mgba/src/gb/io.c

729 lines
17 KiB
C

/* Copyright (c) 2013-2016 Jeffrey Pfau
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <mgba/internal/gb/io.h>
#include <mgba/internal/gb/gb.h>
#include <mgba/internal/gb/sio.h>
#include <mgba/internal/gb/serialize.h>
mLOG_DEFINE_CATEGORY(GB_IO, "GB I/O", "gb.io");
const char* const GBIORegisterNames[] = {
[REG_JOYP] = "JOYP",
[REG_SB] = "SB",
[REG_SC] = "SC",
[REG_DIV] = "DIV",
[REG_TIMA] = "TIMA",
[REG_TMA] = "TMA",
[REG_TAC] = "TAC",
[REG_IF] = "IF",
[REG_NR10] = "NR10",
[REG_NR11] = "NR11",
[REG_NR12] = "NR12",
[REG_NR13] = "NR13",
[REG_NR14] = "NR14",
[REG_NR21] = "NR21",
[REG_NR22] = "NR22",
[REG_NR23] = "NR23",
[REG_NR24] = "NR24",
[REG_NR30] = "NR30",
[REG_NR31] = "NR31",
[REG_NR32] = "NR32",
[REG_NR33] = "NR33",
[REG_NR34] = "NR34",
[REG_NR41] = "NR41",
[REG_NR42] = "NR42",
[REG_NR43] = "NR43",
[REG_NR44] = "NR44",
[REG_NR50] = "NR50",
[REG_NR51] = "NR51",
[REG_NR52] = "NR52",
[REG_LCDC] = "LCDC",
[REG_STAT] = "STAT",
[REG_SCY] = "SCY",
[REG_SCX] = "SCX",
[REG_LY] = "LY",
[REG_LYC] = "LYC",
[REG_DMA] = "DMA",
[REG_BGP] = "BGP",
[REG_OBP0] = "OBP0",
[REG_OBP1] = "OBP1",
[REG_WY] = "WY",
[REG_WX] = "WX",
[REG_KEY1] = "KEY1",
[REG_VBK] = "VBK",
[REG_HDMA1] = "HDMA1",
[REG_HDMA2] = "HDMA2",
[REG_HDMA3] = "HDMA3",
[REG_HDMA4] = "HDMA4",
[REG_HDMA5] = "HDMA5",
[REG_RP] = "RP",
[REG_BCPS] = "BCPS",
[REG_BCPD] = "BCPD",
[REG_OCPS] = "OCPS",
[REG_OCPD] = "OCPD",
[REG_SVBK] = "SVBK",
[REG_IE] = "IE",
};
static const uint8_t _registerMask[] = {
[REG_SC] = 0x7E, // TODO: GBC differences
[REG_IF] = 0xE0,
[REG_TAC] = 0xF8,
[REG_NR10] = 0x80,
[REG_NR11] = 0x3F,
[REG_NR12] = 0x00,
[REG_NR13] = 0xFF,
[REG_NR14] = 0xBF,
[REG_NR21] = 0x3F,
[REG_NR22] = 0x00,
[REG_NR23] = 0xFF,
[REG_NR24] = 0xBF,
[REG_NR30] = 0x7F,
[REG_NR31] = 0xFF,
[REG_NR32] = 0x9F,
[REG_NR33] = 0xFF,
[REG_NR34] = 0xBF,
[REG_NR41] = 0xFF,
[REG_NR42] = 0x00,
[REG_NR43] = 0x00,
[REG_NR44] = 0xBF,
[REG_NR50] = 0x00,
[REG_NR51] = 0x00,
[REG_NR52] = 0x70,
[REG_STAT] = 0x80,
[REG_KEY1] = 0x7E,
[REG_VBK] = 0xFE,
[REG_OCPS] = 0x40,
[REG_BCPS] = 0x40,
[REG_UNK6C] = 0xFE,
[REG_SVBK] = 0xF8,
[REG_IE] = 0xE0,
};
static uint8_t _readKeys(struct GB* gb);
static uint8_t _readKeysFiltered(struct GB* gb);
static void _writeSGBBits(struct GB* gb, int bits) {
if (!bits) {
gb->sgbBit = -1;
memset(gb->sgbPacket, 0, sizeof(gb->sgbPacket));
}
if (bits == gb->currentSgbBits) {
return;
}
gb->currentSgbBits = bits;
if (gb->sgbBit > 128) {
switch (bits) {
case 1:
gb->sgbBit |= 2;
break;
case 2:
gb->sgbBit |= 4;
break;
case 3:
if (gb->sgbBit == 135) {
gb->sgbBit &= ~6;
gb->sgbCurrentController = (gb->sgbCurrentController + 1) & gb->sgbControllers;
}
break;
}
}
if (gb->sgbBit == 128 && bits == 2) {
GBVideoWriteSGBPacket(&gb->video, gb->sgbPacket);
++gb->sgbBit;
}
if (gb->sgbBit >= 128) {
return;
}
switch (bits) {
case 1:
if (gb->sgbBit < 0) {
return;
}
gb->sgbPacket[gb->sgbBit >> 3] |= 1 << (gb->sgbBit & 7);
break;
case 3:
++gb->sgbBit;
default:
break;
}
}
void GBIOInit(struct GB* gb) {
memset(gb->memory.io, 0, sizeof(gb->memory.io));
}
void GBIOReset(struct GB* gb) {
memset(gb->memory.io, 0, sizeof(gb->memory.io));
GBIOWrite(gb, REG_TIMA, 0);
GBIOWrite(gb, REG_TMA, 0);
GBIOWrite(gb, REG_TAC, 0);
GBIOWrite(gb, REG_IF, 1);
GBIOWrite(gb, REG_NR52, 0xF1);
GBIOWrite(gb, REG_NR14, 0x3F);
GBIOWrite(gb, REG_NR10, 0x80);
GBIOWrite(gb, REG_NR11, 0xBF);
GBIOWrite(gb, REG_NR12, 0xF3);
GBIOWrite(gb, REG_NR13, 0xF3);
GBIOWrite(gb, REG_NR24, 0x3F);
GBIOWrite(gb, REG_NR21, 0x3F);
GBIOWrite(gb, REG_NR22, 0x00);
GBIOWrite(gb, REG_NR34, 0x3F);
GBIOWrite(gb, REG_NR30, 0x7F);
GBIOWrite(gb, REG_NR31, 0xFF);
GBIOWrite(gb, REG_NR32, 0x9F);
GBIOWrite(gb, REG_NR44, 0x3F);
GBIOWrite(gb, REG_NR41, 0xFF);
GBIOWrite(gb, REG_NR42, 0x00);
GBIOWrite(gb, REG_NR43, 0x00);
GBIOWrite(gb, REG_NR50, 0x77);
GBIOWrite(gb, REG_NR51, 0xF3);
if (!gb->biosVf) {
GBIOWrite(gb, REG_LCDC, 0x91);
} else {
GBIOWrite(gb, REG_LCDC, 0x00);
}
GBIOWrite(gb, REG_SCY, 0x00);
GBIOWrite(gb, REG_SCX, 0x00);
GBIOWrite(gb, REG_LYC, 0x00);
GBIOWrite(gb, REG_DMA, 0xFF);
GBIOWrite(gb, REG_BGP, 0xFC);
if (gb->model < GB_MODEL_CGB) {
GBIOWrite(gb, REG_OBP0, 0xFF);
GBIOWrite(gb, REG_OBP1, 0xFF);
}
GBIOWrite(gb, REG_WY, 0x00);
GBIOWrite(gb, REG_WX, 0x00);
if (gb->model & GB_MODEL_CGB) {
GBIOWrite(gb, REG_UNK4C, 0);
GBIOWrite(gb, REG_JOYP, 0xFF);
GBIOWrite(gb, REG_VBK, 0);
GBIOWrite(gb, REG_BCPS, 0);
GBIOWrite(gb, REG_OCPS, 0);
GBIOWrite(gb, REG_SVBK, 1);
GBIOWrite(gb, REG_HDMA1, 0xFF);
GBIOWrite(gb, REG_HDMA2, 0xFF);
GBIOWrite(gb, REG_HDMA3, 0xFF);
GBIOWrite(gb, REG_HDMA4, 0xFF);
gb->memory.io[REG_HDMA5] = 0xFF;
} else if (gb->model & GB_MODEL_SGB) {
GBIOWrite(gb, REG_JOYP, 0xFF);
}
GBIOWrite(gb, REG_IE, 0x00);
}
void GBIOWrite(struct GB* gb, unsigned address, uint8_t value) {
switch (address) {
case REG_SB:
GBSIOWriteSB(&gb->sio, value);
break;
case REG_SC:
GBSIOWriteSC(&gb->sio, value);
break;
case REG_DIV:
GBTimerDivReset(&gb->timer);
return;
case REG_NR10:
if (gb->audio.enable) {
GBAudioWriteNR10(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR11:
if (gb->audio.enable) {
GBAudioWriteNR11(&gb->audio, value);
} else {
if (gb->audio.style == GB_AUDIO_DMG) {
GBAudioWriteNR11(&gb->audio, value & _registerMask[REG_NR11]);
}
value = 0;
}
break;
case REG_NR12:
if (gb->audio.enable) {
GBAudioWriteNR12(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR13:
if (gb->audio.enable) {
GBAudioWriteNR13(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR14:
if (gb->audio.enable) {
GBAudioWriteNR14(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR21:
if (gb->audio.enable) {
GBAudioWriteNR21(&gb->audio, value);
} else {
if (gb->audio.style == GB_AUDIO_DMG) {
GBAudioWriteNR21(&gb->audio, value & _registerMask[REG_NR21]);
}
value = 0;
}
break;
case REG_NR22:
if (gb->audio.enable) {
GBAudioWriteNR22(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR23:
if (gb->audio.enable) {
GBAudioWriteNR23(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR24:
if (gb->audio.enable) {
GBAudioWriteNR24(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR30:
if (gb->audio.enable) {
GBAudioWriteNR30(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR31:
if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
GBAudioWriteNR31(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR32:
if (gb->audio.enable) {
GBAudioWriteNR32(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR33:
if (gb->audio.enable) {
GBAudioWriteNR33(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR34:
if (gb->audio.enable) {
GBAudioWriteNR34(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR41:
if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
GBAudioWriteNR41(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR42:
if (gb->audio.enable) {
GBAudioWriteNR42(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR43:
if (gb->audio.enable) {
GBAudioWriteNR43(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR44:
if (gb->audio.enable) {
GBAudioWriteNR44(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR50:
if (gb->audio.enable) {
GBAudioWriteNR50(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR51:
if (gb->audio.enable) {
GBAudioWriteNR51(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR52:
GBAudioWriteNR52(&gb->audio, value);
value &= 0x80;
value |= gb->memory.io[REG_NR52] & 0x0F;
break;
case REG_WAVE_0:
case REG_WAVE_1:
case REG_WAVE_2:
case REG_WAVE_3:
case REG_WAVE_4:
case REG_WAVE_5:
case REG_WAVE_6:
case REG_WAVE_7:
case REG_WAVE_8:
case REG_WAVE_9:
case REG_WAVE_A:
case REG_WAVE_B:
case REG_WAVE_C:
case REG_WAVE_D:
case REG_WAVE_E:
case REG_WAVE_F:
if (!gb->audio.playingCh3 || gb->audio.style != GB_AUDIO_DMG) {
gb->audio.ch3.wavedata8[address - REG_WAVE_0] = value;
} else if(gb->audio.ch3.readable) {
gb->audio.ch3.wavedata8[gb->audio.ch3.window >> 1] = value;
}
break;
case REG_JOYP:
gb->memory.io[REG_JOYP] = value | 0x0F;
_readKeys(gb);
if (gb->model & GB_MODEL_SGB) {
_writeSGBBits(gb, (value >> 4) & 3);
}
return;
case REG_TIMA:
if (value && mTimingUntil(&gb->timing, &gb->timer.irq) > 1) {
mTimingDeschedule(&gb->timing, &gb->timer.irq);
}
if (mTimingUntil(&gb->timing, &gb->timer.irq) == -1) {
return;
}
break;
case REG_TMA:
if (mTimingUntil(&gb->timing, &gb->timer.irq) == -1) {
gb->memory.io[REG_TIMA] = value;
}
break;
case REG_TAC:
value = GBTimerUpdateTAC(&gb->timer, value);
break;
case REG_IF:
gb->memory.io[REG_IF] = value | 0xE0;
GBUpdateIRQs(gb);
return;
case REG_LCDC:
// TODO: handle GBC differences
GBVideoProcessDots(&gb->video, 0);
value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
GBVideoWriteLCDC(&gb->video, value);
break;
case REG_LYC:
GBVideoWriteLYC(&gb->video, value);
break;
case REG_DMA:
GBMemoryDMA(gb, value << 8);
break;
case REG_SCY:
case REG_SCX:
case REG_WY:
case REG_WX:
GBVideoProcessDots(&gb->video, 0);
value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
break;
case REG_BGP:
case REG_OBP0:
case REG_OBP1:
GBVideoProcessDots(&gb->video, 0);
GBVideoWritePalette(&gb->video, address, value);
break;
case REG_STAT:
GBVideoWriteSTAT(&gb->video, value);
value = gb->video.stat;
break;
case 0x50:
GBUnmapBIOS(gb);
if (gb->model >= GB_MODEL_CGB && gb->memory.io[REG_UNK4C] < 0x80) {
gb->model = GB_MODEL_DMG;
GBVideoDisableCGB(&gb->video);
}
break;
case REG_IE:
gb->memory.ie = value;
GBUpdateIRQs(gb);
return;
default:
if (gb->model >= GB_MODEL_CGB) {
switch (address) {
case REG_UNK4C:
break;
case REG_KEY1:
value &= 0x1;
value |= gb->memory.io[address] & 0x80;
break;
case REG_VBK:
GBVideoSwitchBank(&gb->video, value);
break;
case REG_HDMA1:
case REG_HDMA2:
case REG_HDMA3:
case REG_HDMA4:
// Handled transparently by the registers
break;
case REG_HDMA5:
value = GBMemoryWriteHDMA5(gb, value);
break;
case REG_BCPS:
gb->video.bcpIndex = value & 0x3F;
gb->video.bcpIncrement = value & 0x80;
gb->memory.io[REG_BCPD] = gb->video.palette[gb->video.bcpIndex >> 1] >> (8 * (gb->video.bcpIndex & 1));
break;
case REG_BCPD:
if (gb->video.mode != 3) {
GBVideoProcessDots(&gb->video, 0);
GBVideoWritePalette(&gb->video, address, value);
}
return;
case REG_OCPS:
gb->video.ocpIndex = value & 0x3F;
gb->video.ocpIncrement = value & 0x80;
gb->memory.io[REG_OCPD] = gb->video.palette[8 * 4 + (gb->video.ocpIndex >> 1)] >> (8 * (gb->video.ocpIndex & 1));
break;
case REG_OCPD:
if (gb->video.mode != 3) {
GBVideoProcessDots(&gb->video, 0);
GBVideoWritePalette(&gb->video, address, value);
}
return;
case REG_SVBK:
GBMemorySwitchWramBank(&gb->memory, value);
value = gb->memory.wramCurrentBank;
break;
default:
goto failed;
}
goto success;
}
failed:
mLOG(GB_IO, STUB, "Writing to unknown register FF%02X:%02X", address, value);
if (address >= GB_SIZE_IO) {
return;
}
break;
}
success:
gb->memory.io[address] = value;
}
static uint8_t _readKeys(struct GB* gb) {
uint8_t keys = *gb->keySource;
if (gb->sgbCurrentController != 0) {
keys = 0;
}
uint8_t joyp = gb->memory.io[REG_JOYP];
switch (joyp & 0x30) {
case 0x30:
keys = gb->sgbCurrentController;
break;
case 0x20:
keys >>= 4;
break;
case 0x10:
break;
case 0x00:
keys |= keys >> 4;
break;
}
gb->memory.io[REG_JOYP] = (0xCF | joyp) ^ (keys & 0xF);
if (joyp & ~gb->memory.io[REG_JOYP] & 0xF) {
gb->memory.io[REG_IF] |= (1 << GB_IRQ_KEYPAD);
GBUpdateIRQs(gb);
}
return gb->memory.io[REG_JOYP];
}
static uint8_t _readKeysFiltered(struct GB* gb) {
uint8_t keys = _readKeys(gb);
if (!gb->allowOpposingDirections && (keys & 0x30) == 0x20) {
unsigned rl = keys & 0x03;
unsigned ud = keys & 0x0C;
if (!rl) {
keys |= 0x03;
}
if (!ud) {
keys |= 0x0C;
}
}
return keys;
}
uint8_t GBIORead(struct GB* gb, unsigned address) {
switch (address) {
case REG_JOYP:
return _readKeysFiltered(gb);
case REG_IE:
return gb->memory.ie;
case REG_WAVE_0:
case REG_WAVE_1:
case REG_WAVE_2:
case REG_WAVE_3:
case REG_WAVE_4:
case REG_WAVE_5:
case REG_WAVE_6:
case REG_WAVE_7:
case REG_WAVE_8:
case REG_WAVE_9:
case REG_WAVE_A:
case REG_WAVE_B:
case REG_WAVE_C:
case REG_WAVE_D:
case REG_WAVE_E:
case REG_WAVE_F:
if (gb->audio.playingCh3) {
if (gb->audio.ch3.readable || gb->audio.style != GB_AUDIO_DMG) {
return gb->audio.ch3.wavedata8[gb->audio.ch3.window >> 1];
} else {
return 0xFF;
}
} else {
return gb->audio.ch3.wavedata8[address - REG_WAVE_0];
}
break;
case REG_SB:
case REG_SC:
case REG_IF:
case REG_NR10:
case REG_NR11:
case REG_NR12:
case REG_NR14:
case REG_NR21:
case REG_NR22:
case REG_NR24:
case REG_NR30:
case REG_NR32:
case REG_NR34:
case REG_NR41:
case REG_NR42:
case REG_NR43:
case REG_NR44:
case REG_NR50:
case REG_NR51:
case REG_NR52:
case REG_DIV:
case REG_TIMA:
case REG_TMA:
case REG_TAC:
case REG_STAT:
case REG_LCDC:
case REG_SCY:
case REG_SCX:
case REG_LY:
case REG_LYC:
case REG_DMA:
case REG_BGP:
case REG_OBP0:
case REG_OBP1:
case REG_WY:
case REG_WX:
// Handled transparently by the registers
break;
default:
if (gb->model >= GB_MODEL_CGB) {
switch (address) {
case REG_KEY1:
case REG_VBK:
case REG_HDMA1:
case REG_HDMA2:
case REG_HDMA3:
case REG_HDMA4:
case REG_HDMA5:
case REG_BCPS:
case REG_BCPD:
case REG_OCPS:
case REG_OCPD:
case REG_SVBK:
// Handled transparently by the registers
goto success;
default:
break;
}
}
mLOG(GB_IO, STUB, "Reading from unknown register FF%02X", address);
return 0xFF;
}
success:
return gb->memory.io[address] | _registerMask[address];
}
void GBTestKeypadIRQ(struct GB* gb) {
_readKeys(gb);
}
struct GBSerializedState;
void GBIOSerialize(const struct GB* gb, struct GBSerializedState* state) {
memcpy(state->io, gb->memory.io, GB_SIZE_IO);
state->ie = gb->memory.ie;
}
void GBIODeserialize(struct GB* gb, const struct GBSerializedState* state) {
memcpy(gb->memory.io, state->io, GB_SIZE_IO);
gb->memory.ie = state->ie;
if (GBAudioEnableGetEnable(*gb->audio.nr52)) {
GBIOWrite(gb, REG_NR10, gb->memory.io[REG_NR10]);
GBIOWrite(gb, REG_NR11, gb->memory.io[REG_NR11]);
GBIOWrite(gb, REG_NR12, gb->memory.io[REG_NR12]);
GBIOWrite(gb, REG_NR13, gb->memory.io[REG_NR13]);
gb->audio.ch1.control.frequency &= 0xFF;
gb->audio.ch1.control.frequency |= GBAudioRegisterControlGetFrequency(gb->memory.io[REG_NR14] << 8);
gb->audio.ch1.control.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR14] << 8);
GBIOWrite(gb, REG_NR21, gb->memory.io[REG_NR21]);
GBIOWrite(gb, REG_NR22, gb->memory.io[REG_NR22]);
GBIOWrite(gb, REG_NR22, gb->memory.io[REG_NR23]);
gb->audio.ch2.control.frequency &= 0xFF;
gb->audio.ch2.control.frequency |= GBAudioRegisterControlGetFrequency(gb->memory.io[REG_NR24] << 8);
gb->audio.ch2.control.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR24] << 8);
GBIOWrite(gb, REG_NR30, gb->memory.io[REG_NR30]);
GBIOWrite(gb, REG_NR31, gb->memory.io[REG_NR31]);
GBIOWrite(gb, REG_NR32, gb->memory.io[REG_NR32]);
GBIOWrite(gb, REG_NR32, gb->memory.io[REG_NR33]);
gb->audio.ch3.rate &= 0xFF;
gb->audio.ch3.rate |= GBAudioRegisterControlGetRate(gb->memory.io[REG_NR34] << 8);
gb->audio.ch3.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR34] << 8);
GBIOWrite(gb, REG_NR41, gb->memory.io[REG_NR41]);
GBIOWrite(gb, REG_NR42, gb->memory.io[REG_NR42]);
GBIOWrite(gb, REG_NR43, gb->memory.io[REG_NR43]);
gb->audio.ch4.stop = GBAudioRegisterNoiseControlGetStop(gb->memory.io[REG_NR44]);
GBIOWrite(gb, REG_NR50, gb->memory.io[REG_NR50]);
GBIOWrite(gb, REG_NR51, gb->memory.io[REG_NR51]);
}
gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_LCDC, state->io[REG_LCDC]);
gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_SCY, state->io[REG_SCY]);
gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_SCX, state->io[REG_SCX]);
gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_WY, state->io[REG_WY]);
gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_WX, state->io[REG_WX]);
if (gb->model & GB_MODEL_SGB) {
gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_BGP, state->io[REG_BGP]);
gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_OBP0, state->io[REG_OBP0]);
gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_OBP1, state->io[REG_OBP1]);
}
gb->video.stat = state->io[REG_STAT];
}