Browse Prior Art Database

Safe-Guarding Initial Program Loading of Personal Computer Work Stations

IP.com Disclosure Number: IPCOM000113597D
Original Publication Date: 1994-Sep-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Bramnick, AH: AUTHOR [+3]

Abstract

Described is a software implementation that provides a method of safe-guarding the Initial Program Loading (IPL) operations of Personal Computer (PC) work stations. The implementation utilizes a non-maskable interrupt function to ensure un-interrupted IPL loading operations.

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This is the abbreviated version, containing approximately 56% of the total text.

Safe-Guarding Initial Program Loading of Personal Computer Work Stations

      Described is a software implementation that provides a method
of safe-guarding the Initial Program Loading (IPL) operations of
Personal Computer (PC) work stations.  The implementation utilizes a
non-maskable interrupt function to ensure un-interrupted IPL loading
operations.

      In prior art, PC work stations could be rendered unusable due
to possible lock-up situations when running distributed software.
The possible lock-up situation could occur during the first IPL after
an installation, or upgrade, of an operating system.  The lock-up was
typically a result of remote installation of the operating system
software, or as a result of an unusual transient event occurring
during an IPL, such as a power outage.  Recovery was difficult since
the system code never was able to get control of the work station.

      The concept described herein eliminates the possible lockup
situation through the use of the already installed watch-dog timers.
Typically, watch-dog timer devices will be activated in the event of
a transient occurrence.  The concept inserts programming logic early
in the IPL sequence stages of the loading operations.  When
activated, an arm of the watch-dog timer, with its user definable
time-out value, will generate a Non-Maskable Interrupt (NMI) at a
particular time.  The loading of the programming logic at IPL time
will then be given control, if the NMI is tripped...