SUMMARY: ELC won't boot

From: Stewart Castaldi (
Date: Fri Dec 13 1991 - 23:21:08 CST

Original message:
> Here is a neat little problem. We received a brand new ELC this morning
> to replace an SLC. The SLC has a Bridgeway Model# 55203 425MB SCSI disk
> (also known by format as a SEAGATE ST2502N) with SunOS 4.1.1 on it. So we
> simply swapped the SLC and the ELC and attempted to boot. The ELC will
> not boot off of the drive and either hangs or returns the following error
> message:
> Boot disk: Bad magic number in disk label
> Can't open Sun disk label package
> boot-block startup failed
> illegal instruction
> Anyone had a similiar experience, know how to correct this?
> Things we have done:
> 1) Booted the ELC from a brand new 207MB Sun disk.
> 2) Reinstalled the boot block on the Bridgeway disk.
> 3) Rebooted the SLC off of the Bridgeway disk with no problem.
> 4) Changed SCSI cables.
> 5) Installed external SCSI terminator on Bridgeway disk (even though the
> internal terminator was never removed).
> 6) Called Sun support. They are checking out a program to put in the
> NVRAM at this moment.


Following is a solution that was forwarded after passing through two other
sites that encountered the same problem, although with a different disk.


Executive summary:
        Problem is due to a Wren VII firmware bug.
        There is a simple workaround.

The Wren VII drive screws up when issued a "spin up" command with the
"immediate" bit set. Sometime after that command is issued, a subsequent
command will fail (the particular command which fails is a "read", reporting
an "internal target error" status).

The problem does not occur if the "spin-up" command does not have the
immediate bit set. (The immediate bit, when set, means that the device
should start the operation and then complete the SCSI transaction, without
making the CPU waiting for the operation to complete.)

The workaround:

Add the following commands to the NVRAMRC file. The effect is to turn off
the immediate bit on the spinup command.

(program deleted)

Then power cycle. Subsequent attempts to boot from the Wren drive
should be successful.

   Daniel Phaneuf Institut de Recherche d'Hydro-Quebec 1800 Montee Ste-Julie, Varennes
   tel: +1 514-652-8074 Quebec, Canada, J3X 1S1

Here is the program slightly modified due to a suggestion in another posting
using NVRAMRC's from Alain Brossard. I have installed this on the ELC and
the Bridgeway disk has booted and been running without problems for half
a day. Please note that this MAY NOT work in every case. One person said
that their disk vendor replaced the eprom in the disk.

(from monitor level)

        ok nvedit
                0: setenv use-nvramrc? false
                1: true to fcode-debug?
                2: probe-all install-console banner
                3: cd /sd
                4: patch 0 1 sstart
                5: device-end
                6: setenv use-nvramrc? true
                7: <ctrl>C
        ok nvstore
        ok setenv usr-nvramrc? true
        ok reset (or power off/on)

Quoting Alain:

    "In nvedit, the first line is to prevent the manager from rendering
     the machine unusable if he screws up. It happened once here, my guess
     is the manager managed to write an infinite loop which prevented the
     machine from ever being able to give control back to the manager. We
     had to replace the nvram!"

My thanks to the following:
Bob Gough, uunet!!bob
Rune Trengereid, gest20.SINet.SLB.COM!runet
Shelley L. Shostak,!sls
Clemens Duepmeier, idtsun1!duepmeie
Daniel Phaneuf,

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