Support UKI layout

[pointlessone]

I'm not sure if this should be fixed here or in installkernel. I'd love some input on that from the maintainers.

So, basically, in efistub layout installkernel puts kernel into ${efi_root}/EFI/Gentoo/ (where Gentoo part can be configured), but in uki layout it puts kernel into ${efi_root}/EFI/Linux/ (where Linux is hardcoded). So eclean-kernel can find some kernel dirs (e.g. with --list-kernels) but not kernels themselves. It also refuses to remove those dirs because it doesn't find any kernels.

[mgorny]

CC @Nowa-Ammerlaan

[Nowa-Ammerlaan]

Please try eclean-kernel --layout blspec.

Cleaning UKIs should work (it does for me), the only limitation is that eclean-kernel can only use one layout at the time. There is some auto-detection in place to guess which one you want to use, but it does not always get it right.

[pointlessone]

It doesn't seem to work for me:

# eclean-kernel --layout blspec --list-kernels -D
DEBUG:root:Sorter: <ecleankernel.sort.VersionSort object at 0xffffb1bc3ce0>
DEBUG:root:Layout failed: <class 'ecleankernel.layout.blspec.BlSpecLayout'>; exception: /etc/machine-id not found
usage: eclean-kernel [-h] [-V] [-A] [-l] [-p] [--read-kernel-version KERNEL_PATH] [-b BOOTLOADER] [-L LAYOUT] [-r ROOT] [-a] [-d] [-n NUM] [-s SORT_ORDER] [-D] [-M] [--no-bootloader-update] [--no-kernel-install]
                     [-x EXCLUDE]
eclean-kernel: error: Invalid layout: blspec

I'm not sure what the issue is but I can confirm that I don't have that file.

[Nowa-Ammerlaan]

What version is this? It works fine on my end:

eclean-kernel -aA --layout blspec
Preserving currently running kernel (6.10.12-gentoo-dist)
Legend:
[-] file being removed
[x] file does not exist (anymore)
[+] file being kept (used by other kernels)

[pointlessone]

eclean-kernel 2.99.8

[Nowa-Ammerlaan]

I suppose this is the problem:

        # TODO: according to bootctl(1), we should fall back to IMAGE_ID=
        # and then ID= from os-release
        for path in ("etc/kernel/entry-token", "etc/machine-id"):
            try:
                with open(root / path) as f:
                    self.kernel_id = f.read().strip()
                break
            except FileNotFoundError:
                pass
        else:
            raise LayoutNotFound("/etc/machine-id not found")

[pointlessone]

Yeah, I don't have any of those files. So there seem to be some discrepancy between blspec and uki layout in installkernel or somewhere else.

[Nowa-Ammerlaan]

Please let me know if this patch resolves your problem: https://github.com/projg2/eclean-kernel/pull/56

[pointlessone]

Just tried the patch. Sorry, for the delay. It still doesn't work but it fails differently.

# eclean-kernel -aA --layout blspec -D
DEBUG:root:Sorter: <ecleankernel.sort.VersionSort object at 0xffffb05fb410>
DEBUG:root:Layout: <ecleankernel.layout.blspec.BlSpecLayout object at 0xffffb06ebe30>
DEBUG:root:Bootloader failed: <class 'ecleankernel.bootloader.lilo.LILO'>
DEBUG:root:Bootloader failed: <class 'ecleankernel.bootloader.grub2.GRUB2'>
DEBUG:root:Bootloader failed: <class 'ecleankernel.bootloader.grub.GRUB'>
DEBUG:root:Bootloader failed: <class 'ecleankernel.bootloader.yaboot.Yaboot'>
DEBUG:root:Bootloader: <ecleankernel.bootloader.symlinks.Symlinks object at 0xffffb0237560>
DEBUG:root:Unrecognized potential kernel image: PE file /efi/EFI/Linux/gentoo-6.6.51-gentoo-dist-hardened.efi: EOF in section table!
DEBUG:root:in get_removal_list()
Traceback (most recent call last):
  File "/usr/lib/python-exec/python3.12/eclean-kernel", line 8, in <module>
    sys.exit(setuptools_main())
             ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/site-packages/ecleankernel/__main__.py", line 391, in setuptools_main
    sys.exit(main(sys.argv[1:]))
             ^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/site-packages/ecleankernel/__main__.py", line 251, in main
    removals = get_removal_list(
               ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/site-packages/ecleankernel/process.py", line 81, in get_removal_list
    raise SystemError(
SystemError: No vmlinuz found. This seems ridiculous, aborting.

[Nowa-Ammerlaan]

Okay so now it is detecting the layout properly (so the PR does what it should), but there is something weird with this UKI:

DEBUG:root:Unrecognized potential kernel image: PE file /efi/EFI/Linux/gentoo-6.6.51-gentoo-dist-hardened.efi: EOF in section table!

How did you build this, with ukify or dracut?

[pointlessone]

I believe it's built with dracut. At least that's what it looks like when the kernel is being installed.

I wonder if arch is important here. This is an arm64 box.

[Nowa-Ammerlaan]

I believe it's built with dracut. At least that's what it looks like when the kernel is being installed.

Which version of dracut? And which type of objcopy are you using (binutils or llvm)?

It is a known "problem" that dracut creates UKIs that are slightly different then the ones ukify makes. In any case this issue is separate from the layout problem, so @mgorny I think we can merge #56

[pointlessone]

Is there a ticket for that another issue? Do you want me to file one?

[Nowa-Ammerlaan]

Is there a ticket for that another issue? Do you want me to file one?

We can re-use this one I think.

The interesting thing is that ukify support was implemented here: https://github.com/projg2/eclean-kernel/pull/47

The particular check that is failing for you now was not touched, suggesting that dracut itself might not be the issue.

In essence dracut just uses objcopy to build the UKI, we already know that llvm's objcopy sometimes behaves very different compared to the binutils version, which could be the cause of your problem if you are on an llvm profile. Another possibility is that this EOF comes directly from the input files.

[pointlessone]

Oh, I forgot to tell you the versions.

dracut: 103-r4 objcopy: binutils 2.42-r1