KernelDebugRef - Using Default Commands

Reprint Courtesy of International Business Machines Corporation, © International Business Machines Corporation

Kernel Debugger Reference

Introduction Installing the Kernel Debugger The T Terminal Emulator Entering the Debugger Expressions Operator Precedence Binary Operators Unary Operators Numbers Strings Symbol Files Using Kernel Debugger Commands The Breakpoint (BP) Command Breakpoint Commands External Commands Using Default Commands External Debugger Commands Setting Useful Breakpoints Debugging Kernel Device Drivers Debugging VM Start Sessions Debugging a Remote System Notices

Using Default Commands

• ##Z

This command executes the default command. The default command is a string of debugger commands that are executed any time the debugger is entered and there is no breakpoint command attached to the entry. It starts as only the R command, but any string of commands can be used.

• ##ZL

This command lists the default command.

• ##ZS <string>

This command changes the default command. If there are any errors (too long), it returns to the R command.

If you want to process through all the INT 3s in your application or test program, you can use the following command:

ZS "J (BY CS:EIP) == CC 'G';R"

This restarts execution every time you enter the debugger on an INT 3.

A watchpoint can be set up as follows:

ZS "J (WO 40:1234) == 0EED 'r'; T"

This command traces until the word at 40:1234 is equal to hex 0EED. This will not work if you are tracing through the mode-switching code in the operating system or other sections of code that cannot be traced.