Date: 12 May 1998 21:47:08 +0200 From: dag-erli@ifi.uio.no (Dag-Erling Coidan =?iso-8859-1?Q?Sm=F8rgrav?= ) To: Andrew Short <Ashort@concentric.net> Cc: stable@FreeBSD.ORG Subject: Re: PPP hard lock in 2.2.6 Message-ID: <xzplns76zlv.fsf@hrotti.ifi.uio.no> In-Reply-To: Andrew Short's message of "Tue, 12 May 1998 14:00:37 -0400 (EDT)" References: <Pine.SUN.3.96.980512135132.23087D-100000@galileo.cris.com>
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Andrew Short <Ashort@concentric.net> writes: > On Tue, 12 May 1998, Forrest W. Christian wrote: > > On Tue, 12 May 1998, Brian Somers wrote: > > > It's not a problem I've seen. It's *very* unlikely that ppp is > > > wedging the whole machine :-/ but possible I guess... > My (I use it at work, I am not lucky enough to OWN one!) Sun UltraSparc > has a feature that will arrest control from the OS by doing a Stop-A on > the keyboard. Now, I'm not an expert on Sun internals, but UiO is mainly a Sun shop so: what this does is generate a (nonmaskable) interrupt which drops the machine into the BIOS prompt. This is entirely hardware-driven and AFAIK non-intrusive (i.e. if you press Stop-A by accident, just type 'c' to resume operation) except that it f*s up your display. There is no way to do this on a PC, unless some bright motherboard vendor somes up with the idea of producing a motherboard that e.g. drops to a BIOS prompt when the keyboard controller (i8042) asserts the reset pin (which is how FreeBSD reboots when you fastboot or shutdown -r) and somebody builds a keyboard with a key (or preferably a switch hidden underneath the keyboard) which triggers this event. I tried to find information about the 8042 on Intel's web site, but there doesn't seem to be any (except for references to it in chipset or motherboard datasheets). > I have a gut feeling that "stop-a" is somehow embedded in the Sparc > hardware...but I have to ask. It is. -- Noone else has a .sig like this one. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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