You have to turn off legacy keyboard support in your BIOS, otherwise
it will try to trap the USB keyboard and emulate the PS/2 one, which
interferes with the kernel's ability to access the USB keyboard directly.
This will sometimes make the USB keyboard fail to work during the boot
stage(s), but then work properly in the kernel (except that the debugger
probably won't work).
-Matt
Matthew Dillon
<dillon@backplane.com>