[PATCH] kbuild: Bump the build system to 6.1

[David Lechner]

On 1/5/26 2:18 PM, David Lechner wrote:
> On 12/16/25 3:16 AM, Ilias Apalodimas wrote:
>> From: Sughosh Ganu <sughosh.ganu at linaro.org>
>>
>> Our last sync with the kernel was 5.1.
>>
>> We are so out of sync now, that tracking the patches and backporting
>> them one by one makes little sense and it's going to take ages.
>>
>> This is an attempt to sync up Makefiles to 6.1.
>> Unfortunately due to sheer amount of patches this is not easy to review,
>> but that's what we decided during a community call for the bump to 5.1,
>> so we are following the same guidelines here.
>>
>> Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
>> Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>a #rebased on -next
>>
> 
> ...
> 
>> @@ -129,14 +131,14 @@ include/config.h: scripts/Makefile.autoconf create_symlink FORCE
>>  PHONY += create_symlink
>>  create_symlink:
>>  ifdef CONFIG_CREATE_ARCH_SYMLINK
>> -ifneq ($(KBUILD_SRC),)
>> +ifdef building_out_of_srctree
>>  	$(Q)mkdir -p include/asm
>> -	$(Q)if [ -d $(KBUILD_SRC)/arch/$(ARCH)/mach-$(SOC)/include/mach ]; then	\
>> +	$(Q)if [ -d $(srctree)/arch/$(ARCH)/mach-$(SOC)/include/mach ]; then	\
>>  		dest=arch/$(ARCH)/mach-$(SOC)/include/mach;			\
>>  	else									\
>>  		dest=arch/$(ARCH)/include/asm/arch-$(if $(SOC),$(SOC),$(CPU));	\
>>  	fi;									\
>> -	ln -fsn $(KBUILD_SRC)/$$dest include/asm/arch
>> +	ln -fsn $(srctree)/$$dest include/asm/arch
>>  else
>>  	$(Q)if [ -d arch/$(ARCH)/mach-$(SOC)/include/mach ]; then	\
>>  		dest=../../mach-$(SOC)/include/mach;			\
> This breaks out-of-tree builds because the symlink created is broken. For example,
> I have O=build-mt8365_evk so the build directory is a subdirectory of the source
> directory. This causes $(srctree) to be ".." and therefore the link is:
> 
> build-mt8365_evk/include/asm/arch -> ../arch/arm/include/asm/arch-mediatek
> 
> Obviously, there should be a few more ../ in there or it should use an absolute
> path. I'm guessing previously $(KBUILD_SRC) was an absolute path?
> 
> I will see if I can come up with a fix unless someone has any immediate suggestions.
> 

Fix should be trivial. I submitted it at [1].

[1]: https://lore.kernel.org/u-boot/20260105-mtk-fix-build-after-kconfig-change-v1-1-7185a081f7c0@baylibre.com/