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From: "Rodney W. Grimes" <rgrimes@gndrsh.aac.dev.com>
Message-Id: <199504190029.RAA00537@gndrsh.aac.dev.com>
Subject: Fix for motherboards that don't reboot.
To: current@FreeBSD.org
Date: Tue, 18 Apr 1995 17:29:49 -0700 (PDT)
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I spent some time talking with a BIOS engineer today about the problem
of FreeBSD not rebooting on some motherboards and have come up with
the following patch that fixes the problem on the board I have here.

Could others who are having this problem please apply this patch and
let me know if it fixes your problem too?

I am also interested in other boards that don't have this problem if
you can see if it ever does the ``Keyboard reset did not work'' thing.

If we can't produce that message on any board we have probably fixed
this problem once and for all.

The BIOS engineer I was working with claims that this should work for
all BIOS's include MCA machines.

Index: vm_machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/i386/i386/vm_machdep.c,v
retrieving revision 1.35
diff -c -r1.35 vm_machdep.c
*** 1.35	1995/03/19 14:28:41
--- vm_machdep.c	1995/04/18 22:44:31
***************
*** 50,61 ****
--- 50,64 ----
  #include <sys/vnode.h>
  #include <sys/user.h>
  
+ #include <machine/clock.h>
  #include <machine/cpu.h>
  #include <machine/md_var.h>
  
  #include <vm/vm.h>
  #include <vm/vm_kern.h>
  
+ #include <i386/isa/isa.h>
+ 
  #ifdef BOUNCE_BUFFERS
  vm_map_t	io_map;
  volatile int	kvasfreecnt;
***************
*** 803,808 ****
--- 806,817 ----
   */
  void
  cpu_reset() {
+ 
+ 	/* Attempt to do a CPU reset via the keyboard controller */
+ 	outb(IO_KBD + 4, 0xFE);
+ 	DELAY(500000);	/* wait 0.5 sec to see if that did it */
+ 	printf("Keyboard reset did not work, attempting CPU shutdown\n");
+ 	DELAY(1000000);	/* wait 1 sec for printf to complete */
  
  	/* force a shutdown by unmapping entire address space ! */
  	bzero((caddr_t) PTD, NBPG);
-- 
Rod Grimes                                      rgrimes@gndrsh.aac.dev.com
Accurate Automation Company                   Custom computers for FreeBSD