Summary Re: Memory Errors on 3/260

From: Bill Cook (
Date: Fri Oct 19 1990 - 07:53:30 CDT

The Problem:

  3/260 32M crashed several times over a couple of days with errors
  similiar to the following:

> ECC Error Register d1<INTR,INTENA,CE_ENA,CE>
> Memory Error Register d1<INTR,INTENA,CHECK,ERR00> d1<INTR,INTENA,CE_ENA,CE>
> DVMA = 0, context = 4, virtual address = f064007
> pme = a3000032, physical address = 64007
> panic: unknown memory error

The Solution:

   Presented by Kevin Thomas, Mark Morrissey, Sam Horrocks,
                Dave Uraneck, and Greg Earle.
   It is best summarized by Greg Earle, I include his reponse here

These are correctable errors (CE). There is a bug in SunOS 4.0.3 that only
affects the Sun-3/260 and 3/280 series machines (the ones with ECC memory)
that causes the system to panic with that `panic: unknown memory error' message
every time there is a memory error, even if it is correctable and the system
should just say `I found one' or say nothing at all. Call the Sun US Answer
Center and request the 4.0.3 `bigmap' patch which fixes this and one other
bug in /usr/sys/sun3/OBJ/machdep.o.

A quick hack fix (for just the `unknown memory error' part) is

yourmachine# adb -w -k /vmunix /dev/mem
memerr+0x3a?w 0x7202
_memerr+0x3a: 7201 = 7202
memerr+0x3a/w 0x7202
_memerr+0x3a: 7201 = 7202
yourmachine# adb -w /usr/sys/sun3/OBJ/machdep.o
memerr+0x3a?w 0x7202
_memerr+0x3a: 7201 = 7202

You can trust me on this; I was the first person to discover this problem,
find the cause, and develop this patch. It works.
        - Greg Earle
          Sun Microsystems, Inc. - JPL on-site Software Support

I installed the adb patch, and the system has been running fine since.

Thanks to all who responded...
     Ron Vasey
     Kevin W. Thomas
     Mark Morrissey bit!
     Sam Horrocks sam@zola.ICS.UCI.EDU
     Rich Kaul
     Jeff Nieusma nieusma@eclipse.Colorado.EDU
     Jim Ziobro
     Dave Uraneck uunet!uranus!duran
     Greg Earle earle@Sun.COM

and to those whose response is "in the mail".

William A. Cook | Image Aquisition Products Division
Mail Stop 02008 | Internet: bcook@Kodak.COM
Eastman Kodak Company |
Rochester, NY 14650-2008 |

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