Re: [PATCH 1/3] dt-bindings: arm: rockchip: Add ArmSoM Sige7s

[Jianfeng Liu <liujianfeng1994@gmail.com>]

Hi Heiko,

On 2026-10-26 11:43 UTC, Heiko Stuebner wrote:
>> I confirmed this with ArmSoM. They purchased the original CoolPi 4B
>> hardware design from CoolPi and confirmed that no hardware design
>> modifications were made for the Sige7s.
>> 
>> So the Sige7s uses the same hardware design as the CoolPi 4B, rather
>> than being independently designed.
>
>if it's the completely same board, just with a different print on
>the board, why does it need an empty devicetree. When it's completely
>unchanged, what's speaking against just re-using the original one?

The existing CoolPi 4B DTB does work on the Sige7s, and I agree that there
is no hardware difference requiring a separate device tree.

My main reason for adding a separate DTS is to preserve the Sige7s board
identity for long-term upstream support.

The CoolPi 4B appears to be discontinued and is no longer readily available
through the purchase channels listed on its official website
(https://www.cool-pi.com/buy/). In contrast, ArmSoM is actively selling the
Sige7s and has committed to producing it until at least January 2034.

I'm also planning to add mainline U-Boot support for the Sige7s and
integrate it with Stubble-based UEFI booting.

While U-Boot could update the model and compatible properties before
booting Linux, Stubble may replace the firmware-provided DTB with one
bundled with the kernel. Having a Sige7s-specific DTB would preserve the
correct board identity throughout this process without requiring additional
distribution-specific modifications.

This would also avoid confusing users who purchase a Sige7s but find their
system identified as a CoolPi 4B.

The shared dtsi ensures that we do not duplicate the hardware description,
with the two board DTS files differing only in model and compatible.

Would this be a reasonable justification for keeping a separate board DTS?

Best regards,
Jianfeng