Re: adding UEFI to NetBSD /boot/ [was Re: no HDMI on rpi4b NetBSD 10.1]

[Martin Husemann <martin%duskware.de@localhost>]

On Tue, Jul 22, 2025 at 10:52:54AM +0200, Ramiro Aceves wrote:
> Yes, you are right. As you suggested,  the INSTALL document is the right
> place to document it as it is the first document it is supposed to be read
> prior to installation. As is now, it is a very generic evbarm document that
> aims to satisfy the installation of many different boards. But each board
> will have its own hints and tips. Difficult indeed to condense all
> infromation.

Yes, for arm boards it is basically 3 different things:

 - boards booting with FDT and u-boot (but no UEFI), mostly 32bit;
   here you have to make sure the correct dtb file is loaded 
   (names/defaults are in the  u-boot default environment), and the
   right dtb file is available on the FAT partition of your boot medium

 - boards (mostly 64bit) that do not come with (usable) UEFI firmware.
   Here you have to find the proper UEFI firmware and install it (e.g. in
   flash memory)

 - boards that come with proper UEFI firmware right from the start, here
   you can just boot the generic image. This part can be easily documented
   (including boot.cfg) as it is the same on all arm boards

For the first variant we provide various pre-configured images (derived
from the generich image) on armbsd.org. If you have a board that should
be in that list but isn't check if there is a pkgsrc sysutils/u-boot-*
for your device, and try if that works. When it does, let us know so we
can add it to the armbsd.org collection of images.

For the last variant there often is a EDK2 port and some of them are
linked from the wiki (I use that e.g. on Quartz64 and Firefly P2S devices).
This usually come with very good installation instructions.

For others you have to deal with the board specific UEFI firmware (like
in the RPI cases) and "somehow" get that running first. Documenting this
requires board+firmware specific knowledge. This is why knowledge is
sparse. Things like "cmdline.txt" are specific to the RPI firmware
and maybe even boot method used, I wouldn't be suprised if even on RPI
the file would not be used at all when booting NetBSD via the UEFI
boot loader.

Once UEFI runs, everything later is common again and should be well
documented.


Martin