Browse Prior Art Database

Capturing Ring 0 Device Driver Data to an ASCII File

IP.com Disclosure Number: IPCOM000110579D
Original Publication Date: 1992-Dec-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 1 page(s) / 52K

Publishing Venue

IBM

Related People

Heimsoth, DD: AUTHOR [+3]

Abstract

A method is described to capture run-time OS/2* device driver Ring 0 data to an ASCII file to be inspected and manipulated. Ring 0 code cannot perform file Input/Output, but Ring 3 code can perform file Input/Output.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 62% of the total text.

Capturing Ring 0 Device Driver Data to an ASCII File

       A method is described to capture run-time OS/2* device
driver Ring 0 data to an ASCII file to be inspected and manipulated.
Ring 0 code cannot perform file Input/Output, but Ring 3 code can
perform file Input/Output.

      Many OS/2 device driver developers have a need to capture Ring
0 data in an ASCII file for efficient manipulation and problem
determination.  Prior to this method a second machine used as a debug
terminal was required or the system in question required a re-IPL.
For example, if a device driver developer creates a Ring 0 data area
for a device driver and needs to examine its contents during run-time
execution, a likely course of action was: install a debug kernel on
the machine which is of interest, install a debug terminal to monitor
execution and hold the log, create a log file, and dump the data area
to disk.  Another course of action was the OS/2 TRAPDUMP facility
which allows a user to dump all of physical memory to diskette by
hitting a predefined key sequence.

      This procedure requires a system reboot as well as searching
through all of memory for the data in question.

      To eliminate the necessity of installing the debug equipment,
code is included in either the device driver's strategy section or a
separate device driver to field a DosDevIOCtl from a Ring 3
application program.  The function of the DosDevIOCtl is to provide
the Ring 0 device driver with memor...