Hello. I agree with Mouse, except that I also think it would be very
helpful and useful to have a serial console on USB only devices. I wonder
if we could make the console a virtual device which is attached dynamically
to a USB serial port if and when available. that would let the system
think it has a console, but one would only see it when the kernel and the
USB subsystem are up. Yes, I get this would make watching things boot
challenging, but by the time you get to single user mode, the kernel is
fully up and running and USB is or should be available by then.