Lines Matching +full:partition +full:-
1 # SPDX-License-Identifier: GPL-2.0+
9 - UUID -(Universally Unique Identifier)
10 - GUID - (Globally Unique ID)
11 - EFI - (Extensible Firmware Interface)
12 - UEFI - (Unified EFI) - EFI evolution
13 - GPT (GUID Partition Table) - it is the EFI standard part
14 - partitions - lists of available partitions (defined at u-boot):
19 This document describes the GPT partition table format and usage of
20 the gpt command in u-boot.
26 globally unique value. A UUID is a 16-byte (128-bit) number. The number of
29 separated by hyphens, in the form 8-4-4-4-12 for a total of 36 characters
32 For instance, GUID of Basic data partition: EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
33 and GUID of Linux filesystem data: 0FC63DAF-8483-4772-8E79-3D69D8477DE4
38 Successive versions are using MD5 hash, random numbers and SHA-1 hash. All major
46 -------
48 --------------------------------------------------
50 ----------------------------------------------------------
52 -------------------------------------------------- GPT
54 --------------------------------------------------
55 LBA 3 |Entries 5 - 128 |
58 ----------------------------------------------------------
59 LBA 34 |Partition 1 |
61 -----------------------------------
62 |Partition 2 |
64 -----------------------------------
65 |Partition n |
67 ----------------------------------------------------------
68 LBA -34 |Entry 1|Entry 2| Entry 3| Entry 4| Backup
69 -------------------------------------------------- GPT
70 LBA -33 |Entries 5 - 128 |
73 LBA -2 | |
74 --------------------------------------------------
75 LBA -1 |Backup GPT Header |
76 ----------------------------------------------------------
80 Its first partition entry ID has 0xEE value, and disk software, which is not
83 It is possible to define 128 linearly placed partition entries.
85 "LBA -1" means the last addressable block (in the mmc subsystem:
86 "dev_desc->lba - 1")
89 ----------------------------
100 40 8 B First usable LBA for partitions (primary partition table last
102 48 8 B Last usable LBA (secondary partition table first LBA - 1)
104 72 8 B Partition entries starting LBA (always 2 in primary copy)
105 80 4 B Number of partition entries
106 84 4 B Size of a partition entry (usually 128)
107 88 4 B CRC32 of partition array
108 92 * Reserved; must be ZERO (420 bytes for a 512-byte LBA)
115 GPT headers and partition entries are protected by CRC32 (the POSIX CRC32).
118 and "Backup LBA" and therefore different CRC32 check-sum.
123 CRC32 for partition entries (field "CRC32 of partition array") is calculated for
130 Partition Entry Format:
131 ----------------------
134 0 16 B Partition type GUID (Big Endian)
135 16 16 B Unique partition GUID in (Big Endian)
139 56 72 B Partition name (text)
142 Bit 0 - System partition
143 Bit 1 - Hide from EFI
144 Bit 2 - Legacy BIOS bootable
145 Bit 48-63 - Defined and used by the individual partition type
146 For Basic data partition :
147 Bit 60 - Read-only
148 Bit 62 - Hidden
149 Bit 63 - Not mount
151 Creating GPT partitions in U-Boot:
154 To restore GUID partition table one needs to:
155 1. Define partition layout in the environment.
157 "uuid_disk=...;name=u-boot,size=60MiB,uuid=...;
163 The fields 'name' and 'size' are mandatory for every partition.
166 If field 'size' of the last partition is 0, the partition is extended
171 non-existent environment variable. The environment variable will be set to
175 The field 'bootable' is optional, it is used to mark the GPT partition
177 "name=u-boot,size=60MiB;name=boot,size=60Mib,bootable;name=rootfs,size=0"
179 "part list <interface> <dev> -bootable <varname>",
184 3. From u-boot prompt type:
187 Checking (validating) GPT partitions in U-Boot:
192 At u-boot prompt one needs to write:
199 When provided, additionally partition data - name, size and starting
200 offset (last two in LBA) - are compared with data defined in '$partitions'
204 on non-volatile medium stored GPT.
208 U-BOOT> gpt verify mmc 0 $partitions
209 U-BOOT> if test $? = 0; then echo "GPT OK"; else echo "GPT ERR"; fi
211 Renaming GPT partitions from U-Boot:
214 GPT partition names are a mechanism via which userspace and U-Boot can
219 employing 'swap' to exchange 'primary' and 'backup' partition names:
221 U-BOOT> gpt swap mmc 0 primary backup
224 'backup', and vice-versa. Alternatively, single partitions may be
225 renamed. In this example, mmc0's first partition will be renamed
228 U-BOOT> gpt rename mmc 0 1 primary
240 Partition type GUID:
243 For created partition, the used partition type GUID is
244 PARTITION_BASIC_DATA_GUID (EBD0A0A2-B9E5-4433-87C0-68B6B72699C7).
247 can specify a other partition type guid:
249 "uuid_disk=...;name=u-boot,size=60MiB,uuid=...;
251 type=0FC63DAF-8483-4772-8E79-3D69D8477DE4;"
255 (C12A7328-F81F-11D2-BA4B-00A0C93EC93B)
257 (024DEE41-33E7-11D3-9D69-0008C781F39F)
259 (E3C9E316-0B5C-4DB8-817D-F92DF00215AE)
261 (EBD0A0A2-B9E5-4433-87C0-68B6B72699C7)
263 (0FC63DAF-8483-4772-8E79-3D69D8477DE4)
265 (A19D880F-05FC-4D3B-A006-743F0F84911E)
267 (0657FD6D-A4AB-43C4-84E5-0933C84B4F4F)
269 (E6D6D379-F507-44C2-A23C-238F2A3DF928)
271 "uuid_disk=...;name=u-boot,size=60MiB,uuid=...;
274 They are also used to display the type of partition in "part list" command.
282 Please, pay attention at -l switch for parted.
285 (-d switch) passed in UUID string. It can be used to generate partitions UUID
286 passed to u-boot environment variables.
287 If optional CONFIG_RANDOM_UUID is defined then for any partition which environment
294 Partitions layout can be printed by typing "mmc part". Note that each partition