[PATCH] ramips: fix Unifi 6 Lite boot failure with v5.15 kernels

[Jonas Gorski]

On Sat, 5 Nov 2022 at 09:46, Bjørn Mork <bjorn at mork.no> wrote:
>
> David Bauer <mail at david-bauer.net> writes:
> > On 11/4/22 09:29, Bjørn Mork wrote:
> >> You are right that the bootloader must be fixed.  But the vendor isn't
> >> likely to do that as long as they run older kernels. I believe the
> >> OpenWrt policy in such cases is to try to work around the issue.
> >> Replacing the vendor bootloader is a last resort.  Please correct me if
> >> I'm wrong.
> >
> > I haven't tried this yet, but I think we should be able to boot a FIT
> > image configuration which only contains a kernel image. We could then simply
> > use the legacy append-DT like we do for legacy uImage ramips.
> >
> > Not the nicest way, but considering we need it for the target anyways, i consider
> > this the simpler solution.
>
> Yes, that sounds acceptable if it is supported.  Which I guess it should
> be.
>
> I can test it the next time I get a chance.  But that might take a while
> before I'm close enough to these APs to use the console.  Should have
> had a console I could access remotely there, but I don't.

An option is also to set a load address for the dtb in the FIT image,
then U-Boot will relocate it before passing it to the kernel.

This way U-Boot also retains access to the dtb, in case it wants to
update/modify it (e.g. updating the /memory/ node with the actual
memory present, setting the cmdline, setting mac addresses etc).

Jonas