Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> writes: > On Thu, Nov 7, 2024 at 12:37 PM Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote: >> "Rob Herring (Arm)" <robh@xxxxxxxxxx> writes: >> > While OpenFirmware originally allowed walking parent nodes and default >> > root values for #address-cells and #size-cells, FDT has long required >> > explicit values. It's been a warning in dtc for the root node since the >> > beginning (2005) and for any parent node since 2007. Of course, not all >> > FDT uses dtc, but that should be the majority by far. The various >> > extracted OF devicetrees I have dating back to the 1990s (various >> > PowerMac, OLPC, PASemi Nemo) all have explicit root node properties. >> >> I have various old device trees that have been given to me over the >> years, and as far as I can tell they all have these properties (some of >> them are partial trees so it's hard to be 100% sure). > > Apparently CHRP LongTrail only had #address-cells in the root node. > Interestingly, /cpus does have a (zero) @size-cells property. > http://g33rt.be/migrated/Linux/PPC/root.html > http://g33rt.be/migrated/Linux/PPC/DeviceTree.html > > No idea if any of them are still alive. OK. We could fix that up in prom_init() if necessary - there's already a bunch of workarounds in there for longtrail. cheers
