bug#41082: nomodeset

[pelzflorian (Florian Pelz)]

On Wed, May 06, 2020 at 08:56:48AM +0200, Mathieu Othacehe wrote:
> Should we propose the installation of uvesafb service in the
> installation? Or detect that it is currently used and force its install?
> 
> Florian, WDYT?

Yes, IMHO there should be a uvesafb-service-type.  Copying the uvesafb
service from the installer into the config.scm should work (but the
video resolution should be adjusted, probably something higher than
1024x768 is supported by the system).

We could add a uvesafb-service-type to its own gnu/services/….scm.
Autodetection of the best usable resolution via v86d:testvbe could be
added (however the best resolution usable with uvesafb may be less
than the screen’s resolution).

One way such a uvesafb-service-type could work is exactly like in the
installler.  Would it be right to add a uvesafb service that runs
modprobe itself?

Another way is to extend etc-service-type for this the way I wrote at
<https://lists.gnu.org/archive/html/bug-guix/2020-04/msg00320.html>.
Extending other services seems cleaner, but in the discussions by
Brice Waegeneire and Danny Milosavljevic (I put them in Cc) they were
not really satisfied with etc-service-type.

Back then I wrote 
<https://lists.gnu.org/archive/html/bug-guix/2020-04/msg00215.html>:
> When the dust has settled on the kernel-module-configuration-service
> discussed by Brice Waegeneire and Danny Milosavljevic
> <https://lists.gnu.org/archive/html/guix-patches/2020-04/msg00272.html>,
> a proper uvesafb service can be added.  Then I can make and test one
> and it could also be used in the installer.  That would be the clean
> solution.  In particular, it could detect the resolution to use for
> uvesafb automatically by running the attached code testvbe.scm as
> root.  But how to run that code depends on the
> kernel-module-configuration-service if/when it exists.  (I did not
> know how to extend etc-service-type with a file created at runtime not
> build time, but maybe kernel-module-configuration-service works
> differently anyway.)

Regards,
Florian