Struct Header 

pub struct Header {
    pub magic: u32,
    pub totalsize: u32,
    pub off_dt_struct: u32,
    pub off_dt_strings: u32,
    pub off_mem_rsvmap: u32,
    pub version: u32,
    pub last_comp_version: u32,
    pub boot_cpuid_phys: u32,
    pub size_dt_strings: u32,
    pub size_dt_struct: u32,
}

The FDT header structure.

Every device tree blob begins with this header, which contains metadata about the layout and version of the FDT. All fields are stored in big-endian byte order on-disk and are converted to host byte order when parsed.

Fields

magic: u32

FDT header magic number (must be 0xd00dfeed)

totalsize: u32

Total size in bytes of the FDT structure

off_dt_struct: u32

Offset in bytes from the start of the header to the structure block

off_dt_strings: u32

Offset in bytes from the start of the header to the strings block

off_mem_rsvmap: u32

Offset in bytes from the start of the header to the memory reservation block

version: u32

FDT version number

last_comp_version: u32

Last compatible FDT version

boot_cpuid_phys: u32

Physical ID of the boot CPU

size_dt_strings: u32

Length in bytes of the strings block

size_dt_struct: u32

Length in bytes of the structure block

Implementations

impl Header

pub fn from_bytes(data: &[u8]) -> Result<Self, FdtError>

Read a header from a byte slice.

Parses an FDT header from the beginning of a byte slice, validating the magic number and converting all fields from big-endian to host order.

Errors

Returns FdtError::BufferTooSmall if the slice is too small to contain a complete header, or FdtError::InvalidMagic if the magic number doesn’t match the expected value.

pub unsafe fn from_ptr(ptr: *mut u8) -> Result<Self, FdtError>

Read a header from a raw pointer.

Parses an FDT header from the memory location pointed to by ptr, validating the magic number and converting all fields from big-endian to host order. Handles unaligned pointers by copying to an aligned buffer.

Safety

The caller must ensure that the pointer is valid and points to a memory region of at least size_of::<Header>() bytes that contains a valid device tree blob header.

Errors

Returns FdtError::InvalidPtr if the pointer is null, or FdtError::InvalidMagic if the magic number doesn’t match.

pub const fn alignment() -> usize

Returns the required alignment for FDT structures.

Trait Implementations

impl Clone for Header

fn clone(&self) -> Header

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Header

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

Formats the value using the given formatter.