Crate gpt_disk_types

Expand description

Library of GPT disk data types.

GPT disk components

┌───┬───────┬─────────────────┬─────────┬───────────────────┬─────────┐
│MBR│Primary│Primary partition│Partition│Secondary partition│Secondary│
│   │header │entry array      │data     │entry array        │header   │
└───┴───────┴─────────────────┴─────────┴───────────────────┴─────────┘

The first block of the disk contains a protective MBR. See MasterBootRecord::protective_mbr.
The second block of the disk contains the primary GPT header. See GptHeader.
Additional blocks after the header contain the partition entry array. See GptPartitionEntry and GptPartitionEntryArray.
At the end of the disk is a secondary GPT header and partition entry array.

The UEFI Specification specifies that data structures are little endian (section 1.8.1 “Data Structure Descriptions”). Unless otherwise noted, all fields in this library are little endian. This is true even when running the code on a big-endian architecture; the U16Le, U32Le, U64Le, and LbaLe types help enforce this. The little-endian convention is also used for Display implementations. This means bytes within each field will appear reversed when compared with a flat hex dump of GPT data.

Features

bytemuck: Implements bytemuck’s Pod and Zeroable traits for many of the types in this crate. Also enables some methods that rely on byte access.
std: Provides std::error::Error implementations for all of the error types. Off by default.

Examples

Construct a GPT header:

use gpt_disk_types::{guid, Crc32, GptHeader, LbaLe, U32Le};

let header = GptHeader {
    header_crc32: Crc32(U32Le::from_u32(0xa4877843)),
    my_lba: LbaLe::from_u64(1),
    alternate_lba: LbaLe::from_u64(8191),
    first_usable_lba: LbaLe::from_u64(34),
    last_usable_lba: LbaLe::from_u64(8158),
    disk_guid: guid!("57a7feb6-8cd5-4922-b7bd-c78b0914e870"),
    partition_entry_lba: LbaLe::from_u64(2),
    number_of_partition_entries: U32Le::from_u32(128),
    partition_entry_array_crc32: Crc32(U32Le::from_u32(0x9206adff)),
    ..Default::default()
};

Construct a GPT partition entry:

use gpt_disk_types::{guid, GptPartitionEntry, GptPartitionType, LbaLe};

let entry = GptPartitionEntry {
    partition_type_guid: GptPartitionType(guid!(
        "ccf0994f-f7e0-4e26-a011-843e38aa2eac"
    )),
    unique_partition_guid: guid!("37c75ffd-8932-467a-9c56-8cf1f0456b12"),
    starting_lba: LbaLe::from_u64(2048),
    ending_lba: LbaLe::from_u64(4096),
    attributes: Default::default(),
    name: "hello world!".parse().unwrap(),
};