Re: [PATCH v5 2/2] arm64: dts: rockchip: add support for Radxa ROCK Pi E v3.0

[Dragan Simic <dsimic@manjaro.org>]

Hello Fukaumi,

On 2024-08-17 00:20, FUKAUMI Naoki wrote:
> On 8/17/24 07:11, Heiko Stübner wrote:
>> Am Freitag, 16. August 2024, 23:34:29 CEST schrieb FUKAUMI Naoki:
>>> Radxa ROCK Pi E v3.0 is a compact networking SBC[1] using the 
>>> Rockchip
>>> RK3328 chip that ships in a number of RAM/eMMC/WiFi/BT 
>>> configurations:
>>> 
>>> - Rockchip RK3328 SoC
>>> - Quad A53 CPU
>>> - 512MB/1GB/2GB DDR4 RAM
> (snip)
>> can you please describe what is different in that v3 board?
>> Describing what is different to require a separate board should've 
>> been
>> part of the commit message.
>> 
>> Because from those changes, the bottom line currently seems to be
>> the same board with swapped mmc aliases?
> 
> it's new board which uses DDR4 RAM (instead of DDR3 RAM on Pi E).
> different bootloader (U-Boot) is required.
> 
> adding v3 dts seems not to be so important for Linux, but it's very
> important for U-Boot and OpenWrt(it includes bootloader for
> distributed binary).

Aren't there different methods that allow such board variants to be
supported in U-Boot, with no need for a separate DT in the kernel?
IIRC, there are already more than a few examples of such board variants,
which require different DRAM initialization, which is covered in U-Boot
by providing different builds that use the same DT.