1/* 2 * ptgen - partition table generator 3 * Copyright (C) 2006 by Felix Fietkau <nbd@nbd.name> 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 <stdint.h> 30#include <ctype.h> 31#include <fcntl.h> 32#include <stdint.h> 33 34#if __BYTE_ORDER == __BIG_ENDIAN 35#define cpu_to_le32(x) bswap_32(x) 36#elif __BYTE_ORDER == __LITTLE_ENDIAN 37#define cpu_to_le32(x) (x) 38#else 39#error unknown endianness! 40#endif 41 42/* Partition table entry */ 43struct pte { 44 uint8_t active; 45 uint8_t chs_start[3]; 46 uint8_t type; 47 uint8_t chs_end[3]; 48 uint32_t start; 49 uint32_t length; 50}; 51 52struct partinfo { 53 unsigned long size; 54 int type; 55}; 56 57int verbose = 0; 58int active = 1; 59int heads = -1; 60int sectors = -1; 61int kb_align = 0; 62struct partinfo parts[4]; 63char *filename = NULL; 64 65 66/* 67 * parse the size argument, which is either 68 * a simple number (K assumed) or 69 * K, M or G 70 * 71 * returns the size in KByte 72 */ 73static long to_kbytes(const char *string) { 74 int exp = 0; 75 long result; 76 char *end; 77 78 result = strtoul(string, &end, 0); 79 switch (tolower(*end)) { 80 case 'k' : 81 case '\0' : exp = 0; break; 82 case 'm' : exp = 1; break; 83 case 'g' : exp = 2; break; 84 default: return 0; 85 } 86 87 if (*end) 88 end++; 89 90 if (*end) { 91 fprintf(stderr, "garbage after end of number\n"); 92 return 0; 93 } 94 95 /* result: number + 1024^(exp) */ 96 return result * ((2 << ((10 * exp) - 1)) ?: 1); 97} 98 99/* convert the sector number into a CHS value for the partition table */ 100static void to_chs(long sect, unsigned char chs[3]) { 101 int c,h,s; 102 103 s = (sect % sectors) + 1; 104 sect = sect / sectors; 105 h = sect % heads; 106 sect = sect / heads; 107 c = sect; 108 109 chs[0] = h; 110 chs[1] = s | ((c >> 2) & 0xC0); 111 chs[2] = c & 0xFF; 112 113 return; 114} 115 116/* round the sector number up to the next cylinder */ 117static inline unsigned long round_to_cyl(long sect) { 118 int cyl_size = heads * sectors; 119 120 return sect + cyl_size - (sect % cyl_size); 121} 122 123/* round the sector number up to the kb_align boundary */ 124static inline unsigned long round_to_kb(long sect) { 125 return ((sect - 1) / kb_align + 1) * kb_align; 126} 127 128/* check the partition sizes and write the partition table */ 129static int gen_ptable(uint32_t signature, int nr) 130{ 131 struct pte pte[4]; 132 unsigned long sect = 0; 133 int i, fd, ret = -1, start, len; 134 135 memset(pte, 0, sizeof(struct pte) * 4); 136 for (i = 0; i < nr; i++) { 137 if (!parts[i].size) { 138 fprintf(stderr, "Invalid size in partition %d!\n", i); 139 return -1; 140 } 141 pte[i].active = ((i + 1) == active) ? 0x80 : 0; 142 pte[i].type = parts[i].type; 143 start = sect + sectors; 144 if (kb_align != 0) 145 start = round_to_kb(start); 146 pte[i].start = cpu_to_le32(start); 147 sect = start + parts[i].size * 2; 148 if (kb_align == 0) 149 sect = round_to_cyl(sect); 150 pte[i].length = cpu_to_le32(len = sect - start); 151 to_chs(start, pte[i].chs_start); 152 to_chs(start + len - 1, pte[i].chs_end); 153 if (verbose) 154 fprintf(stderr, "Partition %d: start=%ld, end=%ld, size=%ld\n", i, (long) start * 512, ((long) start + (long) len) * 512, (long) len * 512); 155 printf("%ld\n", ((long) start * 512)); 156 printf("%ld\n", ((long) len * 512)); 157 } 158 159 if ((fd = open(filename, O_WRONLY|O_CREAT|O_TRUNC, 0644)) < 0) { 160 fprintf(stderr, "Can't open output file '%s'\n",filename); 161 return -1; 162 } 163 164 lseek(fd, 440, SEEK_SET); 165 if (write(fd, &signature, sizeof(signature)) != sizeof(signature)) { 166 fprintf(stderr, "write failed.\n"); 167 goto fail; 168 } 169 170 lseek(fd, 446, SEEK_SET); 171 if (write(fd, pte, sizeof(struct pte) * 4) != sizeof(struct pte) * 4) { 172 fprintf(stderr, "write failed.\n"); 173 goto fail; 174 } 175 lseek(fd, 510, SEEK_SET); 176 if (write(fd, "\x55\xaa", 2) != 2) { 177 fprintf(stderr, "write failed.\n"); 178 goto fail; 179 } 180 181 ret = 0; 182fail: 183 close(fd); 184 return ret; 185} 186 187static void usage(char *prog) 188{ 189 fprintf(stderr, "Usage: %s [-v] -h <heads> -s <sectors> -o <outputfile> [-a 0..4] [-l <align kB>] [[-t <type>] -p <size>...] \n", prog); 190 exit(1); 191} 192 193int main (int argc, char **argv) 194{ 195 char type = 0x83; 196 int ch; 197 int part = 0; 198 uint32_t signature = 0x5452574F; /* 'OWRT' */ 199 200 while ((ch = getopt(argc, argv, "h:s:p:a:t:o:vl:S:")) != -1) { 201 switch (ch) { 202 case 'o': 203 filename = optarg; 204 break; 205 case 'v': 206 verbose++; 207 break; 208 case 'h': 209 heads = (int) strtoul(optarg, NULL, 0); 210 break; 211 case 's': 212 sectors = (int) strtoul(optarg, NULL, 0); 213 break; 214 case 'p': 215 if (part > 3) { 216 fprintf(stderr, "Too many partitions\n"); 217 exit(1); 218 } 219 parts[part].size = to_kbytes(optarg); 220 parts[part++].type = type; 221 break; 222 case 't': 223 type = (char) strtoul(optarg, NULL, 16); 224 break; 225 case 'a': 226 active = (int) strtoul(optarg, NULL, 0); 227 if ((active < 0) || (active > 4)) 228 active = 0; 229 break; 230 case 'l': 231 kb_align = (int) strtoul(optarg, NULL, 0) * 2; 232 break; 233 case 'S': 234 signature = strtoul(optarg, NULL, 0); 235 break; 236 case '?': 237 default: 238 usage(argv[0]); 239 } 240 } 241 argc -= optind; 242 if (argc || (heads <= 0) || (sectors <= 0) || !filename) 243 usage(argv[0]); 244 245 return gen_ptable(signature, part); 246} 247