);
 502			memory->rtcLatched = true;
 503		}
 504		break;
 505	}
 506}
 507
 508void _GBMBC5(struct GB* gb, uint16_t address, uint8_t value) {
 509	struct GBMemory* memory = &gb->memory;
 510	int bank;
 511	switch (address >> 12) {
 512	case 0x0:
 513	case 0x1:
 514		switch (value) {
 515		case 0:
 516			memory->sramAccess = false;
 517			break;
 518		case 0xA:
 519			memory->sramAccess = true;
 520			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 521			break;
 522		default:
 523			// TODO
 524			mLOG(GB_MBC, STUB, "MBC5 unknown value %02X", value);
 525			break;
 526		}
 527		break;
 528	case 0x2:
 529		bank = (memory->currentBank & 0x100) | value;
 530		GBMBCSwitchBank(gb, bank);
 531		break;
 532	case 0x3:
 533		bank = (memory->currentBank & 0xFF) | ((value & 1) << 8);
 534		GBMBCSwitchBank(gb, bank);
 535		break;
 536	case 0x4:
 537	case 0x5:
 538		if (memory->mbcType == GB_MBC5_RUMBLE && memory->rumble) {
 539			memory->rumble->setRumble(memory->rumble, (value >> 3) & 1);
 540			value &= ~8;
 541		}
 542		GBMBCSwitchSramBank(gb, value & 0xF);
 543		break;
 544	default:
 545		// TODO
 546		mLOG(GB_MBC, STUB, "MBC5 unknown address: %04X:%02X", address, value);
 547		break;
 548	}
 549}
 550
 551void _GBMBC6(struct GB* gb, uint16_t address, uint8_t value) {
 552	struct GBMemory* memory = &gb->memory;
 553	int bank = value;
 554	switch (address >> 10) {
 555	case 0:
 556		switch (value) {
 557		case 0:
 558			memory->mbcState.mbc6.sramAccess = false;
 559			break;
 560		case 0xA:
 561			memory->mbcState.mbc6.sramAccess = true;
 562			break;
 563		default:
 564			// TODO
 565			mLOG(GB_MBC, STUB, "MBC6 unknown value %02X", value);
 566			break;
 567		}
 568		break;
 569	case 0x1:
 570		GBMBCSwitchSramHalfBank(gb, 0, bank);
 571		break;
 572	case 0x2:
 573		GBMBCSwitchSramHalfBank(gb, 1, bank);
 574		break;
 575	case 0x8:
 576	case 0x9:
 577		GBMBCSwitchHalfBank(gb, 0, bank);
 578		break;
 579	case 0xC:
 580	case 0xD:
 581		GBMBCSwitchHalfBank(gb, 1, bank);
 582		break;
 583	case 0x28:
 584	case 0x29:
 585	case 0x2A:
 586	case 0x2B:
 587		if (memory->mbcState.mbc6.sramAccess) {
 588			memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM_HALFBANK - 1)] = value;
 589		}
 590		break;
 591	case 0x2C:
 592	case 0x2D:
 593	case 0x2E:
 594	case 0x2F:
 595		if (memory->mbcState.mbc6.sramAccess) {
 596			memory->mbcState.mbc6.sramBank1[address & (GB_SIZE_EXTERNAL_RAM_HALFBANK - 1)] = value;
 597		}
 598		break;
 599	default:
 600		mLOG(GB_MBC, STUB, "MBC6 unknown address: %04X:%02X", address, value);
 601		break;
 602	}
 603}
 604
 605uint8_t _GBMBC6Read(struct GBMemory* memory, uint16_t address) {
 606	if (!memory->mbcState.mbc6.sramAccess) {
 607		return 0xFF;
 608	}
 609	switch (address >> 12) {
 610	case 0xA:
 611		return memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM_HALFBANK - 1)];
 612	case 0xB:
 613		return memory->mbcState.mbc6.sramBank1[address & (GB_SIZE_EXTERNAL_RAM_HALFBANK - 1)];
 614	}
 615	return 0xFF;
 616}
 617
 618void _GBMBC7(struct GB* gb, uint16_t address, uint8_t value) {
 619	int bank = value & 0x7F;
 620	switch (address >> 13) {
 621	case 0x0:
 622		switch (value) {
 623		default:
 624		case 0:
 625			gb->memory.mbcState.mbc7.access = 0;
 626			break;
 627		case 0xA:
 628			gb->memory.mbcState.mbc7.access |= 1;
 629			break;
 630		}
 631		break;
 632	case 0x1:
 633		GBMBCSwitchBank(gb, bank);
 634		break;
 635	case 0x2:
 636		if (value == 0x40) {
 637			gb->memory.mbcState.mbc7.access |= 2;
 638		} else {
 639			gb->memory.mbcState.mbc7.access &= ~2;
 640		}
 641		break;
 642	case 0x5:
 643		_GBMBC7Write(&gb->memory, address, value);
 644		break;
 645	default:
 646		// TODO
 647		mLOG(GB_MBC, STUB, "MBC7 unknown address: %04X:%02X", address, value);
 648		break;
 649	}
 650}
 651
 652uint8_t _GBMBC7Read(struct GBMemory* memory, uint16_t address) {
 653	struct GBMBC7State* mbc7 = &memory->mbcState.mbc7;
 654	if (mbc7->access != 3) {
 655		return 0xFF;
 656	}
 657	switch (address & 0xF0) {
 658	case 0x20:
 659		if (memory->rotation && memory->rotation->readTiltX) {
 660			int32_t x = -memory->rotation->readTiltX(memory->rotation);
 661			x >>= 21;
 662			x += 0x81D0;
 663			return x;
 664		}
 665		return 0xFF;
 666	case 0x30:
 667		if (memory->rotation && memory->rotation->readTiltX) {
 668			int32_t x = -memory->rotation->readTiltX(memory->rotation);
 669			x >>= 21;
 670			x += 0x81D0;
 671			return x >> 8;
 672		}
 673		return 7;
 674	case 0x40:
 675		if (memory->rotation && memory->rotation->readTiltY) {
 676			int32_t y = -memory->rotation->readTiltY(memory->rotation);
 677			y >>= 21;
 678			y += 0x81D0;
 679			return y;
 680		}
 681		return 0xFF;
 682	case 0x50:
 683		if (memory->rotation && memory->rotation->readTiltY) {
 684			int32_t y = -memory->rotation->readTiltY(memory->rotation);
 685			y >>= 21;
 686			y += 0x81D0;
 687			return y >> 8;
 688		}
 689		return 7;
 690	case 0x60:
 691		return 0;
 692	case 0x80:
 693		return mbc7->eeprom;
 694	default:
 695		return 0xFF;
 696	}
 697}
 698
 699static void _GBMBC7Write(struct GBMemory* memory, uint16_t address, uint8_t value) {
 700	struct GBMBC7State* mbc7 = &memory->mbcState.mbc7;
 701	if (mbc7->access != 3) {
 702		return;
 703	}
 704	switch (address & 0xF0) {
 705	case 0x00:
 706		mbc7->latch = (value & 0x55) == 0x55;
 707		return;
 708	case 0x10:
 709		mbc7->latch |= (value & 0xAA);
 710		if (mbc7->latch == 0xAB && memory->rotation && memory->rotation->sample) {
 711			memory->rotation->sample(memory->rotation);
 712		}
 713		mbc7->latch = 0;
 714		return;
 715	default:
 716		mLOG(GB_MBC, STUB, "MBC7 unknown register: %04X:%02X", address, value);
 717		return;
 718	case 0x80:
 719		break;
 720	}
 721	GBMBC7Field old = memory->mbcState.mbc7.eeprom;
 722	value = GBMBC7FieldFillDO(value); // Hi-Z
 723	if (!GBMBC7FieldIsCS(old) && GBMBC7FieldIsCS(value)) {
 724		mbc7->state = GBMBC7_STATE_IDLE;
 725	}
 726	if (!GBMBC7FieldIsCLK(old) && GBMBC7FieldIsCLK(value)) {
 727		if (mbc7->state == GBMBC7_STATE_READ_COMMAND || mbc7->state == GBMBC7_STATE_EEPROM_WRITE || mbc7->state == GBMBC7_STATE_EEPROM_WRAL) {
 728			mbc7->sr <<= 1;
 729			mbc7->sr |= GBMBC7FieldGetDI(value);
 730			++mbc7->srBits;
 731		}
 732		switch (mbc7->state) {
 733		case GBMBC7_STATE_IDLE:
 734			if (GBMBC7FieldIsDI(value)) {
 735				mbc7->state = GBMBC7_STATE_READ_COMMAND;
 736				mbc7->srBits = 0;
 737				mbc7->sr = 0;
 738			}
 739			break;
 740		case GBMBC7_STATE_READ_COMMAND:
 741			if (mbc7->srBits == 10) {
 742				mbc7->state = 0x10 | (mbc7->sr >> 6);
 743				if (mbc7->state & 0xC) {
 744					mbc7->state &= ~0x3;
 745				}
 746				mbc7->srBits = 0;
 747				mbc7->address = mbc7->sr & 0x7F;
 748			}
 749			break;
 750		case GBMBC7_STATE_DO:
 751			value = GBMBC7FieldSetDO(value, mbc7->sr >> 15);
 752			mbc7->sr <<= 1;
 753			--mbc7->srBits;
 754			if (!mbc7->srBits) {
 755				mbc7->state = GBMBC7_STATE_IDLE;
 756			}
 757			break;
 758		default:
 759			break;
 760		}
 761		switch (mbc7->state) {
 762		case GBMBC7_STATE_EEPROM_EWEN:
 763			mbc7->writable = true;
 764			mbc7->state = GBMBC7_STATE_IDLE;
 765			break;
 766		case GBMBC7_STATE_EEPROM_EWDS:
 767			mbc7->writable = false;
 768			mbc7->state = GBMBC7_STATE_IDLE;
 769			break;
 770		case GBMBC7_STATE_EEPROM_WRITE:
 771			if (mbc7->srBits == 16) {
 772				if (mbc7->writable) {
 773					memory->sram[mbc7->address * 2] = mbc7->sr >> 8;
 774					memory->sram[mbc7->address * 2 + 1] = mbc7->sr;
 775				}
 776				mbc7->state = GBMBC7_STATE_IDLE;
 777			}
 778			break;
 779		case GBMBC7_STATE_EEPROM_ERASE:
 780			if (mbc7->writable) {
 781				memory->sram[mbc7->address * 2] = 0xFF;
 782				memory->sram[mbc7->address * 2 + 1] = 0xFF;
 783			}
 784			mbc7->state = GBMBC7_STATE_IDLE;
 785			break;
 786		case GBMBC7_STATE_EEPROM_READ:
 787			mbc7->srBits = 16;
 788			mbc7->sr = memory->sram[mbc7->address * 2] << 8;
 789			mbc7->sr |= memory->sram[mbc7->address * 2 + 1];
 790			mbc7->state = GBMBC7_STATE_DO;
 791			value = GBMBC7FieldClearDO(value);
 792			break;
 793		case GBMBC7_STATE_EEPROM_WRAL:
 794			if (mbc7->srBits == 16) {
 795				if (mbc7->writable) {
 796					int i;
 797					for (i = 0; i < 128; ++i) {
 798						memory->sram[i * 2] = mbc7->sr >> 8;
 799						memory->sram[i * 2 + 1] = mbc7->sr;
 800					}
 801				}
 802				mbc7->state = GBMBC7_STATE_IDLE;
 803			}
 804			break;
 805		case GBMBC7_STATE_EEPROM_ERAL:
 806			if (mbc7->writable) {
 807				int i;
 808				for (i = 0; i < 128; ++i) {
 809					memory->sram[i * 2] = 0xFF;
 810					memory->sram[i * 2 + 1] = 0xFF;
 811				}
 812			}
 813			mbc7->state = GBMBC7_STATE_IDLE;
 814			break;
 815		default:
 816			break;
 817		}
 818	} else if (GBMBC7FieldIsCS(value) && GBMBC7FieldIsCLK(old) && !GBMBC7FieldIsCLK(value)) {
 819		value = GBMBC7FieldSetDO(value, GBMBC7FieldGetDO(old));
 820	}
 821	mbc7->eeprom = value;
 822}
 823
 824void _GBHuC1(struct GB* gb, uint16_t address, uint8_t value) {
 825	struct GBMemory* memory = &gb->memory;
 826	int bank = value & 0x3F;
 827	switch (address >> 13) {
 828	case 0x0:
 829		switch (value) {
 830		case 0xE:
 831			memory->sramAccess = false;
 832			break;
 833		default:
 834			memory->sramAccess = true;
 835			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 836			break;
 837		}
 838		break;
 839	case 0x1:
 840		GBMBCSwitchBank(gb, bank);
 841		break;
 842	case 0x2:
 843		GBMBCSwitchSramBank(gb, value);
 844		break;
 845	default:
 846		// TODO
 847		mLOG(GB_MBC, STUB, "HuC-1 unknown address: %04X:%02X", address, value);
 848		break;
 849	}
 850}
 851
 852void _GBHuC3(struct GB* gb, uint16_t address, uint8_t value) {
 853	struct GBMemory* memory = &gb->memory;
 854	int bank = value & 0x3F;
 855	if (address & 0x1FFF) {
 856		mLOG(GB_MBC, STUB, "HuC-3 unknown value %04X:%02X", address, value);
 857	}
 858
 859	switch (address >> 13) {
 860	case 0x0:
 861		switch (value) {
 862		case 0xA:
 863			memory->sramAccess = true;
 864			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 865			break;
 866		default:
 867			memory->sramAccess = false;
 868			break;
 869		}
 870		break;
 871	case 0x1:
 872		GBMBCSwitchBank(gb, bank);
 873		break;
 874	case 0x2:
 875		GBMBCSwitchSramBank(gb, bank);
 876		break;
 877	default:
 878		// TODO
 879		mLOG(GB_MBC, STUB, "HuC-3 unknown address: %04X:%02X", address, value);
 880		break;
 881	}
 882}
 883
 884void _GBPocketCam(struct GB* gb, uint16_t address, uint8_t value) {
 885	struct GBMemory* memory = &gb->memory;
 886	int bank = value & 0x3F;
 887	switch (address >> 13) {
 888	case 0x0:
 889		switch (value) {
 890		case 0:
 891			memory->sramAccess = false;
 892			break;
 893		case 0xA:
 894			memory->sramAccess = true;
 895			GBMBCSwitchSramBank(gb, memory->sramCurrentBank);
 896			break;
 897		default:
 898			// TODO
 899			mLOG(GB_MBC, STUB, "Pocket Cam unknown value %02X", value);
 900			break;
 901		}
 902		break;
 903	case 0x1:
 904		GBMBCSwitchBank(gb, bank);
 905		break;
 906	case 0x2:
 907		if (value < 0x10) {
 908			GBMBCSwitchSramBank(gb, value);
 909			memory->mbcState.pocketCam.registersActive = false;
 910		} else {
 911			memory->mbcState.pocketCam.registersActive = true;
 912		}
 913		break;
 914	case 0x5:
 915		address &= 0x7F;
 916		if (address == 0 && value & 1) {
 917			value &= 6; // TODO: Timing
 918			_GBPocketCamCapture(memory);
 919		}
 920		if (address < sizeof(memory->mbcState.pocketCam.registers)) {
 921			memory->mbcState.pocketCam.registers[address] = value;
 922		}
 923		break;
 924	default:
 925		mLOG(GB_MBC, STUB, "Pocket Cam unknown address: %04X:%02X", address, value);
 926		break;
 927	}
 928}
 929
 930uint8_t _GBPocketCamRead(struct GBMemory* memory, uint16_t address) {
 931	if (memory->mbcState.pocketCam.registersActive) {
 932		if ((address & 0x7F) == 0) {
 933			return memory->mbcState.pocketCam.registers[0];
 934		}
 935		return 0;
 936	}
 937	return memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)];
 938}
 939
 940void _GBPocketCamCapture(struct GBMemory* memory) {
 941	if (!memory->cam) {
 942		return;
 943	}
 944	const void* image = NULL;
 945	size_t stride;
 946	enum mColorFormat format;
 947	memory->cam->requestImage(memory->cam, &image, &stride, &format);
 948	if (!image) {
 949		return;
 950	}
 951	memset(&memory->sram[0x100], 0, GBCAM_HEIGHT * GBCAM_WIDTH / 4);
 952	struct GBPocketCamState* pocketCam = &memory->mbcState.pocketCam;
 953	size_t x, y;
 954	for (y = 0; y < GBCAM_HEIGHT; ++y) {
 955		for (x = 0; x < GBCAM_WIDTH; ++x) {
 956			uint32_t gray;
 957			uint32_t color;
 958			switch (format) {
 959			case mCOLOR_XBGR8:
 960			case mCOLOR_XRGB8:
 961			case mCOLOR_ARGB8:
 962			case mCOLOR_ABGR8:
 963				color = ((const uint32_t*) image)[y * stride + x];
 964				gray = (color & 0xFF) + ((color >> 8) & 0xFF) + ((color >> 16) & 0xFF);
 965				break;
 966			case mCOLOR_BGRX8:
 967			case mCOLOR_RGBX8:
 968			case mCOLOR_RGBA8:
 969			case mCOLOR_BGRA8:
 970				color = ((const uint32_t*) image)[y * stride + x];
 971				gray = ((color >> 8) & 0xFF) + ((color >> 16) & 0xFF) + ((color >> 24) & 0xFF);
 972				break;
 973			case mCOLOR_BGR5:
 974			case mCOLOR_RGB5:
 975			case mCOLOR_ARGB5:
 976			case mCOLOR_ABGR5:
 977				color = ((const uint16_t*) image)[y * stride + x];
 978				gray = ((color << 3) & 0xF8) + ((color >> 2) & 0xF8) + ((color >> 7) & 0xF8);
 979				break;
 980			case mCOLOR_BGR565:
 981			case mCOLOR_RGB565:
 982				color = ((const uint16_t*) image)[y * stride + x];
 983				gray = ((color << 3) & 0xF8) + ((color >> 3) & 0xFC) + ((color >> 8) & 0xF8);
 984				break;
 985			case mCOLOR_BGRA5:
 986			case mCOLOR_RGBA5:
 987				color = ((const uint16_t*) image)[y * stride + x];
 988				gray = ((color << 2) & 0xF8) + ((color >> 3) & 0xF8) + ((color >> 8) & 0xF8);
 989				break;
 990			default:
 991				mLOG(GB_MBC, WARN, "Unsupported pixel format: %X", format);
 992				return;
 993			}
 994			uint16_t exposure = (pocketCam->registers[2] << 8) | (pocketCam->registers[3]);
 995			gray = (gray + 1) * exposure / 0x300;
 996			// TODO: Additional processing
 997			int matrixEntry = 3 * ((x & 3) + 4 * (y & 3));
 998			if (gray < pocketCam->registers[matrixEntry + 6]) {
 999				gray = 0x101;
1000			} else if (gray < pocketCam->registers[matrixEntry + 7]) {
1001				gray = 0x100;
1002			} else if (gray < pocketCam->registers[matrixEntry + 8]) {
1003				gray = 0x001;
1004			} else {
1005				gray = 0;
1006			}
1007			int coord = (((x >> 3) & 0xF) * 8 + (y & 0x7)) * 2 + (y & ~0x7) * 0x20;
1008			uint16_t existing;
1009			LOAD_16LE(existing, coord + 0x100, memory->sram);
1010			existing |= gray << (7 - (x & 7));
1011			STORE_16LE(existing, coord + 0x100, memory->sram);
1012		}
1013	}
1014}
1015
1016void _GBTAMA5(struct GB* gb, uint16_t address, uint8_t value) {
1017	struct GBMemory* memory = &gb->memory;
1018	struct GBTAMA5State* tama5 = &memory->mbcState.tama5;
1019	switch (address >> 13) {
1020	case 0x5:
1021		if (address & 1) {
1022			tama5->reg = value;
1023		} else {
1024			value &= 0xF;
1025			if (tama5->reg < GBTAMA5_MAX) {
1026				tama5->registers[tama5->reg] = value;
1027				uint8_t address = ((tama5->registers[GBTAMA5_CS] << 4) & 0x10) | tama5->registers[GBTAMA5_ADDR_LO];
1028				uint8_t out = (tama5->registers[GBTAMA5_WRITE_HI] << 4) | tama5->registers[GBTAMA5_WRITE_LO];
1029				switch (tama5->reg) {
1030				case GBTAMA5_BANK_LO:
1031				case GBTAMA5_BANK_HI:
1032					GBMBCSwitchBank(gb, tama5->registers[GBTAMA5_BANK_LO] | (tama5->registers[GBTAMA5_BANK_HI] << 4));
1033					break;
1034				case GBTAMA5_WRITE_LO:
1035				case GBTAMA5_WRITE_HI:
1036				case GBTAMA5_CS:
1037					break;
1038				case GBTAMA5_ADDR_LO:
1039					switch (tama5->registers[GBTAMA5_CS] >> 1) {
1040					case 0x0: // RAM write
1041						memory->sram[address] = out;
1042						break;
1043					case 0x1: // RAM read
1044						break;
1045					default:
1046						mLOG(GB_MBC, STUB, "TAMA5 unknown address: %X-%02X:%02X", tama5->registers[GBTAMA5_CS] >> 1, address, out);
1047					}
1048					break;
1049				default:
1050					mLOG(GB_MBC, STUB, "TAMA5 unknown write: %02X:%X", tama5->reg, value);
1051					break;
1052				}
1053			} else {
1054				mLOG(GB_MBC, STUB, "TAMA5 unknown write: %02X", tama5->reg);
1055			}
1056		}
1057		break;
1058	default:
1059		mLOG(GB_MBC, STUB, "TAMA5 unknown address: %04X:%02X", address, value);
1060	}
1061}
1062
1063uint8_t _GBTAMA5Read(struct GBMemory* memory, uint16_t address) {
1064	struct GBTAMA5State* tama5 = &memory->mbcState.tama5;
1065	if ((address & 0x1FFF) > 1) {
1066		mLOG(GB_MBC, STUB, "TAMA5 unknown address: %04X", address);
1067	}
1068	if (address & 1) {
1069		return 0xFF;
1070	} else {
1071		uint8_t value = 0xF0;
1072		uint8_t address = ((tama5->registers[GBTAMA5_CS] << 4) & 0x10) | tama5->registers[GBTAMA5_ADDR_LO];
1073		switch (tama5->reg) {
1074		case GBTAMA5_ACTIVE:
1075			return 0xF1;
1076		case GBTAMA5_READ_LO:
1077		case GBTAMA5_READ_HI:
1078			switch (tama5->registers[GBTAMA5_CS] >> 1) {
1079			case 1:
1080				value = memory->sram[address];
1081				break;
1082			default:
1083				mLOG(GB_MBC, STUB, "TAMA5 unknown read: %02X", tama5->reg);
1084				break;
1085			}
1086			if (tama5->reg == GBTAMA5_READ_HI) {
1087				value >>= 4;
1088			}
1089			value |= 0xF0;
1090			return value;
1091		default:
1092			mLOG(GB_MBC, STUB, "TAMA5 unknown read: %02X", tama5->reg);
1093			return 0xF1;
1094		}
1095	}
1096}
1097
1098void GBMBCRTCRead(struct GB* gb) {
1099	struct GBMBCRTCSaveBuffer rtcBuffer;
1100	struct VFile* vf = gb->sramVf;
1101	if (!vf) {
1102		return;
1103	}
1104	vf->seek(vf, gb->sramSize, SEEK_SET);
1105	if (vf->read(vf, &rtcBuffer, sizeof(rtcBuffer)) < (ssize_t) sizeof(rtcBuffer) - 4) {
1106		return;
1107	}
1108
1109	LOAD_32LE(gb->memory.rtcRegs[0], 0, &rtcBuffer.latchedSec);
1110	LOAD_32LE(gb->memory.rtcRegs[1], 0, &rtcBuffer.latchedMin);
1111	LOAD_32LE(gb->memory.rtcRegs[2], 0, &rtcBuffer.latchedHour);
1112	LOAD_32LE(gb->memory.rtcRegs[3], 0, &rtcBuffer.latchedDays);
1113	LOAD_32LE(gb->memory.rtcRegs[4], 0, &rtcBuffer.latchedDaysHi);
1114	LOAD_64LE(gb->memory.rtcLastLatch, 0, &rtcBuffer.unixTime);
1115}
1116
1117void GBMBCRTCWrite(struct GB* gb) {
1118	struct VFile* vf = gb->sramVf;
1119	if (!vf) {
1120		return;
1121	}
1122
1123	uint8_t rtcRegs[5];
1124	memcpy(rtcRegs, gb->memory.rtcRegs, sizeof(rtcRegs));
1125	time_t rtcLastLatch = gb->memory.rtcLastLatch;
1126	_latchRtc(gb->memory.rtc, rtcRegs, &rtcLastLatch);
1127
1128	struct GBMBCRTCSaveBuffer rtcBuffer;
1129	STORE_32LE(rtcRegs[0], 0, &rtcBuffer.sec);
1130	STORE_32LE(rtcRegs[1], 0, &rtcBuffer.min);
1131	STORE_32LE(rtcRegs[2], 0, &rtcBuffer.hour);
1132	STORE_32LE(rtcRegs[3], 0, &rtcBuffer.days);
1133	STORE_32LE(rtcRegs[4], 0, &rtcBuffer.daysHi);
1134	STORE_32LE(gb->memory.rtcRegs[0], 0, &rtcBuffer.latchedSec);
1135	STORE_32LE(gb->memory.rtcRegs[1], 0, &rtcBuffer.latchedMin);
1136	STORE_32LE(gb->memory.rtcRegs[2], 0, &rtcBuffer.latchedHour);
1137	STORE_32LE(gb->memory.rtcRegs[3], 0, &rtcBuffer.latchedDays);
1138	STORE_32LE(gb->memory.rtcRegs[4], 0, &rtcBuffer.latchedDaysHi);
1139	STORE_64LE(gb->memory.rtcLastLatch, 0, &rtcBuffer.unixTime);
1140
1141	if ((size_t) vf->size(vf) < gb->sramSize + sizeof(rtcBuffer)) {
1142		// Writing past the end of the file can invalidate the file mapping
1143		vf->unmap(vf, gb->memory.sram, gb->sramSize);
1144		gb->memory.sram = NULL;
1145	}
1146	vf->seek(vf, gb->sramSize, SEEK_SET);
1147	vf->write(vf, &rtcBuffer, sizeof(rtcBuffer));
1148	if (!gb->memory.sram) {
1149		gb->memory.sram = vf->map(vf, gb->sramSize, MAP_WRITE);
1150		GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
1151	}
1152}