Re: [TRIVIAL PATCH] of: per-file dtc preprocessor flags

From: Masahiro Yamada
Date: Fri Jul 19 2019 - 22:43:56 EST


On Sat, Jul 20, 2019 at 4:28 AM Eugeniy Paltsev
<Eugeniy.Paltsev@xxxxxxxxxxxx> wrote:
>
> As of today we are able to pass custom flags to dtc compiler but not
> to dtc preprocessor.
> This ability is required for including some board-specific header files.
> It allows us to pass defined constants to dts without their duplication
> in several places.

How to use this option in a useful way?

I see a bunch of defined constants under include/dt-bindings/.

If you are talking about code duplication across architectures,
you can include arm dtsi from arm64 dts, or vice versa.
This was made possible by the symbolic links
in scripts/dtc/include-prefixes/.

Could you please elaborate your issues if you cannot solve them
by the current strategy?



> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx>
> ---
> scripts/Makefile.lib | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index f1f38c8cdc74..f2595a608dce 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -166,6 +166,8 @@ dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \
> $(addprefix -I,$(DTC_INCLUDE)) \
> -undef -D__DTS__
>
> +dtc_cpp_flags += $(DTC_CPP_FLAGS_$(basetarget))
> +
> # Useful for describing the dependency of composite objects
> # Usage:
> # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
> --
> 2.21.0
>


--
Best Regards
Masahiro Yamada