Method 2: Using the nm subcommand

This method using the nm subcommand. If the kernel extension is not stripped, the KDB kernel debugger can be used to locate the address of the load point by name.

For example, the nm demokext subcommand returns the address of the demokext routine after it is loaded. This address can then be used to set a breakpoint.

Note: The default prompt is KDB(0)>.
  1. To translate a symbol to an effective address, type the following:
    nm demokext

    The output is similar to the following:

    Symbol Address : 01304040
       TOC Address : 013046D4

    The value of the demokext symbol is the address of the first instruction of the demokext routine. This value can be used to set a breakpoint.

  2. Set the break at the desired location by typing the following:
    b 01304040+e0

    KDB displays the address at which the breakpoint is set.

  3. Display the word at the breakpoint by typing the following:
    dw 01304040+e0

    The results are similar to the following:

    01304120: 80830000 30840001 90830000 809F0030  ....0..........0

    This can be checked against the assembly code in the listing to verify that the break is set to the correct location.

  4. Clear all breakpoints by typing the following:
    ca