Crate that parses ATag messages from a given memory address.

This is based on https://www.simtec.co.uk/products/SWLINUX/files/booting_article.html#appendix_tag_reference. Please open a pull request for missing tags.

To get started with this crate, create a [Atags] struct with a given memory position. The iter() method will return an iterator that returns [Atag] entries.

use atags::{Atag, Atags};

let mut buffer = [
// Core tag
0x00, 0x00, 0x00, 0x05, // size
0x54, 0x41, 0x00, 0x01, // tag
0x00, 0x00, 0x00, 0x01, //  flags
0x00, 0x00, 0x10, 0x00, //  page_size
0x12, 0x34, 0x56, 0x78, //  root_device_number

// Empty tag
0x0, 0x0, 0x0, 0x0, // size
0x0, 0x0, 0x0, 0x0, // tag
];
let ptr = core::ptr::NonNull::new(buffer.as_mut_ptr()).unwrap();
let tags = unsafe { Atags::new(ptr.cast()) };

for tag in tags.iter() {
// first tag is a core tag
match tag {
Atag::Core(core) => {
assert_eq!(core.flags, 1);
assert_eq!(core.page_size, 0x1000);
assert_eq!(core.root_device_number, 0x12345678);
},
// Do something with the other tags
// In this example we only get 1 core tag and nothing else
_ => panic!("Unknown tag {:?}", tag),
}
}

Features

nightly

Will enable the nightly strict_provenance feature in this crate.

• Core docs
• Tracking issue