[Alug] Kernel Dumping garbage to Port 80h

Wayne Stallwood wayne.stallwood at btinternet.com
Mon Sep 23 01:08:01 BST 2002


How about rather than getting the cpu_khz from the system map, using the 
Bogomips value, Isn't the kernel already aware of this (I thought it used 
bogomips for some other timing)

But I may give your suggestion a go anyway

Cheers

Wayne

On Sunday 22 September 2002 23:09, Paul wrote:
> Hi Wayne
>
> Another alternative to generating a delay of a fixed period would be to use
> the 8254 or the APIC timer - Neither is a portable solution, and both
> liable to lcoking up the system if you are not carefull. On balance,
> perhaps dummy IO writes is the easiest method...
>
> On the other hand, a software loop might avoid any IO conflicts..
>
> extern unsigned long cpu_khz;	/* clock frequency exported by the kernel */
> /* grep /boot/System.map for it - It should be there for 2.4.x kernels. */
> for (t=0; t<(time_delay/cpu_khz; t++) ;
>
>
> Regards, Paul.
>
> On Sunday 22 Sep 2002 9:15 pm, Wayne Stallwood wrote:
> > I thought that a sleep call would be the obvious solution, but I keep
> > thinking that there is a reason Linus didn't do this, I was put off the
> > dummy jumps as Linus infers that this causes a problem on faster
> > machines, given that this was written at a time when a P500 was a fast
> > machine and I am sitting on a 1Ghz Athlon I think there may be some issue
> > with doing this.
>
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