Re: [PATCH] of: unittest: Statically apply overlays using fdtoverlay

From: Viresh Kumar
Date: Thu Jan 21 2021 - 00:15:20 EST


On 20-01-21, 23:00, Frank Rowand wrote:
> unittest.c first unflattens overlay_base.dtb during early boot. Then later
> it does some phandle resolution using the overlay metadata from overlay_base.
> Then it removes the overlay metadata from the in kernel devicetree data
> structure. It is a hack, it is ugly, but it enables some overlay unit
> tests.
>
> Quit trying to change overlay_base.dts.

I have already done so (in the latest series I sent yesterday).

> In my suggested changes to the base patch I put overlay_base.dtb in the
> list of overlays for fdtoverlay to apply (apply_static_overlay in the
> Makefile) because overlay_base.dts is compiled as an overlay into
> overlay_base.dtb and it can be applied on top of the base tree
> testcases.dtb. This gives a little bit more testcase data for
> fdtoverlay from an existing dtb.

Okay, but fdtoverlay tool can't apply overlay_base.dtb to
testcases.dtb as none of its node have the __overlay__ property and so
I have entirely skipped overlay_base.dtb and overlay.dtb now.

Yes this reduces the test coverage a bit as you said, but I don't see
a way to make it work right now. And I am not even sure if it is a
fdtoverlay bug, it expects the __overlay__ thing to be there for each
node, otherwise it can't figure out where this node should be applied.

--
viresh