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extern crate core;
pub mod util;
use core::str;
use util::{align, SliceRead, SliceReadError};
const MAGIC_NUMBER : u32 = 0xd00dfeed;
const SUPPORTED_VERSION: u32 = 17;
const OF_DT_BEGIN_NODE : u32 = 0x00000001;
const OF_DT_END_NODE : u32 = 0x00000002;
const OF_DT_PROP : u32 = 0x00000003;
#[derive(Debug)]
pub enum DeviceTreeError {
InvalidMagicNumber,
SizeMismatch,
SliceReadError(SliceReadError),
ParseError(usize),
Utf8Error,
VersionNotSupported,
}
#[derive(Debug)]
pub struct DeviceTree {
pub version: u32,
pub boot_cpuid_phys: u32,
pub reserved: Vec<(u64, u64)>,
pub root: Node,
}
#[derive(Debug)]
pub struct Node {
pub name: String,
pub props: Vec<(String, Vec<u8>)>,
pub children: Vec<Node>,
}
impl From<SliceReadError> for DeviceTreeError {
fn from(e: SliceReadError) -> DeviceTreeError {
DeviceTreeError::SliceReadError(e)
}
}
impl From<str::Utf8Error> for DeviceTreeError {
fn from(_: str::Utf8Error) -> DeviceTreeError {
DeviceTreeError::Utf8Error
}
}
impl DeviceTree {
pub fn load(buffer: &[u8]) -> Result<DeviceTree, DeviceTreeError> {
if try!(buffer.read_be_u32(0)) != MAGIC_NUMBER {
return Err(DeviceTreeError::InvalidMagicNumber)
}
if try!(buffer.read_be_u32(4)) as usize != buffer.len() {
return Err(DeviceTreeError::SizeMismatch);
}
let version = try!(buffer.read_be_u32(20));
if version != SUPPORTED_VERSION {
return Err(DeviceTreeError::VersionNotSupported);
}
let off_dt_struct = try!(buffer.read_be_u32(8)) as usize;
let off_dt_strings = try!(buffer.read_be_u32(12)) as usize;
let off_mem_rsvmap = try!(buffer.read_be_u32(16)) as usize;
let boot_cpuid_phys = try!(buffer.read_be_u32(28));
let mut reserved = Vec::new();
let mut pos = off_mem_rsvmap;
loop {
let offset = try!(buffer.read_be_u64(pos));
pos += 8;
let size = try!(buffer.read_be_u64(pos));
pos += 8;
reserved.push((offset, size));
if size == 0 {
break;
}
}
let (_, root) = try!(Node::load(buffer, off_dt_struct, off_dt_strings));
Ok(DeviceTree{
version: version,
boot_cpuid_phys: boot_cpuid_phys,
reserved: reserved,
root: root,
})
}
}
impl Node {
fn load(buffer: &[u8], start: usize, off_dt_strings: usize)
-> Result<(usize, Node), DeviceTreeError> {
if try!(buffer.read_be_u32(start)) != OF_DT_BEGIN_NODE {
return Err(DeviceTreeError::ParseError(start))
}
let raw_name = try!(buffer.read_bstring0(start+4));
let mut pos = align(start + 4 + raw_name.len() + 1, 4);
let mut props = Vec::new();
while try!(buffer.read_be_u32(pos)) == OF_DT_PROP {
let val_size = try!(buffer.read_be_u32(pos+4)) as usize;
let name_offset = try!(buffer.read_be_u32(pos+8)) as usize;
let val_start = pos + 12;
let val_end = val_start + val_size;
let val = try!(buffer.subslice(val_start, val_end));
let prop_name = try!(
buffer.read_bstring0(off_dt_strings + name_offset)
);
props.push((
try!(str::from_utf8(prop_name)).to_owned(),
val.to_owned(),
));
pos = align(val_end, 4);
}
let mut children = Vec::new();
while try!(buffer.read_be_u32(pos)) == OF_DT_BEGIN_NODE {
let (new_pos, child_node) = try!(Node::load(buffer, pos,
off_dt_strings));
pos = new_pos;
children.push(child_node);
}
if try!(buffer.read_be_u32(pos)) != OF_DT_END_NODE {
return Err(DeviceTreeError::ParseError(pos))
}
pos += 4;
Ok((pos, Node{
name: try!(str::from_utf8(raw_name)).to_owned(),
props: props,
children: children,
}))
}
}