Force the lowest CPU frequency ?

[Joel Carnat <joel%carnat.net@localhost>]

Hi,

I know speedstep is not available in netbsd/xen.
But would there be a way to force the lowest cpu frequency once for  
all, before booting the xen kernel ?

I have a small machine that can run from 1GHz to 2GHz but keeping the  
CPU @1GHz helps keep it cool and silent.
And I don't really need the 2GHz for daily use.

TIA,
    Jo