disk/part_dos.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2001
   4  * Raymond Lo, lo@routefree.com
   5  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   6  */
   7
   8 /*
   9  * Support for harddisk partitions.
  10  *
  11  * To be compatible with LinuxPPC and Apple we use the standard Apple
  12  * SCSI disk partitioning scheme. For more information see:
  13  * http://developer.apple.com/techpubs/mac/Devices/Devices-126.html#MARKER-14-92
  14  */
  15
  16 #include <common.h>
  17 #include <blk.h>
  18 #include <command.h>
  19 #include <ide.h>
  20 #include <memalign.h>
  21 #include <asm/unaligned.h>
  22 #include <linux/compiler.h>
  23 #include "part_dos.h"
  24 #include <part.h>
  25
  26 #define DOS_PART_DEFAULT_SECTOR 512
  27
  28 /* should this be configurable? It looks like it's not very common at all
  29  * to use large numbers of partitions */
  30 #define MAX_EXT_PARTS 256
  31
  32 static inline int is_extended(int part_type)
  33 {
  34     return (part_type == DOS_PART_TYPE_EXTENDED ||
  35             part_type == DOS_PART_TYPE_EXTENDED_LBA ||
  36             part_type == DOS_PART_TYPE_EXTENDED_LINUX);
  37 }
  38
  39 static int get_bootable(dos_partition_t *p)
  40 {
  41         int ret = 0;
  42
  43         if (p->sys_ind == 0xef)
  44                 ret |= PART_EFI_SYSTEM_PARTITION;
  45         if (p->boot_ind == 0x80)
  46                 ret |= PART_BOOTABLE;
  47         return ret;
  48 }
  49
  50 static void print_one_part(dos_partition_t *p, lbaint_t ext_part_sector,
  51                            int part_num, unsigned int disksig)
  52 {
  53         lbaint_t lba_start = ext_part_sector + get_unaligned_le32(p->start4);
  54         lbaint_t lba_size  = get_unaligned_le32(p->size4);
  55
  56         printf("%3d\t%-10" LBAFlength "u\t%-10" LBAFlength
  57                 "u\t%08x-%02x\t%02x%s%s\n",
  58                 part_num, lba_start, lba_size, disksig, part_num, p->sys_ind,
  59                 (is_extended(p->sys_ind) ? " Extd" : ""),
  60                 (get_bootable(p) ? " Boot" : ""));
  61 }
  62
  63 static int test_block_type(unsigned char *buffer)
  64 {
  65         int slot;
  66         struct dos_partition *p;
  67         int part_count = 0;
  68
  69         if((buffer[DOS_PART_MAGIC_OFFSET + 0] != 0x55) ||
  70             (buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) ) {
  71                 return (-1);
  72         } /* no DOS Signature at all */
  73         p = (struct dos_partition *)&buffer[DOS_PART_TBL_OFFSET];
  74
  75         /* Check that the boot indicators are valid and count the partitions. */
  76         for (slot = 0; slot < 4; ++slot, ++p) {
  77                 if (p->boot_ind != 0 && p->boot_ind != 0x80)
  78                         break;
  79                 if (p->sys_ind)
  80                         ++part_count;
  81         }
  82
  83         /*
  84          * If the partition table is invalid or empty,
  85          * check if this is a DOS PBR
  86          */
  87         if (slot != 4 || !part_count) {
  88                 if (!strncmp((char *)&buffer[DOS_PBR_FSTYPE_OFFSET],
  89                              "FAT", 3) ||
  90                     !strncmp((char *)&buffer[DOS_PBR32_FSTYPE_OFFSET],
  91                              "FAT32", 5))
  92                         return DOS_PBR; /* This is a DOS PBR and not an MBR */
  93         }
  94         if (slot == 4)
  95                 return DOS_MBR; /* This is an DOS MBR */
  96
  97         /* This is neither a DOS MBR nor a DOS PBR */
  98         return -1;
  99 }
 100
 101 static int part_test_dos(struct blk_desc *desc)
 102 {
 103 #ifndef CONFIG_SPL_BUILD
 104         ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, mbr,
 105                         DIV_ROUND_UP(desc->blksz, sizeof(legacy_mbr)));
 106
 107         if (blk_dread(desc, 0, 1, (ulong *)mbr) != 1)
 108                 return -1;
 109
 110         if (test_block_type((unsigned char *)mbr) != DOS_MBR)
 111                 return -1;
 112
 113         if (desc->sig_type == SIG_TYPE_NONE && mbr->unique_mbr_signature) {
 114                 desc->sig_type = SIG_TYPE_MBR;
 115                 desc->mbr_sig = mbr->unique_mbr_signature;
 116         }
 117 #else
 118         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, desc->blksz);
 119
 120         if (blk_dread(desc, 0, 1, (ulong *)buffer) != 1)
 121                 return -1;
 122
 123         if (test_block_type(buffer) != DOS_MBR)
 124                 return -1;
 125 #endif
 126
 127         return 0;
 128 }
 129
 130 /*  Print a partition that is relative to its Extended partition table
 131  */
 132 static void print_partition_extended(struct blk_desc *desc,
 133                                      lbaint_t ext_part_sector,
 134                                      lbaint_t relative,
 135                                      int part_num, unsigned int disksig)
 136 {
 137         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, desc->blksz);
 138         dos_partition_t *pt;
 139         int i;
 140
 141         /* set a maximum recursion level */
 142         if (part_num > MAX_EXT_PARTS)
 143         {
 144                 printf("** Nested DOS partitions detected, stopping **\n");
 145                 return;
 146     }
 147
 148         if (blk_dread(desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
 149                 printf ("** Can't read partition table on %d:" LBAFU " **\n",
 150                         desc->devnum, ext_part_sector);
 151                 return;
 152         }
 153         i=test_block_type(buffer);
 154         if (i != DOS_MBR) {
 155                 printf ("bad MBR sector signature 0x%02x%02x\n",
 156                         buffer[DOS_PART_MAGIC_OFFSET],
 157                         buffer[DOS_PART_MAGIC_OFFSET + 1]);
 158                 return;
 159         }
 160
 161         if (!ext_part_sector)
 162                 disksig = get_unaligned_le32(&buffer[DOS_PART_DISKSIG_OFFSET]);
 163
 164         /* Print all primary/logical partitions */
 165         pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 166         for (i = 0; i < 4; i++, pt++) {
 167                 /*
 168                  * fdisk does not show the extended partitions that
 169                  * are not in the MBR
 170                  */
 171
 172                 if ((pt->sys_ind != 0) &&
 173                     (ext_part_sector == 0 || !is_extended (pt->sys_ind)) ) {
 174                         print_one_part(pt, ext_part_sector, part_num, disksig);
 175                 }
 176
 177                 /* Reverse engr the fdisk part# assignment rule! */
 178                 if ((ext_part_sector == 0) ||
 179                     (pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
 180                         part_num++;
 181                 }
 182         }
 183
 184         /* Follows the extended partitions */
 185         pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 186         for (i = 0; i < 4; i++, pt++) {
 187                 if (is_extended (pt->sys_ind)) {
 188                         lbaint_t lba_start
 189                                 = get_unaligned_le32 (pt->start4) + relative;
 190
 191                         print_partition_extended(desc, lba_start,
 192                                                  !ext_part_sector ? lba_start :
 193                                                  relative, part_num, disksig);
 194                 }
 195         }
 196
 197         return;
 198 }
 199
 200
 201 /*  Print a partition that is relative to its Extended partition table
 202  */
 203 static int part_get_info_extended(struct blk_desc *desc,
 204                                   lbaint_t ext_part_sector, lbaint_t relative,
 205                                   int part_num, int which_part,
 206                                   struct disk_partition *info, uint disksig)
 207 {
 208         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, desc->blksz);
 209         struct disk_partition wdinfo = { 0 };
 210         dos_partition_t *pt;
 211         int i, ret;
 212         int dos_type;
 213
 214         /* set a maximum recursion level */
 215         if (part_num > MAX_EXT_PARTS)
 216         {
 217                 printf("** Nested DOS partitions detected, stopping **\n");
 218                 return -1;
 219     }
 220
 221         if (blk_dread(desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
 222                 printf ("** Can't read partition table on %d:" LBAFU " **\n",
 223                         desc->devnum, ext_part_sector);
 224                 return -1;
 225         }
 226         if (buffer[DOS_PART_MAGIC_OFFSET] != 0x55 ||
 227                 buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) {
 228                 printf ("bad MBR sector signature 0x%02x%02x\n",
 229                         buffer[DOS_PART_MAGIC_OFFSET],
 230                         buffer[DOS_PART_MAGIC_OFFSET + 1]);
 231                 return -1;
 232         }
 233
 234         if (CONFIG_IS_ENABLED(PARTITION_UUIDS) && !ext_part_sector)
 235                 disksig = get_unaligned_le32(&buffer[DOS_PART_DISKSIG_OFFSET]);
 236
 237         ret = part_get_info_whole_disk(desc, &wdinfo);
 238         if (ret)
 239                 return ret;
 240
 241         /* Print all primary/logical partitions */
 242         pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 243         for (i = 0; i < 4; i++, pt++) {
 244                 /*
 245                  * fdisk does not show the extended partitions that
 246                  * are not in the MBR
 247                  */
 248                 if (((pt->boot_ind & ~0x80) == 0) &&
 249                     (pt->sys_ind != 0) &&
 250                     (part_num == which_part) &&
 251                     (ext_part_sector == 0 || is_extended(pt->sys_ind) == 0)) {
 252                         if (wdinfo.blksz > DOS_PART_DEFAULT_SECTOR)
 253                                 info->blksz = wdinfo.blksz;
 254                         else
 255                                 info->blksz = DOS_PART_DEFAULT_SECTOR;
 256                         info->start = (lbaint_t)(ext_part_sector +
 257                                         get_unaligned_le32(pt->start4));
 258                         info->size  = (lbaint_t)get_unaligned_le32(pt->size4);
 259                         part_set_generic_name(desc, part_num,
 260                                               (char *)info->name);
 261                         /* sprintf(info->type, "%d, pt->sys_ind); */
 262                         strcpy((char *)info->type, "U-Boot");
 263                         info->bootable = get_bootable(pt);
 264                         if (CONFIG_IS_ENABLED(PARTITION_UUIDS)) {
 265                                 char str[12];
 266
 267                                 sprintf(str, "%08x-%02x", disksig, part_num);
 268                                 disk_partition_set_uuid(info, str);
 269                         }
 270                         info->sys_ind = pt->sys_ind;
 271                         return 0;
 272                 }
 273
 274                 /* Reverse engr the fdisk part# assignment rule! */
 275                 if ((ext_part_sector == 0) ||
 276                     (pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
 277                         part_num++;
 278                 }
 279         }
 280
 281         /* Follows the extended partitions */
 282         pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 283         for (i = 0; i < 4; i++, pt++) {
 284                 if (is_extended (pt->sys_ind)) {
 285                         lbaint_t lba_start
 286                                 = get_unaligned_le32 (pt->start4) + relative;
 287
 288                         return part_get_info_extended(desc, lba_start,
 289                                  ext_part_sector == 0 ? lba_start : relative,
 290                                  part_num, which_part, info, disksig);
 291                 }
 292         }
 293
 294         /* Check for DOS PBR if no partition is found */
 295         dos_type = test_block_type(buffer);
 296
 297         if (dos_type == DOS_PBR) {
 298                 info->start = 0;
 299                 info->size = desc->lba;
 300                 if (wdinfo.blksz > DOS_PART_DEFAULT_SECTOR)
 301                         info->blksz = wdinfo.blksz;
 302                 else
 303                         info->blksz = DOS_PART_DEFAULT_SECTOR;
 304                 info->bootable = 0;
 305                 strcpy((char *)info->type, "U-Boot");
 306                 disk_partition_clr_uuid(info);
 307                 return 0;
 308         }
 309
 310         return -1;
 311 }
 312
 313 static void __maybe_unused part_print_dos(struct blk_desc *desc)
 314 {
 315         printf("Part\tStart Sector\tNum Sectors\tUUID\t\tType\n");
 316         print_partition_extended(desc, 0, 0, 1, 0);
 317 }
 318
 319 static int __maybe_unused part_get_info_dos(struct blk_desc *desc, int part,
 320                                             struct disk_partition *info)
 321 {
 322         return part_get_info_extended(desc, 0, 0, 1, part, info, 0);
 323 }
 324
 325 int is_valid_dos_buf(void *buf)
 326 {
 327         return test_block_type(buf) == DOS_MBR ? 0 : -1;
 328 }
 329
 330 #if IS_ENABLED(CONFIG_CMD_MBR)
 331 static void lba_to_chs(lbaint_t lba, unsigned char *rc, unsigned char *rh,
 332                        unsigned char *rs)
 333 {
 334         unsigned int c, h, s;
 335         /* use fixed CHS geometry */
 336         unsigned int sectpertrack = 63;
 337         unsigned int heads = 255;
 338
 339         c = (lba + 1) / sectpertrack / heads;
 340         h = (lba + 1) / sectpertrack - c * heads;
 341         s = (lba + 1) - (c * heads + h) * sectpertrack;
 342
 343         if (c > 1023) {
 344                 c = 1023;
 345                 h = 254;
 346                 s = 63;
 347         }
 348
 349         *rc = c & 0xff;
 350         *rh = h;
 351         *rs = s + ((c & 0x300) >> 2);
 352 }
 353
 354 static void mbr_fill_pt_entry(dos_partition_t *pt, lbaint_t start,
 355                 lbaint_t relative, lbaint_t size, uchar sys_ind, bool bootable)
 356 {
 357         pt->boot_ind = bootable ? 0x80 : 0x00;
 358         pt->sys_ind = sys_ind;
 359         lba_to_chs(start, &pt->cyl, &pt->head, &pt->sector);
 360         lba_to_chs(start + size - 1, &pt->end_cyl, &pt->end_head, &pt->end_sector);
 361         put_unaligned_le32(relative, &pt->start4);
 362         put_unaligned_le32(size, &pt->size4);
 363 }
 364
 365 int write_mbr_partitions(struct blk_desc *dev,
 366                 struct disk_partition *p, int count, unsigned int disksig)
 367 {
 368         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev->blksz);
 369         lbaint_t ext_part_start = 0, ext_part_size = 0, ext_part_sect = 0;
 370         dos_partition_t *pt;
 371         int i;
 372
 373         memset(buffer, 0, dev->blksz);
 374         buffer[DOS_PART_MAGIC_OFFSET] = 0x55;
 375         buffer[DOS_PART_MAGIC_OFFSET + 1] = 0xaa;
 376         put_unaligned_le32(disksig, &buffer[DOS_PART_DISKSIG_OFFSET]);
 377         pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 378
 379         /* create all primary partitions */
 380         for (i = 0; i < 4 && i < count; i++, pt++) {
 381                 mbr_fill_pt_entry(pt, p[i].start, p[i].start, p[i].size,
 382                                   p[i].sys_ind, p[i].bootable);
 383                 if (is_extended(p[i].sys_ind)) {
 384                         ext_part_start = p[i].start;
 385                         ext_part_size = p[i].size;
 386                         ext_part_sect = p[i].start;
 387                 }
 388         }
 389
 390         if (i < count && !ext_part_start) {
 391                 printf("%s: extended partition is needed for more than 4 partitions\n",
 392                         __func__);
 393                 return -1;
 394         }
 395
 396         /* write MBR */
 397         if (blk_dwrite(dev, 0, 1, buffer) != 1) {
 398                 printf("%s: failed writing 'MBR' (1 blks at 0x0)\n",
 399                        __func__);
 400                 return -1;
 401         }
 402
 403         /* create extended volumes */
 404         for (; i < count; i++) {
 405                 lbaint_t next_ebr = 0;
 406
 407                 memset(buffer, 0, dev->blksz);
 408                 buffer[DOS_PART_MAGIC_OFFSET] = 0x55;
 409                 buffer[DOS_PART_MAGIC_OFFSET + 1] = 0xaa;
 410                 pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 411
 412                 mbr_fill_pt_entry(pt, p[i].start, p[i].start - ext_part_sect,
 413                                   p[i].size, p[i].sys_ind, p[i].bootable);
 414
 415                 if (i + 1 < count) {
 416                         pt++;
 417                         next_ebr = p[i].start + p[i].size;
 418                         mbr_fill_pt_entry(pt, next_ebr,
 419                                           next_ebr - ext_part_start,
 420                                           p[i+1].start + p[i+1].size - next_ebr,
 421                                           DOS_PART_TYPE_EXTENDED, 0);
 422                 }
 423
 424                 /* write EBR */
 425                 if (blk_dwrite(dev, ext_part_sect, 1, buffer) != 1) {
 426                         printf("%s: failed writing 'EBR' (1 blks at 0x%lx)\n",
 427                                __func__, ext_part_sect);
 428                         return -1;
 429                 }
 430                 ext_part_sect = next_ebr;
 431         }
 432
 433         /* Update the partition table entries*/
 434         part_init(dev);
 435
 436         return 0;
 437 }
 438
 439 int layout_mbr_partitions(struct disk_partition *p, int count,
 440                           lbaint_t total_sectors)
 441 {
 442         struct disk_partition *ext = NULL;
 443         int i, j;
 444         lbaint_t ext_vol_start;
 445
 446         /* calculate primary partitions start and size if needed */
 447         if (!p[0].start)
 448                 p[0].start = DOS_PART_DEFAULT_GAP;
 449         for (i = 0; i < 4 && i < count; i++) {
 450                 if (!p[i].start)
 451                         p[i].start = p[i - 1].start + p[i - 1].size;
 452                 if (!p[i].size) {
 453                         lbaint_t end = total_sectors;
 454                         lbaint_t allocated = 0;
 455
 456                         for (j = i + 1; j < 4 && j < count; j++) {
 457                                 if (p[j].start) {
 458                                         end = p[j].start;
 459                                         break;
 460                                 }
 461                                 allocated += p[j].size;
 462                         }
 463                         p[i].size = end - allocated - p[i].start;
 464                 }
 465                 if (p[i].sys_ind == 0x05)
 466                         ext = &p[i];
 467         }
 468
 469         if (count <= 4)
 470                 return 0;
 471
 472         if (!ext) {
 473                 log_err("extended partition is needed for more than 4 partitions\n");
 474                 return -EINVAL;
 475         }
 476
 477         /* calculate extended volumes start and size if needed */
 478         ext_vol_start = ext->start;
 479         for (i = 4; i < count; i++) {
 480                 if (!p[i].start)
 481                         p[i].start = ext_vol_start + DOS_PART_DEFAULT_GAP;
 482                 if (!p[i].size) {
 483                         lbaint_t end = ext->start + ext->size;
 484                         lbaint_t allocated = 0;
 485
 486                         for (j = i + 1; j < count; j++) {
 487                                 if (p[j].start) {
 488                                         end = p[j].start - DOS_PART_DEFAULT_GAP;
 489                                         break;
 490                                 }
 491                                 allocated += p[j].size + DOS_PART_DEFAULT_GAP;
 492                         }
 493                         p[i].size = end - allocated - p[i].start;
 494                 }
 495                 ext_vol_start = p[i].start + p[i].size;
 496         }
 497
 498         return 0;
 499 }
 500 #endif
 501
 502 int write_mbr_sector(struct blk_desc *desc, void *buf)
 503 {
 504         if (is_valid_dos_buf(buf))
 505                 return -1;
 506
 507         /* write MBR */
 508         if (blk_dwrite(desc, 0, 1, buf) != 1) {
 509                 printf("%s: failed writing '%s' (1 blks at 0x0)\n",
 510                        __func__, "MBR");
 511                 return 1;
 512         }
 513
 514         /* Update the partition table entries*/
 515         part_init(desc);
 516
 517         return 0;
 518 }
 519
 520 U_BOOT_PART_TYPE(dos) = {
 521         .name           = "DOS",
 522         .part_type      = PART_TYPE_DOS,
 523         .max_entries    = DOS_ENTRY_NUMBERS,
 524         .get_info       = part_get_info_ptr(part_get_info_dos),
 525         .print          = part_print_ptr(part_print_dos),
 526         .test           = part_test_dos,
 527 };