1.\" Copyright (c) 2004 Marcel Moolenaar 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 15.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 16.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 17.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 18.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 19.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 20.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 21.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD: src/gnu/usr.bin/gdb/kgdb/kgdb.1,v 1.10 2006/10/21 17:39:35 ru Exp $ 26.\" 27.Dd May 15, 2012 28.Dt KGDB 1 29.Os 30.Sh NAME 31.Nm kgdb 32.Nd "kernel debugger" 33.Sh SYNOPSIS 34.Nm 35.Op Fl a | Fl f | Fl fullname 36.Op Fl q | Fl quiet 37.Op Fl t | Fl tui-mode 38.Op Fl v 39.Op Fl w 40.Op Fl d Ar crashdir 41.Op Fl c Ar core | Fl n Ar dumpnr | Fl r Ar device 42.Op Ar kernel Op Ar core 43.Sh DESCRIPTION 44The 45.Nm 46utility is a debugger based on 47.Xr gdb 1 48that allows debugging of kernel core files. 49.Pp 50The options are as follows: 51.Bl -tag -width ".Fl d Ar crashdir" 52.It Fl a 53Increase the annotation level. 54An annotation level of 1 features the historical 55.Fl fullname 56option of 57.Xr gdb 1 . 58This is useful when running 59.Nm 60in Emacs. 61The 62.Fl f 63or 64.Fl fullname 65options are supported for backward compatibility as well. 66.It Fl q 67Suppress printing of the banner when the debugger starts. 68The 69.Fl quiet 70form is supported for compatibility as well. 71.It Fl t 72Activate the Text User Interface (TUI). The 73.Fl tui-mode 74shows the source file, assembly output, program registers and 75gdb commands in separate text windows. It implicitly sets the 76.Fl quiet 77option as well. 78.It Fl v 79Increase verbosity. 80.It Fl w 81Opens kmem-based targets in read-write mode. 82.It Fl d Ar crashdir 83Use 84.Ar crashdir 85instead of the default, 86.Pa /var/crash 87to locate kernel core dump files in. 88The name 89.Pa vmcore. 90plus the dump number will be appended to determine 91the actual dump file name. 92.It Fl c Ar core 93Explicitly use 94.Ar core 95as the core dump file. 96.It Fl n Ar dumpnr 97Use the kernel core dump file numbered 98.Ar dumpnr 99for debugging. 100.It Fl r Ar device 101Use 102.Ar device 103to connect 104.Nm 105to for a remote debugging session. 106.El 107.Pp 108The 109.Fl c , n , 110and 111.Fl r 112options are mutually exclusive. 113.Pp 114Optionally, the name of the kernel symbol file and 115the name of the core dump file can be supplied on the 116command-line as positional arguments. 117If no kernel symbol file name has been given, the 118symbol file of the currently running kernel will be 119used. 120If no core dump file has been specified through either 121of the options or the last command-line argument, 122.Pa /dev/mem 123will be opened to allow debugging the currently running 124kernel. 125.Sh FILES 126.Bl -tag -width ".Pa /var/crash" 127.It Pa /dev/mem 128Default memory image to open if no core dump file 129has been specified. 130.It Pa /var/crash 131Default directory to locate kernel core dump files. 132.El 133.Sh SEE ALSO 134.Xr gdb 1 135.Sh HISTORY 136The 137.Nm 138utility first appeared in its current form in 139.Fx 5.3 140and was later ported to 141.Dx 1.5 . 142