/* 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 "io.h" #include "gb/gb.h" 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, 0x05, 0); GBIOWrite(gb, 0x06, 0); GBIOWrite(gb, 0x07, 0); GBIOWrite(gb, 0x10, 0x80); GBIOWrite(gb, 0x11, 0xBF); GBIOWrite(gb, 0x12, 0xF3); GBIOWrite(gb, 0x12, 0xF3); GBIOWrite(gb, 0x14, 0xBF); GBIOWrite(gb, 0x16, 0x3F); GBIOWrite(gb, 0x17, 0x00); GBIOWrite(gb, 0x19, 0xBF); GBIOWrite(gb, 0x1A, 0x7F); GBIOWrite(gb, 0x1B, 0xFF); GBIOWrite(gb, 0x1C, 0x9F); GBIOWrite(gb, 0x1E, 0xBF); GBIOWrite(gb, 0x20, 0xFF); GBIOWrite(gb, 0x21, 0x00); GBIOWrite(gb, 0x22, 0x00); GBIOWrite(gb, 0x23, 0xBF); GBIOWrite(gb, 0x24, 0x77); GBIOWrite(gb, 0x25, 0xF3); GBIOWrite(gb, 0x26, 0xF1); GBIOWrite(gb, 0x40, 0x91); GBIOWrite(gb, 0x42, 0x00); GBIOWrite(gb, 0x43, 0x00); GBIOWrite(gb, 0x45, 0x00); GBIOWrite(gb, 0x47, 0xFC); GBIOWrite(gb, 0x48, 0xFF); GBIOWrite(gb, 0x49, 0xFF); GBIOWrite(gb, 0x4A, 0x00); GBIOWrite(gb, 0x4B, 0x00); GBIOWrite(gb, 0xFF, 0x00); } void GBIOWrite(struct GB* gb, unsigned address, uint8_t value) { switch (address) { case REG_DIV: GBTimerDivReset(&gb->timer); return; case REG_TIMA: // ??? return; case REG_TMA: // Handled transparently by the registers 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 value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value); GBVideoWriteLCDC(&gb->video, value); break; case REG_SCY: case REG_SCX: case REG_WY: case REG_WX: case REG_BGP: case REG_OBP0: case REG_OBP1: value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value); break; case REG_STAT: GBVideoWriteSTAT(&gb->video, value); break; case REG_IE: gb->memory.ie = value; GBUpdateIRQs(gb); return; default: // TODO: Log if (address >= GB_SIZE_IO) { return; } break; } gb->memory.io[address] = value; } static uint8_t _readKeys(struct GB* gb) { uint8_t keys = *gb->keySource; switch (gb->memory.io[REG_JOYP] & 0x30) { case 0x20: keys >>= 4; break; case 0x10: break; default: // ??? keys = 0; break; } return 0xC0 | (gb->memory.io[REG_JOYP] | 0xF) ^ (keys & 0xF); } uint8_t GBIORead(struct GB* gb, unsigned address) { switch (address) { case REG_JOYP: return _readKeys(gb); case REG_IF: break; case REG_IE: return gb->memory.ie; case REG_DIV: case REG_TIMA: case REG_TMA: case REG_TAC: break; default: // TODO: Log if (address >= GB_SIZE_IO) { return 0; } break; } return gb->memory.io[address]; }