On Thu, Jan 21, 2021 at 12:27:28PM +0530, Viresh Kumar wrote:

On 21-01-21, 17:34, David Gibson wrote:

quoted

No, this is the wrong way around.  The expected operation here is that
you apply overlay (1) to the base tree, giving you, say, output1.dtb.
output1.dtb is (effectively) a base tree itself, to which you can then
apply overlay-(2).

Thanks for the confirmation about this.

quoted

Merging overlays is
something that could make sense, but fdtoverlay will not do it at
present.

FWIW, I think it works fine right now even if it not intentional.

No, it definitely will not work in general.  It might kinda work in a
few trivial cases, but it absolutely will not do the neccessary
handling in some cases.

I
did inspect the output dtb (made by merging two overlays) using
fdtdump and it looked okay.

Ok.. but if you're using these bizarre messed up "dtbs" that this test
code seems to be, I don't really trust that tells you much.

But yeah, I understand that we shouldn't
do it.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson