[PATCH v3 3/8] scripts/Makefile.lib: Statically define *-u-boot.dtsi files location

[Bryan Brattlof]

Hi Sumit!

On December 28, 2023 thus sayeth Sumit Garg:
> Allow u-boot to build DTB from a different directory tree such that
> *-u-boot.dtsi files can be included from a common location. Currently
> that location is arch/$(ARCH)/dts/, so statically define that common
> location.
> 
> This is needed for platform owners to start building DTB files from
> devicetree-rebasing directory but still being able to include
> *-u-boot.dtsi files.
> 
> Reviewed-by: Tom Rini <trini at konsulko.com>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> Signed-off-by: Sumit Garg <sumit.garg at linaro.org>
> ---
> 

...

> 
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index 27b9437027c..09330421856 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib

...

>  # Uncomment for debugging
> @@ -190,6 +192,7 @@ dtsi_include_list += $(CONFIG_DEVICE_TREE_INCLUDES)
>  dtc_cpp_flags  = -Wp,-MD,$(depfile).pre.tmp -nostdinc                    \
>  		 $(UBOOTINCLUDE)                                         \
>  		 -I$(dir $<)                                             \
> +		 -I$(u_boot_dtsi_loc)                                     \
>  		 -I$(srctree)/arch/$(ARCH)/dts/include                   \
>  		 -I$(srctree)/include                                    \
>  		 -D__ASSEMBLY__                                          \
> @@ -328,7 +331,7 @@ cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
>  	  echo '$(pound)include "$(f)"' >> $(pre-tmp);) \
>  	$(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $(pre-tmp) ; \
>  	$(DTC) -O dtb -o $@ -b 0 \
> -		-i $(dir $<) $(DTC_FLAGS) \
> +		-i $(dir $<) -i $(u_boot_dtsi_loc) $(DTC_FLAGS) \
>  		-d $(depfile).dtc.tmp $(dtc-tmp) || \
>  		(echo "Check $(shell pwd)/$(pre-tmp) for errors" && false) \
>  		; \

One of the issues I see with having a separate OF_UPSTREAM and U-Boot dt 
directory is when we have U-Boot board files that use dtsi files in the 
OF_UPSTREAM folder.

For example our reference boards uses the primary bootloader's dtb (eg: 
k3-am62a7-r5-sk.dts) which #includes the k3-am62a7-sk.dts that will be 
found in the OF_UPSTREAM directory and modifies it to give it the 
perspective of the micro-controller it will be running on during boot.

What do you think if we have both paths included regardless if 
OF_UPSTREAM is selected or not? IDK if this will break anyone else

~Bryan