Serial Console for the Rock64

[inos]

finally I was able to change the baudrate by altering the dtb

Code:

## be careful and make a backup of the dtb file!

sudo apt install device-tree-compiler

# dtb -> dts
dtc -I dtb -O dts -o <dts file> <dtb file>

# change the settings
# here: within the fiq-debugger section
# set baudrate to 0x1c200

# dts -> dtb
dtc -O dtb -o <dtb file> <dts file>

and applying the code below within the u-boot console

Code:

env set baudrate 115200
saveenv

When starting up the board, the very first bytes are coming with the high baudrate until the environment is restored from the boot device but that's not a big problem.
Indeed, the high baudrate was the reason for the data-drop using the RPi 1.
Despite of the fact, that this solution doesn't survive kernel updates, for the time being I can live with this situation.