[Buildroot] Include kernel's dtsi from customised dts in buiuldroot-external

[Bruno Kremel]

Hi Baruch,


Baruch Siach <baruch at tkos.co.il> writes:

> Hi Bruno,
>
> On Tue, Aug 22, 2017 at 01:01:10AM +0200, Bruno Kremel wrote:
>> I have set up buildroot external for Toradex Colibri iMX6 board. I would
>> like to customise kernel default dts, so I have made a copy of this dts
>> to my external board/toradex/colibiri-imx6 and then in the defconfig I
>> set up the path to custom dts:
>> BR2_LINUX_KERNEL_USE_CUSTOM_DTS=y
>> BR2_LINUX_KERNEL_CUSTOM_DTS_PATH="$(BR2_EXTERNAL)/board/toradex/colibri-imx6/imx6dl-colibri-mcp-25.dts"
>>
>> This successfully makes buildroot use my modified dts file. But this
>> file inludes some kernel dtsi files.
>> Namely:
>> #include <dt-bindings/input/input.h>
>> #include <dt-bindings/interrupt-controller/irq.h>
>> #include "imx6dl.dtsi"
>> #include "imx6qdl-colibri.dtsi"
>>
>> These are however not found by dts compiler during build and I end up
>> with dtc failing on undefined symbols in devicetree.
>
> So the pre-processor find the include files, but some symbols are missing. Is
> that correct?
>
>> How can I specify dts include path such that it will use kernel dtsi
>> files or what is the correct way to include these from external?
>
> The LINUX_BUILD_CMDS macro should copy your custom dts to arch/arm/boot/dts,
> which is where the .dtsi files should be located. Can you verify that?
This helps a lot. I was suspicious about file not being copied.
I just did a copy of vanilla dts from kernel over my modified one and
now it works.

So it is indeed error in my dts (don't know exactly where, but at least
I know that it's not the include)

Anyway for anybody having the same problem it was these kind of errors:
Error: arch/arm/boot/dts/imx6dl-colibri-mcp-25.dts:113.1-12 Label or path hdmi_audio not found
(more of those)

>
> What errors do you see?
>
> Does the kernel you took your base dts file from match the kernel you build?
>
> baruch

Thanks a lot.