[LinuxBIOS] Timer frequencies

Myles Watson myles at pel.cs.byu.edu
Fri Oct 5 18:20:24 CEST 2007


> Subject: Re: [LinuxBIOS] Timer frequencies
> Myles Watson wrote:
> > I got Bochs to fail the same way the hardware (my Tyan s2892) fails when
> > I turned down the timer tick interrupt frequency.  I'm having trouble
> > finding the place where the timer gets set up.  (Grepping for
> > time,rtc,timer,hz, etc.)
> >
> > Can someone tell me where I can make the interrupts come at 100 Hz in
> > LinuxBIOS?
> >
> > Thanks,
> >
> > Myles
> >
> 
> 
> I believe that you are looking for calibrate_tsc() in
> cpu\x86\tsc\delay_tsc.c. That only sets up channel2. No reason you
> couldn't make changes in your mainboard but I'm not sure the setting
> will stick. I would expect the linux kernel reprogram the PIT (maybe not
> if it is using ACPI timer or HPET)?
> 

I'll check it out.  I'm actually booting Windows with ADLO, so I just need
to make it happy at boot time.

Thanks,
Myles

> Marc
> --
> Marc Jones
> Senior Firmware Engineer
> (970) 226-9684 Office
> mailto:Marc.Jones at amd.com
> http://www.amd.com/embeddedprocessors







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