/*
   * Copyright (C) 2008 RuggedCom, Inc.
   * Richard Retanubun <RichardRetanubun@RuggedCom.com>
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  /*
   * NOTE:
   *   when CONFIG_SYS_64BIT_LBA is not defined, lbaint_t is 32 bits; this
   *   limits the maximum size of addressable storage to < 2 Terra Bytes
   */
  #include <asm/unaligned.h>
  #include <common.h>
  #include <command.h>
  #include <ide.h>
  #include <inttypes.h>
  #include <malloc.h>
  #include <part_efi.h>
  #include <linux/ctype.h>
  
  DECLARE_GLOBAL_DATA_PTR;
  
  #ifdef HAVE_BLOCK_DEVICE
  /**
   * efi_crc32() - EFI version of crc32 function
   * @buf: buffer to calculate crc32 of
   * @len - length of buf
   *
   * Description: Returns EFI-style CRC32 value for @buf
   */
  static inline u32 efi_crc32(const void *buf, u32 len)
  {
  	return crc32(0, buf, len);
  }
  
  /*
   * Private function prototypes
   */
  
  static int pmbr_part_valid(struct partition *part);
  static int is_pmbr_valid(legacy_mbr * mbr);
  static int is_gpt_valid(block_dev_desc_t *dev_desc, u64 lba,
  				gpt_header *pgpt_head, gpt_entry **pgpt_pte);
  static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
  				gpt_header * pgpt_head);
  static int is_pte_valid(gpt_entry * pte);
  
  static char *print_efiname(gpt_entry *pte)
  {
  	static char name[PARTNAME_SZ + 1];
  	int i;
  	for (i = 0; i < PARTNAME_SZ; i++) {
  		u8 c;
  		c = pte->partition_name[i] & 0xff;
  		c = (c && !isprint(c)) ? '.' : c;
  		name[i] = c;
  	}
  	name[PARTNAME_SZ] = 0;
  	return name;
  }
  
  static efi_guid_t system_guid = PARTITION_SYSTEM_GUID;
  
  static inline int is_bootable(gpt_entry *p)
  {
  	return p->attributes.fields.legacy_bios_bootable ||
  		!memcmp(&(p->partition_type_guid), &system_guid,
  			sizeof(efi_guid_t));
  }
  
  static int validate_gpt_header(gpt_header *gpt_h, lbaint_t lba,
  		lbaint_t lastlba)
  {
  	uint32_t crc32_backup = 0;
  	uint32_t calc_crc32;
  
  	/* Check the GPT header signature */
  	if (le64_to_cpu(gpt_h->signature) != GPT_HEADER_SIGNATURE) {
  		printf("%s signature is wrong: 0x%llX != 0x%llX
  ",
  		       "GUID Partition Table Header",
  		       le64_to_cpu(gpt_h->signature),
  		       GPT_HEADER_SIGNATURE);
  		return -1;
  	}
  
  	/* Check the GUID Partition Table CRC */
  	memcpy(&crc32_backup, &gpt_h->header_crc32, sizeof(crc32_backup));
  	memset(&gpt_h->header_crc32, 0, sizeof(gpt_h->header_crc32));
  
  	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
  		le32_to_cpu(gpt_h->header_size));
  
  	memcpy(&gpt_h->header_crc32, &crc32_backup, sizeof(crc32_backup));
  
  	if (calc_crc32 != le32_to_cpu(crc32_backup)) {
  		printf("%s CRC is wrong: 0x%x != 0x%x
  ",
  		       "GUID Partition Table Header",
  		       le32_to_cpu(crc32_backup), calc_crc32);
  		return -1;
  	}
  
  	/*
  	 * Check that the my_lba entry points to the LBA that contains the GPT
  	 */
  	if (le64_to_cpu(gpt_h->my_lba) != lba) {
  		printf("GPT: my_lba incorrect: %llX != " LBAF "
  ",
  		       le64_to_cpu(gpt_h->my_lba),
  		       lba);
  		return -1;
  	}
  
  	/*
  	 * Check that the first_usable_lba and that the last_usable_lba are
  	 * within the disk.
  	 */
  	if (le64_to_cpu(gpt_h->first_usable_lba) > lastlba) {
  		printf("GPT: first_usable_lba incorrect: %llX > " LBAF "
  ",
  		       le64_to_cpu(gpt_h->first_usable_lba), lastlba);
  		return -1;
  	}
  	if (le64_to_cpu(gpt_h->last_usable_lba) > lastlba) {
  		printf("GPT: last_usable_lba incorrect: %llX > " LBAF "
  ",
  		       le64_to_cpu(gpt_h->last_usable_lba), lastlba);
  		return -1;
  	}
  
  	debug("GPT: first_usable_lba: %llX last_usable_lba: %llX last lba: "
  	      LBAF "
  ", le64_to_cpu(gpt_h->first_usable_lba),
  	      le64_to_cpu(gpt_h->last_usable_lba), lastlba);
  
  	return 0;
  }
  
  static int validate_gpt_entries(gpt_header *gpt_h, gpt_entry *gpt_e)
  {
  	uint32_t calc_crc32;
  
  	/* Check the GUID Partition Table Entry Array CRC */
  	calc_crc32 = efi_crc32((const unsigned char *)gpt_e,
  		le32_to_cpu(gpt_h->num_partition_entries) *
  		le32_to_cpu(gpt_h->sizeof_partition_entry));
  
  	if (calc_crc32 != le32_to_cpu(gpt_h->partition_entry_array_crc32)) {
  		printf("%s: 0x%x != 0x%x
  ",
  		       "GUID Partition Table Entry Array CRC is wrong",
  		       le32_to_cpu(gpt_h->partition_entry_array_crc32),
  		       calc_crc32);
  		return -1;
  	}
  
  	return 0;
  }
  
  static void prepare_backup_gpt_header(gpt_header *gpt_h)
  {
  	uint32_t calc_crc32;
  	uint64_t val;
  
  	/* recalculate the values for the Backup GPT Header */
  	val = le64_to_cpu(gpt_h->my_lba);
  	gpt_h->my_lba = gpt_h->alternate_lba;
  	gpt_h->alternate_lba = cpu_to_le64(val);
  	gpt_h->partition_entry_lba =
  			cpu_to_le64(le64_to_cpu(gpt_h->last_usable_lba) + 1);
  	gpt_h->header_crc32 = 0;
  
  	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
  			       le32_to_cpu(gpt_h->header_size));
  	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
  }
  
  #ifdef CONFIG_EFI_PARTITION
  /*
   * Public Functions (include/part.h)
   */
  
  void print_part_efi(block_dev_desc_t * dev_desc)
  {
  	ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
  	gpt_entry *gpt_pte = NULL;
  	int i = 0;
  	char uuid[37];
  	unsigned char *uuid_bin;
  
  	if (!dev_desc) {
  		printf("%s: Invalid Argument(s)
  ", __func__);
  		return;
  	}
  	/* This function validates AND fills in the GPT header and PTE */
  	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
  			 gpt_head, &gpt_pte) != 1) {
  		printf("%s: *** ERROR: Invalid GPT ***
  ", __func__);
  		if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
  				 gpt_head, &gpt_pte) != 1) {
  			printf("%s: *** ERROR: Invalid Backup GPT ***
  ",
  			       __func__);
  			return;
  		} else {
  			printf("%s: ***        Using Backup GPT ***
  ",
  			       __func__);
  		}
  	}
  
  	debug("%s: gpt-entry at %p
  ", __func__, gpt_pte);
  
  	printf("Part\tStart LBA\tEnd LBA\t\tName
  ");
  	printf("\tAttributes
  ");
  	printf("\tType GUID
  ");
  	printf("\tPartition GUID
  ");
  
  	for (i = 0; i < le32_to_cpu(gpt_head->num_partition_entries); i++) {
  		/* Stop at the first non valid PTE */
  		if (!is_pte_valid(&gpt_pte[i]))
  			break;
  
  		printf("%3d\t0x%08llx\t0x%08llx\t\"%s\"
  ", (i + 1),
  			le64_to_cpu(gpt_pte[i].starting_lba),
  			le64_to_cpu(gpt_pte[i].ending_lba),
  			print_efiname(&gpt_pte[i]));
  		printf("\tattrs:\t0x%016llx
  ", gpt_pte[i].attributes.raw);
  		uuid_bin = (unsigned char *)gpt_pte[i].partition_type_guid.b;
  		uuid_bin_to_str(uuid_bin, uuid, UUID_STR_FORMAT_GUID);
  		printf("\ttype:\t%s
  ", uuid);
  		uuid_bin = (unsigned char *)gpt_pte[i].unique_partition_guid.b;
  		uuid_bin_to_str(uuid_bin, uuid, UUID_STR_FORMAT_GUID);
  		printf("\tguid:\t%s
  ", uuid);
  	}
  
  	/* Remember to free pte */
  	free(gpt_pte);
  	return;
  }
  
  int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
  				disk_partition_t * info)
  {
  	ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
  	gpt_entry *gpt_pte = NULL;
  
  	/* "part" argument must be at least 1 */
  	if (!dev_desc || !info || part < 1) {
  		printf("%s: Invalid Argument(s)
  ", __func__);
  		return -1;
  	}
  
  	/* This function validates AND fills in the GPT header and PTE */
  	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
  			gpt_head, &gpt_pte) != 1) {
  		printf("%s: *** ERROR: Invalid GPT ***
  ", __func__);
  		if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
  				 gpt_head, &gpt_pte) != 1) {
  			printf("%s: *** ERROR: Invalid Backup GPT ***
  ",
  			       __func__);
  			return -1;
  		} else {
  			printf("%s: ***        Using Backup GPT ***
  ",
  			       __func__);
  		}
  	}
  
  	if (part > le32_to_cpu(gpt_head->num_partition_entries) ||
  	    !is_pte_valid(&gpt_pte[part - 1])) {
  		debug("%s: *** ERROR: Invalid partition number %d ***
  ",
  			__func__, part);
  		free(gpt_pte);
  		return -1;
  	}
  
  	/* The 'lbaint_t' casting may limit the maximum disk size to 2 TB */
  	info->start = (lbaint_t)le64_to_cpu(gpt_pte[part - 1].starting_lba);
  	/* The ending LBA is inclusive, to calculate size, add 1 to it */
  	info->size = (lbaint_t)le64_to_cpu(gpt_pte[part - 1].ending_lba) + 1
  		     - info->start;
  	info->blksz = dev_desc->blksz;
  
  	sprintf((char *)info->name, "%s",
  			print_efiname(&gpt_pte[part - 1]));
  	sprintf((char *)info->type, "U-Boot");
  	info->bootable = is_bootable(&gpt_pte[part - 1]);
  #ifdef CONFIG_PARTITION_UUIDS
  	uuid_bin_to_str(gpt_pte[part - 1].unique_partition_guid.b, info->uuid,
  			UUID_STR_FORMAT_GUID);
  #endif
  
  	debug("%s: start 0x" LBAF ", size 0x" LBAF ", name %s
  ", __func__,
  	      info->start, info->size, info->name);
  
  	/* Remember to free pte */
  	free(gpt_pte);
  	return 0;
  }
  
  int get_partition_info_efi_by_name(block_dev_desc_t *dev_desc,
  	const char *name, disk_partition_t *info)
  {
  	int ret;
  	int i;
  	for (i = 1; i < GPT_ENTRY_NUMBERS; i++) {
  		ret = get_partition_info_efi(dev_desc, i, info);
  		if (ret != 0) {
  			/* no more entries in table */
  			return -1;
  		}
  		if (strcmp(name, (const char *)info->name) == 0) {
  			/* matched */
  			return 0;
  		}
  	}
  	return -2;
  }
  
  int test_part_efi(block_dev_desc_t * dev_desc)
  {
  	ALLOC_CACHE_ALIGN_BUFFER_PAD(legacy_mbr, legacymbr, 1, dev_desc->blksz);
  
  	/* Read legacy MBR from block 0 and validate it */
  	if ((dev_desc->block_read(dev_desc->dev, 0, 1, (ulong *)legacymbr) != 1)
  		|| (is_pmbr_valid(legacymbr) != 1)) {
  		return -1;
  	}
  	return 0;
  }
  
  /**
   * set_protective_mbr(): Set the EFI protective MBR
   * @param dev_desc - block device descriptor
   *
   * @return - zero on success, otherwise error
   */
  static int set_protective_mbr(block_dev_desc_t *dev_desc)
  {
  	/* Setup the Protective MBR */
  	ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, p_mbr, 1);
  	memset(p_mbr, 0, sizeof(*p_mbr));
  
  	if (p_mbr == NULL) {
  		printf("%s: calloc failed!
  ", __func__);
  		return -1;
  	}
  	/* Append signature */
  	p_mbr->signature = MSDOS_MBR_SIGNATURE;
  	p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT;
  	p_mbr->partition_record[0].start_sect = 1;
  	p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba - 1;
  
  	/* Write MBR sector to the MMC device */
  	if (dev_desc->block_write(dev_desc->dev, 0, 1, p_mbr) != 1) {
  		printf("** Can't write to device %d **
  ",
  			dev_desc->dev);
  		return -1;
  	}
  
  	return 0;
  }
  
  int write_gpt_table(block_dev_desc_t *dev_desc,
  		gpt_header *gpt_h, gpt_entry *gpt_e)
  {
  	const int pte_blk_cnt = BLOCK_CNT((gpt_h->num_partition_entries
  					   * sizeof(gpt_entry)), dev_desc);
  	u32 calc_crc32;
  
  	debug("max lba: %x
  ", (u32) dev_desc->lba);
  	/* Setup the Protective MBR */
  	if (set_protective_mbr(dev_desc) < 0)
  		goto err;
  
  	/* Generate CRC for the Primary GPT Header */
  	calc_crc32 = efi_crc32((const unsigned char *)gpt_e,
  			      le32_to_cpu(gpt_h->num_partition_entries) *
  			      le32_to_cpu(gpt_h->sizeof_partition_entry));
  	gpt_h->partition_entry_array_crc32 = cpu_to_le32(calc_crc32);
  
  	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
  			      le32_to_cpu(gpt_h->header_size));
  	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
  
  	/* Write the First GPT to the block right after the Legacy MBR */
  	if (dev_desc->block_write(dev_desc->dev, 1, 1, gpt_h) != 1)
  		goto err;
  
  	if (dev_desc->block_write(dev_desc->dev, 2, pte_blk_cnt, gpt_e)
  	    != pte_blk_cnt)
  		goto err;
  
  	prepare_backup_gpt_header(gpt_h);
  
  	if (dev_desc->block_write(dev_desc->dev,
  				  (lbaint_t)le64_to_cpu(gpt_h->last_usable_lba)
  				  + 1,
  				  pte_blk_cnt, gpt_e) != pte_blk_cnt)
  		goto err;
  
  	if (dev_desc->block_write(dev_desc->dev,
  				  (lbaint_t)le64_to_cpu(gpt_h->my_lba), 1,
  				  gpt_h) != 1)
  		goto err;
  
  	debug("GPT successfully written to block device!
  ");
  	return 0;
  
   err:
  	printf("** Can't write to device %d **
  ", dev_desc->dev);
  	return -1;
  }
  
  int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
  		disk_partition_t *partitions, int parts)
  {
  	lbaint_t offset = (lbaint_t)le64_to_cpu(gpt_h->first_usable_lba);
  	lbaint_t start;
  	lbaint_t last_usable_lba = (lbaint_t)
  			le64_to_cpu(gpt_h->last_usable_lba);
  	int i, k;
  	size_t efiname_len, dosname_len;
  #ifdef CONFIG_PARTITION_UUIDS
  	char *str_uuid;
  	unsigned char *bin_uuid;
  #endif
  
  	for (i = 0; i < parts; i++) {
  		/* partition starting lba */
  		start = partitions[i].start;
  		if (start && (start < offset)) {
  			printf("Partition overlap
  ");
  			return -1;
  		}
  		if (start) {
  			gpt_e[i].starting_lba = cpu_to_le64(start);
  			offset = start + partitions[i].size;
  		} else {
  			gpt_e[i].starting_lba = cpu_to_le64(offset);
  			offset += partitions[i].size;
  		}
  		if (offset >= last_usable_lba) {
  			printf("Partitions layout exceds disk size
  ");
  			return -1;
  		}
  		/* partition ending lba */
  		if ((i == parts - 1) && (partitions[i].size == 0))
  			/* extend the last partition to maximuim */
  			gpt_e[i].ending_lba = gpt_h->last_usable_lba;
  		else
  			gpt_e[i].ending_lba = cpu_to_le64(offset - 1);
  
  		/* partition type GUID */
  		memcpy(gpt_e[i].partition_type_guid.b,
  			&PARTITION_BASIC_DATA_GUID, 16);
  
  #ifdef CONFIG_PARTITION_UUIDS
  		str_uuid = partitions[i].uuid;
  		bin_uuid = gpt_e[i].unique_partition_guid.b;
  
  		if (uuid_str_to_bin(str_uuid, bin_uuid, UUID_STR_FORMAT_STD)) {
  			printf("Partition no. %d: invalid guid: %s
  ",
  				i, str_uuid);
  			return -1;
  		}
  #endif
  
  		/* partition attributes */
  		memset(&gpt_e[i].attributes, 0,
  		       sizeof(gpt_entry_attributes));
  
  		/* partition name */
  		efiname_len = sizeof(gpt_e[i].partition_name)
  			/ sizeof(efi_char16_t);
  		dosname_len = sizeof(partitions[i].name);
  
  		memset(gpt_e[i].partition_name, 0,
  		       sizeof(gpt_e[i].partition_name));
  
  		for (k = 0; k < min(dosname_len, efiname_len); k++)
  			gpt_e[i].partition_name[k] =
  				(efi_char16_t)(partitions[i].name[k]);
  
  		debug("%s: name: %s offset[%d]: 0x" LBAF
  		      " size[%d]: 0x" LBAF "
  ",
  		      __func__, partitions[i].name, i,
  		      offset, i, partitions[i].size);
  	}
  
  	return 0;
  }
  
  int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h,
  		char *str_guid, int parts_count)
  {
  	gpt_h->signature = cpu_to_le64(GPT_HEADER_SIGNATURE);
  	gpt_h->revision = cpu_to_le32(GPT_HEADER_REVISION_V1);
  	gpt_h->header_size = cpu_to_le32(sizeof(gpt_header));
  	gpt_h->my_lba = cpu_to_le64(1);
  	gpt_h->alternate_lba = cpu_to_le64(dev_desc->lba - 1);
  	gpt_h->first_usable_lba = cpu_to_le64(34);
  	gpt_h->last_usable_lba = cpu_to_le64(dev_desc->lba - 34);
  	gpt_h->partition_entry_lba = cpu_to_le64(2);
  	gpt_h->num_partition_entries = cpu_to_le32(GPT_ENTRY_NUMBERS);
  	gpt_h->sizeof_partition_entry = cpu_to_le32(sizeof(gpt_entry));
  	gpt_h->header_crc32 = 0;
  	gpt_h->partition_entry_array_crc32 = 0;
  
  	if (uuid_str_to_bin(str_guid, gpt_h->disk_guid.b, UUID_STR_FORMAT_GUID))
  		return -1;
  
  	return 0;
  }
  
  int gpt_restore(block_dev_desc_t *dev_desc, char *str_disk_guid,
  		disk_partition_t *partitions, int parts_count)
  {
  	int ret;
  
  	gpt_header *gpt_h = calloc(1, PAD_TO_BLOCKSIZE(sizeof(gpt_header),
  						       dev_desc));
  	gpt_entry *gpt_e;
  
  	if (gpt_h == NULL) {
  		printf("%s: calloc failed!
  ", __func__);
  		return -1;
  	}
  
  	gpt_e = calloc(1, PAD_TO_BLOCKSIZE(GPT_ENTRY_NUMBERS
  					       * sizeof(gpt_entry),
  					       dev_desc));
  	if (gpt_e == NULL) {
  		printf("%s: calloc failed!
  ", __func__);
  		free(gpt_h);
  		return -1;
  	}
  
  	/* Generate Primary GPT header (LBA1) */
  	ret = gpt_fill_header(dev_desc, gpt_h, str_disk_guid, parts_count);
  	if (ret)
  		goto err;
  
  	/* Generate partition entries */
  	ret = gpt_fill_pte(gpt_h, gpt_e, partitions, parts_count);
  	if (ret)
  		goto err;
  
  	/* Write GPT partition table */
  	ret = write_gpt_table(dev_desc, gpt_h, gpt_e);
  
  err:
  	free(gpt_e);
  	free(gpt_h);
  	return ret;
  }
  
  int is_valid_gpt_buf(block_dev_desc_t *dev_desc, void *buf)
  {
  	gpt_header *gpt_h;
  	gpt_entry *gpt_e;
  
  	/* determine start of GPT Header in the buffer */
  	gpt_h = buf + (GPT_PRIMARY_PARTITION_TABLE_LBA *
  		       dev_desc->blksz);
  	if (validate_gpt_header(gpt_h, GPT_PRIMARY_PARTITION_TABLE_LBA,
  				dev_desc->lba))
  		return -1;
  
  	/* determine start of GPT Entries in the buffer */
  	gpt_e = buf + (le64_to_cpu(gpt_h->partition_entry_lba) *
  		       dev_desc->blksz);
  	if (validate_gpt_entries(gpt_h, gpt_e))
  		return -1;
  
  	return 0;
  }
  
  int write_mbr_and_gpt_partitions(block_dev_desc_t *dev_desc, void *buf)
  {
  	gpt_header *gpt_h;
  	gpt_entry *gpt_e;
  	int gpt_e_blk_cnt;
  	lbaint_t lba;
  	int cnt;
  
  	if (is_valid_gpt_buf(dev_desc, buf))
  		return -1;
  
  	/* determine start of GPT Header in the buffer */
  	gpt_h = buf + (GPT_PRIMARY_PARTITION_TABLE_LBA *
  		       dev_desc->blksz);
  
  	/* determine start of GPT Entries in the buffer */
  	gpt_e = buf + (le64_to_cpu(gpt_h->partition_entry_lba) *
  		       dev_desc->blksz);
  	gpt_e_blk_cnt = BLOCK_CNT((le32_to_cpu(gpt_h->num_partition_entries) *
  				   le32_to_cpu(gpt_h->sizeof_partition_entry)),
  				  dev_desc);
  
  	/* write MBR */
  	lba = 0;	/* MBR is always at 0 */
  	cnt = 1;	/* MBR (1 block) */
  	if (dev_desc->block_write(dev_desc->dev, lba, cnt, buf) != cnt) {
  		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")
  ",
  		       __func__, "MBR", cnt, lba);
  		return 1;
  	}
  
  	/* write Primary GPT */
  	lba = GPT_PRIMARY_PARTITION_TABLE_LBA;
  	cnt = 1;	/* GPT Header (1 block) */
  	if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_h) != cnt) {
  		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")
  ",
  		       __func__, "Primary GPT Header", cnt, lba);
  		return 1;
  	}
  
  	lba = le64_to_cpu(gpt_h->partition_entry_lba);
  	cnt = gpt_e_blk_cnt;
  	if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_e) != cnt) {
  		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")
  ",
  		       __func__, "Primary GPT Entries", cnt, lba);
  		return 1;
  	}
  
  	prepare_backup_gpt_header(gpt_h);
  
  	/* write Backup GPT */
  	lba = le64_to_cpu(gpt_h->partition_entry_lba);
  	cnt = gpt_e_blk_cnt;
  	if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_e) != cnt) {
  		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")
  ",
  		       __func__, "Backup GPT Entries", cnt, lba);
  		return 1;
  	}
  
  	lba = le64_to_cpu(gpt_h->my_lba);
  	cnt = 1;	/* GPT Header (1 block) */
  	if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_h) != cnt) {
  		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")
  ",
  		       __func__, "Backup GPT Header", cnt, lba);
  		return 1;
  	}
  
  	return 0;
  }
  #endif
  
  /*
   * Private functions
   */
  /*
   * pmbr_part_valid(): Check for EFI partition signature
   *
   * Returns: 1 if EFI GPT partition type is found.
   */
  static int pmbr_part_valid(struct partition *part)
  {
  	if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
  		get_unaligned_le32(&part->start_sect) == 1UL) {
  		return 1;
  	}
  
  	return 0;
  }
  
  /*
   * is_pmbr_valid(): test Protective MBR for validity
   *
   * Returns: 1 if PMBR is valid, 0 otherwise.
   * Validity depends on two things:
   *  1) MSDOS signature is in the last two bytes of the MBR
   *  2) One partition of type 0xEE is found, checked by pmbr_part_valid()
   */
  static int is_pmbr_valid(legacy_mbr * mbr)
  {
  	int i = 0;
  
  	if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
  		return 0;
  
  	for (i = 0; i < 4; i++) {
  		if (pmbr_part_valid(&mbr->partition_record[i])) {
  			return 1;
  		}
  	}
  	return 0;
  }
  
  /**
   * is_gpt_valid() - tests one GPT header and PTEs for validity
   *
   * lba is the logical block address of the GPT header to test
   * gpt is a GPT header ptr, filled on return.
   * ptes is a PTEs ptr, filled on return.
   *
   * Description: returns 1 if valid,  0 on error.
   * If valid, returns pointers to PTEs.
   */
  static int is_gpt_valid(block_dev_desc_t *dev_desc, u64 lba,
  			gpt_header *pgpt_head, gpt_entry **pgpt_pte)
  {
  	if (!dev_desc || !pgpt_head) {
  		printf("%s: Invalid Argument(s)
  ", __func__);
  		return 0;
  	}
  
  	/* Read GPT Header from device */
  	if (dev_desc->block_read(dev_desc->dev, (lbaint_t)lba, 1, pgpt_head)
  			!= 1) {
  		printf("*** ERROR: Can't read GPT header ***
  ");
  		return 0;
  	}
  
  	if (validate_gpt_header(pgpt_head, (lbaint_t)lba, dev_desc->lba))
  		return 0;
  
  	/* Read and allocate Partition Table Entries */
  	*pgpt_pte = alloc_read_gpt_entries(dev_desc, pgpt_head);
  	if (*pgpt_pte == NULL) {
  		printf("GPT: Failed to allocate memory for PTE
  ");
  		return 0;
  	}
  
  	if (validate_gpt_entries(pgpt_head, *pgpt_pte)) {
  		free(*pgpt_pte);
  		return 0;
  	}
  
  	/* We're done, all's well */
  	return 1;
  }
  
  /**
   * alloc_read_gpt_entries(): reads partition entries from disk
   * @dev_desc
   * @gpt - GPT header
   *
   * Description: Returns ptes on success,  NULL on error.
   * Allocates space for PTEs based on information found in @gpt.
   * Notes: remember to free pte when you're done!
   */
  static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
  					 gpt_header * pgpt_head)
  {
  	size_t count = 0, blk_cnt;
  	gpt_entry *pte = NULL;
  
  	if (!dev_desc || !pgpt_head) {
  		printf("%s: Invalid Argument(s)
  ", __func__);
  		return NULL;
  	}
  
  	count = le32_to_cpu(pgpt_head->num_partition_entries) *
  		le32_to_cpu(pgpt_head->sizeof_partition_entry);
  
  	debug("%s: count = %u * %u = %zu
  ", __func__,
  	      (u32) le32_to_cpu(pgpt_head->num_partition_entries),
  	      (u32) le32_to_cpu(pgpt_head->sizeof_partition_entry), count);
  
  	/* Allocate memory for PTE, remember to FREE */
  	if (count != 0) {
  		pte = memalign(ARCH_DMA_MINALIGN,
  			       PAD_TO_BLOCKSIZE(count, dev_desc));
  	}
  
  	if (count == 0 || pte == NULL) {
  		printf("%s: ERROR: Can't allocate 0x%zX "
  		       "bytes for GPT Entries
  ",
  			__func__, count);
  		return NULL;
  	}
  
  	/* Read GPT Entries from device */
  	blk_cnt = BLOCK_CNT(count, dev_desc);
  	if (dev_desc->block_read (dev_desc->dev,
  		(lbaint_t)le64_to_cpu(pgpt_head->partition_entry_lba),
  		(lbaint_t) (blk_cnt), pte)
  		!= blk_cnt) {
  
  		printf("*** ERROR: Can't read GPT Entries ***
  ");
  		free(pte);
  		return NULL;
  	}
  	return pte;
  }
  
  /**
   * is_pte_valid(): validates a single Partition Table Entry
   * @gpt_entry - Pointer to a single Partition Table Entry
   *
   * Description: returns 1 if valid,  0 on error.
   */
  static int is_pte_valid(gpt_entry * pte)
  {
  	efi_guid_t unused_guid;
  
  	if (!pte) {
  		printf("%s: Invalid Argument(s)
  ", __func__);
  		return 0;
  	}
  
  	/* Only one validation for now:
  	 * The GUID Partition Type != Unused Entry (ALL-ZERO)
  	 */
  	memset(unused_guid.b, 0, sizeof(unused_guid.b));
  
  	if (memcmp(pte->partition_type_guid.b, unused_guid.b,
  		sizeof(unused_guid.b)) == 0) {
  
  		debug("%s: Found an unused PTE GUID at 0x%08X
  ", __func__,
  		      (unsigned int)(uintptr_t)pte);
  
  		return 0;
  	} else {
  		return 1;
  	}
  }
  #endif