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

[Ramiro Aceves <ea1abz%gmail.com@localhost>]

El 22 de julio de 2025 18:38:46 CEST, Steve Rikli <sr%genyosha.net@localhost> escribió:
>On Tue, Jul 22, 2025 at 12:26:59PM +0200, Martin Husemann wrote:
>> 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.
>
>I think a summary like this of the ~3 board types could be helpful in
>the INSTALL guide, particularly if a couple common board/SoC examples
>could be listed for each type.
>

Yes, It would be great.


>The evbarm-aarch64 INSTALL guide almost doesn't mention UEFI; mostly
>references to bootaa64.efi in "subdirectory structure" and "Upgrading a
>previously-installed NetBSD System".
>
>Whereas there's a section about "Installation for Armv7 and AArch64
>devices with U-Boot". This looks like a common section across the
>evbarm-* INSTALL guides.
>
>I was thinking a section right after that e.g. "Installation for Armv7
>and AArch64 devices with UEFI" and some of your notes would be a useful
>starting point. That admittedly may not be applicable to some of the
>other evbarm-* INSTALL guides.
>
>The steps about dd'ing images and such are in-common, but the U-Boot
>section mentions e.g. installing board-specific U-Boot, while INSTALL
>has nothing comparable for UEFI.
>
>> 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.
>
>Yes. IME rpi4b with UEFI notices the presence/absence of cmdline.txt
>but NetBSD appears to not make use of it.
>

I would be good to especify which settings affect NetBSD behaviour or not.



>> Once UEFI runs, everything later is common again and should be well
>> documented.
>
>Agreed. Once I had NetBSD itself installed and running on the sysdisk,
>post-install configuration for rpi4 was nearly identical to my other 
>i386 and amd64 systems. Pleasantly so.  :-)
>

Just to clarify it , the only method to have HDMI output in the RPi4 is via UEFI firmware?

Thanks.



>Cheers,
>sr.