feat: add initial support for custom bootloaders

usr/lib/akshara/utils/helpers.py

@@ -35,6 +35,7 @@ def resolve_config(system_config: dict) -> dict:
                 "auto-update": system_config["auto-update"]
                 if isinstance(system_config.get("auto-update"), dict)
                 else {"enabled": False},
+                "boot": system_config["boot"],
             }
         except IndexError:
             output.error("base track must include distro-config")
@@ -96,6 +97,12 @@ def resolve_config(system_config: dict) -> dict:
             else base_config["auto-update"]
         )
 
+        base_config["boot"] = (
+            system_config["boot"]
+            if isinstance(system_config.get("boot"), dict)
+            else base_config["boot"]
+        )
+
         return base_config
 
 

usr/lib/akshara/utils/update.py

@@ -15,8 +15,13 @@ def update_cleanup() -> None:
     """Clean-up from previous rebase/update."""
 
     # FIXME: should not ideally handle /var/cache/blendOS explicitly
+    for path in (
+        "/etc/grub.d",
+        "/etc/default/grub",
+        "/var/cache/akshara/rootfs/var/cache/blendOS",
+    ):
         subprocess.run(
-        ["umount", "-l", "/var/cache/akshara/rootfs/var/cache/blendOS"],
+            ["umount", "-l", path],
             stdout=subprocess.DEVNULL,
             stderr=subprocess.DEVNULL,
         )
@@ -135,21 +140,108 @@ def merge_var(new_rootfs: RootFS, overrides_keep_new: dict) -> None:
                 )
 
 
-def replace_boot_files() -> None:
+def is_bind_mnt(src, mountpoint) -> bool:
-    """Replace files in /boot with those from new rootfs."""
+    """Checks if /boot presently has /.tmp.boot bind-mounted to it.
-    new_boot_files = []
 
-    for f in os.listdir("/.update_rootfs/boot"):
+    Args:
-        if not os.path.isdir(f"/.update_rootfs/boot/{f}"):
+        src: Source directory of bind-mount.
-            subprocess.run(["mv", f"/.update_rootfs/boot/{f}", "/boot"])
+        mountpoint: Mountpoint for bind-mount.
-            new_boot_files.append(f)
+    """
+    with open("/proc/self/mountinfo") as mountinfo_file:
+        for line in mountinfo_file:
+            parts = line.strip().split()
+            if parts[3] != "/" and parts[3] == src and parts[4] == mountpoint:
+                return True
+    return False
 
-    for f in os.listdir("/boot"):
-        if not os.path.isdir(f"/boot/{f}"):
-            if f not in new_boot_files:
-                subprocess.run(["rm", "-f", f"/boot/{f}"])
 
-    subprocess.run(["grub-mkconfig", "-o", "/boot/grub/grub.cfg"])
+def handle_boot(new_rootfs, boot_config) -> None:
+    """Handles /boot partition."""
+
+    if os.path.isdir("/.tmp.boot"):
+        if is_bind_mnt("/.tmp.boot", "/boot"):
+            subprocess.run(["umount", "-l", "/boot"])
+        subprocess.run(["rm", "-rf", "/.tmp.boot"])
+
+    subprocess.run(["cp", "-ax", os.path.join(str(new_rootfs), "boot"), "/.tmp.boot"])
+    subprocess.run(["mount", "--bind", "/.tmp.boot", "/boot"])
+
+    if boot_config["type"] == "bios":
+        if boot_config["loader"] == "grub":
+            if (
+                subprocess.run(
+                    [
+                        "grub-install",
+                        f"--directory={os.path.join(str(new_rootfs), 'usr/lib/grub/i386-pc')}",
+                        "--target=i386-pc",
+                        boot_config["device"],
+                    ]
+                ).returncode
+                != 0
+            ):
+                output.error("aborting update...")
+                subprocess.run(["umount", "-l", "/boot"])
+                subprocess.run(["rm", "-rf", "/.tmp.boot"])
+                output.error("failed to install GRUB")
+                exit(1)
+        else:
+            subprocess.run(["umount", "-l", "/boot"])
+            subprocess.run(["rm", "-rf", "/.tmp.boot"])
+            output.error("unsupported bootloader for BIOS configuration")
+            exit(1)
+    elif boot_config["type"] == "uefi":
+        if boot_config["loader"] == "grub":
+            if (
+                subprocess.run(
+                    [
+                        "grub-install",
+                        f"--directory={os.path.join(str(new_rootfs), 'usr/lib/grub/x86_64-efi')}",
+                        "--efi-directory=/boot",
+                        "--target=x86_64-efi",
+                        "--removable",
+                        "--bootloader-id=blendOS",
+                    ]
+                )
+                != 0
+            ):
+                output.error("aborting update...")
+                subprocess.run(["umount", "-l", "/boot"])
+                subprocess.run(["rm", "-rf", "/.tmp.boot"])
+                output.error("failed to install GRUB")
+                exit(1)
+        else:
+            subprocess.run(["umount", "-l", "/boot"])
+            subprocess.run(["rm", "-rf", "/.tmp.boot"])
+            output.error("unsupported bootloader for BIOS configuration")
+            exit(1)
+    else:
+        subprocess.run(["umount", "-l", "/boot"])
+        subprocess.run(["rm", "-rf", "/.tmp.boot"])
+        output.error(f"unsupported system type - {boot_config['type']}")
+        exit(1)
+
+    if boot_config["loader"] == "grub":
+        new_rootfs.exec(["grub-mkconfig", "-o", "/grub.cfg"])
+        subprocess.run(["cp", f"{new_rootfs}/grub.cfg", "/boot/grub/grub.cfg"])
+
+    subprocess.run(["umount", "-l", "/boot"])
+
+    # Replace /boot with /.tmp.boot
+    # FIXME: should be atomic
+    for tmp_boot, dirs, files in os.walk("/.tmp.boot"):
+        boot = tmp_boot.replace("/tmp.boot", "/boot", 1)
+        for path in dirs + files:
+            subprocess.run(["rm", "-rf", "--", os.path.join(boot, path)])
+            subprocess.run(
+                [
+                    "cp",
+                    "-ax",
+                    os.path.join(tmp_boot, path),
+                    os.path.join(boot, path),
+                ]
+            )
+
+    subprocess.run(["rm", "-rf", "/.tmp.boot"])
 
 
 def update() -> None:
@@ -194,6 +286,7 @@ def update() -> None:
         else {}
     )
 
+    output.info("merging /etc...")
     merge_etc(new_rootfs, overrides_keep_new)
 
     try:
@@ -221,6 +314,7 @@ def update() -> None:
         output.error("malformed /etc/shadow")
         sys.exit(1)
 
+    output.info("merging /var...")
     merge_var(new_rootfs, overrides_keep_new)
 
     with open(
@@ -242,6 +336,6 @@ def update() -> None:
 
     subprocess.run(["cp", "-ax", str(new_rootfs), "/.update_rootfs"])
 
-    replace_boot_files()
+    handle_boot(new_rootfs, system_config["boot"])
 
     print()

usr/lib/dracut/modules.d/10akshara/handle-update.sh

@@ -6,7 +6,7 @@ echo
 mount -o remount,rw "$NEWROOT" >/dev/null 2>&1 || true
 
 # Remove "$NEWROOT"/.successful-update if exists
-rm -f "$NEWROOT"/.successful-update "$NEWROOT"/.update
+rm -f "$NEWROOT"/.successful-update "$NEWROOT"/.update "$NEWROOT"/.tmp.boot
 
 # Check if there is an available update
 if [ -d "$NEWROOT"/.update_rootfs ]; then