guest/rialto/src/fdt.rs

// Copyright 2023, The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//! High-level FDT functions.

use core::ops::Range;
use libfdt::{Fdt, FdtError};

/// Reads the DICE data range from the given `fdt`.
pub fn read_dice_range_from(fdt: &Fdt) -> libfdt::Result<Range<usize>> {
    let node = fdt.node(c"/reserved-memory")?.ok_or(FdtError::NotFound)?;
    let node = node.next_compatible(c"google,open-dice")?.ok_or(FdtError::NotFound)?;
    node.first_reg()?.try_into()
}

pub(crate) fn read_vendor_hashtree_root_digest(fdt: &Fdt) -> libfdt::Result<Option<&[u8]>> {
    let node = fdt.node(c"/avf")?.ok_or(FdtError::NotFound)?;
    node.getprop(c"vendor_hashtree_descriptor_root_digest")
}

pub(crate) fn read_is_strict_boot(fdt: &Fdt) -> libfdt::Result<bool> {
    match fdt.chosen()? {
        Some(node) => Ok(node.getprop(c"avf,strict-boot")?.is_some()),
        None => Ok(false),
    }
}