123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175 |
- /* sd2snes - SD card based universal cartridge for the SNES
- Copyright (C) 2009-2010 Maximilian Rehkopf <otakon@gmx.net>
- 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
- smc.c: SMC file related operations
- */
- #include <avr/io.h>
- #include <util/delay.h>
- #include "fileops.h"
- #include "config.h"
- #include "uart.h"
- #include "smc.h"
- uint32_t hdr_addr[6] = {0xffb0, 0x101b0, 0x7fb0, 0x81b0, 0x40ffb0, 0x4101b0};
- uint8_t countAllASCII(uint8_t* data, int size) {
- uint8_t res = 0;
- do {
- size--;
- if(data[size] >= 0x20 && data[size] <= 0x7e) {
- res++;
- }
- } while (size);
- return res;
- }
- uint8_t countAllJISX0201(uint8_t* data, int size) {
- uint8_t res = 0;
- do {
- size--;
- if((data[size] >= 0x20 && data[size] <= 0x7e)
- ||(data[size] >= 0xa1 && data[size] <= 0xdf)) {
- res++;
- }
- } while (size);
- return res;
- }
- uint8_t isFixed(uint8_t* data, int size, uint8_t value) {
- uint8_t res = 1;
- do {
- size--;
- if(data[size] != value) {
- res = 0;
- }
- } while (size);
- return res;
- }
- uint8_t checkChksum(uint16_t cchk, uint16_t chk) {
- uint32_t sum = cchk + chk;
- uint8_t res = 0;
- if(sum==0x0000ffff) {
- res = 0x10;
- }
- return res;
- }
- void smc_id(snes_romprops_t* props) {
- uint8_t score, maxscore=1, score_idx=2; // assume LoROM
- snes_header_t* header = &(props->header);
-
- for(uint8_t num = 0; num < 6; num++) {
- if(!file_readblock(header, hdr_addr[num], sizeof(snes_header_t))
- || file_res) {
- // dprintf("uh oh... %d\n", file_res);
- // _delay_ms(30);
- score = 0;
- } else {
- score = smc_headerscore(header)/(1+(num&1));
- if((file_handle.fsize & 0x2ff) == 0x200) {
- if(num&1) {
- score+=20;
- } else {
- score=0;
- }
- } else {
- if(!(num&1)) {
- score+=20;
- } else {
- score=0;
- }
- }
- }
- // dprintf("%d: offset = %lX; score = %d\n", num, hdr_addr[num], score);
- // _delay_ms(100);
- if(score>=maxscore) {
- score_idx=num;
- maxscore=score;
- }
- }
- if(score_idx & 1) {
- props->offset = 0x200;
- } else {
- props->offset = 0;
- }
-
- // restore the chosen one
- // dprintf("winner is %d\n", score_idx);
- // _delay_ms(30);
- file_readblock(header, hdr_addr[score_idx], sizeof(snes_header_t));
- switch(header->map & 0xef) {
- case 0x20:
- props->mapper_id = 1;
- break;
- case 0x21:
- props->mapper_id = 0;
- break;
- case 0x25:
- props->mapper_id = 2;
- break;
- default: // invalid/unsupported mapper, use header location
- switch(score_idx) {
- case 0:
- case 1:
- props->mapper_id = 0;
- break;
- case 2:
- case 3:
- props->mapper_id = 1;
- break;
- case 4:
- case 5:
- props->mapper_id = 2;
- break;
- default:
- props->mapper_id = 1; // whatever
- }
- }
- if(header->romsize == 0 || header->romsize > 13) {
- header->romsize = 13;
- }
- props->ramsize_bytes = (uint32_t)1024 << header->ramsize;
- props->romsize_bytes = (uint32_t)1024 << header->romsize;
- props->expramsize_bytes = (uint32_t)1024 << header->expramsize;
- // dprintf("ramsize_bytes: %ld\n", props->ramsize_bytes);
- if(props->ramsize_bytes > 32768 || props->ramsize_bytes < 2048) {
- props->ramsize_bytes = 0;
- }
- // dprintf("ramsize_bytes: %ld\n", props->ramsize_bytes);
- f_lseek(&file_handle, 0);
- }
- uint8_t smc_headerscore(snes_header_t* header) {
- uint8_t score=0;
- score += countAllASCII(header->maker, sizeof(header->maker));
- score += countAllASCII(header->gamecode, sizeof(header->gamecode));
- score += isFixed(header->fixed_00, sizeof(header->fixed_00), 0x00);
- score += countAllJISX0201(header->name, sizeof(header->name));
- score += 3*isFixed(&header->fixed_33, sizeof(header->fixed_33), 0x33);
- score += checkChksum(header->cchk, header->chk);
- return score;
- }
|