External dts building

[Simon Glass]

Hi Giulio,

On Thu, 14 Oct 2021 at 15:12, Giulio Benetti
<giulio.benetti at benettiengineering.com> wrote:
>
> Hi Simon,
>
> Il giorno 14 ott 2021, alle ore 22:43, Simon Glass <sjg at chromium.org> ha scritto:
>
> Hi Giulio,
>
> On Thu, 14 Oct 2021 at 13:23, Giulio Benetti
> <giulio.benetti at benettiengineering.com> wrote:
>
>
> Hi Simon,
>
>
> Il giorno 14 ott 2021, alle ore 20:24, Simon Glass <sjg at chromium.org> ha scritto:
>
>
> Hi,
>
>
> On Thu, 14 Oct 2021 at 07:46, Tom Rini <trini at konsulko.com> wrote:
>
>
> On Thu, Oct 14, 2021 at 02:53:30AM +0200, Giulio Benetti wrote:
>
>
> Hello All,
>
>
> is there a way to pass a dts file without touching the arch/arm/boot/dts/Makefile?
>
>
> On Buildroot we support the possibility to pass an external dts by copying it to the uboot sources to
>
> be built but since uboot version 2020.01 it doesn’t work anymore.
>
>
> So I’ve proposed a patch to prepend the dts file in the Makefile above, but this has drawbacks, like we reconfigure(it keeps adding files every time).
>
>
> So I ask you, is there a more canonical way already to achieve this?
>
>
> Not exactly, and it's something we're very much actively discussing
>
> right now.
>
>
> Are you using 'make DEVICE_TREE=xxx' ?
>
>
> Yes but it doesn’t work if you don’t add an entry into arch/arm/dts/Makefile
>
> Before version 2020.01 worked, but not after it.
>
>
> What board are you building?
>
>
> A20-OLinuXino-Lime_defconfig for but without CONFIG_DEFAULT_DEVICE_TREE undefined,
> so if you try to pass DEVICE_TREE= pointing to an external .dts file copied to arch/arm/dts/ make doesn’t find the entry in Makefile and it can’t build it.
>
> This is useful in build systems like Buildroot where you can provide an external defconfig as well as an external .dts file.
>
> So here the solution I see is to create an entry in arch/arm/dts/Makefile on the top of the file afte copying the .dts file we want to build.
> But on Buildroot they’ve pointed me to ask upstream(here) if there’s a more canonical way or to work together to achieve the goal:
>
> https://patchwork.ozlabs.org/project/buildroot/patch/20210209201303.195093-1-giulio.benetti@benettiengineering.com/

How about not disabling CONFIG_DEFAULT_DEVICE_TREE ? That should work OK.

Regards,
Simon

>
> Sorry if this e-mail is html but I’m on mobile :-/
>
> Best regards
> Giulio Benetti
>
>
> Regards,
> Simon