MdePkg/Include/Uefi/UefiGpt.h

   1 /** @file
   2   EFI Guid Partition Table Format Definition.
   3
   4 Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #ifndef __UEFI_GPT_H__
  10 #define __UEFI_GPT_H__
  11
  12 ///
  13 /// The primary GUID Partition Table Header must be
  14 /// located in LBA 1 (i.e., the second logical block).
  15 ///
  16 #define PRIMARY_PART_HEADER_LBA 1
  17 ///
  18 /// EFI Partition Table Signature: "EFI PART".
  19 ///
  20 #define EFI_PTAB_HEADER_ID      SIGNATURE_64 ('E','F','I',' ','P','A','R','T')
  21 ///
  22 /// Minimum bytes reserve for EFI entry array buffer.
  23 ///
  24 #define EFI_GPT_PART_ENTRY_MIN_SIZE 16384
  25
  26 #pragma pack(1)
  27
  28 ///
  29 /// GPT Partition Table Header.
  30 ///
  31 typedef struct {
  32   ///
  33   /// The table header for the GPT partition Table.
  34   /// This header contains EFI_PTAB_HEADER_ID.
  35   ///
  36   EFI_TABLE_HEADER  Header;
  37   ///
  38   /// The LBA that contains this data structure.
  39   ///
  40   EFI_LBA           MyLBA;
  41   ///
  42   /// LBA address of the alternate GUID Partition Table Header.
  43   ///
  44   EFI_LBA           AlternateLBA;
  45   ///
  46   /// The first usable logical block that may be used
  47   /// by a partition described by a GUID Partition Entry.
  48   ///
  49   EFI_LBA           FirstUsableLBA;
  50   ///
  51   /// The last usable logical block that may be used
  52   /// by a partition described by a GUID Partition Entry.
  53   ///
  54   EFI_LBA           LastUsableLBA;
  55   ///
  56   /// GUID that can be used to uniquely identify the disk.
  57   ///
  58   EFI_GUID          DiskGUID;
  59   ///
  60   /// The starting LBA of the GUID Partition Entry array.
  61   ///
  62   EFI_LBA           PartitionEntryLBA;
  63   ///
  64   /// The number of Partition Entries in the GUID Partition Entry array.
  65   ///
  66   UINT32            NumberOfPartitionEntries;
  67   ///
  68   /// The size, in bytes, of each the GUID Partition
  69   /// Entry structures in the GUID Partition Entry
  70   /// array. This field shall be set to a value of 128 x 2^n where n is
  71   /// an integer greater than or equal to zero (e.g., 128, 256, 512, etc.).
  72   ///
  73   UINT32            SizeOfPartitionEntry;
  74   ///
  75   /// The CRC32 of the GUID Partition Entry array.
  76   /// Starts at PartitionEntryLBA and is
  77   /// computed over a byte length of
  78   /// NumberOfPartitionEntries * SizeOfPartitionEntry.
  79   ///
  80   UINT32            PartitionEntryArrayCRC32;
  81 } EFI_PARTITION_TABLE_HEADER;
  82
  83 ///
  84 /// GPT Partition Entry.
  85 ///
  86 typedef struct {
  87   ///
  88   /// Unique ID that defines the purpose and type of this Partition. A value of
  89   /// zero defines that this partition entry is not being used.
  90   ///
  91   EFI_GUID  PartitionTypeGUID;
  92   ///
  93   /// GUID that is unique for every partition entry. Every partition ever
  94   /// created will have a unique GUID.
  95   /// This GUID must be assigned when the GUID Partition Entry is created.
  96   ///
  97   EFI_GUID  UniquePartitionGUID;
  98   ///
  99   /// Starting LBA of the partition defined by this entry
 100   ///
 101   EFI_LBA   StartingLBA;
 102   ///
 103   /// Ending LBA of the partition defined by this entry.
 104   ///
 105   EFI_LBA   EndingLBA;
 106   ///
 107   /// Attribute bits, all bits reserved by UEFI
 108   /// Bit 0:      If this bit is set, the partition is required for the platform to function. The owner/creator of the
 109   ///             partition indicates that deletion or modification of the contents can result in loss of platform
 110   ///             features or failure for the platform to boot or operate. The system cannot function normally if
 111   ///             this partition is removed, and it should be considered part of the hardware of the system.
 112   ///             Actions such as running diagnostics, system recovery, or even OS install or boot, could
 113   ///             potentially stop working if this partition is removed. Unless OS software or firmware
 114   ///             recognizes this partition, it should never be removed or modified as the UEFI firmware or
 115   ///             platform hardware may become non-functional.
 116   /// Bit 1:      If this bit is set, then firmware must not produce an EFI_BLOCK_IO_PROTOCOL device for
 117   ///             this partition. By not producing an EFI_BLOCK_IO_PROTOCOL partition, file system
 118   ///             mappings will not be created for this partition in UEFI.
 119   /// Bit 2:      This bit is set aside to let systems with traditional PC-AT BIOS firmware implementations
 120   ///             inform certain limited, special-purpose software running on these systems that a GPT
 121   ///             partition may be bootable. The UEFI boot manager must ignore this bit when selecting
 122   ///             a UEFI-compliant application, e.g., an OS loader.
 123   /// Bits 3-47:  Undefined and must be zero. Reserved for expansion by future versions of the UEFI
 124   ///             specification.
 125   /// Bits 48-63: Reserved for GUID specific use. The use of these bits will vary depending on the
 126   ///             PartitionTypeGUID. Only the owner of the PartitionTypeGUID is allowed
 127   ///             to modify these bits. They must be preserved if Bits 0-47 are modified..
 128   ///
 129   UINT64    Attributes;
 130   ///
 131   /// Null-terminated name of the partition.
 132   ///
 133   CHAR16    PartitionName[36];
 134 } EFI_PARTITION_ENTRY;
 135
 136 #pragma pack()
 137 #endif
 138
 139