gptman

Pure Rust library to read and modify GUID partition tables.

Things you can do

• Read/Write GPT from 512 and 4096 bytes sector size disks
• Create a new GPT on a disk
• Insert/delete a partition in the table
• Align partitions automatically (to sector size)
• Resize a partition
• Copy/clone a partition from one disk and insert it into another
• Change partition type
• Fix partitions order
• Change disk GUID
• Change partition name
• Change partition GUID
• Toggle legacy BIOS bootable
• Toggle no block IO protocol
• Toggle required partition flag
• Toggle attributes
• Swap partition indexes
• Copy/clone all partitions from one disk and insert it to another
• Write protective MBR

Installation

Cargo.toml:

[dependencies]
gptman = "3"

Feature Flags

To disable default features:

[dependencies]
gptman = { version = "3", default-features = false }

Usage

Reading all the partitions of a disk:

let mut f = std::fs::File::open("tests/fixtures/disk1.img")
    .expect("could not open disk");
let gpt = gptman::GPT::find_from(&mut f)
    .expect("could not find GPT");

println!("Disk GUID: {:?}", gpt.header.disk_guid);

for (i, p) in gpt.iter() {
    if p.is_used() {
        println!("Partition #{}: type = {:?}, size = {} bytes, starting lba = {}",
            i,
            p.partition_type_guid,
            p.size().unwrap() * gpt.sector_size,
            p.starting_lba);
    }
}

Creating new partitions:

let mut f = std::fs::File::open("tests/fixtures/disk1.img")
    .expect("could not open disk");
let mut gpt = gptman::GPT::find_from(&mut f)
    .expect("could not find GPT");

let free_partition_number = gpt.iter().find(|(i, p)| p.is_unused()).map(|(i, _)| i)
    .expect("no more places available");
let size = gpt.get_maximum_partition_size()
    .expect("no more space available");
let starting_lba = gpt.find_optimal_place(size)
    .expect("could not find a place to put the partition");
let ending_lba = starting_lba + size - 1;

gpt[free_partition_number] = gptman::GPTPartitionEntry {
    partition_type_guid: [0xff; 16],
    unique_partition_guid: [0xff; 16],
    starting_lba,
    ending_lba,
    attribute_bits: 0,
    partition_name: "A Robot Named Fight!".into(),
};

Creating a new partition table with one entry that fills the entire disk:

let ss = 512;
let data = vec![0; 100 * ss as usize];
let mut cur = std::io::Cursor::new(data);
let mut gpt = gptman::GPT::new_from(&mut cur, ss as u64, [0xff; 16])
    .expect("could not create partition table");

gpt[1] = gptman::GPTPartitionEntry {
    partition_type_guid: [0xff; 16],
    unique_partition_guid: [0xff; 16],
    starting_lba: gpt.header.first_usable_lba,
    ending_lba: gpt.header.last_usable_lba,
    attribute_bits: 0,
    partition_name: "A Robot Named Fight!".into(),
};