Conference 49.910::kav30

153.0. "Special request from AEON regarding disk boot f/w" by ZYDECO::BODA (Realtime Expertise Center) Thu Jun 08 1995 21:49

From:	ZYDECO::BODA         "Alan T Boda * Realtime Expertise Center *"  8-JUN-1995 14:47:20.59
To:	EICMFG::KAV30_SUPP, HELIX::ELN
CC:	BODA
Subj:	AEON making a request about our KAV30 disk boot - for a common customer

Hi,

During the past week I've been working an issue for OWENS-ILLINOIS INC.
They are using VAXELN V4.5 on AEON's VME300 (rtVAX-300 based) target.
The problem in a nutshell:

	- User application references a shareable image.
	- Shareable image (written in C) has initialized string variables.
	- When booting system image from ethernet, at runtime, all is fine.
	- If they boot from disk, when the user job that references the
	  shareable is created, the initialized string variables in the
	  shareable have been cleared.  Note: prior to the job creation,
	  the shareable's string variables are intact with the proper values.

Using their exact simple test program, I could not replicate the problem
using a KAV30 booting from disk.  Also, since we both were using the
VAXELN kit generic rtVAX-300 kernel (300KER.EXE), this rules out AEON's
VME300 kernel.  This started pointing to the disk boot code in the VME300
firmware.  So they contacted AEON. 

Mike Hoy of AEON then called me.  He has replicated what Owens-Illinois is
seeing.  AEON cannot figure out what they might be doing incorrectly in their
disk boot code.  Mike said they don't attempt to interpret anything in the
disk boot load and they start execution at %x1800.

My hypothesis is that a shareable image KSD has been corrupted somehow
by the disk load sequence and appears as a demand zero section. This would
result in the string being cleared.

AEON has made a special request that I check with VAXELN engineering or KAV30
engineering for suggestions regarding special situations that need to be
considered in the disk boot sequence?  Unfortunately, Owens-Illinois is
about to release their updated software, but can do so only to their customers
who have ethernet boot capability.

Thanks for any assistance you can give.

Regards,

Alan

P.S. Also cross-posted in the KAV30 notes conference.

FYI,

	For unknown reasons, there are problems when booting from disk with
AEON's VME300.  Runtime problems occur when the system image contains shareable
images that do not have the EXE psect attribute.  Runtime problems include
those as described in the base note.  We've even had another customer using
the AEON VME300 when they included internet services.  A sporadic access 
violation occurred in the EZDRIVER when internet services were included and 
when they booted from the VME300 disk.  The accvio did not occur when booting
from ether (system image rebuilt for ether boot).  We resolved this problem 
for AEON by providing the customer with an EZDRIVER that was linked against
object libraries rather than shareable libraries.

Presently AEON has no explanation why this is happening when using their
disk boot.  None of these symptoms occur with a KAV30 diskboot.

Alan