Browse Prior Art Database

Ring Zero Messaging Facilities for OS/2 Device Drivers

IP.com Disclosure Number: IPCOM000121918D
Original Publication Date: 1991-Oct-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 1 page(s) / 43K

Publishing Venue

IBM

Related People

Musta, CA: AUTHOR

Abstract

OS/2 Device Drivers have historically had no way to output messages either to the console or to a log file while running at privilege level zero. Although this interface was originally written for LAN Transport Device Drivers, it allows message display and logging from any Ring 0 program both during its initialization, task and interrupt time processing.

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This is the abbreviated version, containing approximately 72% of the total text.

Ring Zero Messaging Facilities for OS/2 Device Drivers

      OS/2 Device Drivers have historically had no way to
output messages either to the console or to a log file while running
at privilege level zero. Although this interface was originally
written for LAN Transport Device Drivers, it allows message display
and logging from any Ring 0 program both during its initialization,
task and interrupt time processing.

      Problems related to LAN Transport tend to be costly in terms of
customer time and resources needed to isolate and fix the problem.
When a problem has been encountered one must first isolate the
failing component.  This task in itself may take days.  Many times
the component reporting a problem is not the cause.  The real cause
may be a series of events which have happened some time in the
distant past. Once the problem has been isolated it must then be
recreated using the right trace levels and debug tools.

      If a device driver had a method of logging problems encountered
during run time, the debugging effort would be greatly simplified.
Isolating and routing the problem to the appropriate development
group could be greatly enhanced, thereby taking less time to turn
around a fix to the customer.

      The system is made up of a device driver and an associated ring
three thread. Device drivers can format a message and pass it to the
Message Device Driver at its IDC AttachDD entry point or call it on a
DevIOCTl.  The message format i...