Subject: 68040 bug may cause system crash (Re: Pentium Bug may cause system crash)
To: None <current-users@NetBSD.ORG>
From: None <is@Beverly.Rhein.DE>
List: current-users
Date: 11/22/1997 14:06:44
David Jones ( wrote:
: To add more fuel to the fire: a co-worker told me about this today:
: Tell your 68040-based machine to
:     unlk a7
: and it will never speak to you again (at least until power-cycle).  I tried
: it on my HP425T.  Locked solid.
: It causes a core dump on an '030.

The latter is caused by the normal operation, and your failure to use it

unlk a7 does a  (in C language)

u_int8_t *sp;

sp = sp;
sp = *(u_int8_t **)sp;
sp += 4;

to your cpu stack.

To generate a stack where this doesnt crash the program is not entirely trivial.
link a7,#somenegativenumber might help.

	Ignatios Souvatzis