Subject: Re: [PATCH v2] powerpc: dts: Build devicetrees of enabled platforms

From: J. Neuschäfer <[email-masked]>
Date: Fri, 06 Mar 2026 08:39:35 +0000

On Thu, Mar 05, 2026 at 10:32:41AM +0100, Christophe Leroy (CS GROUP) wrote:
> 
> 
> Le 05/03/2026 à 10:15, J. Neuschäfer via B4 Relay a écrit :
> > From: "J. Neuschäfer" <[email-masked]>
> > 
> > Follow the same approach as other architectures such as Arm or RISC-V,
> > and build devicetrees based on platforms selected in Kconfig. This makes
> > it unnecessary to use CONFIG_OF_ALL_DTBS on PowerPC in order to build
> > DTB files.
> > 
> > This makes it easier to use other build and test infrastructure such as
> > `make dtbs_check`, and is a first step towards generating FIT images
> > that include all the relevant DTBs with `make image.fit`.
> > 
> > Signed-off-by: J. Neuschäfer <[email-masked]>
> > ---
> > Changes in v2:
> > - Use "dtb-$(FOO) += foo.dtb" format on every line, avoid backslashes
> >    (suggested by Geert Uytterhoeven)
> > - Link to v1: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fr%2F20260119-mpc83xx-dtb-v1-1-522f841290bf%40posteo.net&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C9264db0cd3014d5c30c608de7a97cd4c%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639082989567825654%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=QS4N0muz5oPD3WzZQE3FsF5ghDDu9PSJ79iA5R%2FAd3w%3D&reserved=0
> > ---
> >   arch/powerpc/boot/dts/Makefile     | 111 +++++++++++++++++++++++++++++++++++++
> >   arch/powerpc/boot/dts/fsl/Makefile |  79 ++++++++++++++++++++++++++
> >   2 files changed, 190 insertions(+)
> > 
> > diff --git a/arch/powerpc/boot/dts/Makefile b/arch/powerpc/boot/dts/Makefile
> > index 0cd0d8558b475c..7fce8c819d3d72 100644
> > --- a/arch/powerpc/boot/dts/Makefile
> > +++ b/arch/powerpc/boot/dts/Makefile
> > @@ -3,3 +3,114 @@
> >   subdir-y += fsl
> >   dtb-$(CONFIG_OF_ALL_DTBS) := $(patsubst $(src)/%.dts,%.dtb, $(wildcard $(src)/*.dts))
> > +
> > +# PPC44x platforms
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += arches.dtb
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += bamboo.dtb
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += bluestone.dtb
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += glacier.dtb
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += eiger.dtb
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += katmai.dtb
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += rainier.dtb
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += redwood.dtb
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += sequoia.dtb
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += taishan.dtb
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += yosemite.dtb
> > +dtb-$(CONFIG_PPC44x_SIMPLE) += icon.dtb
> 
> Why so many lines ? You should be able to fit approximaly four per line,
> 
> dtb-$(CONFIG_PPC44x_SIMPLE) += arches.dtb bamboo.dtb bluestone.dtb
> glacier.dtb
> dtb-$(CONFIG_PPC44x_SIMPLE) += eiger.dtb katmai.dtb rainier.dtb redwood.dtb
> dtb-$(CONFIG_PPC44x_SIMPLE) += sequoia.dtb taishan.dtb
>  yosemite.dtb icon.dtb

Hm, fair enough, that would work too, and make it visually somewhat
clearer what belongs together.

I'll wait for more comments, but I think this is a good enough
improvement for a v3, while still keeping potential edit churn away as
Geert Uytterhoeven previously pointed out:

>> Even when it wouldn't fit on a single line, having separate
>> 
>>     dtb-$(CONFIG_FOO) += bar1.dtb
>>     dtb-$(CONFIG_FOO) += bar2.dtb
>> 
>> lines not only makes it a little bit shorter, but avoids the churn of
>> adding a backslash to the previous line when adding new entries.

Best Regards,
J. Neuschäfer