Re: Upgrading bootloader

[Colin Walters <walters verbum org>]

On Wed, Apr 25, 2018, at 7:05 AM, Alex Kiernan wrote:
> I've a need to upgrade the bootloader and boot scripts (U-Boot) as
> part of a deployment. Right now I'm deploying a systemd unit which
> upgrades it on reboot, but you obviously end up with the first reboot
> going through the old bootloader.

There was a thread on bootloader updates here:
https://mail.gnome.org/archives/ostree-list/2018-February/msg00001.html

> The grub2 code looks like it has support for doing that kind of thing,
> but the u-boot code doesn't - am I right in my thinking, or am I
> missing something?

I am not aware of any code in the grub2 backend which updates the actual
bootloader code (MBR, ESP).

What you want here may fall into a "post-deploy-script" infrastructure?
Basically after doing a deployment, walk over /usr/lib/ostree/post-deploy.d/
and run each script as a container or so.
See also https://github.com/ostreedev/ostree/issues/1026
(Though that case differs from this as you want to write outside of the deployment
 root, and in fact see the raw physical devices...which I'm not sure we should
 do for every script by default)