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

[Chen-Yu Tsai]

On Tue, Nov 18, 2025 at 5:36 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno at collabora.com> wrote:
>
> 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 at kernel.org>
> > ---
> > 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).

The in-tree scripts/make_fit.py can take a list of DTBs to pack, so
it's conceivable that someone would just use a wildcard path.

We do something similar downstream in ChromeOS, but we probably won't
get this change anytime soon.

OOTH the "make fit" target uses arch/arm64/boot/dts/dtbs-list , which
it seems is also used for DTB install?


ChenYu

> Cheers,
> Angelo
>
> > [1] https://lore.kernel.org/all/20251114222759.4181152-1-robh@kernel.org/
> > ---
> >   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
>
>
>