[bug#57070] [PATCH] bootloader: extlinux: support for optional FDTDIR

[Mathieu Othacehe <othacehe@gnu.org>]

Hey,

OK, so I read the long thread. There's still something unclear to me. If
FDTDIR is not passed, where is located the device tree that is loaded?
Directly in the /boot partition?

It looks like the corresponding code is in the label_boot function of
the u-boot/boot/pxe_utils.c file. I quickly read this part hoping to
find a way to define a priority between device trees located in the
FDTDIR directory and device trees installed elsewhere.

> * gnu/bootloader.scm (<bootloader>)[device-tree-support?]: new field.

You need to document this new field in the "Bootloader Configuration"
documentation section.

> * gnu/tests/bootloader.scm: add tests for FDTDIR modification.

This will test for regressions on an x86_64-linux machine that will
probably never use this FDTDIR thing. As those tests are expensive to
run an maintain we can probably remove the test.

Thanks,

Mathieu