How to port Armbian to a new RK3399 SoM

[GEB]

Hi All,

I'm planning to use an RK3399-based system-on-module for an embedded application, and would like some advice about the work required to produce an Armbian build that runs on it. The SoM is made by Graperain ( https://www.graperain.com/ARM-Embedded-RK3399-System-On-Module-Gf/ ), and they have provided an SDK which is clearly an old copy of the Rockchip's github repo (4.4 kernel) with some unidentified tweaks to get it working on this board (including .dts files and presumably some bootloader stuff?). I realize this particular board is likely not of interest to the community, but I figure the general discussion around getting a new board running may be.

 

My high-level goal is to get Ubuntu running on this thing with high confidence in the stability of the system, with a preference for Ubuntu 18.04 or 20.04 if possible. For various reasons, I don't have a lot of confidence in the software provided by the board vendor. I've been very impressed with Armbian both in general and from having run it on another RK3399 system. I've even tried an armbian build for the Firefly on this SoM (Armbian_20.05.0-trunk_Firefly-rk3399_bionic_current_5.4.39), and it appears to mostly just work. Thus, I'd like to use armbian on my board if practical.

 

I've read some of the threads about adding a new board to an existing family, but I'm quite new to all of this, so I'd appreciate any thoughts on what work would be required to port Armbian onto this board and feel really confident in the result. My impression is that the main things required are the board config file, device tree stuff, bootloader, the kernel config, and potentially some kernel patches required for some of the required drivers. Beyond just getting a system running, I'm really interested in how much work is required to assure a really stable system. Which of these areas tends to eat up the most time, and am I missing any? Also, which of these steps are easy or trivial given that I have a running system based on the rockchip 4.4 sources?

 

Thanks so much for your work Armbian, and any thoughts you might have here as well,
George

[Werner]

It is actually not a big issue staying on Linux 4.4.x when running on RK3399. Those sources proven most stable. Newers suffering from various issues.

For a new board bring up I'd recommend forking the build repository and start reading at the documentation:https://docs.armbian.com/Developer-Guide_Build-Preparation/

[GEB]

Hi Werner,

I was definitely wondering whether it would make more sense to stay on the 4.4 "legacy" kernel or move to a more recent 5.x kernel. I was hoping for the latter just because I'd generally prefer a kernel from the mainline linux sources rather than the rockchip repo, but if 4.4 is more stable at this point, that probably settles it.

 

I did read the build docs, and successfully built and ran the image using the Firefly RK3399 board config. And while that happens to boot on my board, I'd like to better understand what I need to do to to be sure I've got the hardware config and such correct for my board. The device tree blob I have looks quite different from the Firefly one, so I'm starting by trying to figure out what the important differences are there.

 

George