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KGDB(1) 		     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]]

DEPRECATION NOTICE
     This version of kgdb is deprecated and will be removed from future versions
     of  the  FreeBSD  base  system.   A newer version of kgdb is available from
     ports or packages (devel/gdb).

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 fea-
		  tures the historical -fullname option of gdb(1).  This is use-
		  ful 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 identi-
		  cal  to  what  --wcore used to do in previous gdb versions for
		  FreeBSD.)

     -d crashdir  Use crashdir instead of the default, /var/crash to locate ker-
		  nel 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 session.

     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 currently
     running kernel will be used.  If no  core	dump  file  has  been  specified
     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.

FreeBSD 11.1			  July 5, 2017				 KGDB(1)
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