xref: /freebsd/sys/contrib/edk2/Include/Uefi/UefiGpt.h (revision f7c32ed617858bcd22f8d1b03199099d50125721)
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 
140