Add support for installing static grub configs

Currently these are duplicated in osbuild and coreos-assembler.
We will aim to deduplicate them here.

Ideally we'd add support for "day 2" updates of these; I started
on a patch for that but it's sadly messy.

This is an incremental improvement.

src/bootupd.rs

@@ -30,6 +30,7 @@ pub(crate) fn install(
     source_root: &str,
     dest_root: &str,
     device: Option<&str>,
+    with_static_configs: bool,
     target_components: Option<&[String]>,
 ) -> Result<()> {
     // TODO: Change this to an Option<&str>; though this probably balloons into having
@@ -62,6 +63,7 @@ pub(crate) fn install(
     }
 
     let mut state = SavedState::default();
+    let mut installed_efi = false;
     for component in target_components {
         // skip for BIOS if device is empty
         if component.name() == "BIOS" && device.is_empty() {
@@ -77,10 +79,18 @@ pub(crate) fn install(
             .with_context(|| format!("installing component {}", component.name()))?;
         log::info!("Installed {} {}", component.name(), meta.meta.version);
         state.installed.insert(component.name().into(), meta);
+        if component.name() == "EFI" {
+            installed_efi = true;
+        }
+    }
+    let sysroot = &openat::Dir::open(dest_root)?;
+
+    if with_static_configs {
+        crate::grubconfigs::install(sysroot, installed_efi)?;
     }
 
-    let sysroot = openat::Dir::open(dest_root)?;
-    let mut state_guard = SavedState::unlocked(sysroot).context("failed to acquire write lock")?;
+    let mut state_guard =
+        SavedState::unlocked(sysroot.try_clone()?).context("failed to acquire write lock")?;
     state_guard
         .update_state(&state)
         .context("failed to update state")?;

src/cli/bootupd.rs

@@ -52,6 +52,10 @@ pub struct InstallOpts {
     #[clap(long)]
     device: Option<String>,
 
+    /// Enable installation of the built-in static config files
+    #[clap(long)]
+    with_static_configs: bool,
+
     #[clap(long = "component")]
     /// Only install these components
     components: Option<Vec<String>>,
@@ -90,6 +94,7 @@ impl DCommand {
             &opts.src_root,
             &opts.dest_root,
             opts.device.as_deref(),
+            opts.with_static_configs,
             opts.components.as_deref(),
         )
         .context("boot data installation failed")?;

src/grubconfigs.rs

@@ -0,0 +1,51 @@
+use std::{
+    os::unix::prelude::OsStrExt,
+    path::{Path, PathBuf},
+};
+
+use anyhow::{Context, Result};
+use openat_ext::OpenatDirExt;
+
+const CONFIGDIR: &str = "/usr/lib/bootupd/grub2-static";
+
+pub(crate) fn find_efi_vendordir(efidir: &openat::Dir) -> Result<PathBuf> {
+    for d in efidir.list_self()? {
+        let d = d?;
+        if d.file_name().as_bytes() == b"BOOT" {
+            continue;
+        }
+        let meta = efidir.metadata(d.file_name())?;
+        if !meta.is_dir() {
+            continue;
+        }
+        return Ok(d.file_name().into());
+    }
+    anyhow::bail!("Failed to find EFI vendor dir")
+}
+
+/// Install the static GRUB config files.
+pub(crate) fn install(target_root: &openat::Dir, efi: bool) -> Result<()> {
+    let bootdir = &target_root.sub_dir("boot").context("Opening /boot")?;
+
+    bootdir
+        .copy_file(&Path::new(CONFIGDIR).join("grub-static.cfg"), "grub.cfg")
+        .context("Copying grub-static.cfg")?;
+    println!("Installed: grub.cfg");
+
+    let efidir = efi
+        .then(|| {
+            target_root
+                .sub_dir_optional("boot/efi")
+                .context("Opening /boot/efi")
+        })
+        .transpose()?
+        .flatten();
+    if let Some(efidir) = efidir.as_ref() {
+        let vendordir = find_efi_vendordir(efidir)?;
+        let target = &vendordir.join("grub.cfg");
+        efidir.copy_file(&Path::new(CONFIGDIR).join("grub-static-efi.cfg"), target)?;
+        println!("Installed: {target:?}");
+    }
+
+    Ok(())
+}

src/main.rs

@@ -23,6 +23,8 @@ mod coreos;
 mod daemon;
 #[cfg(any(target_arch = "x86_64", target_arch = "aarch64"))]
 mod efi;
+#[cfg(any(target_arch = "x86_64", target_arch = "aarch64", target_arch = "powerpc64"))]
+mod grubconfigs;
 mod filetree;
 mod ipc;
 mod model;