common/gpt/gpt.h

   1 /* nbdkit
   2  * Copyright (C) 2018-2019 Red Hat Inc.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  * * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * * Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * * Neither the name of Red Hat nor the names of its contributors may be
  16  * used to endorse or promote products derived from this software without
  17  * specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  26  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #ifndef NBDKIT_GPT_H
  34 #define NBDKIT_GPT_H
  35
  36 struct gpt_header {
  37   char signature[8];
  38   char revision[4];
  39   uint32_t header_size;
  40   uint32_t crc;
  41   uint32_t reserved;
  42   uint64_t current_lba;
  43   uint64_t backup_lba;
  44   uint64_t first_usable_lba;
  45   uint64_t last_usable_lba;
  46   char guid[16];
  47   uint64_t partition_entries_lba;
  48   uint32_t nr_partition_entries;
  49   uint32_t size_partition_entry;
  50   uint32_t crc_partitions;
  51 };
  52
  53 #define GPT_SIGNATURE "EFI PART"
  54 #define GPT_REVISION "\0\0\1\0" /* revision 1.0 */
  55
  56 struct gpt_entry {
  57   char partition_type_guid[16];
  58   char unique_guid[16];
  59   uint64_t first_lba;
  60   uint64_t last_lba;
  61   uint64_t attributes;
  62   char name[72];                /* UTF-16LE */
  63 };
  64
  65 /* GPT_MIN_PARTITIONS is the minimum number of partitions and is
  66  * defined by the UEFI standard (assuming 512 byte sector size).
  67  *
  68  * In plugins such as the partitioning plugin, if we are requested to
  69  * allocate more than GPT_MIN_PARTITIONS then we increase the
  70  * partition table in chunks of this size.  Note that clients may not
  71  * support > GPT_MIN_PARTITIONS.
  72  *
  73  * GPT_PT_ENTRY_SIZE is the minimum specified by the UEFI spec, but
  74  * increasing it is not useful.
  75  */
  76 #define GPT_MIN_PARTITIONS 128
  77 #define GPT_PT_ENTRY_SIZE 128
  78
  79 #endif /* NBDKIT_GPT_H */