The debugger prompt

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All work in the KDB kernel debugger and the kdb command is performed at the debugger prompt.

On a uniprocessor system, the KDB kernel debugger prompt is KDB(0)> and the kdb command prompt is (0)>. When you are debugging a multiprocessor system, the number enclosed in parentheses indicates the processor that is being debugged. Many subcommands, such as those that display or modify registers, apply only to the current processor.

As shown in the following example, the cpu subcommand can be used to change the current processor:

(0)> dr r1
r1  : 2FF3B338   2FF3B338
(0)> cpu 1
(1)> dr r1
r1  : 2FF3AA20   2FF3AA20
(1)>

Many subcommands can produce a large amount of output. To keep the output from scrolling off the screen, the debugger implements a pager which displays a more (^C to quit) ? prompt after each full screen of data. When you see the prompt, you can do one of the following:

  • Press the space bar to view the next line of output.
  • Press the Enter key to view the next page of output.
  • Press Ctrl+C to abort the current subcommand and return to the main debugger prompt.

The pager is controlled with the set subcommand using the screen_size and scroll options. For more information, see the set subcommand.