On 2024-08-17 21:28, Dragan Simic wrote:
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.
As an example, please have a look at the following files in U-Boot:
- arch/arm/dts/rk3399-nanopi-m4-u-boot.dtsi
- arch/arm/dts/rk3399-nanopi-m4-2gb-u-boot.dtsi
- configs/nanopi-m4-rk3399_defconfig
- configs/nanopi-m4-2gb-rk3399_defconfig
Basically, there's no need for separate DTs in the kernel, just to
support
board variants with different DRAM types in U-Boot.
