Subject: Re: the prom: to map or not to map
To: Jason Brazile <>
From: Chris G. Demetriou <>
List: netbsd-ports
Date: 06/12/1997 11:11:31
> > At system startup time, the firmware is living in a known location in
> > VA space: that covered by the first L1 PTE.  Therefore, I squirrel
> > that away, and when necessary swap it with the 'normal' first L1 PTE
> > of the running process, do the firmware access, then swap it back.
> Hmm, the PTE of the running process.

yeah.  it's expensive (translation buffer invalidate!) and ugly, but
it works.

That technique is only used on systems which don't have 'native'
console support.