Crazy clock

Matthew Dillon dillon at apollo.backplane.com
Tue Dec 7 11:59:33 PST 2004


:> :The problem is that the BIOS might mess with the timer directly like my
:> :notebook does. We can't detect changes from System Management Mode.
:> 
:>     Ugh.  You're right.  SMM bypasses everything.  Somebody needs to shoot
:>     Intel.
:
:Apart from the shooting bit, is there something I could do to debug the
:situation? 
:
:-Atte

    No.  I think if that user-timer-1 option works you should just stick with
    it.

    Obviously I should add support for other timebases, despite the fact that
    most of them are broken.  I think FreeBSD did get that one right though
    their support infrastructure is ridiculously complex for the purpose.
    e.g. the ACPI timer (which is an unlatched ripple counter on many chipsets
    and thus cannot simply be read once to get a stable value), and the LAPIC
    timer.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>





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