i'm not sure what the cannonical way to do this is but
in plan9.ini i set mouseport=usb and then i have modified the
mouse-setting part of /rc/bin/termrc to read like this

if(test -f /dev/mousectl && ~ $mouseport ps2 ps2intellimouse 0 1 2 usb){
if(~ $mouseport usb)
usbstart
if not
aux/mouse $mouseport
# parse vgasize into fields
vgasize=`{echo $vgasize}
if(! ~ $"monitor '' && ! ~ `{cat /dev/user} none)
aux/vga -l $vgasize
if(~ $accupoint 1)
pipefile -dr /bin/aux/accupoint /dev/mouse
}

d'oh. keyboard. i think it might be time to go home. ;-)

- erik

On 3/16/07, Glenn Holmer wrote:
> Some time ago, I put Plan 9 on a machine with a USB mouse and somebody
> was able to help me add a few lines to plan9.ini to make it work. Now
> I've switched from PS/2 to USB keyboard on a machine with an existing
> Plan 9 installation. Is there a similar incantation that will make
> this keyboard work? (GRUB and Linux see it OK.)

AFAIK Plan 9 doesn't support USB keyboards. However, a lot of BIOSes
have some sort of "legacy" option to present a USB keyboard to the OS
as if it were PS2.
But, the fact that the keyboard works in grub suggests your BIOS is
already doing this (at least I didn't have any luck getting grub to
respond to a USB keyboard). Not sure why you're then running into
problems when Plan 9 boots... Maybe the BIOS hands off responsibility
after the OS initialises USB or something - worth a look through the
BIOS menus.

the usb driver switches off legacy mode, so if you need
that, and don't need any other usb devices, try not including
the usb driver and leave legacy mode on in the bios.
if it's a terminal and usb mouse is needed too, that might
not work (legacy mode is supposed to support the mouse too
so that DOS will work, but i don't think i've tried it myself).

On 3/22/07, C H Forsyth wrote:
> the usb driver switches off legacy mode, so if you need
> that, and don't need any other usb devices, try not including
> the usb driver and leave legacy mode on in the bios.
> if it's a terminal and usb mouse is needed too, that might
> not work (legacy mode is supposed to support the mouse too
> so that DOS will work, but i don't think i've tried it myself).
>

I've had no luck on some BIOSes with using legacy mode for both
keyboard and mouse. I distinctly remember having to pick one or the
other to get FreeBSD to work. But that was many years ago, and on a
different machine. :-)