disk/part_efi.c

   1 /*
   2  * Copyright (C) 2008 RuggedCom, Inc.
   3  * Richard Retanubun <RichardRetanubun@RuggedCom.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * NOTE:
  10  *   when CONFIG_SYS_64BIT_LBA is not defined, lbaint_t is 32 bits; this
  11  *   limits the maximum size of addressable storage to < 2 Terra Bytes
  12  */
  13 #include <asm/unaligned.h>
  14 #include <common.h>
  15 #include <command.h>
  16 #include <ide.h>
  17 #include <malloc.h>
  18 #include <part_efi.h>
  19 #include <linux/ctype.h>
  20
  21 DECLARE_GLOBAL_DATA_PTR;
  22
  23 #ifdef HAVE_BLOCK_DEVICE
  24 /**
  25  * efi_crc32() - EFI version of crc32 function
  26  * @buf: buffer to calculate crc32 of
  27  * @len - length of buf
  28  *
  29  * Description: Returns EFI-style CRC32 value for @buf
  30  */
  31 static inline u32 efi_crc32(const void *buf, u32 len)
  32 {
  33         return crc32(0, buf, len);
  34 }
  35
  36 /*
  37  * Private function prototypes
  38  */
  39
  40 static int pmbr_part_valid(struct partition *part);
  41 static int is_pmbr_valid(legacy_mbr * mbr);
  42 static int is_gpt_valid(block_dev_desc_t *dev_desc, u64 lba,
  43                                 gpt_header *pgpt_head, gpt_entry **pgpt_pte);
  44 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
  45                                 gpt_header * pgpt_head);
  46 static int is_pte_valid(gpt_entry * pte);
  47
  48 static char *print_efiname(gpt_entry *pte)
  49 {
  50         static char name[PARTNAME_SZ + 1];
  51         int i;
  52         for (i = 0; i < PARTNAME_SZ; i++) {
  53                 u8 c;
  54                 c = pte->partition_name[i] & 0xff;
  55                 c = (c && !isprint(c)) ? '.' : c;
  56                 name[i] = c;
  57         }
  58         name[PARTNAME_SZ] = 0;
  59         return name;
  60 }
  61
  62 static efi_guid_t system_guid = PARTITION_SYSTEM_GUID;
  63
  64 static inline int is_bootable(gpt_entry *p)
  65 {
  66         return p->attributes.fields.legacy_bios_bootable ||
  67                 !memcmp(&(p->partition_type_guid), &system_guid,
  68                         sizeof(efi_guid_t));
  69 }
  70
  71 #ifdef CONFIG_EFI_PARTITION
  72 /*
  73  * Public Functions (include/part.h)
  74  */
  75
  76 void print_part_efi(block_dev_desc_t * dev_desc)
  77 {
  78         ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
  79         gpt_entry *gpt_pte = NULL;
  80         int i = 0;
  81         char uuid[37];
  82         unsigned char *uuid_bin;
  83
  84         if (!dev_desc) {
  85                 printf("%s: Invalid Argument(s)\n", __func__);
  86                 return;
  87         }
  88         /* This function validates AND fills in the GPT header and PTE */
  89         if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
  90                          gpt_head, &gpt_pte) != 1) {
  91                 printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
  92                 if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
  93                                  gpt_head, &gpt_pte) != 1) {
  94                         printf("%s: *** ERROR: Invalid Backup GPT ***\n",
  95                                __func__);
  96                         return;
  97                 } else {
  98                         printf("%s: ***        Using Backup GPT ***\n",
  99                                __func__);
 100                 }
 101         }
 102
 103         debug("%s: gpt-entry at %p\n", __func__, gpt_pte);
 104
 105         printf("Part\tStart LBA\tEnd LBA\t\tName\n");
 106         printf("\tAttributes\n");
 107         printf("\tType GUID\n");
 108         printf("\tPartition GUID\n");
 109
 110         for (i = 0; i < le32_to_cpu(gpt_head->num_partition_entries); i++) {
 111                 /* Stop at the first non valid PTE */
 112                 if (!is_pte_valid(&gpt_pte[i]))
 113                         break;
 114
 115                 printf("%3d\t0x%08llx\t0x%08llx\t\"%s\"\n", (i + 1),
 116                         le64_to_cpu(gpt_pte[i].starting_lba),
 117                         le64_to_cpu(gpt_pte[i].ending_lba),
 118                         print_efiname(&gpt_pte[i]));
 119                 printf("\tattrs:\t0x%016llx\n", gpt_pte[i].attributes.raw);
 120                 uuid_bin = (unsigned char *)gpt_pte[i].partition_type_guid.b;
 121                 uuid_bin_to_str(uuid_bin, uuid, UUID_STR_FORMAT_GUID);
 122                 printf("\ttype:\t%s\n", uuid);
 123                 uuid_bin = (unsigned char *)gpt_pte[i].unique_partition_guid.b;
 124                 uuid_bin_to_str(uuid_bin, uuid, UUID_STR_FORMAT_GUID);
 125                 printf("\tguid:\t%s\n", uuid);
 126         }
 127
 128         /* Remember to free pte */
 129         free(gpt_pte);
 130         return;
 131 }
 132
 133 int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
 134                                 disk_partition_t * info)
 135 {
 136         ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
 137         gpt_entry *gpt_pte = NULL;
 138
 139         /* "part" argument must be at least 1 */
 140         if (!dev_desc || !info || part < 1) {
 141                 printf("%s: Invalid Argument(s)\n", __func__);
 142                 return -1;
 143         }
 144
 145         /* This function validates AND fills in the GPT header and PTE */
 146         if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
 147                         gpt_head, &gpt_pte) != 1) {
 148                 printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
 149                 if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
 150                                  gpt_head, &gpt_pte) != 1) {
 151                         printf("%s: *** ERROR: Invalid Backup GPT ***\n",
 152                                __func__);
 153                         return -1;
 154                 } else {
 155                         printf("%s: ***        Using Backup GPT ***\n",
 156                                __func__);
 157                 }
 158         }
 159
 160         if (part > le32_to_cpu(gpt_head->num_partition_entries) ||
 161             !is_pte_valid(&gpt_pte[part - 1])) {
 162                 debug("%s: *** ERROR: Invalid partition number %d ***\n",
 163                         __func__, part);
 164                 free(gpt_pte);
 165                 return -1;
 166         }
 167
 168         /* The 'lbaint_t' casting may limit the maximum disk size to 2 TB */
 169         info->start = (lbaint_t)le64_to_cpu(gpt_pte[part - 1].starting_lba);
 170         /* The ending LBA is inclusive, to calculate size, add 1 to it */
 171         info->size = (lbaint_t)le64_to_cpu(gpt_pte[part - 1].ending_lba) + 1
 172                      - info->start;
 173         info->blksz = dev_desc->blksz;
 174
 175         sprintf((char *)info->name, "%s",
 176                         print_efiname(&gpt_pte[part - 1]));
 177         sprintf((char *)info->type, "U-Boot");
 178         info->bootable = is_bootable(&gpt_pte[part - 1]);
 179 #ifdef CONFIG_PARTITION_UUIDS
 180         uuid_bin_to_str(gpt_pte[part - 1].unique_partition_guid.b, info->uuid,
 181                         UUID_STR_FORMAT_GUID);
 182 #endif
 183
 184         debug("%s: start 0x" LBAF ", size 0x" LBAF ", name %s\n", __func__,
 185               info->start, info->size, info->name);
 186
 187         /* Remember to free pte */
 188         free(gpt_pte);
 189         return 0;
 190 }
 191
 192 int get_partition_info_efi_by_name(block_dev_desc_t *dev_desc,
 193         const char *name, disk_partition_t *info)
 194 {
 195         int ret;
 196         int i;
 197         for (i = 1; i < GPT_ENTRY_NUMBERS; i++) {
 198                 ret = get_partition_info_efi(dev_desc, i, info);
 199                 if (ret != 0) {
 200                         /* no more entries in table */
 201                         return -1;
 202                 }
 203                 if (strcmp(name, (const char *)info->name) == 0) {
 204                         /* matched */
 205                         return 0;
 206                 }
 207         }
 208         return -2;
 209 }
 210
 211 int test_part_efi(block_dev_desc_t * dev_desc)
 212 {
 213         ALLOC_CACHE_ALIGN_BUFFER_PAD(legacy_mbr, legacymbr, 1, dev_desc->blksz);
 214
 215         /* Read legacy MBR from block 0 and validate it */
 216         if ((dev_desc->block_read(dev_desc->dev, 0, 1, (ulong *)legacymbr) != 1)
 217                 || (is_pmbr_valid(legacymbr) != 1)) {
 218                 return -1;
 219         }
 220         return 0;
 221 }
 222
 223 /**
 224  * set_protective_mbr(): Set the EFI protective MBR
 225  * @param dev_desc - block device descriptor
 226  *
 227  * @return - zero on success, otherwise error
 228  */
 229 static int set_protective_mbr(block_dev_desc_t *dev_desc)
 230 {
 231         /* Setup the Protective MBR */
 232         ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, p_mbr, 1);
 233         memset(p_mbr, 0, sizeof(*p_mbr));
 234
 235         if (p_mbr == NULL) {
 236                 printf("%s: calloc failed!\n", __func__);
 237                 return -1;
 238         }
 239         /* Append signature */
 240         p_mbr->signature = MSDOS_MBR_SIGNATURE;
 241         p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT;
 242         p_mbr->partition_record[0].start_sect = 1;
 243         p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba;
 244
 245         /* Write MBR sector to the MMC device */
 246         if (dev_desc->block_write(dev_desc->dev, 0, 1, p_mbr) != 1) {
 247                 printf("** Can't write to device %d **\n",
 248                         dev_desc->dev);
 249                 return -1;
 250         }
 251
 252         return 0;
 253 }
 254
 255 int write_gpt_table(block_dev_desc_t *dev_desc,
 256                 gpt_header *gpt_h, gpt_entry *gpt_e)
 257 {
 258         const int pte_blk_cnt = BLOCK_CNT((gpt_h->num_partition_entries
 259                                            * sizeof(gpt_entry)), dev_desc);
 260         u32 calc_crc32;
 261         u64 val;
 262
 263         debug("max lba: %x\n", (u32) dev_desc->lba);
 264         /* Setup the Protective MBR */
 265         if (set_protective_mbr(dev_desc) < 0)
 266                 goto err;
 267
 268         /* Generate CRC for the Primary GPT Header */
 269         calc_crc32 = efi_crc32((const unsigned char *)gpt_e,
 270                               le32_to_cpu(gpt_h->num_partition_entries) *
 271                               le32_to_cpu(gpt_h->sizeof_partition_entry));
 272         gpt_h->partition_entry_array_crc32 = cpu_to_le32(calc_crc32);
 273
 274         calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
 275                               le32_to_cpu(gpt_h->header_size));
 276         gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
 277
 278         /* Write the First GPT to the block right after the Legacy MBR */
 279         if (dev_desc->block_write(dev_desc->dev, 1, 1, gpt_h) != 1)
 280                 goto err;
 281
 282         if (dev_desc->block_write(dev_desc->dev, 2, pte_blk_cnt, gpt_e)
 283             != pte_blk_cnt)
 284                 goto err;
 285
 286         /* recalculate the values for the Backup GPT Header */
 287         val = le64_to_cpu(gpt_h->my_lba);
 288         gpt_h->my_lba = gpt_h->alternate_lba;
 289         gpt_h->alternate_lba = cpu_to_le64(val);
 290         gpt_h->header_crc32 = 0;
 291
 292         calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
 293                               le32_to_cpu(gpt_h->header_size));
 294         gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
 295
 296         if (dev_desc->block_write(dev_desc->dev,
 297                                   (lbaint_t)le64_to_cpu(gpt_h->last_usable_lba)
 298                                   + 1,
 299                                   pte_blk_cnt, gpt_e) != pte_blk_cnt)
 300                 goto err;
 301
 302         if (dev_desc->block_write(dev_desc->dev,
 303                                   (lbaint_t)le64_to_cpu(gpt_h->my_lba), 1,
 304                                   gpt_h) != 1)
 305                 goto err;
 306
 307         debug("GPT successfully written to block device!\n");
 308         return 0;
 309
 310  err:
 311         printf("** Can't write to device %d **\n", dev_desc->dev);
 312         return -1;
 313 }
 314
 315 int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
 316                 disk_partition_t *partitions, int parts)
 317 {
 318         lbaint_t offset = (lbaint_t)le64_to_cpu(gpt_h->first_usable_lba);
 319         lbaint_t start;
 320         lbaint_t last_usable_lba = (lbaint_t)
 321                         le64_to_cpu(gpt_h->last_usable_lba);
 322         int i, k;
 323         size_t efiname_len, dosname_len;
 324 #ifdef CONFIG_PARTITION_UUIDS
 325         char *str_uuid;
 326         unsigned char *bin_uuid;
 327 #endif
 328
 329         for (i = 0; i < parts; i++) {
 330                 /* partition starting lba */
 331                 start = partitions[i].start;
 332                 if (start && (start < offset)) {
 333                         printf("Partition overlap\n");
 334                         return -1;
 335                 }
 336                 if (start) {
 337                         gpt_e[i].starting_lba = cpu_to_le64(start);
 338                         offset = start + partitions[i].size;
 339                 } else {
 340                         gpt_e[i].starting_lba = cpu_to_le64(offset);
 341                         offset += partitions[i].size;
 342                 }
 343                 if (offset >= last_usable_lba) {
 344                         printf("Partitions layout exceds disk size\n");
 345                         return -1;
 346                 }
 347                 /* partition ending lba */
 348                 if ((i == parts - 1) && (partitions[i].size == 0))
 349                         /* extend the last partition to maximuim */
 350                         gpt_e[i].ending_lba = gpt_h->last_usable_lba;
 351                 else
 352                         gpt_e[i].ending_lba = cpu_to_le64(offset - 1);
 353
 354                 /* partition type GUID */
 355                 memcpy(gpt_e[i].partition_type_guid.b,
 356                         &PARTITION_BASIC_DATA_GUID, 16);
 357
 358 #ifdef CONFIG_PARTITION_UUIDS
 359                 str_uuid = partitions[i].uuid;
 360                 bin_uuid = gpt_e[i].unique_partition_guid.b;
 361
 362                 if (uuid_str_to_bin(str_uuid, bin_uuid, UUID_STR_FORMAT_STD)) {
 363                         printf("Partition no. %d: invalid guid: %s\n",
 364                                 i, str_uuid);
 365                         return -1;
 366                 }
 367 #endif
 368
 369                 /* partition attributes */
 370                 memset(&gpt_e[i].attributes, 0,
 371                        sizeof(gpt_entry_attributes));
 372
 373                 /* partition name */
 374                 efiname_len = sizeof(gpt_e[i].partition_name)
 375                         / sizeof(efi_char16_t);
 376                 dosname_len = sizeof(partitions[i].name);
 377
 378                 memset(gpt_e[i].partition_name, 0,
 379                        sizeof(gpt_e[i].partition_name));
 380
 381                 for (k = 0; k < min(dosname_len, efiname_len); k++)
 382                         gpt_e[i].partition_name[k] =
 383                                 (efi_char16_t)(partitions[i].name[k]);
 384
 385                 debug("%s: name: %s offset[%d]: 0x" LBAF
 386                       " size[%d]: 0x" LBAF "\n",
 387                       __func__, partitions[i].name, i,
 388                       offset, i, partitions[i].size);
 389         }
 390
 391         return 0;
 392 }
 393
 394 int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h,
 395                 char *str_guid, int parts_count)
 396 {
 397         gpt_h->signature = cpu_to_le64(GPT_HEADER_SIGNATURE);
 398         gpt_h->revision = cpu_to_le32(GPT_HEADER_REVISION_V1);
 399         gpt_h->header_size = cpu_to_le32(sizeof(gpt_header));
 400         gpt_h->my_lba = cpu_to_le64(1);
 401         gpt_h->alternate_lba = cpu_to_le64(dev_desc->lba - 1);
 402         gpt_h->first_usable_lba = cpu_to_le64(34);
 403         gpt_h->last_usable_lba = cpu_to_le64(dev_desc->lba - 34);
 404         gpt_h->partition_entry_lba = cpu_to_le64(2);
 405         gpt_h->num_partition_entries = cpu_to_le32(GPT_ENTRY_NUMBERS);
 406         gpt_h->sizeof_partition_entry = cpu_to_le32(sizeof(gpt_entry));
 407         gpt_h->header_crc32 = 0;
 408         gpt_h->partition_entry_array_crc32 = 0;
 409
 410         if (uuid_str_to_bin(str_guid, gpt_h->disk_guid.b, UUID_STR_FORMAT_GUID))
 411                 return -1;
 412
 413         return 0;
 414 }
 415
 416 int gpt_restore(block_dev_desc_t *dev_desc, char *str_disk_guid,
 417                 disk_partition_t *partitions, int parts_count)
 418 {
 419         int ret;
 420
 421         gpt_header *gpt_h = calloc(1, PAD_TO_BLOCKSIZE(sizeof(gpt_header),
 422                                                        dev_desc));
 423         gpt_entry *gpt_e;
 424
 425         if (gpt_h == NULL) {
 426                 printf("%s: calloc failed!\n", __func__);
 427                 return -1;
 428         }
 429
 430         gpt_e = calloc(1, PAD_TO_BLOCKSIZE(GPT_ENTRY_NUMBERS
 431                                                * sizeof(gpt_entry),
 432                                                dev_desc));
 433         if (gpt_e == NULL) {
 434                 printf("%s: calloc failed!\n", __func__);
 435                 free(gpt_h);
 436                 return -1;
 437         }
 438
 439         /* Generate Primary GPT header (LBA1) */
 440         ret = gpt_fill_header(dev_desc, gpt_h, str_disk_guid, parts_count);
 441         if (ret)
 442                 goto err;
 443
 444         /* Generate partition entries */
 445         ret = gpt_fill_pte(gpt_h, gpt_e, partitions, parts_count);
 446         if (ret)
 447                 goto err;
 448
 449         /* Write GPT partition table */
 450         ret = write_gpt_table(dev_desc, gpt_h, gpt_e);
 451
 452 err:
 453         free(gpt_e);
 454         free(gpt_h);
 455         return ret;
 456 }
 457 #endif
 458
 459 /*
 460  * Private functions
 461  */
 462 /*
 463  * pmbr_part_valid(): Check for EFI partition signature
 464  *
 465  * Returns: 1 if EFI GPT partition type is found.
 466  */
 467 static int pmbr_part_valid(struct partition *part)
 468 {
 469         if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
 470                 get_unaligned_le32(&part->start_sect) == 1UL) {
 471                 return 1;
 472         }
 473
 474         return 0;
 475 }
 476
 477 /*
 478  * is_pmbr_valid(): test Protective MBR for validity
 479  *
 480  * Returns: 1 if PMBR is valid, 0 otherwise.
 481  * Validity depends on two things:
 482  *  1) MSDOS signature is in the last two bytes of the MBR
 483  *  2) One partition of type 0xEE is found, checked by pmbr_part_valid()
 484  */
 485 static int is_pmbr_valid(legacy_mbr * mbr)
 486 {
 487         int i = 0;
 488
 489         if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
 490                 return 0;
 491
 492         for (i = 0; i < 4; i++) {
 493                 if (pmbr_part_valid(&mbr->partition_record[i])) {
 494                         return 1;
 495                 }
 496         }
 497         return 0;
 498 }
 499
 500 /**
 501  * is_gpt_valid() - tests one GPT header and PTEs for validity
 502  *
 503  * lba is the logical block address of the GPT header to test
 504  * gpt is a GPT header ptr, filled on return.
 505  * ptes is a PTEs ptr, filled on return.
 506  *
 507  * Description: returns 1 if valid,  0 on error.
 508  * If valid, returns pointers to PTEs.
 509  */
 510 static int is_gpt_valid(block_dev_desc_t *dev_desc, u64 lba,
 511                         gpt_header *pgpt_head, gpt_entry **pgpt_pte)
 512 {
 513         u32 crc32_backup = 0;
 514         u32 calc_crc32;
 515         u64 lastlba;
 516
 517         if (!dev_desc || !pgpt_head) {
 518                 printf("%s: Invalid Argument(s)\n", __func__);
 519                 return 0;
 520         }
 521
 522         /* Read GPT Header from device */
 523         if (dev_desc->block_read(dev_desc->dev, (lbaint_t)lba, 1, pgpt_head)
 524                         != 1) {
 525                 printf("*** ERROR: Can't read GPT header ***\n");
 526                 return 0;
 527         }
 528
 529         /* Check the GPT header signature */
 530         if (le64_to_cpu(pgpt_head->signature) != GPT_HEADER_SIGNATURE) {
 531                 printf("GUID Partition Table Header signature is wrong:"
 532                         "0x%llX != 0x%llX\n",
 533                         le64_to_cpu(pgpt_head->signature),
 534                         GPT_HEADER_SIGNATURE);
 535                 return 0;
 536         }
 537
 538         /* Check the GUID Partition Table CRC */
 539         memcpy(&crc32_backup, &pgpt_head->header_crc32, sizeof(crc32_backup));
 540         memset(&pgpt_head->header_crc32, 0, sizeof(pgpt_head->header_crc32));
 541
 542         calc_crc32 = efi_crc32((const unsigned char *)pgpt_head,
 543                 le32_to_cpu(pgpt_head->header_size));
 544
 545         memcpy(&pgpt_head->header_crc32, &crc32_backup, sizeof(crc32_backup));
 546
 547         if (calc_crc32 != le32_to_cpu(crc32_backup)) {
 548                 printf("GUID Partition Table Header CRC is wrong:"
 549                         "0x%x != 0x%x\n",
 550                        le32_to_cpu(crc32_backup), calc_crc32);
 551                 return 0;
 552         }
 553
 554         /* Check that the my_lba entry points to the LBA that contains the GPT */
 555         if (le64_to_cpu(pgpt_head->my_lba) != lba) {
 556                 printf("GPT: my_lba incorrect: %llX != %llX\n",
 557                         le64_to_cpu(pgpt_head->my_lba),
 558                         lba);
 559                 return 0;
 560         }
 561
 562         /* Check the first_usable_lba and last_usable_lba are within the disk. */
 563         lastlba = (u64)dev_desc->lba;
 564         if (le64_to_cpu(pgpt_head->first_usable_lba) > lastlba) {
 565                 printf("GPT: first_usable_lba incorrect: %llX > %llX\n",
 566                         le64_to_cpu(pgpt_head->first_usable_lba), lastlba);
 567                 return 0;
 568         }
 569         if (le64_to_cpu(pgpt_head->last_usable_lba) > lastlba) {
 570                 printf("GPT: last_usable_lba incorrect: %llX > %llX\n",
 571                         le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
 572                 return 0;
 573         }
 574
 575         debug("GPT: first_usable_lba: %llX last_usable_lba %llX last lba %llX\n",
 576                 le64_to_cpu(pgpt_head->first_usable_lba),
 577                 le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
 578
 579         /* Read and allocate Partition Table Entries */
 580         *pgpt_pte = alloc_read_gpt_entries(dev_desc, pgpt_head);
 581         if (*pgpt_pte == NULL) {
 582                 printf("GPT: Failed to allocate memory for PTE\n");
 583                 return 0;
 584         }
 585
 586         /* Check the GUID Partition Table Entry Array CRC */
 587         calc_crc32 = efi_crc32((const unsigned char *)*pgpt_pte,
 588                 le32_to_cpu(pgpt_head->num_partition_entries) *
 589                 le32_to_cpu(pgpt_head->sizeof_partition_entry));
 590
 591         if (calc_crc32 != le32_to_cpu(pgpt_head->partition_entry_array_crc32)) {
 592                 printf("GUID Partition Table Entry Array CRC is wrong:"
 593                         "0x%x != 0x%x\n",
 594                         le32_to_cpu(pgpt_head->partition_entry_array_crc32),
 595                         calc_crc32);
 596
 597                 free(*pgpt_pte);
 598                 return 0;
 599         }
 600
 601         /* We're done, all's well */
 602         return 1;
 603 }
 604
 605 /**
 606  * alloc_read_gpt_entries(): reads partition entries from disk
 607  * @dev_desc
 608  * @gpt - GPT header
 609  *
 610  * Description: Returns ptes on success,  NULL on error.
 611  * Allocates space for PTEs based on information found in @gpt.
 612  * Notes: remember to free pte when you're done!
 613  */
 614 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
 615                                          gpt_header * pgpt_head)
 616 {
 617         size_t count = 0, blk_cnt;
 618         gpt_entry *pte = NULL;
 619
 620         if (!dev_desc || !pgpt_head) {
 621                 printf("%s: Invalid Argument(s)\n", __func__);
 622                 return NULL;
 623         }
 624
 625         count = le32_to_cpu(pgpt_head->num_partition_entries) *
 626                 le32_to_cpu(pgpt_head->sizeof_partition_entry);
 627
 628         debug("%s: count = %u * %u = %zu\n", __func__,
 629               (u32) le32_to_cpu(pgpt_head->num_partition_entries),
 630               (u32) le32_to_cpu(pgpt_head->sizeof_partition_entry), count);
 631
 632         /* Allocate memory for PTE, remember to FREE */
 633         if (count != 0) {
 634                 pte = memalign(ARCH_DMA_MINALIGN,
 635                                PAD_TO_BLOCKSIZE(count, dev_desc));
 636         }
 637
 638         if (count == 0 || pte == NULL) {
 639                 printf("%s: ERROR: Can't allocate 0x%zX "
 640                        "bytes for GPT Entries\n",
 641                         __func__, count);
 642                 return NULL;
 643         }
 644
 645         /* Read GPT Entries from device */
 646         blk_cnt = BLOCK_CNT(count, dev_desc);
 647         if (dev_desc->block_read (dev_desc->dev,
 648                 (lbaint_t)le64_to_cpu(pgpt_head->partition_entry_lba),
 649                 (lbaint_t) (blk_cnt), pte)
 650                 != blk_cnt) {
 651
 652                 printf("*** ERROR: Can't read GPT Entries ***\n");
 653                 free(pte);
 654                 return NULL;
 655         }
 656         return pte;
 657 }
 658
 659 /**
 660  * is_pte_valid(): validates a single Partition Table Entry
 661  * @gpt_entry - Pointer to a single Partition Table Entry
 662  *
 663  * Description: returns 1 if valid,  0 on error.
 664  */
 665 static int is_pte_valid(gpt_entry * pte)
 666 {
 667         efi_guid_t unused_guid;
 668
 669         if (!pte) {
 670                 printf("%s: Invalid Argument(s)\n", __func__);
 671                 return 0;
 672         }
 673
 674         /* Only one validation for now:
 675          * The GUID Partition Type != Unused Entry (ALL-ZERO)
 676          */
 677         memset(unused_guid.b, 0, sizeof(unused_guid.b));
 678
 679         if (memcmp(pte->partition_type_guid.b, unused_guid.b,
 680                 sizeof(unused_guid.b)) == 0) {
 681
 682                 debug("%s: Found an unused PTE GUID at 0x%08X\n", __func__,
 683                       (unsigned int)(uintptr_t)pte);
 684
 685                 return 0;
 686         } else {
 687                 return 1;
 688         }
 689 }
 690 #endif