Re: RPI 4/5 u-boot new port, is there any interest?

On Wed, Jun 4, 2025 at 8:50 AM Mark Millard <[email protected]> wrote:
>
> On Jun 4, 2025, at 05:33, Klaus Küchemann <[email protected]> wrote:
>
> > a while ago, I spoke in more detail with bz@ about u-boot for the Pi5. There are ways to create a new port...
> > Now I had a longer conversation with Hugo Kirnbichler on Discord. Hugo managed to patch u-boot for the RPI CM4 to make it NVMe bootable (compiled under FreeBSD).
> > Details would go beyond the scope here for the first.
> >
> > What I would like to know:
> > Is FreeBSD still interested in supporting the RPI4/5?
> > Goodbye Pi in FreeBSD or Hello Pi , especially now ? :-)
> >
> > Then Hugo and I might be willing to create a new port.
> > There's no other way to proceed...
>
> I wonder if FreeBSD's kboot (LinuxBoot context) might be a
> way to avoid both EDK2 and a FreeBSD specific U-Boot and
> better track booting what Linux can boot (once FreeBSD has
> kernel support for the context).

In aarch64, UEFI is still around in LinuxBoot environments. Granted,
it's just the UEFI runtime that is needed. The linux kernel handles the
hand off, and then "provides" sufficient metadata to the exec'd kernel
to reconnect to this. So there needs to be some kind of thing that
provides this. I don't know what the state of play is with the uboot
vs edk2 ports to the rpi5. But once you have the minimal Linux kernel
booted, FreeBSD could further boot from there. But if you can boot
linux.efi, chances are quite good you could boot FreeBSD's loader.efi
so I struggle to see how this would help, though it might.

Warner

> I've no clue if it might well apply to a RPi* context. But
> other aarch64 boards?
>
> > the u-boot mailing lists are aware of the problems, but nothing is happening because they don't need it for Linux. All the patches we know of are GPL’d from 3rd party companies or OS-projects afaik.
> >
> > Because it’s not really fun :-) , I don't want to continue this work if there is no official interest from FreeBSD.
> > If you are interested, we would be happy to discuss the details here.
>
>
>
> ===
> Mark Millard
> marklmi at yahoo.com
>