Browse Prior Art Database

Initial Microcode Load Electronically Erasable ROS Update Method

IP.com Disclosure Number: IPCOM000100030D
Original Publication Date: 1990-Mar-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Clarke, RR: AUTHOR [+3]

Abstract

This article describes a technique which allows read-only storage (ROS) to be updated online and from a remote location.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 63% of the total text.

Initial Microcode Load Electronically Erasable ROS Update Method

       This article describes a technique which allows read-only
storage (ROS) to be updated online and from a remote location.

      When a problem is discovered in the ROS on a communications I/O
processor (IOP) or I/O adapter (IOA), the card must be replaced.
When this occurs in the field, card replacement can be costly.  The
technique disclosed herein will allow the ROS to be updated online,
and from a remote location.  This can also be applied in a
development or manufacturing environment.  Further, the field stock
does not have to be updated in the case of a ROS code change.

      Since the IOP and IOAs all have the electronically erasable ROS
(EEROS) chips to hold their ROS, the solution is a way to program
them online.  First, a compare routine is loaded, which determines
whether an update is required for any of the cards.  If any updates
are required, a second routine is loaded to perform the update.

      On one system, the following decisions were made:
-    Because of architecture restraints, hardware levels are not
allowed to change during 'operational' mode (normal operation).  To
avoid this problem, the update is performed at initial microcode load
(IML) time.
-    To avoid any requirement for the user to determine when an
update is necessary, the update would occur automatically at
power-on.
-    The system direct-access storage device (DASD) contains the most...