Kernel Debugger User Guide

The Kernel Debugger is essentially a replacement OS/2 Kernel module that contains an in-built debugger component. With the debugger one may halt system execution, inspect and alter memory and registers and display system control blocks. The debugger is controlled from a dump ASCII terminal (the debugging console) which is connected to the machine under test (MUT), either directly or via a modem-modem link, through one of its COMx ports. The debugger supports a comprehensive command set, which is fully described in the Kernel Debugger and Dump Formatter Command Reference.

The debug kernel is distributed in two forms:

ALLSTRICT

This version of the kernel contains all optional self diagnostic (otherwise known as strict or assertion checking) code. Besides this functional difference many of the system control blocks have extra accounting and signature fields. This has a number of consequences that may affect problem diagnosis:
• Performance characteristics will be different since extra checking and acounting is being performed.

• Memory useage will be different because of extra diagnostic code, extensions to system control blocks and in some cases additional space to cause page faults rather than overlays by erroneous code.

• Timing critical problems might not be re-createable under the ALLSTRICT kernel.

• Secondary problems may be detected or even introduced through the use of additional diagnostic code.
HSTRICT
This version of the kernel is essential the RETAIL kernel with the debugger component. It contains only a limited set of strict checking code. The system control blocks are of the same form as those used by in the RETAIL kernel. The performance characteristics of the HSTRICT kernel are closer to those of the RETAIL kernel than the ALLSTRICT kernel. For this reason the HSTRICT kernel is recommended as a first choice when diagnosing application and non-system problems.

The base version of the ALLSTRICT kernel is distributed with the OS/2 Developer's Toolkit. Versions of the HSTRICT and ALLSTRICT kernels for fix packs may be obtained from the following sources:

• The OS/2 Base Product CDROM for WARP is distributed with the ALLSTRICT kernel and Dump Formatter. (For the initial release of WARP this was only available on the US version of WARP).

• The Developer Connection CDROM - this may be ordered through the Developer Assistance Program (DAP) or the System Library Subscription Service (SLSS).

• From your local IBM Marketing Representative.

• From the World Wide Web at URL:

              ftp://service.boulder.ibm.com

• For IBM customers from by FTP from the node:

              ftp.software.ibm.com, directory ps\products\os2\fixes\debug
  

• For IBM internal users by FTP to the SDM at node:

              sdm.austin.ibm.com
  
  

  Logon using Id and Password Anonymous. A list of files is contained in files.bbs.

Note:

The Kernel Debugger packages obtainable from the SDM are equipped with an installation procedure and two text files dbsetup.txt and modemset.txt that give instructions on how to install the debugger for local and remote debugging via a modem.

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