Reducing initramfs size and speed up the generation

[Dimitri John Ledkov]

On Fri, 21 Jul 2023 at 21:08, Steve Langasek <steve.langasek at ubuntu.com> wrote:
>
> On Fri, Jul 21, 2023 at 07:33:58PM +0100, Dimitri John Ledkov wrote:
> > If it is a concern that v5.15 jammy kernel may potentially be used
> > after partial / incomplete upgrade to Mantic, we can opt into using XZ
> > compressed firmware or I can backport ZSTD firmware support to jammy
> > GA kernel - it is a trivial patch (given that ZSTD itself is otherwise
> > available and used by the jammy kernel).
>
> The scenario here is that the user has just upgraded to mantic, so they get
> the new linux firmware and the new kernel; they reboot to mantic, but there
> is a regression of some kind; they reboot back to the jammy kernel (which is
> the N-1 kernel on their system) to debug it, and that kernel has regressed
> support for their hardware because it can no longer load the needed firmware
> from the root filesystem.
>
> This is a realistic enough scenario that I think it is worth backporting the
> zstd support onto jammy's 5.15 kernel.

This portion will be tracked in
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2028550 submitted
in https://lists.ubuntu.com/archives/kernel-team/2023-July/141355.html

As previously described it was fairly trivial backport of 3 files
changed, 98 insertions(+), 8 deletions(-)

-- 
okurrr,

Dimitri