Add support for building UKI addons

mkosi/__init__.py

@@ -1902,6 +1902,35 @@ def install_uki(
             f.write("fi\n")
 
 
+def build_uki_addon(context: Context, config: Path, output: Path) -> None:
+    cmd: list[PathString] = [
+        "build",
+        "--output", output,
+        "--config", config,
+    ]  # fmt: skip
+
+    options: list[PathString] = [
+        "--bind", output.parent, output.parent,
+        "--ro-bind", config, config,
+    ]  # fmt: skip
+
+    with complete_step(f"Generating UKI addon for {config}"):
+        run_ukify(context, cmd, options)
+
+
+def install_uki_addons(context: Context) -> None:
+    if not context.config.unified_kernel_image_addons:
+        return
+
+    addon_dir = context.root / "boot/loader/addons"
+    with umask(~0o755):
+        addon_dir.mkdir(parents=True, exist_ok=True)
+
+    for addon in context.config.unified_kernel_image_addons:
+        output = addon_dir / addon.with_suffix(".addon.efi").name
+        build_uki_addon(context, config=addon, output=output)
+
+
 def install_kernel(context: Context, partitions: Sequence[Partition]) -> None:
     # Iterates through all kernel versions included in the image and generates a combined
     # kernel+initrd+cmdline+osrelease EFI file from it and places it in the /EFI/Linux directory of
@@ -1943,6 +1972,9 @@ def install_kernel(context: Context, partitions: Sequence[Partition]) -> None:
         if context.config.bootloader == Bootloader.uki:
             break
 
+    if want_uki(context):
+        install_uki_addons(context)
+
 
 def make_uki(
     context: Context, stub: Path, kver: str, kimg: Path, microcode: list[Path], output: Path

mkosi/config.py

@@ -1588,6 +1588,7 @@ class Config:
     shim_bootloader: ShimBootloader
     unified_kernel_images: ConfigFeature
     unified_kernel_image_format: str
+    unified_kernel_image_addons: list[Path]
     initrds: list[Path]
     initrd_packages: list[str]
     initrd_volatile_packages: list[str]
@@ -2552,6 +2553,15 @@ def parse_ini(path: Path, only_sections: Collection[str] = ()) -> Iterator[tuple
         # default=
         help="Specify the format used for the UKI filename",
     ),
+    ConfigSetting(
+        dest="unified_kernel_image_addons",
+        long="--unified-kernel-image-addon",
+        metavar="PATH",
+        section="Content",
+        parse=config_make_list_parser(delimiter=",", parse=make_path_parser()),
+        recursive_paths=("mkosi.uki-addons/",),
+        help="Configuration files to generate UKI addons",
+    ),
     ConfigSetting(
         dest="initrds",
         long="--initrd",
@@ -4479,6 +4489,7 @@ def summary(config: Config) -> str:
                     Shim Bootloader: {config.shim_bootloader}
               Unified Kernel Images: {config.unified_kernel_images}
         Unified Kernel Image Format: {config.unified_kernel_image_format}
+        Unified Kernel Image Addons: {line_join_list(config.unified_kernel_image_addons)}
                             Initrds: {line_join_list(config.initrds)}
                     Initrd Packages: {line_join_list(config.initrd_packages)}
            Initrd Volatile Packages: {line_join_list(config.initrd_volatile_packages)}

mkosi/resources/man/mkosi.md

@@ -984,6 +984,14 @@ boolean argument: either `1`, `yes`, or `true` to enable, or `0`, `no`,
     | `&h`      | `roothash=` or `usrhash=` value of kernel argument |
     | `&c`      | Number of tries used for boot attempt counting     |
 
+`UnifiedKernelImageAddons=`, `--unified-kernel-image-addon`
+:   Build additional UKI addons. Takes a comma separated list of paths to
+    `ukify` config files. This option may be used multiple times in which case
+    each config gets built into a corresponding addon. Each addon has the name
+    of the config file, with the extension replaced with `.addon.efi`.
+    Config files in the `mkosi.uki-addons/` directory are automatically picked
+    up.
+
 `Initrds=`, `--initrd`
 :   Use user-provided initrd(s). Takes a comma separated list of paths to initrd
     files. This option may be used multiple times in which case the initrd lists

tests/test_json.py

@@ -340,6 +340,9 @@ def test_config() -> None:
                     "Target": "/"
                 }
             ],
+            "UnifiedKernelImageAddons": [
+                "/my-addon.conf"
+            ],
             "UnifiedKernelImageFormat": "myuki",
             "UnifiedKernelImages": "auto",
             "UnitProperties": [
@@ -515,6 +518,7 @@ def test_config() -> None:
         tools_tree_packages=[],
         tools_tree_release=None,
         tools_tree_repositories=["abc"],
+        unified_kernel_image_addons=[Path("/my-addon.conf")],
         unified_kernel_image_format="myuki",
         unified_kernel_images=ConfigFeature.auto,
         unit_properties=["PROPERTY=VALUE"],