[PATCH] cmd_dtc: Enable generation of device tree symbols

[Frank Rowand]

+frank

On 1/25/21 4:57 AM, Uwe Kleine-König wrote:
> Adding the -@ switch to dtc results in the binary devicetrees containing
> a list of symbolic references and their paths. This is necessary to
> apply device tree overlays e.g. on Raspberry Pi as described on
> https://www.raspberrypi.org/documentation/configuration/device-tree.md.
> 
> Obviously the downside of this change is an increas of the size of the
> generated dtbs, for an arm out-of-tree build (multi_v7_defconfig):
> 
> 	$ du -s arch/arm/boot/dts*
> 	101380	arch/arm/boot/dts-pre
> 	114308	arch/arm/boot/dts-post
> 
> so this is in average an increase of 12.8% in size.
> 
> Signed-off-by: Uwe Kleine-König <uwe at kleine-koenig.org>
> ---
>  scripts/Makefile.lib | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index 213677a5ed33..0683a5808f7f 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -319,7 +319,7 @@ $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
>  
>  quiet_cmd_dtc = DTC     $@
>  cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
> -	$(DTC) -O $(patsubst .%,%,$(suffix $@)) -o $@ -b 0 \
> +	$(DTC) -@ -O $(patsubst .%,%,$(suffix $@)) -o $@ -b 0 \
>  		$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
>  		-d $(depfile).dtc.tmp $(dtc-tmp) ; \
>  	cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
>