Custom kernel compilation

The 96boards - rock960

My goals with this board

The rock960 showed interesting technical characteristics, I wanted to acquire this board and have fun. The decision to spend some money on this board was greatly influenced by the upstream support. It may not be complete but I know Heiko Stubner, maintainer of the rockchip platform, is doing a great job so it would be a question of time before having all the bits supported mainstream.

My goal is to have this board working with an upstream kernel, if it is close to full support, I'm perfectly fine to contribute and bring my stone to the edifice.

Ordering the board

There are two versions of this board, a light one with 2GB of memory and 16GB of eMMC and a stronger one with 4GB of memory and 32GB of eMMC. I choose the later because, by experience, advanced benchmarking programs often blow memory and are impossible to run on a 2GB system without triggering the Out-Of-Memory killer (swap is not an option for obvious reasons).

I received the board well packaged:  I was expecting a box with the board and the power supply but surprisingly it was packaged with a metal box designed to improve the thermal dissipation with a thermal paste. A good point to prevent thermal mitigation too soon when evaluating the performance of the board.

Console setup

Usually, a console output adapter must be purchased in addition to a 96boards to have access to the reset button as well as an tty USB adapter via micro USB. The rock960 has already a console output which must be plugged with a TTL - USB serial adapter. This adapter is widely available over internet, for example on the 96boards web site in the accessories section.

It took me some time to figure out what was the connection for the console on the board, so to make it simple GND, data+, data-, the 5V is unplugged. The image below illustrates the connection:

As specified above the console connection is easy when we know how to plug the USB-TTL adapter. The software side is also very simple but, even it is not a rare, it is an uncommon setup: 1500000 bauds 8N1

There are several tools to deal with the console like minicom or stty. The documentation is widely available on the web. Personnaly, I have a preference for ser2net because I can access directly the consoles of all my boards from any host via a server managing them.

First try ...

Now the console is setup, I can power up the board and see the output from u-boot and the kernel ...