So NanoPi duo has a slow blue flashing LED once its started up...I can't get through one apt upgrade without the blue LED starting to flash rapidly, and upgrade process not finishing. Seems like something is hanging. Anyone have any idea what a rapid flashing blue LED means?

Hey is there any onboard firmware that gets loaded without an SD card? Trying to figure out if I should be seeing any debug output on the serial port without an SD card...currently nothing is coming out of it. I hope the serial port only gets enabled once the linux kernel is loaded otherwise it seem...