microdroid_manager/src/metadata.rs

// Copyright 2021, 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.

//! Payload metadata from /dev/block/by-name/payload-metadata

use crate::ioutil;

use anyhow::Result;
use log::info;
use microdroid_metadata::{read_metadata, Metadata};
use std::time::Duration;

const WAIT_TIMEOUT: Duration = Duration::from_secs(10);
const PAYLOAD_METADATA_PATH: &str = "/dev/block/by-name/payload-metadata";

/// loads payload metadata from /dev/block/by-name/paylaod-metadata
pub fn load() -> Result<Metadata> {
    info!("loading payload metadata...");
    let file = ioutil::wait_for_file(PAYLOAD_METADATA_PATH, WAIT_TIMEOUT)?;
    read_metadata(file)
}