usb keyboard dying at loader prompt

[Andriy Gapon]

on 06/11/2008 14:34 Andriy Gapon said the following:
> I have a quite strange problem.
> This is with 7-BETA amd64.
> All of USB is out of kernel and is loaded via modules.
> BIOS has "Legacy USB" enabled.
> I have only a USB keyboard, no PS/2 port.
> 
> The keyboard works file in BIOS and for selecting boot device in boot0
> menu. It also works in loader menu. If in the menu I select to go to
> loader prompt then it works for about 5 seconds and then "dies" - no
> reaction to key presses, no led change, nothing.
> I haven't actually verified if the keyboard would still work if I stayed
> in loader menu for longer than ~10 seconds.
> 
> This doesn't happen if USB is built into kernel.
> 
> Weird...


I did more experimentation and the behavior seems to be quite random -
sometimes keyboard works ok for long time in all places, sometimes it
stops working after some period of time, sometimes it doesn't work from
the start and couple of times I experienced boot process going astray.
Not sure what stage that was, there were endless messages spewed on the
screen very fast, I couldn't read them.

This leads me to the following "crazy" question - is it possible that
our boot chain corrupts some vital BIOS memory? I think loader would be
a primary suspect. I am not sure of anything, but a wild guess is that
RAM where BIOS stores some USB-related stuff gets corrupted. Maybe it's
overwritten when kernel and modules are loaded...

-- 
Andriy Gapon