[PATCH v2 2/2] kbuild: Bump the build system to 5.1

[Fabio Estevam]

Hi Ilias,

On Fri, Jun 27, 2025 at 3:57 PM Ilias Apalodimas
<ilias.apalodimas at linaro.org> wrote:
>
> Our last sync with the kernel was 5.1. Even that was a partial one
> as some patches from 4.x kernels were already missing making the
> transition to a modern kbuild infeasible.
>
> 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 Makefile[.lib/.kbuild].
> Unfortunately due to sheer amount of patches this is not easy to review,
> but that's what we decided during a community call.
>
> One of the biggest changes is get rid of partial linking entirely and
> build .a archives isntead of .o.
> We diaviate from the kernel on that. Instead of calling a custom script
> to create the archive symbol table, we call ar with rcTP (isntead of
> rcSTP) since we want a resulting archive that's sauble with the linker.
>
> The only affected platforms are PPC ones. Unfortunately I don't have any
> of them around to test, but the objdump of the resulting files --
> arch/powerpc/lib/built-in.[oa] looks identical.
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>

This commit breaks the mx6sabresd_defconfig build on my Ubuntu 2022.04 machine:

$ make mx6sabresd_defconfig
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
  YACC    scripts/kconfig/zconf.tab.c
  LEX     scripts/kconfig/zconf.lex.c
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf
#
# configuration written to .config
#
$ make
scripts/kconfig/conf  --syncconfig Kconfig
  UPD     include/config.h
  CFG     u-boot.cfg
  GEN     include/autoconf.mk
  GEN     include/autoconf.mk.dep
  CFG     spl/u-boot.cfg
  GEN     spl/include/autoconf.mk
make: *** arch/arm/mach-imx/: Is a directory.  Stop.