On 07-01-21, 14:28, Masahiro Yamada wrote: > On Wed, Jan 6, 2021 at 12:21 AM Rob Herring <robh+dt@xxxxxxxxxx> wrote: > > > > On Tue, Jan 5, 2021 at 4:24 AM Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote: > > > > > > Hello, > > > > > > Here is an attempt to make some changes in the kernel to allow building > > > of device tree overlays. > > > > > > While at it, I would also like to discuss about how we should mention > > > the base DT blobs in the Makefiles for the overlays, so they can be > > > build tested to make sure the overlays apply properly. > > > > > > A simple way is to mention that with -base extension, like this: > > > > > > $(overlay-file)-base := platform-base.dtb > > > > > > Any other preference ? > > Viresh's patch is not enough. > > We will need to change .gitignore > and scripts/Makefile.dtbinst as well. Thanks. > In my understanding, the build rule is completely the same > between .dtb and .dtbo Right. > As Rob mentioned, I am not sure if we really need/want > a separate extension. > > > A counter approach is to use an extension like '.ovl.dtb' > It clarifies it is an overlay fragment without changing > anything in our build system or the upstream DTC project. > > We use chained extension in some places, for example, > .dt.yaml for schema yaml files. > > > > dtb-$(CONFIG_ARCH_FOO) += \ > foo-board.dtb \ > foo-overlay1.ovl.dtb \ > foo-overlay2.ovl.dtb > > > Overlay DT source file names must end with '.ovl.dts' I am fine with any approach that you guys feel is better, .dts or .ovl.dts. I wanted to start a discussion where we can resolve this and be done with it. Thanks. -- viresh
