[Assist] linux-libre-lts does not boot with now-default zstd initrd compression

[Einhard Leichtfuß]

Hi,

this should be a bug report, but I repeatedly failed creating an issue
on the bug-tracker, being given the following error / warning messages:

> Sorry, in order to prevent spam, there are posting constraints on members newer than 2 days, and with fewer than 2 posts. Please try again in 20 minutes.

> Sorry, that post has too many non-dictionary words. Consider putting long command-line outputs and URLs into a file and attaching it with the 'Browse' button below.

(Neither waiting t: 20min < t < 2d, nor moving the URLs to a file helped.)


mkinitcpio switched to zstd as default compression algorithm with
version 30, as announced in the Arch news [0].  This happened knowing
that, on Arch, linux-lts moved to version 5.10, with support for zstd.
However, on Parabola, linux-libre-lts is still at version 5.4, without
support for zstd.  Furthermore, on armv7h, linux-libre is at version
5.8, also without support for zstd.

Hence, machines updated to the latest versions of mkinitcpio and
linux-libre-lts (or linux-libre on armv7h), and the default
mkinitcpio.conf will refuse to boot that kernel.

The natural workaround is to set COMPRESSION to some other value in
mkinitcpio.conf and to subsequently rebuild the initrd.

It is worth noting that linux-libre-lts is recommended in the
Installation Guide [1].

I suggest making an announcement in the news and/or adapting the default
mkinitcpio.conf.


Regards,
Einhard


[0]
https://archlinux.org/news/moving-to-zstandard-images-by-default-on-mkinitcpio/
[1] https://wiki.parabola.nu/Installation_Guide#Install_a_kernel