tools/firmware-utils/src/ptgen.c

   1 /*
   2  * ptgen - partition table generator
   3  * Copyright (C) 2006 by Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * uses parts of afdisk
   6  * Copyright (C) 2002 by David Roetzel <david@roetzel.de>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21  */
  22
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27 #include <stdlib.h>
  28 #include <stdio.h>
  29 #include <ctype.h>
  30 #include <fcntl.h>
  31
  32 #if __BYTE_ORDER == __BIG_ENDIAN
  33 #define cpu_to_le16(x) bswap_16(x)
  34 #elif __BYTE_ORDER == __LITTLE_ENDIAN
  35 #define cpu_to_le16(x) (x)
  36 #else
  37 #error unknown endianness!
  38 #endif
  39
  40 /* Partition table entry */
  41 struct pte {
  42         unsigned char active;
  43         unsigned char chs_start[3];
  44         unsigned char type;
  45         unsigned char chs_end[3];
  46         unsigned int start;
  47         unsigned int length;
  48 };
  49
  50 struct partinfo {
  51         unsigned long size;
  52         int type;
  53 };
  54
  55 int verbose = 0;
  56 int active = 1;
  57 int heads = -1;
  58 int sectors = -1;
  59 struct partinfo parts[4];
  60 char *filename = NULL;
  61
  62
  63 /*
  64  * parse the size argument, which is either
  65  * a simple number (K assumed) or
  66  * K, M or G
  67  *
  68  * returns the size in KByte
  69  */
  70 static long to_kbytes(const char *string) {
  71         int exp = 0;
  72         long result;
  73         char *end;
  74
  75         result = strtoul(string, &end, 0);
  76         switch (tolower(*end)) {
  77                         case 'k' :
  78                         case '\0' : exp = 0; break;
  79                         case 'm' : exp = 1; break;
  80                         case 'g' : exp = 2; break;
  81                         default: return 0;
  82         }
  83
  84         if (*end)
  85                 end++;
  86
  87         if (*end) {
  88                 fprintf(stderr, "garbage after end of number\n");
  89                 return 0;
  90         }
  91
  92         /* result: number + 1024^(exp) */
  93         return result * ((2 << ((10 * exp) - 1)) ?: 1);
  94 }
  95
  96 /* convert the sector number into a CHS value for the partition table */
  97 static void to_chs(long sect, unsigned char chs[3]) {
  98         int c,h,s;
  99
 100         s = (sect % sectors) + 1;
 101         sect = sect / sectors;
 102         h = sect % heads;
 103         sect = sect / heads;
 104         c = sect;
 105
 106         chs[0] = h;
 107         chs[1] = s | ((c >> 2) & 0xC0);
 108         chs[2] = c & 0xFF;
 109
 110         return;
 111 }
 112
 113 /* round the sector number up to the next cylinder */
 114 static inline unsigned long round_to_cyl(long sect) {
 115         int cyl_size = heads * sectors;
 116
 117         return sect + cyl_size - ((sect % cyl_size) ?: cyl_size);
 118 }
 119
 120 /* check the partition sizes and write the partition table */
 121 static int gen_ptable(int nr)
 122 {
 123         struct pte pte[4];
 124         unsigned long sect = 0;
 125         int i, fd, ret = -1, start, len;
 126
 127         memset(pte, 0, sizeof(struct pte) * 4);
 128         for (i = 0; i < nr; i++) {
 129                 if (!parts[i].size) {
 130                         fprintf(stderr, "Invalid size in partition %d!\n", i);
 131                         return -1;
 132                 }
 133                 pte[i].active = ((i + 1) == active) ? 0x80 : 0;
 134                 pte[i].type = parts[i].type;
 135                 pte[i].start = cpu_to_le16(start = sect + sectors);
 136                 sect = round_to_cyl(start + parts[i].size * 2);
 137                 pte[i].length = cpu_to_le16(len = sect - start);
 138                 to_chs(start, pte[i].chs_start);
 139                 to_chs(start + len - 1, pte[i].chs_end);
 140                 if (verbose)
 141                         fprintf(stderr, "Partition %d: start=%ld, end=%ld, size=%ld\n", i, (long) start * 512, ((long) start + (long) len) * 512, (long) len * 512);
 142                 printf("%ld\n", ((long) start * 512));
 143         }
 144
 145         if ((fd = open(filename, O_WRONLY|O_CREAT, 0644)) < 0) {
 146                 fprintf(stderr, "Can't open output file '%s'\n",filename);
 147                 return -1;
 148         }
 149
 150         lseek(fd, 446, SEEK_SET);
 151         if (write(fd, pte, sizeof(struct pte) * 4) != sizeof(struct pte) * 4) {
 152                 fprintf(stderr, "write failed.\n");
 153                 goto fail;
 154         }
 155         lseek(fd, 510, SEEK_SET);
 156         if (write(fd, "\x55\xaa", 2) != 2) {
 157                 fprintf(stderr, "write failed.\n");
 158                 goto fail;
 159         }
 160
 161         ret = 0;
 162 fail:
 163         close(fd);
 164         return ret;
 165 }
 166
 167 static void usage(char *prog)
 168 {
 169         fprintf(stderr, "Usage: %s [-v] -h <heads> -s <sectors> -o <outputfile> [-a 0..4] [[-t <type>] -p <size>...] \n", prog);
 170         exit(1);
 171 }
 172
 173 int main (int argc, char **argv)
 174 {
 175         char type = 0x83;
 176         int ch;
 177         int part = 0;
 178
 179         while ((ch = getopt(argc, argv, "h:s:p:a:t:o:v")) != -1) {
 180                 switch (ch) {
 181                 case 'o':
 182                         filename = optarg;
 183                         break;
 184                 case 'v':
 185                         verbose++;
 186                         break;
 187                 case 'h':
 188                         heads = (int) strtoul(optarg, NULL, 0);
 189                         break;
 190                 case 's':
 191                         sectors = (int) strtoul(optarg, NULL, 0);
 192                         break;
 193                 case 'p':
 194                         if (part > 3) {
 195                                 fprintf(stderr, "Too many partitions\n");
 196                                 exit(1);
 197                         }
 198                         parts[part].size = to_kbytes(optarg);
 199                         parts[part++].type = type;
 200                         break;
 201                 case 't':
 202                         type = (char) strtoul(optarg, NULL, 16);
 203                         break;
 204                 case 'a':
 205                         active = (int) strtoul(optarg, NULL, 0);
 206                         if ((active < 0) || (active > 4))
 207                                 active = 0;
 208                         break;
 209                 case '?':
 210                 default:
 211                         usage(argv[0]);
 212                 }
 213         }
 214         argc -= optind;
 215         if (argc || (heads <= 0) || (sectors <= 0) || !filename)
 216                 usage(argv[0]);
 217
 218         return gen_ptable(part);
 219 }