Kernel Extensions and Device Support Programming Concepts

Using the KDB Kernel Debug Program

This section contains the following sections:

The example files provide a demonstration kernel extension and a program to load, execute, and unload the extension. These programs may be compiled, linked, and executed as indicated in the following material. Note, to use these programs to follow the examples you need a machine with a C compiler, a console, and running with a KDB kernel enabled for debugging. To use the KDB Kernel Debugger you will need exclusive use of the machine.

Examples using the KDB Kernel Debugger with the demonstration programs are included in each of the following sections. The examples are shown in tables which contain two columns. The first column of the table contains an indication of the system prompt and the user input to perform each step. The second column of each table explains the function of the command and includes example output, where applicable. In the examples, since only the console is used, the demo program is switched between the background and the foreground as needed.

Example Files

The files listed below are used in examples throughout this section.

demo.c - Source program to load, execute, and unload a demonstration kernel extension.
demokext.c - Source for a demonstration kernel extension
demo.h - Include file used by demo.c and demokext.c
demokext.exp - Export file for linking demokext
comp_link - Example script to build demonstration program and kernel extension

To build the demonstration programs:

Save each of the above files in a directory
As the root user, execute the comp_link script

This script produces:

An executable file demo
An executable file demokext
A list file demokext.lst
A map file demokext.map

The following sections describe compilation and link options used in the comp_link script in more detail and also cover using the map and list files.