Red Bear OS — microkernel OS in Rust, based on Redox

Derivative of Redox OS (https://www.redox-os.org) adding:
- AMD GPU driver (amdgpu) via LinuxKPI compat layer
- ext4 filesystem support (ext4d scheme daemon)
- ACPI fixes for AMD bare metal (x2APIC, DMAR, IVRS, MCFG)
- Custom branding (hostname, os-release, boot identity)

Build system is full upstream Redox with RBOS overlay in local/.
Patches for kernel, base, and relibc are symlinked from local/patches/
and protected from make clean/distclean. Custom recipes live in
local/recipes/ with symlinks into the recipes/ search path.

Build:  make all CONFIG_NAME=redbear-full
Sync:   ./local/scripts/sync-upstream.sh

local/recipes/system/firmware-loader/source/src/main.rs

@@ -0,0 +1,106 @@
+mod blob;
+mod scheme;
+
+use std::env;
+use std::path::PathBuf;
+use std::process;
+
+use log::{error, info, LevelFilter, Metadata, Record};
+use redox_scheme::{SignalBehavior, Socket};
+
+use blob::FirmwareRegistry;
+use scheme::FirmwareScheme;
+
+struct StderrLogger {
+    level: LevelFilter,
+}
+
+impl log::Log for StderrLogger {
+    fn enabled(&self, metadata: &Metadata) -> bool {
+        metadata.level() <= self.level
+    }
+
+    fn log(&self, record: &Record) {
+        if self.enabled(record.metadata()) {
+            eprintln!("[{}] {}", record.level(), record.args());
+        }
+    }
+
+    fn flush(&self) {}
+}
+
+fn init_logging(level: LevelFilter) {
+    if log::set_boxed_logger(Box::new(StderrLogger { level })).is_err() {
+        return;
+    }
+    log::set_max_level(level);
+}
+
+fn default_firmware_dir() -> PathBuf {
+    PathBuf::from("/usr/firmware/")
+}
+
+fn run() -> Result<(), String> {
+    let firmware_dir = env::var("FIRMWARE_DIR")
+        .map(PathBuf::from)
+        .unwrap_or_else(|_| default_firmware_dir());
+
+    info!(
+        "firmware-loader: starting with directory {}",
+        firmware_dir.display()
+    );
+
+    let registry = FirmwareRegistry::new(&firmware_dir)
+        .map_err(|e| format!("failed to initialize firmware registry: {e}"))?;
+
+    let socket = Socket::create("firmware")
+        .map_err(|e| format!("failed to register firmware scheme: {e}"))?;
+    info!("firmware-loader: registered scheme:firmware");
+
+    let mut firmware_scheme = FirmwareScheme::new(registry);
+
+    loop {
+        let request = match socket.next_request(SignalBehavior::Restart) {
+            Ok(Some(request)) => request,
+            Ok(None) => {
+                info!("firmware-loader: scheme unmounted, exiting");
+                break;
+            }
+            Err(e) => {
+                error!("firmware-loader: failed to read scheme request: {}", e);
+                continue;
+            }
+        };
+
+        let response = match request.handle_scheme_block_mut(&mut firmware_scheme) {
+            Ok(response) => response,
+            Err(_request) => {
+                error!("firmware-loader: failed to handle request");
+                continue;
+            }
+        };
+
+        if let Err(e) = socket.write_response(response, SignalBehavior::Restart) {
+            error!("firmware-loader: failed to write response: {}", e);
+        }
+    }
+
+    Ok(())
+}
+
+fn main() {
+    let log_level = match env::var("FIRMWARE_LOADER_LOG").as_deref() {
+        Ok("debug") => LevelFilter::Debug,
+        Ok("trace") => LevelFilter::Trace,
+        Ok("warn") => LevelFilter::Warn,
+        Ok("error") => LevelFilter::Error,
+        _ => LevelFilter::Info,
+    };
+
+    init_logging(log_level);
+
+    if let Err(e) = run() {
+        error!("firmware-loader: fatal error: {}", e);
+        process::exit(1);
+    }
+}