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 *dev_desc)
 102 {
 103 #ifndef CONFIG_SPL_BUILD
 104         ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, mbr,
 105                         DIV_ROUND_UP(dev_desc->blksz, sizeof(legacy_mbr)));
 106
 107         if (blk_dread(dev_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 (dev_desc->sig_type == SIG_TYPE_NONE &&
 114             mbr->unique_mbr_signature != 0) {
 115                 dev_desc->sig_type = SIG_TYPE_MBR;
 116                 dev_desc->mbr_sig = mbr->unique_mbr_signature;
 117         }
 118 #else
 119         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
 120
 121         if (blk_dread(dev_desc, 0, 1, (ulong *)buffer) != 1)
 122                 return -1;
 123
 124         if (test_block_type(buffer) != DOS_MBR)
 125                 return -1;
 126 #endif
 127
 128         return 0;
 129 }
 130
 131 /*  Print a partition that is relative to its Extended partition table
 132  */
 133 static void print_partition_extended(struct blk_desc *dev_desc,
 134                                      lbaint_t ext_part_sector,
 135                                      lbaint_t relative,
 136                                      int part_num, unsigned int disksig)
 137 {
 138         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
 139         dos_partition_t *pt;
 140         int i;
 141
 142         /* set a maximum recursion level */
 143         if (part_num > MAX_EXT_PARTS)
 144         {
 145                 printf("** Nested DOS partitions detected, stopping **\n");
 146                 return;
 147     }
 148
 149         if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
 150                 printf ("** Can't read partition table on %d:" LBAFU " **\n",
 151                         dev_desc->devnum, ext_part_sector);
 152                 return;
 153         }
 154         i=test_block_type(buffer);
 155         if (i != DOS_MBR) {
 156                 printf ("bad MBR sector signature 0x%02x%02x\n",
 157                         buffer[DOS_PART_MAGIC_OFFSET],
 158                         buffer[DOS_PART_MAGIC_OFFSET + 1]);
 159                 return;
 160         }
 161
 162         if (!ext_part_sector)
 163                 disksig = get_unaligned_le32(&buffer[DOS_PART_DISKSIG_OFFSET]);
 164
 165         /* Print all primary/logical partitions */
 166         pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 167         for (i = 0; i < 4; i++, pt++) {
 168                 /*
 169                  * fdisk does not show the extended partitions that
 170                  * are not in the MBR
 171                  */
 172
 173                 if ((pt->sys_ind != 0) &&
 174                     (ext_part_sector == 0 || !is_extended (pt->sys_ind)) ) {
 175                         print_one_part(pt, ext_part_sector, part_num, disksig);
 176                 }
 177
 178                 /* Reverse engr the fdisk part# assignment rule! */
 179                 if ((ext_part_sector == 0) ||
 180                     (pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
 181                         part_num++;
 182                 }
 183         }
 184
 185         /* Follows the extended partitions */
 186         pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 187         for (i = 0; i < 4; i++, pt++) {
 188                 if (is_extended (pt->sys_ind)) {
 189                         lbaint_t lba_start
 190                                 = get_unaligned_le32 (pt->start4) + relative;
 191
 192                         print_partition_extended(dev_desc, lba_start,
 193                                 ext_part_sector == 0  ? lba_start : relative,
 194                                 part_num, disksig);
 195                 }
 196         }
 197
 198         return;
 199 }
 200
 201
 202 /*  Print a partition that is relative to its Extended partition table
 203  */
 204 static int part_get_info_extended(struct blk_desc *dev_desc,
 205                                   lbaint_t ext_part_sector, lbaint_t relative,
 206                                   int part_num, int which_part,
 207                                   struct disk_partition *info, uint disksig)
 208 {
 209         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
 210         dos_partition_t *pt;
 211         int i;
 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(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
 222                 printf ("** Can't read partition table on %d:" LBAFU " **\n",
 223                         dev_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)
 235         if (!ext_part_sector)
 236                 disksig = get_unaligned_le32(&buffer[DOS_PART_DISKSIG_OFFSET]);
 237 #endif
 238
 239         /* Print all primary/logical partitions */
 240         pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 241         for (i = 0; i < 4; i++, pt++) {
 242                 /*
 243                  * fdisk does not show the extended partitions that
 244                  * are not in the MBR
 245                  */
 246                 if (((pt->boot_ind & ~0x80) == 0) &&
 247                     (pt->sys_ind != 0) &&
 248                     (part_num == which_part) &&
 249                     (ext_part_sector == 0 || is_extended(pt->sys_ind) == 0)) {
 250                         info->blksz = DOS_PART_DEFAULT_SECTOR;
 251                         info->start = (lbaint_t)(ext_part_sector +
 252                                         get_unaligned_le32(pt->start4));
 253                         info->size  = (lbaint_t)get_unaligned_le32(pt->size4);
 254                         part_set_generic_name(dev_desc, part_num,
 255                                               (char *)info->name);
 256                         /* sprintf(info->type, "%d, pt->sys_ind); */
 257                         strcpy((char *)info->type, "U-Boot");
 258                         info->bootable = get_bootable(pt);
 259 #if CONFIG_IS_ENABLED(PARTITION_UUIDS)
 260                         sprintf(info->uuid, "%08x-%02x", disksig, part_num);
 261 #endif
 262                         info->sys_ind = pt->sys_ind;
 263                         return 0;
 264                 }
 265
 266                 /* Reverse engr the fdisk part# assignment rule! */
 267                 if ((ext_part_sector == 0) ||
 268                     (pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
 269                         part_num++;
 270                 }
 271         }
 272
 273         /* Follows the extended partitions */
 274         pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 275         for (i = 0; i < 4; i++, pt++) {
 276                 if (is_extended (pt->sys_ind)) {
 277                         lbaint_t lba_start
 278                                 = get_unaligned_le32 (pt->start4) + relative;
 279
 280                         return part_get_info_extended(dev_desc, lba_start,
 281                                  ext_part_sector == 0 ? lba_start : relative,
 282                                  part_num, which_part, info, disksig);
 283                 }
 284         }
 285
 286         /* Check for DOS PBR if no partition is found */
 287         dos_type = test_block_type(buffer);
 288
 289         if (dos_type == DOS_PBR) {
 290                 info->start = 0;
 291                 info->size = dev_desc->lba;
 292                 info->blksz = DOS_PART_DEFAULT_SECTOR;
 293                 info->bootable = 0;
 294                 strcpy((char *)info->type, "U-Boot");
 295 #if CONFIG_IS_ENABLED(PARTITION_UUIDS)
 296                 info->uuid[0] = 0;
 297 #endif
 298                 return 0;
 299         }
 300
 301         return -1;
 302 }
 303
 304 static void __maybe_unused part_print_dos(struct blk_desc *dev_desc)
 305 {
 306         printf("Part\tStart Sector\tNum Sectors\tUUID\t\tType\n");
 307         print_partition_extended(dev_desc, 0, 0, 1, 0);
 308 }
 309
 310 static int __maybe_unused part_get_info_dos(struct blk_desc *dev_desc, int part,
 311                       struct disk_partition *info)
 312 {
 313         return part_get_info_extended(dev_desc, 0, 0, 1, part, info, 0);
 314 }
 315
 316 int is_valid_dos_buf(void *buf)
 317 {
 318         return test_block_type(buf) == DOS_MBR ? 0 : -1;
 319 }
 320
 321 #if IS_ENABLED(CONFIG_CMD_MBR)
 322 static void lba_to_chs(lbaint_t lba, unsigned char *rc, unsigned char *rh,
 323                        unsigned char *rs)
 324 {
 325         unsigned int c, h, s;
 326         /* use fixed CHS geometry */
 327         unsigned int sectpertrack = 63;
 328         unsigned int heads = 255;
 329
 330         c = (lba + 1) / sectpertrack / heads;
 331         h = (lba + 1) / sectpertrack - c * heads;
 332         s = (lba + 1) - (c * heads + h) * sectpertrack;
 333
 334         if (c > 1023) {
 335                 c = 1023;
 336                 h = 254;
 337                 s = 63;
 338         }
 339
 340         *rc = c & 0xff;
 341         *rh = h;
 342         *rs = s + ((c & 0x300) >> 2);
 343 }
 344
 345 static void mbr_fill_pt_entry(dos_partition_t *pt, lbaint_t start,
 346                 lbaint_t relative, lbaint_t size, uchar sys_ind, bool bootable)
 347 {
 348         pt->boot_ind = bootable ? 0x80 : 0x00;
 349         pt->sys_ind = sys_ind;
 350         lba_to_chs(start, &pt->cyl, &pt->head, &pt->sector);
 351         lba_to_chs(start + size - 1, &pt->end_cyl, &pt->end_head, &pt->end_sector);
 352         put_unaligned_le32(relative, &pt->start4);
 353         put_unaligned_le32(size, &pt->size4);
 354 }
 355
 356 int write_mbr_partitions(struct blk_desc *dev,
 357                 struct disk_partition *p, int count, unsigned int disksig)
 358 {
 359         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev->blksz);
 360         lbaint_t ext_part_start = 0, ext_part_size = 0, ext_part_sect = 0;
 361         dos_partition_t *pt;
 362         int i;
 363
 364         memset(buffer, 0, dev->blksz);
 365         buffer[DOS_PART_MAGIC_OFFSET] = 0x55;
 366         buffer[DOS_PART_MAGIC_OFFSET + 1] = 0xaa;
 367         put_unaligned_le32(disksig, &buffer[DOS_PART_DISKSIG_OFFSET]);
 368         pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 369
 370         /* create all primary partitions */
 371         for (i = 0; i < 4 && i < count; i++, pt++) {
 372                 mbr_fill_pt_entry(pt, p[i].start, p[i].start, p[i].size,
 373                                   p[i].sys_ind, p[i].bootable);
 374                 if (is_extended(p[i].sys_ind)) {
 375                         ext_part_start = p[i].start;
 376                         ext_part_size = p[i].size;
 377                         ext_part_sect = p[i].start;
 378                 }
 379         }
 380
 381         if (i < count && !ext_part_start) {
 382                 printf("%s: extended partition is needed for more than 4 partitions\n",
 383                         __func__);
 384                 return -1;
 385         }
 386
 387         /* write MBR */
 388         if (blk_dwrite(dev, 0, 1, buffer) != 1) {
 389                 printf("%s: failed writing 'MBR' (1 blks at 0x0)\n",
 390                        __func__);
 391                 return -1;
 392         }
 393
 394         /* create extended volumes */
 395         for (; i < count; i++) {
 396                 lbaint_t next_ebr = 0;
 397
 398                 memset(buffer, 0, dev->blksz);
 399                 buffer[DOS_PART_MAGIC_OFFSET] = 0x55;
 400                 buffer[DOS_PART_MAGIC_OFFSET + 1] = 0xaa;
 401                 pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
 402
 403                 mbr_fill_pt_entry(pt, p[i].start, p[i].start - ext_part_sect,
 404                                   p[i].size, p[i].sys_ind, p[i].bootable);
 405
 406                 if (i + 1 < count) {
 407                         pt++;
 408                         next_ebr = p[i].start + p[i].size;
 409                         mbr_fill_pt_entry(pt, next_ebr,
 410                                           next_ebr - ext_part_start,
 411                                           p[i+1].start + p[i+1].size - next_ebr,
 412                                           DOS_PART_TYPE_EXTENDED, 0);
 413                 }
 414
 415                 /* write EBR */
 416                 if (blk_dwrite(dev, ext_part_sect, 1, buffer) != 1) {
 417                         printf("%s: failed writing 'EBR' (1 blks at 0x%lx)\n",
 418                                __func__, ext_part_sect);
 419                         return -1;
 420                 }
 421                 ext_part_sect = next_ebr;
 422         }
 423
 424         /* Update the partition table entries*/
 425         part_init(dev);
 426
 427         return 0;
 428 }
 429
 430 int layout_mbr_partitions(struct disk_partition *p, int count,
 431                           lbaint_t total_sectors)
 432 {
 433         struct disk_partition *ext = NULL;
 434         int i, j;
 435         lbaint_t ext_vol_start;
 436
 437         /* calculate primary partitions start and size if needed */
 438         if (!p[0].start)
 439                 p[0].start = DOS_PART_DEFAULT_GAP;
 440         for (i = 0; i < 4 && i < count; i++) {
 441                 if (!p[i].start)
 442                         p[i].start = p[i - 1].start + p[i - 1].size;
 443                 if (!p[i].size) {
 444                         lbaint_t end = total_sectors;
 445                         lbaint_t allocated = 0;
 446
 447                         for (j = i + 1; j < 4 && j < count; j++) {
 448                                 if (p[j].start) {
 449                                         end = p[j].start;
 450                                         break;
 451                                 }
 452                                 allocated += p[j].size;
 453                         }
 454                         p[i].size = end - allocated - p[i].start;
 455                 }
 456                 if (p[i].sys_ind == 0x05)
 457                         ext = &p[i];
 458         }
 459
 460         if (count < 4)
 461                 return 0;
 462
 463         if (!ext) {
 464                 log_err("extended partition is needed for more than 4 partitions\n");
 465                 return -EINVAL;
 466         }
 467
 468         /* calculate extended volumes start and size if needed */
 469         ext_vol_start = ext->start;
 470         for (i = 4; i < count; i++) {
 471                 if (!p[i].start)
 472                         p[i].start = ext_vol_start + DOS_PART_DEFAULT_GAP;
 473                 if (!p[i].size) {
 474                         lbaint_t end = ext->start + ext->size;
 475                         lbaint_t allocated = 0;
 476
 477                         for (j = i + 1; j < count; j++) {
 478                                 if (p[j].start) {
 479                                         end = p[j].start - DOS_PART_DEFAULT_GAP;
 480                                         break;
 481                                 }
 482                                 allocated += p[j].size + DOS_PART_DEFAULT_GAP;
 483                         }
 484                         p[i].size = end - allocated - p[i].start;
 485                 }
 486                 ext_vol_start = p[i].start + p[i].size;
 487         }
 488
 489         return 0;
 490 }
 491 #endif
 492
 493 int write_mbr_sector(struct blk_desc *dev_desc, void *buf)
 494 {
 495         if (is_valid_dos_buf(buf))
 496                 return -1;
 497
 498         /* write MBR */
 499         if (blk_dwrite(dev_desc, 0, 1, buf) != 1) {
 500                 printf("%s: failed writing '%s' (1 blks at 0x0)\n",
 501                        __func__, "MBR");
 502                 return 1;
 503         }
 504
 505         /* Update the partition table entries*/
 506         part_init(dev_desc);
 507
 508         return 0;
 509 }
 510
 511 U_BOOT_PART_TYPE(dos) = {
 512         .name           = "DOS",
 513         .part_type      = PART_TYPE_DOS,
 514         .max_entries    = DOS_ENTRY_NUMBERS,
 515         .get_info       = part_get_info_ptr(part_get_info_dos),
 516         .print          = part_print_ptr(part_print_dos),
 517         .test           = part_test_dos,
 518 };