KGDB(1) 		  BSD General Commands Manual		       KGDB(1)

NAME
     kgdb — kernel debugger

SYNOPSIS
     kgdb [-a | -f | -fullname] [-b rate] [-q | -quiet] [-v] [-w]
	  [-d crashdir] [-c core | -n dumpnr | -r device] [kernel [core]]

DESCRIPTION
     The kgdb utility is a debugger based on gdb(1) that allows debugging of
     kernel core files.

     The options are as follows:

     -a 	  Increase the annotation level.  An annotation level of 1
		  features the historical -fullname option of gdb(1).  This is
		  useful when running kgdb in Emacs.  The -f or -fullname
		  options are supported for backward compatibility as well.

     -b rate	  Set the baudrate to rate.

     -q 	  Suppress printing of the banner when the debugger starts.
		  The -quiet form is supported for compatibility as well.

     -v 	  Increase verbosity.

     -w 	  Opens kmem-based targets in read-write mode.	(This is iden‐
		  tical to what --wcore used to do in previous gdb versions
		  for FreeBSD.)

     -d crashdir  Use crashdir instead of the default, /var/crash to locate
		  kernel core dump files in.  The name vmcore. plus the dump
		  number will be appended to determine the actual dump file
		  name.

     -c core	  Explicitly use core as the core dump file.

     -n dumpnr	  Use the kernel core dump file numbered dumpnr for debugging.

     -r device	  Use device to connect kgdb to for a remote debugging ses‐
		  sion.

     The -c, -n, and -r options are mutually exclusive.

     Optionally, the name of the kernel symbol file and the name of the core
     dump file can be supplied on the command-line as positional arguments.
     If no kernel symbol file name has been given, the symbol file of the cur‐
     rently running kernel will be used.  If no core dump file has been speci‐
     fied through either of the options or the last command-line argument,
     /dev/mem will be opened to allow debugging the currently running kernel.

FILES
     /dev/mem	 Default memory image to open if no core dump file has been
		 specified.

     /var/crash  Default directory to locate kernel core dump files.

SEE ALSO
     gdb(1)

HISTORY
     The kgdb utility first appeared in its current form in FreeBSD 5.3.

BSD			       October 11, 2006 			   BSD