GRUB and USB questions

[Sarah Sharp]

I have a couple of questions about how GRUB handles USB.  I'm a Linux
kernel developer, not a GRUB developer, so please bare with me. :)

I heard that GRUB does not support EHCI host controllers yet.  Is
that still true?  If so, how does GRUB work on the newer Intel chipsets
with rate matching hubs (EHCI host controllers without an integrated
UHCI/OHCI companion controller)?

Does GRUB use the PS2 keyboard emulation that the BIOS provides during
boot?  Or does it directly use the USB device through the UHCI or OHCI
controller?

How does GRUB handle booting off of a USB device?  Will it need to have
support for the host controller the device is under to work, or can it
use some support from the BIOS instead?

Thanks!

Sarah Sharp
Open Source Technology Center
Intel Corp