Hi Marek, On Fri, 7 Nov 2025 at 17:44, Marek Vasut <[email protected]> wrote: > > On 11/7/25 4:56 PM, Tom Rini wrote: > > On Fri, Nov 07, 2025 at 03:06:47PM +0100, Marek Vasut wrote: > >> On 11/7/25 10:12 AM, Heinrich Schuchardt wrote: > >>> On 11/6/25 22:08, Marek Vasut wrote: > >>>> In case DEVICE_TREE_DEBUG is set, produce a diff between the base DT and > >>>> DT with U-Boot extras, to show how much does the U-Boot DT differ from > >>>> the base DT. This is particularly useful together with OF_UPSTREAM, to > >>>> minimize the diff between upstream DTs and U-Boot DTs. > >>>> > >>>> Example usage: > >>>> $ make r8a779g3_sparrowhawk_defconfig && make DEVICE_TREE_DEBUG=1 > >>>> $ cat ./dts/upstream/src/arm64/renesas/r8a779g3-sparrow-hawk.dtb.diff > >>>> > >>>> This still has a downside. Even 'dtc -I dts -O dts ...' applied on > >>>> base DT and U-Boot augmented DT can produce different phandle IDs > >>>> for the same node in those two DTs, which results in a lot of noise > >>>> in the resulting diff. The only way I can think of is to patch DTC > >>>> to emit full paths in those phandles instead, something like a > >>>> phandle = <&{/full/path/to/remote/end} ...>; > >> > >> What bothers me is ^ this part. > >> > >> Hello Heinrich, > >> > >>> Without documentation developers will not know about the new feature. > >>> Could you, please, add a doc/build/ change in the next iteration. > >> Sure, although I am not convinced it should go in in its current form. > >> Please see my first line of comment. > > > > Maybe we put it in the u-boot-extras repo for now as a standalone > > script, so people can be asked to run it and look at the output? > I'd say no, because the output is full of noise unless the phandle > non-resolution gets somehow improved.
Another idea would be to create an fdtdiff tool which does this. We already have fdtgrep[1] Regards, Simon [1] https://github.com/devicetree-org/fdt-tools
