commands/partition/partition.c

   1 /*      partition 1.13 - Make a partition table         Author: Kees J. Bot
   2  *                                                              27 Apr 1992
   3  */
   4 #define nil ((void*)0)
   5 #include <stdio.h>
   6 #include <sys/types.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9 #include <fcntl.h>
  10 #include <minix/config.h>
  11 #include <minix/const.h>
  12 #include <minix/partition.h>
  13 #include <minix/u64.h>
  14 #include <machine/partition.h>
  15 #include <sys/stat.h>
  16 #include <string.h>
  17 #include <errno.h>
  18 #include <sys/ioctl.h>
  19 #include <limits.h>
  20
  21 #define SECTOR_SIZE     512
  22
  23 #define arraysize(a)    (sizeof(a)/sizeof((a)[0]))
  24 #define arraylimit(a)   ((a) + arraysize(a))
  25
  26 char *arg0;
  27
  28 void report(const char *label)
  29 {
  30         fprintf(stderr, "%s: %s: %s\n", arg0, label, strerror(errno));
  31 }
  32
  33 void fatal(const char *label)
  34 {
  35         report(label);
  36         exit(1);
  37 }
  38
  39 int aflag;                      /* Add a new partition to the current table. */
  40 int mflag;                      /* Minix rules, no need for alignment. */
  41 int rflag;                      /* Report current partitions. */
  42 int fflag;                      /* Force making a table even if too small. */
  43 int nflag;                      /* Play-act, don't really do it. */
  44
  45 int cylinders, heads, sectors;  /* Device's geometry */
  46 int pad;                        /* Partitions must be padded. */
  47
  48 /* Descriptions of the device to divide and the partitions to make, including
  49  * gaps between partitions.
  50  */
  51 char *device;
  52 struct part_entry primary, table[2 * NR_PARTITIONS + 1];
  53 int npart;
  54
  55 /* Extra flags at construction time. */
  56 #define EXPAND_FLAG     0x01    /* Add the remaining sectors to this one */
  57 #define EXIST_FLAG      0x02    /* Use existing partition */
  58
  59 void find_exist(struct part_entry *exist, int sysind, int nr)
  60 {
  61         int f;
  62         u16_t signature;
  63         struct part_entry oldtable[NR_PARTITIONS];
  64         int n, i;
  65         u32_t minlow, curlow;
  66         struct part_entry *cur;
  67         char *nr_s[] = { "", "second ", "third ", "fourth" };
  68
  69         if ((f= open(device, O_RDONLY)) < 0
  70
  71                 || lseek(f, (off_t) PART_TABLE_OFF, SEEK_SET) == -1
  72
  73                 || read(f, oldtable, sizeof(oldtable)) < 0
  74
  75                 || read(f, &signature, sizeof(signature)) < 0
  76
  77                 || close(f) < 0
  78         ) fatal(device);
  79
  80         minlow= 0;
  81         n= 0;
  82         for (;;) {
  83                 curlow= -1;
  84                 cur= nil;
  85                 for (i= 0; i < NR_PARTITIONS; i++) {
  86                         if (signature == 0xAA55
  87                                 && oldtable[i].sysind != NO_PART
  88                                 && oldtable[i].lowsec >= minlow
  89                                 && oldtable[i].lowsec < curlow
  90                         ) {
  91                                 cur= &oldtable[i];
  92                                 curlow= oldtable[i].lowsec;
  93                         }
  94                 }
  95                 if (n == nr) break;
  96                 n++;
  97                 minlow= curlow+1;
  98         }
  99
 100         if (cur == nil || cur->sysind != sysind) {
 101                 fprintf(stderr,
 102                 "%s: Can't find a %sexisting partition of type 0x%02X\n",
 103                         arg0, nr_s[nr], sysind);
 104                 exit(1);
 105         }
 106         *exist = *cur;
 107 }
 108
 109 void write_table(void)
 110 {
 111         int f;
 112         u16_t signature= 0xAA55;
 113         struct part_entry newtable[NR_PARTITIONS];
 114         int i;
 115
 116         if (nflag) {
 117                 printf("(Table not written)\n");
 118                 return;
 119         }
 120
 121         for (i= 0; i < NR_PARTITIONS; i++) newtable[i]= table[1 + 2*i];
 122
 123         if ((f= open(device, O_WRONLY)) < 0
 124
 125                 || lseek(f, (off_t) PART_TABLE_OFF, SEEK_SET) == -1
 126
 127                 || write(f, newtable, sizeof(newtable)) < 0
 128
 129                 || write(f, &signature, sizeof(signature)) < 0
 130
 131                 || close(f) < 0
 132         ) fatal(device);
 133 }
 134
 135 void sec2dos(unsigned long sec, unsigned char *dos)
 136 /* Translate a sector number into the three bytes DOS uses. */
 137 {
 138         unsigned secspcyl= heads * sectors;
 139         unsigned cyl;
 140
 141         cyl= sec / secspcyl;
 142         dos[2]= cyl;
 143         dos[1]= ((sec % sectors) + 1) | ((cyl >> 2) & 0xC0);
 144         dos[0]= (sec % secspcyl) / sectors;
 145 }
 146
 147 void show_chs(unsigned long pos)
 148 {
 149         int cyl, head, sec;
 150
 151         if (pos == -1) {
 152                 cyl= head= 0;
 153                 sec= -1;
 154         } else {
 155                 cyl= pos / (heads * sectors);
 156                 head= (pos / sectors) - (cyl * heads);
 157                 sec= pos % sectors;
 158         }
 159         printf("  %4d/%03d/%02d", cyl, head, sec);
 160 }
 161
 162 void show_part(struct part_entry *p)
 163 {
 164         static int banner= 0;
 165         int n;
 166
 167         n= p - table;
 168         if ((n % 2) == 0) return;
 169
 170         if (!banner) {
 171                 printf(
 172         "Part     First         Last         Base      Size       Kb\n");
 173                 banner= 1;
 174         }
 175
 176         printf("%3d ", (n-1) / 2);
 177         show_chs(p->lowsec);
 178         show_chs(p->lowsec + p->size - 1);
 179         printf("  %8lu  %8lu  %7lu\n", p->lowsec, p->size, p->size / 2);
 180 }
 181
 182 void usage(void)
 183 {
 184         fprintf(stderr,
 185                 "Usage: partition [-mfn] device [type:]length[+*] ...\n");
 186         exit(1);
 187 }
 188
 189 #define between(a, c, z)        ((unsigned) ((c) - (a)) <= ((z) - (a)))
 190
 191 void parse(char *descr)
 192 {
 193         int seen= 0, sysind, flags, c;
 194         unsigned long lowsec, size;
 195
 196         lowsec= 0;
 197
 198         if (strchr(descr, ':') == nil) {
 199                 /* A hole. */
 200                 if ((npart % 2) != 0) {
 201                         fprintf(stderr, "%s: Two holes can't be adjacent.\n",
 202                                 arg0);
 203                         exit(1);
 204                 }
 205                 sysind= NO_PART;
 206                 seen|= 1;
 207         } else {
 208                 /* A partition. */
 209                 if ((npart % 2) == 0) {
 210                         /* Need a hole before this partition. */
 211                         if (npart == 0) {
 212                                 /* First hole contains the partition table. */
 213                                 table[0].size= 1;
 214                         }
 215                         npart++;
 216                 }
 217                 sysind= 0;
 218                 for (;;) {
 219                         c= *descr++;
 220                         if (between('0', c, '9'))
 221                                 c= (c - '0') + 0x0;
 222                         else
 223                         if (between('a', c, 'z'))
 224                                 c= (c - 'a') + 0xa;
 225                         else
 226                         if (between('A', c, 'Z'))
 227                                 c= (c - 'A') + 0xA;
 228                         else
 229                                 break;
 230                         sysind= 0x10 * sysind + c;
 231                         seen|= 1;
 232                 }
 233                 if (c != ':') usage();
 234         }
 235
 236         flags= 0;
 237
 238         if (strncmp(descr, "exist", 5) == 0 && (npart % 2) == 1) {
 239                 struct part_entry exist;
 240
 241                 find_exist(&exist, sysind, (npart - 1) / 2);
 242                 sysind= exist.sysind;
 243                 lowsec= exist.lowsec;
 244                 size= exist.size;
 245                 flags |= EXIST_FLAG;
 246                 descr += 5;
 247                 c= *descr++;
 248                 seen|= 2;
 249         } else {
 250                 size= 0;
 251                 while (between('0', (c= *descr++), '9')) {
 252                         size= 10 * size + (c - '0');
 253                         seen|= 2;
 254                 }
 255         }
 256
 257         for (;;) {
 258                 if (c == '*')
 259                         flags|= ACTIVE_FLAG;
 260                 else
 261                 if (c == '+' && !(flags & EXIST_FLAG))
 262                         flags|= EXPAND_FLAG;
 263                 else
 264                         break;
 265                 c= *descr++;
 266         }
 267
 268         if (seen != 3 || c != 0) usage();
 269
 270         if (npart == arraysize(table)) {
 271                 fprintf(stderr, "%s: too many partitions, only %d possible.\n",
 272                         arg0, NR_PARTITIONS);
 273                 exit(1);
 274         }
 275         table[npart].bootind= flags;
 276         table[npart].sysind= sysind;
 277         table[npart].lowsec= lowsec;
 278         table[npart].size= size;
 279         npart++;
 280 }
 281
 282 void geometry(void)
 283 /* Get the geometry of the drive the device lives on, and the base and size
 284  * of the device.
 285  */
 286 {
 287         int fd;
 288         struct partition geometry;
 289         struct stat sb;
 290
 291         if ((fd= open(device, O_RDONLY)) < 0) fatal(device);
 292
 293         /* Get the geometry of the drive, and the device's base and size. */
 294         if (ioctl(fd, DIOCGETP, &geometry) < 0)
 295         {
 296                 /* Use the same fake geometry as part. */
 297                 if (fstat(fd, &sb) < 0)
 298                         fatal(device);
 299                 geometry.base= cvul64(0);
 300                 geometry.size= cvul64(sb.st_size);
 301                 geometry.sectors= 32;
 302                 geometry.heads= 64;
 303                 geometry.cylinders= (sb.st_size-1)/SECTOR_SIZE/
 304                         (geometry.sectors*geometry.heads) + 1;
 305         }
 306         close(fd);
 307         primary.lowsec= div64u(geometry.base, SECTOR_SIZE);
 308         primary.size= div64u(geometry.size, SECTOR_SIZE);
 309         cylinders= geometry.cylinders;
 310         heads= geometry.heads;
 311         sectors= geometry.sectors;
 312
 313         /* Is this a primary partition table?  If so then pad partitions. */
 314         pad= (!mflag && primary.lowsec == 0);
 315 }
 316
 317 void boundary(struct part_entry *pe, int exp)
 318 /* Expand or reduce a primary partition to a track or cylinder boundary to
 319  * avoid giving the fdisk's of simpler operating systems a fit.
 320  */
 321 {
 322         unsigned n;
 323
 324         n= !pad ? 1 : pe == &table[0] ? sectors : heads * sectors;
 325         if (exp) pe->size+= n - 1;
 326         pe->size= ((pe->lowsec + pe->size) / n * n) - pe->lowsec;
 327 }
 328
 329 void distribute(void)
 330 /* Fit the partitions onto the device.  Try to start and end them on a
 331  * cylinder boundary if so required.  The first partition is to start on
 332  * track 1, not on cylinder 1.
 333  */
 334 {
 335         struct part_entry *pe, *exp;
 336         long count;
 337         unsigned long base, oldbase;
 338
 339         do {
 340                 exp= nil;
 341                 base= primary.lowsec;
 342                 count= primary.size;
 343
 344                 for (pe= table; pe < arraylimit(table); pe++) {
 345                         oldbase= base;
 346                         if (pe->bootind & EXIST_FLAG) {
 347                                 if (base > pe->lowsec) {
 348                                         fprintf(stderr,
 349         "%s: fixed partition %d is preceded by too big partitions/holes\n",
 350                                                 arg0, ((pe - table) - 1) / 2);
 351                                         exit(1);
 352                                 }
 353                                 exp= nil;       /* XXX - Extend before? */
 354                         } else {
 355                                 pe->lowsec= base;
 356                                 boundary(pe, 1);
 357                                 if (pe->bootind & EXPAND_FLAG) exp= pe;
 358                         }
 359                         base= pe->lowsec + pe->size;
 360                         count-= base - oldbase;
 361                 }
 362                 if (count < 0) {
 363                         if (fflag) break;
 364                         fprintf(stderr, "%s: %s is %ld sectors too small\n",
 365                                 arg0, device, -count);
 366                         exit(1);
 367                 }
 368                 if (exp != nil) {
 369                         /* Add leftover space to the partition marked for
 370                          * expanding.
 371                          */
 372                         exp->size+= count;
 373                         boundary(exp, 0);
 374                         exp->bootind&= ~EXPAND_FLAG;
 375                 }
 376         } while (exp != nil);
 377
 378         for (pe= table; pe < arraylimit(table); pe++) {
 379                 if (pe->sysind == NO_PART) {
 380                         memset(pe, 0, sizeof(*pe));
 381                 } else {
 382                         sec2dos(pe->lowsec, &pe->start_head);
 383                         sec2dos(pe->lowsec + pe->size - 1, &pe->last_head);
 384                         pe->bootind&= ACTIVE_FLAG;
 385                 }
 386                 show_part(pe);
 387         }
 388 }
 389
 390 int main(int argc, char **argv)
 391 {
 392         int i;
 393
 394         if ((arg0= strrchr(argv[0], '/')) == nil) arg0= argv[0]; else arg0++;
 395
 396         i= 1;
 397         while (i < argc && argv[i][0] == '-') {
 398                 char *opt= argv[i++] + 1;
 399
 400                 if (opt[0] == '-' && opt[1] == 0) break;
 401
 402                 while (*opt != 0) switch (*opt++) {
 403                 case 'a':       aflag= 1;       break;
 404                 case 'm':       mflag= 1;       break;
 405                 case 'r':       rflag= 1;       break;
 406                 case 'f':       fflag= 1;       break;
 407                 case 'n':       nflag= 1;       break;
 408                 default:        usage();
 409                 }
 410         }
 411
 412         if (rflag) {
 413                 if (aflag) usage();
 414                 if ((argc - i) != 1) usage();
 415                 fprintf(stderr, "%s: -r is not yet implemented\n", __func__);
 416                 exit(1);
 417         } else {
 418                 if ((argc - i) < 1) usage();
 419                 if (aflag) fprintf(stderr, "%s: -a is not yet implemented\n", __func__);
 420
 421                 device= argv[i++];
 422                 geometry();
 423
 424                 while (i < argc) parse(argv[i++]);
 425
 426                 distribute();
 427                 write_table();
 428         }
 429         exit(0);
 430 }