Guix System for embedded systems roadmap.

[Mathieu Othacehe <m.othacehe@gmail.com>]

Hello,

At Fosdem 2020, I gave a talk about using GNU Guix as an alternative to
Yocto, focusing on cross-compiling a Guix System. Here's a status and
my personal roadmap on this topic.

* On core-updates, since commit
  d594963856690f1aacf228c8a83e406d33bc44ce, cross-compiling a bare-bones
  Guix System disk-image for Pine A64 works. This is propably true for
  other boards too.

* On the same commit, the produced disk-image weights 1.9 GiB, which is
  obviously too big. I'm working on reducing this closure size. See:
  https://issues.guix.info/issue/39941 and
  https://issues.guix.info/issue/40071.

* While cross-compilation is important, Guix also supports emulated
  compilation with --system. Producing a Guix System disk-image with
  --system is currently broken and needs to be fix. See
  https://lists.gnu.org/archive/html/guix-devel/2019-12/msg00099.html.

* Somehow related to the previous point, producing a disk-image,
  currently means spawning a virtual machine. This can be very slow, and
  using --system, we currently emulate the execution of a virtual
  machine for a foreign architecture.

  I'd like to propose an alternative mechanism which would be faster and
  not involving virtual machines. Maybe producing the disk-image in a
  container?

* Increase board support catalog, even if it's tricky because many
  boards need proprietary blobs to boot (such as Raspberry Pis). The
  effort started by Danny on wip-buildroot could be resumed.

* Finally, as we discussed during Guix Days[1], it would be nice to have
  a webservice, where you could select your board, the packages/services
  you want to install, and a disk-image, cross-compiled or not, would be
  generated for you! It implies that all the points listed above are
  solved, but it could be quite nice :)

Feedback welcome!

Thanks,

Mathieu

[1]:
http://git.savannah.gnu.org/cgit/guix/maintenance.git/tree/doc/guix-days-2020/growing-guix.org