sd2snes/src/smc.c
2013-10-06 14:52:40 +01:00

289 lines
8.6 KiB
C

/* 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 "fileops.h"
#include "config.h"
#include "uart.h"
#include "smc.h"
#include "string.h"
#include "fpga_spi.h"
snes_romprops_t romprops;
uint32_t hdr_addr[6] = {0xffb0, 0x101b0, 0x7fb0, 0x81b0, 0x40ffb0, 0x4101b0};
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 = 1;
}
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);
props->has_dspx = 0;
props->has_st0010 = 0;
props->has_cx4 = 0;
props->fpga_features = 0;
props->fpga_conf = NULL;
for(uint8_t num = 0; num < 6; num++) {
score = smc_headerscore(hdr_addr[num], header);
printf("%d: offset = %lX; score = %d\n", num, hdr_addr[num], score); // */
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); */
file_readblock(header, hdr_addr[score_idx], sizeof(snes_header_t));
if(header->name[0x13] == 0x00 || header->name[0x13] == 0xff) {
if(header->name[0x14] == 0x00) {
const uint8_t n15 = header->map;
if(n15 == 0x00 || n15 == 0x80 || n15 == 0x84 || n15 == 0x9c
|| n15 == 0xbc || n15 == 0xfc) {
if(header->licensee == 0x33 || header->licensee == 0xff) {
props->mapper_id = 0;
/*XXX do this properly */
props->ramsize_bytes = 0x8000;
props->romsize_bytes = 0x100000;
props->expramsize_bytes = 0;
props->mapper_id = 3; /* BS-X Memory Map */
props->region = 0; /* BS-X only existed in Japan */
return;
}
}
}
}
switch(header->map & 0xef) {
case 0x21: /* HiROM */
props->mapper_id = 0;
if(header->map == 0x31 && (header->carttype == 0x03 || header->carttype == 0x05)) {
props->has_dspx = 1;
props->dsp_fw = DSPFW_1B;
props->fpga_features |= FEAT_DSPX;
}
break;
case 0x20: /* LoROM */
props->mapper_id = 1;
if (header->map == 0x20 && header->carttype == 0xf3) {
props->has_cx4 = 1;
props->dsp_fw = CX4FW;
props->fpga_conf = FPGA_CX4;
props->fpga_features |= FEAT_CX4;
}
else if ((header->map == 0x20 && header->carttype == 0x03) ||
(header->map == 0x30 && header->carttype == 0x05 && header->licensee != 0xb2)) {
props->has_dspx = 1;
props->fpga_features |= FEAT_DSPX;
/* Pilotwings uses DSP1 instead of DSP1B */
if(!memcmp(header->name, "PILOTWINGS", 10)) {
props->dsp_fw = DSPFW_1;
} else {
props->dsp_fw = DSPFW_1B;
}
} else if (header->map == 0x20 && header->carttype == 0x05) {
props->has_dspx = 1;
props->dsp_fw = DSPFW_2;
props->fpga_features |= FEAT_DSPX;
} else if (header->map == 0x30 && header->carttype == 0x05 && header->licensee == 0xb2) {
props->has_dspx = 1;
props->dsp_fw = DSPFW_3;
props->fpga_features |= FEAT_DSPX;
} else if (header->map == 0x30 && header->carttype == 0x03) {
props->has_dspx = 1;
props->dsp_fw = DSPFW_4;
props->fpga_features |= FEAT_DSPX;
} else if (header->map == 0x30 && header->carttype == 0xf6 && header->romsize >= 0xa) {
props->has_dspx = 1;
props->has_st0010 = 1;
props->dsp_fw = DSPFW_ST0010;
props->fpga_features |= FEAT_ST0010;
header->ramsize = 2;
}
break;
case 0x25: /* ExHiROM */
props->mapper_id = 2;
break;
case 0x22: /* ExLoROM */
if(file_handle.fsize > 0x400200) {
props->mapper_id = 6; /* SO96 */
} else {
props->mapper_id = 1;
}
break;
default: /* invalid/unsupported mapper, use header location */
switch(score_idx) {
case 0:
case 1:
props->mapper_id = 0;
break;
case 2:
case 3:
if(file_handle.fsize > 0x800200) {
props->mapper_id = 6; /* SO96 interleaved */
} else if(file_handle.fsize > 0x400200) {
props->mapper_id = 1; /* ExLoROM */
} else {
props->mapper_id = 1; /* LoROM */
}
break;
case 4:
case 5:
props->mapper_id = 2;
break;
default:
props->mapper_id = 1; // whatever
}
}
if(header->romsize == 0 || header->romsize > 13) {
props->romsize_bytes = 1024;
header->romsize = 0;
if(file_handle.fsize >= 1024) {
while(props->romsize_bytes < file_handle.fsize-1) {
header->romsize++;
props->romsize_bytes <<= 1;
}
}
}
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;
}
props->region = (header->destcode <= 1 || header->destcode >= 13) ? 0 : 1;
/*dprintf("ramsize_bytes: %ld\n", props->ramsize_bytes); */
}
uint8_t smc_headerscore(uint32_t addr, snes_header_t* header) {
int score=0;
uint8_t reset_inst;
uint16_t header_offset;
if((addr & 0xfff) == 0x1b0) {
header_offset = 0x200;
} else {
header_offset = 0;
}
if((file_readblock(header, addr, sizeof(snes_header_t)) < sizeof(snes_header_t))
|| file_res) {
return 0;
}
uint8_t mapper = header->map & ~0x10;
uint16_t resetvector = header->vect_reset; /* not endian safe! */
uint32_t file_addr = (((addr - header_offset) & ~0x7fff) | (resetvector & 0x7fff)) + header_offset;
if(resetvector < 0x8000) return 0;
score += 2*isFixed(&header->licensee, sizeof(header->licensee), 0x33);
score += 4*checkChksum(header->cchk, header->chk);
if(header->carttype < 0x08) score++;
if(header->romsize < 0x10) score++;
if(header->ramsize < 0x08) score++;
if(header->destcode < 0x0e) score++;
if((addr-header_offset) == 0x007fc0 && mapper == 0x20) score += 2;
if((addr-header_offset) == 0x00ffc0 && mapper == 0x21) score += 2;
if((addr-header_offset) == 0x007fc0 && mapper == 0x22) score += 2;
if((addr-header_offset) == 0x40ffc0 && mapper == 0x25) score += 2;
file_readblock(&reset_inst, file_addr, 1);
switch(reset_inst) {
case 0x78: /* sei */
case 0x18: /* clc */
case 0x38: /* sec */
case 0x9c: /* stz abs */
case 0x4c: /* jmp abs */
case 0x5c: /* jml abs */
score += 8;
break;
case 0xc2: /* rep */
case 0xe2: /* sep */
case 0xad: /* lda abs */
case 0xae: /* ldx abs */
case 0xac: /* ldy abs */
case 0xaf: /* lda abs long */
case 0xa9: /* lda imm */
case 0xa2: /* ldx imm */
case 0xa0: /* ldy imm */
case 0x20: /* jsr abs */
case 0x22: /* jsl abs */
score += 4;
break;
case 0x40: /* rti */
case 0x60: /* rts */
case 0x6b: /* rtl */
case 0xcd: /* cmp abs */
case 0xec: /* cpx abs */
case 0xcc: /* cpy abs */
score -= 4;
break;
case 0x00: /* brk */
case 0x02: /* cop */
case 0xdb: /* stp */
case 0x42: /* wdm */
case 0xff: /* sbc abs long indexed */
score -= 8;
break;
}
if(score && addr > 0x400000) score += 4;
if(score < 0) score = 0;
return score;
}