Hi Geert, On 12/9/18 9:49 PM, David Gibson wrote: > On Fri, Dec 07, 2018 at 09:19:24AM +0100, Geert Uytterhoeven wrote: >> Hi David, >> >> Thanks for your answer! >> >> On Fri, Dec 7, 2018 at 2:44 AM David Gibson <david@xxxxxxxxxxxxxxxxxxxxx> wrote: >>> On Thu, Dec 06, 2018 at 01:56:45PM +0100, Geert Uytterhoeven wrote: >>>> Some early revisions of SoCs may have hardware bugs that need to be >>>> fixed up in DT. Currently we are handling this by including DTS files >>>> and fixing up nodes and properties, to create different DTB files for >>>> different SoC revisons (see arch/arm64/boot/dts/renesas/*es1*). >>>> >>>> As an alternative, I'm envisioning the use of DT overlays and the >>>> fdtoverlay tool, in the hope of simplifying the generation of DTBs for >>>> the various SoC/board combinations. >>>> >>>> Ideally, such DTBs would not contain symbols, to avoid inflating DTB >>>> size. Hence if fixup overlays would not contain symbolic references, >>>> there would be no need for symbols. >>>> >>>> For anchors, the "&{/path/to/node@address}" syntax is working fine. >>>> For phandles, while documented on >>>> https://elinux.org/Device_Tree_Mysteries, and while working fine for the >>>> non-overlay case, dtc seems to have issues interpreting the DTB: < snip > I have updated elinux.org with the limitation for overlays that you report and that David explained. -Frank