Re: [PATCH v2] kbuild: fix compilation of dtb specified on command-line without make rule

[Rob Herring]

On Wed, Nov 26, 2025 at 4:00 AM Thomas De Schampheleire
<thomas.de_schampheleire@xxxxxxxxx> wrote:
>
> Since commit e7e2941300d2 ("kbuild: split device tree build rules into
> scripts/Makefile.dtbs"), it is no longer possible to compile a device tree
> blob that is not specified in a make rule
> like:
>     dtb-$(CONFIG_FOO) += foo.dtb
>
> Before the mentioned commit, one could copy a dts file to e.g.
> arch/arm64/boot/dts/ (or a new subdirectory) and then convert it to a dtb
> file using:
>     make ARCH=arm64 foo.dtb
>
> In this scenario, both 'dtb-y' and 'dtb-' are empty, and the inclusion of
> scripts/Makefile.dtbs relies on 'targets' to contain the MAKECMDGOALS. The
> value of 'targets', however, is only final later in the code.
>
> Move the conditional include of scripts/Makefile.dtbs down to where the
> value of 'targets' is final. Since Makefile.dtbs updates 'always-y' which is
> used as a prerequisite in the build rule, the build rule also needs to move
> down.
>
> Fixes: e7e2941300d2 ("kbuild: split device tree build rules into scripts/Makefile.dtbs")
> Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@xxxxxxxxx>
> ---
> v2: fix 'make dtbs' by moving the 'Build' rule along
>
>  scripts/Makefile.build | 26 ++++++++++++++------------
>  1 file changed, 14 insertions(+), 12 deletions(-)

Acked-by: Rob Herring (Arm) <robh@xxxxxxxxxx>