NAME
kgdb
—
kernel debugger
SYNOPSIS
kgdb |
[-a | -f |
-fullname ] [-q |
-quiet ] [-t |
-tui-mode ] [-v ]
[-w ] [-d
crashdir] [-c
core | -n
dumpnr | -r
device] [kernel
[core]] |
DESCRIPTION
Thekgdb
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 runningkgdb
in Emacs. The-f
or-fullname
options are supported for backward compatibility as well. -q
- Suppress printing of the banner when the debugger starts. The
-quiet
form is supported for compatibility as well. -t
- Activate the Text User Interface (TUI). The
-tui-mode
shows the source file, assembly output, program registers and gdb commands in separate text windows. It implicitly sets the-quiet
option as well. -v
- Increase verbosity.
-w
- Opens kmem-based targets in read-write mode.
-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.
SEE ALSO
HISTORY
The kgdb
utility first appeared in its
current form in FreeBSD 5.3 and was later ported to
DragonFly 1.5.