# Re: \[PATCH 09/19\] powerpc: boot: Build devicetrees when CONFIG\_MPC831x=y

- From: Christophe Leroy \<hidden\>
- Date: 2025-01-06 14:20:04 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2025/01/2878207
- Thread: https://ratatoskr.run/linuxppc-dev/2025/01/2875330/t.md

```text


Le 02/01/2025 à 19:31, J. Neuschäfer via B4 Relay a écrit :
> [Vous ne recevez pas souvent de courriers de devnull+j.ne.posteo.net@kernel.org. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ]
>
> From: "J. Neuschäfer" <redacted>
>
> In order to produce useful FIT images, the kernel needs to know which
> devicetrees to build. To that end, follow the same approach as other
> architectures, and enable devicetrees per platform.

Why do you need that ? Why not just use CONFIG_EXTRA_TARGETS for that ?

>
> Signed-off-by: J. Neuschäfer <redacted>
> ---
>
> I've only enabled MPC831x devicetrees, because that's the hardware I have.
> ---
>   arch/powerpc/boot/dts/Makefile | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/arch/powerpc/boot/dts/Makefile b/arch/powerpc/boot/dts/Makefile
> index 0cd0d8558b475cfe342f36f4b78240ef88dd2e37..6aee895d5baaa2c978d4b1c82a6d198d9e166ea2 100644
> --- a/arch/powerpc/boot/dts/Makefile
> +++ b/arch/powerpc/boot/dts/Makefile
> @@ -3,3 +3,8 @@
>   subdir-y += fsl
>
>   dtb-$(CONFIG_OF_ALL_DTBS) := $(patsubst $(src)/%.dts,%.dtb, $(wildcard $(src)/*.dts))
> +
> +dtb-$(CONFIG_MPC831x) += \
> +       kmeter1.dtb \
> +       mpc8313erdb.dtb \
> +       mpc8315erdb.dtb

How will it know which one of the three to put in the FIT image ? Or do you want all three in the FIT image ? In that case how do you select which one to use at boot ?

>
> --
> 2.45.2
>
>


```