Re: [PATCH] NMI trap revised (was Re: NMI errors in 2.0.30??)

Mark H. Wood (mwood@mhw.OIT.IUPUI.EDU)
Thu, 15 May 1997 13:10:41 -0500 (EST)


On Fri, 9 May 1997, Riccardo Facchetti wrote:

> On Fri, 9 May 1997 tenthumbs@cybernex.net wrote:
>
> >
> > On Fri, 9 May 1997 17:01:56 +0200, you wrote:
> >
> > > After studying lots of specs and testing it on several motherboards, it
> > > seems that those bits are implemented almost everywhere and hard-wired to zeroes
> > > on the remaining MB's. We probably should honor them and report the reason
> > > to the user if we find any.
> > >
> >
> > Well, I have very little faith in motherboard manufacturers and BIOS writers, so
> > I wouldn't believe anything I didn't set myself.
>
> This is not a point. The BIOS setup is done by you with your hands. You
> can decide to enable/disable the NMIs and enable/disable Parity or ECC
> checks. Since this configuration is alredy done by the BIOS, which tests
> the machine before booting it, you should be confident that when the "Now
> booting the kernel" message is displayed, the machine is reasonably set
> up. No kernel initialization is needed, and forcing some initialization
> not done at BIOS stage can be very dangerous (See my PATCH3 e-mail
> about NMI tests with non-NMI memory).

Unless you have a BIOS that doesn't have all these fancy setups. The
Phoenix BIOS on my DECpc LPX has no controls for parity, memory timing,
or any of the other things people are always telling me to set. It will
set the clock, turn ROM shadowing and caching on and off, and that's
about it.

Mark H. Wood, Lead System Programmer MWOOD@INDYVAX.IUPUI.EDU
Those who will not learn from history are doomed to reimplement it.