multiboot2-header

Rust library with type definitions and parsing functions for Multiboot2 headers. This library is no_std and can be used in bootloaders.

What this library is good for: - writing a small binary which writes you a valid Multiboot2 header into a file (such as header.bin) - understanding Multiboot2 headers better - analyze Multiboot2 headers at runtime

What this library is not optimal for: - compiling a Multiboot2 header statically into an object file using only Rust code

Features and Usage in no_std

This library is always no_std. However, the builder-feature requires the alloc-crate to be available. You need the builder only if you want to construct new headers. For parsing, this is not relevant.

```toml

without builder-feature (and without alloc-crate)

multiboot2-header = { version = "", default-features = false }

else (requires alloc-crate)

multiboot2-header = "" ```

Example 1: Builder + Parse

```rust use multiboot2header::builder::{InformationRequestHeaderTagBuilder, Multiboot2HeaderBuilder}; use multiboot2header::{HeaderTagFlag, HeaderTagISA, MbiTagType, RelocatableHeaderTag, RelocatableHeaderTagPreference, Multiboot2Header};

/// Small example that creates a Multiboot2 header and parses it afterwards. fn main() { // We create a Multiboot2 header during runtime here. A practical example is that your // program gets the header from a file and parses it afterwards. let mb2hdrbytes = Multiboot2HeaderBuilder::new(HeaderTagISA::I386) .relocatabletag(RelocatableHeaderTag::new( HeaderTagFlag::Required, 0x1337, 0xdeadbeef, 4096, RelocatableHeaderTagPreference::None, )) .informationrequesttag( InformationRequestHeaderTagBuilder::new(HeaderTagFlag::Required) .addirs(&[MbiTagType::Cmdline, MbiTagType::BootLoaderName]), ) .build();

// Cast bytes in vector to Multiboot2 information structure
let mb2_hdr = unsafe { Multiboot2Header::from_addr(mb2_hdr_bytes.as_ptr() as usize) };
println!("{:#?}", mb2_hdr);

} ```

Example 2: Multiboot2 header as static data in Rust file

You can use the builder, construct a Multiboot2 header, write it to a file and include it like this: ```

[used]

[no_mangle]

[linksection = ".text.multiboot2header"]

static MULTIBOOT2HDR: &[u8; 64] = includebytes!("mb2hdrdump.bin"); ``` You may need a special linker script to place this in a LOAD segment with a file offset with less than 32768 bytes. See specification.

MSRV

The MSRV is 1.52.1 stable.

License & Contribution

See main README file.