Question related to FreeBSD Serial Console...

[Aaron Wohl]

If you do try a USB keyboard be sure and test reboot -d (make a kernel
core).  On the intel servers I have reboot -d (or any panic) causes the
kernel to lockup forever.  In the routine where it writes out kernel
dumps it pools for a control-c hit on the console that routine (poll for
a char) turns out to block on USB keyboards during shutdown, I suspect
too much of the user level USB code has been turned off by then.

I ended up turning off the kernel (5.1) USB support, not running the usb
deamon and removing moused.  To save on USB related kernel crashes.