fdt-rs 0.2.0

A flattened device tree parser for embedded no-std environments
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# fdt-rs

A Flattened Device Tree parser for embedded no-std environments

## Usage

Add this to your `Cargo.toml`:

```toml
[dependencies.fdt-rs]
version = "0.2"
```

and this to your crate root:

```rust
extern crate fdt_rs;
```

## Features

This crate can be used without the standard library (`#![no_std]`) by disabling
the default `std` feature. Use this in `Cargo.toml`:

```toml
[dependencies.fdt-rs]
version = "0.2"
default-features = false
# features = ["ascii"]    # <--- Uncomment if you wish to use the ascii crate for str's
```

The `"ascii"` feature will configure the `Str` type returned by string accessor
methods to be of type `AsciiStr` provided by the [ascii crate](https://docs.rs/ascii/1.0.0/ascii/).
Without this feature enabled, `str` references will be returned.

## Example

The following example stashes a flattened device tree in memory, parses that
device tree into a `fdt_rs::DevTree` object, searches the device tree for the
first "ns16550a" compatible node, and if found prints that node's name.

```rust
extern crate fdt_rs;
use fdt_rs::*;

// Place a device tree image into the rust binary and
// align it to a 32-byte boundary by using a wrapper struct.
#[repr(align(4))] struct _Wrapper<T>(T);
pub const FDT: &[u8] = &_Wrapper(*include_bytes!("../tests/riscv64-virt.dtb")).0;

fn main() {
    // Initialize the devtree using an &[u8] array.
    let devtree = unsafe {

        // Get the actual size of the device tree after reading its header.
        let size = DevTree::read_totalsize(FDT).unwrap();
        let buf = &FDT[..size];

        // Create the device tree handle
        DevTree::new(buf).unwrap()
    };

    // Find the first "ns16550a" compatible node within the device tree.
    // If found, print the name of that node (including unit address).
    if let Some(node) = devtree.find_first_compatible_node("ns16550a") {
        println!("{}", node.name().unwrap());
    }


    // Use our own custom search method to find bootargs
    //
    // Find a node with a custom zero-length property "company,secret"
    if let Some((compatible_prop, _)) = devtree.find_prop(
            |prop|
                Ok((prop.name()? == "bootargs"))) {
        unsafe {
            println!("{}", compatible_prop.get_str().unwrap());
        }
    }
}

```