Bug#701656: initramfs rescue shell doesn't recognize USB keyboard

[Alexander Perlis <aperlis@math.lsu.edu>]

Package: initramfs-tools
Version: 0.109

The initramfs rescue shell doesn't recognize the USB keyboard if I do an 
expert install of Debian 7.0 and in response to "Drivers to include in 
the initrd" choose "targeted" instead of "generic". Same behavior with 
Debian 6.0 and "yaird" choice, in which case the initramfs-tools version 
is 0.98.2. In either case, the USB keyboard driver seems to not be included.

I'm landing in the initramfs rescue shell early in the boot process due 
to an incorrect kernel root= parameter in the GRUB configuration (due to 
an unrelated installer bug, which has been reported separately). I get:

  ALERT!  /dev/sde1 does not exist.  Dropping to a shell!

  BusyBox v1.17.1 (Debian 1:1.17.1-8) built-in shell (ash)
  Enter 'help' for a list of built-in commands.

  /bin/sh: can't access tty; job control turned off
  (initramfs)

At this point there is a blinking cursor. On systems with a PS/2 
keyboard, I can type commands. With both a PS/2 keyboard and a USB 
keyboard, only the PS/2 keyboard works. But some of our machines don't 
have PS/2 ports! On those machines, I'm not totally stuck. Whereas the 
preceding BIOS and GRUB components did respond to the USB keyboard, the 
rescue shell at this point does not.