On Thu, Jan 21, 2021 at 12:27:28PM +0530, Viresh Kumar wrote:
> On 21-01-21, 17:34, David Gibson wrote:
> > 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.
> 
> > 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