/* sd2snes - SD card based universal cartridge for the SNES Copyright (C) 2009-2010 Maximilian Rehkopf AVR firmware portion Inspired by and based on code from sd2iec, written by Ingo Korb et al. See sdcard.c|h, config.h. FAT file system access based on code by ChaN, Jim Brain, Ingo Korb, see ff.c|h. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License only. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA snes.c: SNES hardware control and monitoring */ #include #include "avrcompat.h" #include "config.h" #include "uart.h" #include "snes.h" #include "memory.h" #include "fileops.h" #include "ff.h" #include "led.h" #include "smc.h" uint8_t initloop=1; uint32_t saveram_crc, saveram_crc_old; void snes_init() { DDRD |= _BV(PD5); // PD5 = RESET_DIR DDRD |= _BV(PD6); // PD6 = RESET snes_reset(1); } /* * sets the SNES reset state. * * state: put SNES in reset state when 1, release when 0 */ void snes_reset(int state) { if(state) { DDRD |= _BV(PD6); // /RESET pin -> out PORTD &= ~_BV(PD6); // /RESET = 0 PORTD |= _BV(PD5); // RESET_DIR = 1; } else { PORTD &= ~_BV(PD5); // RESET_DIR = 0; DDRD &= ~_BV(PD6); // /RESET pin -> in PORTD |= _BV(PD6); // /RESET = pullup } } /* * gets the SNES reset state. * * returns: 1 when reset, 0 when not reset */ uint8_t get_snes_reset() { // DDRD &= ~_BV(PD6); // /RESET pin -> in // PORTD &= ~_BV(PD5); // RESET_DIR (external buffer) = 0 return !(PIND & _BV(PD6)); } /* * SD2SNES main loop. * monitors SRAM changes and other things */ uint32_t diffcount = 0, samecount = 0, didnotsave = 0; uint8_t sram_valid = 0; void snes_main_loop() { if(!romprops.ramsize_bytes)return; if(initloop) { saveram_crc_old = calc_sram_crc(SRAM_SAVE_ADDR, romprops.ramsize_bytes); initloop=0; } saveram_crc = calc_sram_crc(SRAM_SAVE_ADDR, romprops.ramsize_bytes); sram_valid = sram_reliable(); if(crc_valid && sram_valid) { if(saveram_crc != saveram_crc_old) { if(samecount) { diffcount=1; } else { diffcount++; didnotsave++; } samecount=0; } if(saveram_crc == saveram_crc_old) { samecount++; } if(diffcount>=1 && samecount==5) { uart_putc('U'); uart_puthexshort(saveram_crc); uart_putcrlf(); set_busy_led(1); save_sram(file_lfn, romprops.ramsize_bytes, SRAM_SAVE_ADDR); set_busy_led(0); didnotsave=0; } if(didnotsave>50) { diffcount=0; uart_putc('V'); set_busy_led(1); save_sram(file_lfn, romprops.ramsize_bytes, SRAM_SAVE_ADDR); didnotsave=0; set_busy_led(0); } saveram_crc_old = saveram_crc; } dprintf("crc_valid=%d sram_valid=%d diffcount=%ld samecount=%ld, didnotsave=%ld\n", crc_valid, sram_valid, diffcount, samecount, didnotsave); } /* * SD2SNES menu loop. * monitors menu selection. return when selection was made. */ uint8_t menu_main_loop() { uint8_t cmd = 0; sram_writebyte(0, SRAM_CMD_ADDR); while(!cmd) { if(!get_snes_reset()) { while(!sram_reliable()); cmd = sram_readbyte(SRAM_CMD_ADDR); } if(get_snes_reset()) { cmd = 0; } } return cmd; } void get_selected_name(uint8_t* fn) { uint32_t addr = sram_readlong(SRAM_FD_ADDR); dprintf("fd addr=%lX\n", addr); sram_readblock(fn, addr+0x41+SRAM_MENU_ADDR, 256); }