RE: chicken and egg problem
You are right, you cannot mount an USB drive, because the system hangs, before you get to the shell/installer prompt.
With the install kernel already hanging during the hardware probing stage, the only possibility is capturing of the dmesg through the serial port.
Because you set up logging in the boot loader prompt
the dmesg output will be directed to the serial port.
A verbose boot would even be better:
Code:
boot> set tty com0
boot> boot -c
.......
......
UKC> verbose
autoconf verbose enabled
UKC> quit