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KGDB(1) FreeBSD 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
identical 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
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.
FreeBSD 14.0-RELEASE-p11 October 11, 2006 FreeBSD 14.0-RELEASE-p11