Here are the steps I followed. The host OS is Ubuntu 12.04 LTS. These steps worked with the stock OS that came with the board. But after the board was update to Android it doesn't seem to work.
- Start minicom on host machine as root:# sudo minicom -o -s -w
Select serial port setup option
Select serial port /dev/ttyACM0
Set baud rate to 115200
Set Hardware flow control to No
Set Software flow control to No
Press Enter and then press Esc to exit the menu.
Reset the board, and wait for a moment
I was expecting to see command prompt, but nothing showed up.
BTW I can connect to the board with adb.
Thank you for your help in advance.