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Date: Mon, 20 Jan 2025 18:57:59 +0000
Message-Id: <D774PQ9SBXGN.2JIXM10VQVUNH@posteo.net>
From: "Sertonix" <sertonix@posteo.net>
To: "Mark Hills" <mark@xwax.org>, <~alpine/users@lists.alpinelinux.org>
Subject: Re: Solutions for EFI booting / copying kernels
References: <8f3899df-71b7-6562-7688-7bebc6ac1f94@xwax.org>
In-Reply-To: <8f3899df-71b7-6562-7688-7bebc6ac1f94@xwax.org>

> I have a few Alpine systems which use EFI to boot with syslinux.
>
> I'd like to improve this setup.
>
> The kernel+initramfs are copied to /efi, where syslinux finds them.
>
> Invariably, after "apk upgrade" I forget to do this copy, resulting in a=
=20
> system that won't boot.
>
> I tried to automate it with kernel-hooks.d; this is run after kernel=20
> upgrades:
>
>   $ cat /etc/kernel-hooks.d/efi.hook
>   cp --verbose --update \
>         /boot/vmlinuz-* /boot/initramfs-* \
>         /efi
>
> But is buggy because it runs before initramfs is updated (details below.)
>
> My own "trigger" on apk upgrade could work, but there's no path I can add=
=20
> one to (they must originate from a package)
>
> Regular syslinux (on MBR) reads the ext4 /boot partition; the EFI variant=
=20
> cannot do this, and otherwise that would seem to be the best solution.=20
> Perhaps GRUB can, but I like syslinux as it feels straightforward (unlike=
=20
> GRUB)

I think it should work if you mount the EFI partition at /boot instead
of /efi. Then there isn't any copying needed.

You would need to copy all existing contents of /boot to /efi and then
change in /etc/fstab change /efi to /boot. Then you should be able to
reboot/upgrade just fine. To clean up the duplicate files you would need
to unmount /boot after a reboot and then remove the files that were
hidden by the mount (and probably reboot before any upgrade). Be carefull
to not delete the wrong file though.