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

[Bjørn Mork]

Robert Marko <robimarko at gmail.com> writes:

> What should be done is to expand mkimage with an option to align to an
> 8-byte boundary.

Definitely.

However, this implies that mkimage must mangle the output of libfdt to
align one specific property.  AFAICS, there are no such possibilities in
device tree.  So the toolbox available to mkimage is the same as for the
mkimage caller: Change, add or move properties around until the
alignment of the "data" property is ok. But mkimage cannot take the
shortcuts my quick-fix abuses, for several reasons.  I believe mkimage
must be able to do the alignment by local modifications of each fdt
image node, and I'm not sure it can change any of the properties?
Except maybe description?  But a better method migh be changing the
order.  I guess this can be done.  E.g move one of the hashes in front
of data, provided the size of the property isn't 8-byte aligned. Haven't
checked.

But I don't think such a fix is within my capabilities after a quick
look at the mkimage code. And I believe the Unifi 6 Lite case needs a
fix right now.  It's a robust device with working console-less recovery,
but I don't think regular recovery sessions is a nice user experience...

Personally, I got fed up after crawling around in the attic 3 times to
push the reset button over the last few months.  Which is why finally I
ended up mounting a console and figuring out the root cause.  Adn here
we are.

I believe the only reason this isn't a major complaint, is because there
aren't many users testing v5.15 kernels on this device. Yet

(Unrelated, but I can recommend using bluetooth consoles for stuff like
this - my APs are still in the attic, but I can access the console from
the living room below.  And with PoE power I can force a hard reset if
necessary.  So no more need to crawl around in the attic.  Hopefully)


Bjørn