git.zerfleddert.de Git - 32620_extract/blob - extract.c

   1 /* Extractor for Geraet 32620 ROM files
   2  *
   3  * Copyright (c) 2020 Michael Gernoth <michael@gernoth.net>
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy
   6  * of this software and associated documentation files (the "Software"), to
   7  * deal in the Software without restriction, including without limitation the
   8  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   9  * sell copies of the Software, and to permit persons to whom the Software is
  10  * furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23 #include <errno.h>
  24 #include <inttypes.h>
  25 #include <fcntl.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31 #include <unistd.h>
  32
  33 int main(int argc, char **argv)
  34 {
  35         uint8_t header[64];
  36         uint32_t adrs[(64/3)+1] = { 0 };
  37         uint8_t last_cs = 0;
  38         int fd;
  39         int r;
  40         int i;
  41         int count = 0;
  42
  43         if (argc != 3) {
  44                 fprintf(stderr, "Syntax: %s in.bin prefix\n", argv[0]);
  45                 exit(EXIT_FAILURE);
  46         }
  47
  48         fd = open(argv[1], O_RDONLY);
  49         if (fd == -1) {
  50                 perror("Can't open ROM");
  51                 exit(EXIT_FAILURE);
  52         }
  53
  54         r = read(fd, header, sizeof(header));
  55         if (r != sizeof(header)) {
  56                 perror("Can't read header");
  57                 exit(EXIT_FAILURE);
  58         }
  59
  60         /*
  61          * From: https://blog.ardy.io/2020/8/geraet-32620/
  62          *
  63          * 00000000 01000000 01000011 10110111 01001010 01000011 11000011 01011000
  64          * ^^^^^^^^ ^^^^^^^^ ^^^^^^^^|                          |
  65          * LIIIIIII LIILIIII I????LII
  66          *        I   I    I I      +-- Amplification (Default: 3)
  67          *        I   I    I +--------- Remaining chip select line? (but not quite?)
  68          *        I   I    +----------- Address (HI Byte)
  69          *        I   +---------------- Chip Select lines A15, A14, A13
  70          *        +-------------------- Address (LO Byte)
  71          */
  72         for (i = 0; i < 62; i+=3) {
  73                 uint8_t hi, lo, amp, cs;
  74                 uint32_t adr;
  75
  76                 lo = header[i];
  77                 if ((header[i+2] & 0xf8) & 0x40) {
  78                         cs = ((header[i+1] & 0xe0) >> 5) - 2;
  79                 } else {
  80                         cs = (((header[i+1] & 0xe0) >> 5) | (1 << 3)) - 4;
  81                 }
  82
  83                 //EOF?!
  84                 if ((header[i+2] & 0xf8) == 0xf8)
  85                         cs = last_cs;
  86                 else
  87                         last_cs = cs;
  88
  89                 hi = header[i+1] & 0x1f;
  90                 amp = header[i+2] & 0x3;
  91
  92                 adr = ((hi << 8) | lo) + (cs * 8192);
  93                 if (cs == 0)
  94                         adr += sizeof(header);
  95
  96                 printf("%02d. hi: 0x%02x, lo: 0x%02x, cs: 0x%02x -> adr: 0x%04x; amp: 0x%02x\n",
  97                        i/3, hi, lo, cs, adr, amp);
  98
  99                 adrs[i/3] = adr;
 100                 if ((header[i+2] & 0xf8) == 0xf8)
 101                         break;
 102
 103                 count++;
 104         }
 105
 106         for (i = 0; i < count; i++) {
 107                 uint8_t buf[65536];
 108                 uint32_t len;
 109                 char file[32];
 110                 int fd_out;
 111
 112                 lseek(fd, adrs[i], SEEK_SET);
 113
 114                 len = adrs[i+1] - adrs[i];
 115
 116                 if (!len)
 117                         break;
 118
 119                 printf("%02d. Length: %d\n", i, len);
 120                 memset(file, 0, sizeof(file));
 121                 snprintf(file, sizeof(file)-1, "%s-%02d.raw", argv[2], i);
 122
 123                 fd_out = open(file, O_WRONLY|O_CREAT|O_TRUNC, 0644);
 124                 if (fd_out == -1) {
 125                         perror("Can't open out");
 126                         exit(EXIT_FAILURE);
 127                 }
 128
 129                 r = read(fd, buf, len);
 130                 if (r != len) {
 131                         perror("Can't read content");
 132                         exit(EXIT_FAILURE);
 133                 }
 134
 135                 r = write(fd_out, buf, len);
 136                 if (r != len) {
 137                         perror("Can't write content");
 138                         exit(EXIT_FAILURE);
 139                 }
 140
 141                 close(fd_out);
 142
 143         }
 144
 145         close(fd);
 146
 147         return EXIT_SUCCESS;
 148 }