Ludovic Courtès <ludo@gnu.org> writes:

>    3. UEFI support documented and possibly improved.
>
>       We can certainly document the UEFI setup and add the /boot/efi
>       partition in some of the ‘operating-system’ examples.
>
>       The more difficult part is the installation: do we need to make a
>       second, UEFI-specific, installation image?  When I installed
>       GuixSD on UEFI, I booted our installation image as “legacy”, but
>       then GRUB would default to a legacy install, not a UEFI install:
>
>         https://lists.gnu.org/archive/html/guix-devel/2016-12/msg00799.html
>
>       I’m not sure exactly what needs to be done.  Thoughts?

I plan to work on this over the next few days. The most common way is to
create a "hybrid" disk image that supports both UEFI and BIOS boot. IIRC
Debian achieves this by using Isolinux to create the EFI payload and
chainload to Grub. More information next week :-)