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Date: Thu, 22 Jun 1995 14:40:01 -0700
Message-Id: <199506222140.OAA27154@freefall.cdrom.com>
From: regnauld@tetard.frmug.fr.net
Reply-To: regnauld@tetard.frmug.fr.net
To: freebsd-bugs
Subject: i386/541: Alternate Reset method by unmapping ALSO broken
In-Reply-To: Your message of Thu, 22 Jun 1995 20:01:46 +0200
	<199506221801.UAA01032@tetard.freenix.fr>
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>Number:         541
>Category:       i386
>Synopsis:       Alternate Reset method by unmapping ALSO broken
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-bugs (FreeBSD bugs mailing list)
>State:          open
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Jun 22 14:40:01 1995
>Originator:     Philippe Regnauld
>Organization:
>Release:        FreeBSD 2.0-BUILT-19950615 i386
>Environment:

	- 486 DX 2/80 (*Processor is AMD*)
	- Motherboard is 30pin/72pin RAM  486 VLB Isa
	  (keyboard controller could not be located)
	- FreeBSD 2.0.5 current
	
>Description:

	Keyboard Reset supposedly bogus, and shutdown -r or reboot
	systematically produces:

	Keyboard reset did not work, attempting CPU shutdown
	
	... and then the system hangs.

	I've tried localizing the problem by inserting visual checkpoints
	in /sys/i386/i386/vm_machdep.c (line 786+)

	----
	
        /* force a shutdown by unmapping entire address space ! */
  ->    printf("Unmapping address space:");
        bzero((caddr_t) PTD, NBPG);
  ->    printf(" Done.\n");

        /* "good night, sweet prince .... <THUNK!>" */
  ->    printf("Pmap Update:");
        pmap_update();
  ->    printf(" Done.\n");

        /* NOTREACHED */
        while(1);

	---

	After recompiling a kernel and booting it, the result is this:
	
	Keyboard reset did not work, attempting CPU shutdown
	Unmapping address space:

	... and nothing more.

	Obviously bzero((caddr_t) PTD, NBPG) never makes it...
	(Pretty annoying, as I can't be away long if it crashes and
	attempts to reboot while I'm not around (like this summer...))

>How-To-Repeat:

	# shutdown -r now
	  or
	# reboot
	

>Fix:
	
	Unknown.

>Audit-Trail:
>Unformatted: