Struct Header 

pub struct Header<'a>(/* private fields */);

A parsed complete Multiboot2 header.

It consists of the fixed Multiboot2BasicHeader prefix followed by all header tags (see HeaderTagType). Multiboot2BasicHeader represents only that prefix; use this type when working with the complete, dynamically sized header.

Use this to parse a header from a pointer. To construct a header, use Builder (requires the builder feature).

Implementations

impl<'a> Header<'a>

pub unsafe fn load(ptr: *const Multiboot2BasicHeader) -> Result<Self, LoadError>

Loads a complete Header from a pointer.

If the header is invalid, it returns a LoadError. This may be because:

• ptr is a null pointer
• ptr is not 8-byte aligned
• the reported total size is invalid
• the magic value of the header is not present
• the checksum field is invalid
• the tag sequence is incomplete or malformed
• the mandatory end tag is missing

Safety

• ptr must be valid for reading the complete reported header size. Otherwise, this function might cause invalid machine state or crash your binary.
• The memory at ptr must not be modified after calling load or the program may observe unsynchronized mutation.

Examples found in repository

examples/minimal.rs (line 28)

fn main() {
    // We create a Multiboot2 header during runtime here. A more practical
    // example, however, would be that you parse the header from kernel binary
    // at runtime.
    let header_bytes = Builder::new(HeaderTagISA::I386)
        .relocatable_tag(RelocatableHeaderTag::new(
            HeaderTagFlag::Required,
            0x1337,
            0xdeadbeef,
            4096,
            RelocatableHeaderTagPreference::None,
        ))
        .information_request_tag(InformationRequestHeaderTag::new(
            HeaderTagFlag::Required,
            &[
                MbiTagType::Cmdline.into(),
                MbiTagType::BootLoaderName.into(),
            ],
        ))
        .build();

    let header = unsafe { Header::load(header_bytes.as_ptr()) }.unwrap();
    println!("{header:#?}");
}

pub fn find_header(buffer: &[u8]) -> Result<(Self, usize), LoadError>

Tries finding a Multiboot2 header in a given slice of binary data.

Performs basic checks, such as length checks and a checksum match.

The Multiboot2 header must be contained completely within the first HEADER_SEARCH_LIMIT bytes of the OS image, and must be 64-bit aligned.

On success, it returns the parsed header and an index into the original buffer pointing to where the header starts.

Parameters

• buffer: 64-bit aligned buffer describing the first HEADER_SEARCH_LIMIT bytes of a potential Multiboot2 kernel image.

pub fn iter(&self) -> TagIter<'_>

Returns a TagIter.

pub const fn verify_checksum(&self) -> Result<(), (u32, u32)>

Wrapper around Multiboot2BasicHeader::verify_checksum.

pub const fn header_magic(&self) -> u32

Wrapper around Multiboot2BasicHeader::header_magic.

pub const fn arch(&self) -> HeaderTagISA

Wrapper around Multiboot2BasicHeader::arch.

pub const fn length(&self) -> u32

Wrapper around Multiboot2BasicHeader::length.

pub const fn checksum(&self) -> u32

Wrapper around Multiboot2BasicHeader::checksum.

pub const fn calc_checksum(magic: u32, arch: HeaderTagISA, length: u32) -> u32

Wrapper around Multiboot2BasicHeader::calc_checksum.

pub fn information_request_tag(&self) -> Option<&InformationRequestHeaderTag>

Search for the InformationRequestHeaderTag header tag.

pub fn address_tag(&self) -> Option<&AddressHeaderTag>

Search for the AddressHeaderTag header tag.

pub fn entry_address_tag(&self) -> Option<&EntryAddressHeaderTag>

Search for the EntryAddressHeaderTag header tag.

pub fn entry_address_efi32_tag(&self) -> Option<&EntryEfi32HeaderTag>

Search for the EntryEfi32HeaderTag header tag.

pub fn entry_address_efi64_tag(&self) -> Option<&EntryEfi64HeaderTag>

Search for the EntryEfi64HeaderTag header tag.

pub fn console_flags_tag(&self) -> Option<&ConsoleHeaderTag>

Search for the ConsoleHeaderTag header tag.

pub fn framebuffer_tag(&self) -> Option<&FramebufferHeaderTag>

Search for the FramebufferHeaderTag header tag.

pub fn module_align_tag(&self) -> Option<&ModuleAlignHeaderTag>

Search for the ModuleAlignHeaderTag header tag.

pub fn efi_boot_services_tag(&self) -> Option<&EfiBootServiceHeaderTag>

Search for the EfiBootServiceHeaderTag header tag.

pub fn relocatable_tag(&self) -> Option<&RelocatableHeaderTag>

Search for the RelocatableHeaderTag header tag.

Trait Implementations

impl Debug for Header<'_>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Eq for Header<'a>

impl<'a> PartialEq for Header<'a>

fn eq(&self, other: &Header<'a>) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<'a> StructuralPartialEq for Header<'a>