Re: [PATCH] arm64: dts: mediatek: Apply all DT overlays at build time

[AngeloGioacchino Del Regno]

Il 17/11/25 22:13, Rob Herring (Arm) ha scritto:
> It's a requirement that DT overlays be applied at build time in order to
> validate them as overlays are not validated on their own.
>
> Add targets for all the Mediatek overlays.
>
> Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
> ---
> This will soon be a warning[1].
>
> Note that if it is desired that the combined .dtb is not installed, then
> the combined .dtb should be added to 'dtb-' variable instead.

Uhm, sorry, can't we do something such that we don't generate a DTB with a
preapplied overlay?

Even something like generating those and deleting before build finalization
could work, I guess, though that'd be hacky maybe.

I don't know if this is the case, but I'm worried that various people have
scripts to copy DTBs somewhere (in some partition) or embed those in images,
and if they get the preapplied overlay dtbs in the same place, havoc could
happen as the bootloaders might be selecting wrong dtbs (as a plus, there is
no dtbo that varies machine compatible strings, rightfully).

Cheers,
Angelo

> [1] https://lore.kernel.org/all/20251114222759.4181152-1-robh@xxxxxxxxxx/
> ---
>   arch/arm64/boot/dts/mediatek/Makefile | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/mediatek/Makefile b/arch/arm64/boot/dts/mediatek/Makefile
> index a4df4c21399e..4e92bd9f0e53 100644
> --- a/arch/arm64/boot/dts/mediatek/Makefile
> +++ b/arch/arm64/boot/dts/mediatek/Makefile
> @@ -15,16 +15,30 @@ dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-acelink-ew-7886cax.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-mini.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-emmc.dtbo
> +mt7986a-bananapi-bpi-r3-emmc-dtbs := mt7986a-bananapi-bpi-r3.dtb mt7986a-bananapi-bpi-r3-emmc.dtbo
> +dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-emmc.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-nand.dtbo
> +mt7986a-bananapi-bpi-r3-nand-dtbs := mt7986a-bananapi-bpi-r3.dtb mt7986a-bananapi-bpi-r3-nand.dtbo
> +dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-nand.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-nor.dtbo
> +mt7986a-bananapi-bpi-r3-nor-dtbs := mt7986a-bananapi-bpi-r3.dtb mt7986a-bananapi-bpi-r3-nor.dtbo
> +dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-nor.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-sata.dtbo
> +mt7986a-bananapi-bpi-r3-sata-dtbs := mt7986a-bananapi-bpi-r3.dtb mt7986a-bananapi-bpi-r3-sata.dtbo
> +dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-sata.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-sd.dtbo
> +mt7986a-bananapi-bpi-r3-sd-dtbs := mt7986a-bananapi-bpi-r3.dtb mt7986a-bananapi-bpi-r3-sd.dtbo
> +dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-sd.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-rfb.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986b-rfb.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7988a-bananapi-bpi-r4.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7988a-bananapi-bpi-r4-2g5.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7988a-bananapi-bpi-r4-emmc.dtbo
> +mt7988a-bananapi-bpi-r4-emmc-dtbs := mt7988a-bananapi-bpi-r4.dtb mt7988a-bananapi-bpi-r4-emmc.dtbo
> +dtb-$(CONFIG_ARCH_MEDIATEK) += mt7988a-bananapi-bpi-r4-emmc.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7988a-bananapi-bpi-r4-sd.dtbo
> +mt7988a-bananapi-bpi-r4-sd-dtbs := mt7988a-bananapi-bpi-r4.dtb mt7988a-bananapi-bpi-r4-sd.dtbo
> +dtb-$(CONFIG_ARCH_MEDIATEK) += mt7988a-bananapi-bpi-r4-sd.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt8167-pumpkin.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt8173-elm.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt8173-elm-hana.dtb
> @@ -104,6 +118,8 @@ dtb-$(CONFIG_ARCH_MEDIATEK) += mt8390-genio-700-evk.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt8395-kontron-3-5-sbc-i1200.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt8395-radxa-nio-12l.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt8395-radxa-nio-12l-8-hd-panel.dtbo
> +mt8395-radxa-nio-12l-8-hd-panel-dtbs := mt8395-radxa-nio-12l.dtb mt8395-radxa-nio-12l-8-hd-panel.dtbo
> +dtb-$(CONFIG_ARCH_MEDIATEK) += mt8395-radxa-nio-12l-8-hd-panel.dtb
>   dtb-$(CONFIG_ARCH_MEDIATEK) += mt8516-pumpkin.dtb
>   
>   # Device tree overlays support