Current Beta 1 version of Volumio for UDOO send the startup logs to the serial console port, but does not support user access on it (see udoo.org/ProjectsAndTutorial … ial-cable/).
Opening a connection, however, is very simple.
Open any connection and login as root
T0:23:respawn:/sbin/getty -L ttyS0 115200 vt100
#T0:23:respawn:/sbin/getty -L ttyS0 115200 vt100
T0:23:respawn:/sbin/getty -L ttymxc1 115200 vt100
Save the file
shutdown -r 0
If you look at serial console, you’ll now see the prompt, and you will be able to login normally.
Note: that’s the main console, while you type you might see console messages popping up, with all connected side effects
However, the connection will be always available, independently from the network situation.