Re: software reset

Jamie Lokier (jamie@shareable.org)
Wed, 30 Apr 2003 20:31:38 +0100


Eric W. Biederman wrote:
> > On Wed, Apr 30, 2003 at 05:04:59AM -0600, Eric W. Biederman wrote:
> > >
> > > And as an interesting data point all a triple fault does on a modern
> > > system is to put the cpu in a weird stopped state. Some hardware
> > > usually the southbridge then detects this and if properly configured
> > > will trigger the reset line.
> > >
> > > I believe this may actually go back into history as far as the 486 but
> > > I have not done the researched to see how far back this behavior goes.
> >
> > Try 286. It was the fastest (actually only) way to make a 286 switch back
> > from protected to real mode.
>
> A triple fault would put a 286 into coma mode? And the hardware had to
> reset the chip?

And then, after the reset, a flag would tell the BIOS to jump directly
to application's real mode code instead of booting as usual.

-- Jamie
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