install: mount separate boot partition to /sysroot/boot on ostree

If we're installing alongside existing ostree and there's a
separate boot partition, we need to mount it to the sysroot's
/boot so ostree can write bootloader entries there.

Signed-off-by: Huijing Hei <[email protected]>

Author: HuijingHei

crates/lib/src/install.rs

@@ -769,6 +769,17 @@ async fn initialize_ostree_root(state: &State, root_setup: &RootSetup) -> Result
     // Another implementation: https://github.com/coreos/coreos-assembler/blob/3cd3307904593b3a131b81567b13a4d0b6fe7c90/src/create_disk.sh#L295
     crate::lsm::ensure_dir_labeled(rootfs_dir, "", Some("/".into()), 0o755.into(), sepolicy)?;
 
+    // If we're installing alongside existing ostree and there's a separate boot partition,
+    // we need to mount it to the sysroot's /boot so ostree can write bootloader entries there
+    if has_ostree && root_setup.boot.is_some() {
+        if let Some(boot) = &root_setup.boot {
+            let source_boot = &boot.source;
+            let target_boot = root_setup.physical_root_path.join(BOOT);
+            tracing::debug!("Mount {source_boot} to {target_boot} on ostree");
+            bootc_mount::mount(source_boot, &target_boot)?;
+        }
+    }
+
     // And also label /boot AKA xbootldr, if it exists
     if rootfs_dir.try_exists("boot")? {
         crate::lsm::ensure_dir_labeled(rootfs_dir, "boot", None, 0o755.into(), sepolicy)?;