I updated the firmware, the system boots and I can see output (uboot + linux) on the serial console but the keyboard input is not working and the machine is not responding to keyboard strokes.
There are 2 USB cables - one for the ttyACM0/1 and the other for ttyUSB0. ttyACM1 is used for rebooting and it works. ttyUSB0 is used for serial console (output works but input does not work, as explained above).
How to solve this issue?
Make sure that Hardware Flow control is disabled in your serial terminal program.
I disabled hardware control flow through minicom but there is still no input on ttyUSB0.
Can you attach the jumper that puts the uBMC microcontroller on ttyACM0/1 back into DFU mode? The uBMC is also attached to the serial console lines and I wonder if the firmware is blocking input.
Thank you, that was the issue, after connecting the jumper and issuing the re command, ttyUSB0 is taking inputs again.
ACM0/1 are now gone and the uBMC is in DFU mode.