Re: [PATCH v3] kbuild: Enable DT schema checks for %.dtb targets

[Marijn Suijten <marijn.suijten@somainline.org>]

On 2022-06-23 17:43:57, Dmitry Baryshkov wrote:
> It is possible to build a single dtb, but not with DT schema validation
> enabled. Enable the schema validation to run for %.dtb and %.dtbo
> targets. Anyone building a dtb for a specific platform *should* pay
> attention to schema warnings.
> 
> This could be supported with a separate %.dt.yaml target instead.
> However, the .dt.yaml format is considered an intermediate format and
> could possibly go away at some point if schema checking is integrated
> into dtc. Also, the plan is to enable the schema checks by default once
> platforms are free of warnings, and this is a move in that direction.
> 
> This patch differs from the previous one ([1]) in the fact that it
> requires specifying VALIDATE_DT=1 to run the checks while doing the
> build. Thus default build procedures would not obtain additional build
> dependency, while maintainers can still build a single DTB file an get
> only corresponding warnings.
> 
> [1] https://lore.kernel.org/all/20210913145146.766080-1-robh@kernel.org/
> 
> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Cc: linux-kbuild@vger.kernel.org
> Co-developed-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Thanks, glad to see this back rather than having to resort to reverting
75e895343d5a ("Revert "kbuild: Enable DT schema checks for %.dtb
targets"") locally.

Tested-by: Marijn Suijten <marijn.suijten@somainline.org>

> ---
>  Makefile | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index c43d825a3c4c..0942922384c4 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1365,11 +1365,17 @@ endif
>  
>  ifneq ($(dtstree),)
>  
> -%.dtb: include/config/kernel.release scripts_dtc
> -	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
> +ifneq ($(VALIDATE_DT),)
> +DT_YAML = $(dtstree)/$*.dt.yaml
> +DT_CHECK = dt_binding_check
> +export CHECK_DTBS=y
> +endif
>  
> -%.dtbo: include/config/kernel.release scripts_dtc
> -	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
> +%.dtb: include/config/kernel.release scripts_dtc $(DT_CHECK)
> +	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@ $(DT_YAML)
> +
> +%.dtbo: include/config/kernel.release scripts_dtc $(DT_CHECK)
> +	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@ $(DT_YAML)
>  
>  PHONY += dtbs dtbs_install dtbs_check
>  dtbs: include/config/kernel.release scripts_dtc
> @@ -1654,6 +1660,10 @@ help:
>  	@echo  '		3: more obscure warnings, can most likely be ignored'
>  	@echo  '		e: warnings are being treated as errors'
>  	@echo  '		Multiple levels can be combined with W=12 or W=123'
> +	@$(if $(dtstree), \
> +		echo '  make VALIDATE_DT=y [targets] Validate all DT processsed during the build'; \
> +		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
> +		)
>  	@echo  ''
>  	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
>  	@echo  'For further info see the ./README file'
> -- 
> 2.35.1
>