xref: /freebsd/usr.sbin/config/config.8 (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
1.\" Copyright (c) 1980, 1991, 1993
2.\"	The Regents of the University of California.  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.\" 4. Neither the name of the University nor the names of its contributors
13.\"    may be used to endorse or promote products derived from this software
14.\"    without specific prior written permission.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.\"     @(#)config.8	8.2 (Berkeley) 4/19/94
29.\" $FreeBSD$
30.\"
31.Dd May 8, 2007
32.Dt CONFIG 8
33.Os
34.Sh NAME
35.Nm config
36.Nd build system configuration files
37.Sh SYNOPSIS
38.Nm
39.Op Fl CVgp
40.Op Fl d Ar destdir
41.Ar SYSTEM_NAME
42.Nm
43.Op Fl x Ar kernel
44.Sh DESCRIPTION
45.\" This is the old version of the
46.\" .Nm
47.\" utility.
48.\" It understands the old autoconfiguration scheme
49.\" used on the HP300, i386, DECstation, and derivative platforms.
50.\" The new version of
51.\" .Nm
52.\" is used with the
53.\" SPARC platform.
54.\" Only the version of
55.\" .Nm
56.\" applicable to the architecture that you are running
57.\" will be installed on your machine.
58.\" .Pp
59The
60.Nm
61utility builds a set of system configuration files from the file
62.Ar SYSTEM_NAME
63which describes
64the system to configure.
65A second file
66tells
67.Nm
68what files are needed to generate a system and
69can be augmented by configuration specific set of files
70that give alternate files for a specific machine
71(see the
72.Sx FILES
73section below).
74.Pp
75Available options and operands:
76.Bl -tag -width ".Ar SYSTEM_NAME"
77.It Fl V
78Print the
79.Nm
80version number.
81.It Fl C
82If the INCLUDE_CONFIG_FILE is present in a configuration file,
83kernel image will contain full configuration files included
84literally (preserving comments).
85This flag is kept for backward compatibility.
86.It Fl d Ar destdir
87Use
88.Ar destdir
89as the output directory, instead of the default one.
90Note that
91.Nm
92does not append
93.Ar SYSTEM_NAME
94to the directory given.
95.It Fl g
96Configure a system for debugging.
97.It Fl x Ar kernel
98Print kernel configuration file embedded into a kernel
99file.
100This option makes sense only if
101.Cd "options INCLUDE_CONFIG_FILE"
102entry was present in your configuration file.
103.It Fl p
104Configure a system for profiling; for example,
105.Xr kgmon 8
106and
107.Xr gprof 1 .
108If two or more
109.Fl p
110options are supplied,
111.Nm
112configures a system for high resolution profiling.
113.It Ar SYSTEM_NAME
114Specify the name of the system configuration file
115containing device specifications, configuration options
116and other system parameters for one system configuration.
117.El
118.Pp
119The
120.Nm
121utility should be run from the
122.Pa conf
123subdirectory of the system source (usually
124.Pa /sys/ Ns Va ARCH Ns Pa /conf ) ,
125where
126.Va ARCH
127represents one of the architectures supported by
128.Fx .
129The
130.Nm
131utility creates the directory
132.Pa ../compile/ Ns Ar SYSTEM_NAME
133or the one given with the
134.Fl d
135option
136as necessary and places all output files there.
137The output of
138.Nm
139consists of a number of files; for the
140.Tn i386 ,
141they are:
142.Pa Makefile ,
143used by
144.Xr make 1
145in building the system;
146header files,
147definitions of
148the number of various devices that will be compiled into the system.
149.Pp
150After running
151.Nm ,
152it is necessary to run
153.Dq Li make depend
154in the directory where the new makefile
155was created.
156The
157.Nm
158utility prints a reminder of this when it completes.
159.Pp
160If any other error messages are produced by
161.Nm ,
162the problems in the configuration file should be corrected and
163.Nm
164should be run again.
165Attempts to compile a system that had configuration errors
166are likely to fail.
167.Sh DEBUG KERNELS
168Traditional
169.Bx
170kernels are compiled without symbols due to the heavy load on the
171system when compiling a
172.Dq debug
173kernel.
174A debug kernel contains complete symbols for all the source files, and
175enables an experienced kernel programmer to analyse the cause of a problem.
176The
177debuggers available prior to
178.Bx 4.4 Lite
179were able to find some information
180from a normal kernel;
181.Xr gdb 1
182provides very little support for normal kernels, and a debug kernel is needed
183for any meaningful analysis.
184.Pp
185For reasons of history, time and space, building a debug kernel is not the
186default with
187.Fx :
188a debug kernel takes up to 30% longer to build and
189requires about 30 MB of disk storage in the build directory, compared to about 6
190MB for a non-debug kernel.
191A debug kernel is about 11 MB in size, compared to
192about 2 MB for a non-debug kernel.
193This space is used both in the root file
194system and at run time in memory.
195Use the
196.Fl g
197option to build a debug kernel.
198With this option,
199.Nm
200causes two kernel files to be built in the kernel build directory:
201.Bl -bullet
202.It
203.Pa kernel.debug
204is the complete debug kernel.
205.It
206.Pa kernel
207is a copy of the kernel with the debug symbols stripped off.
208This is equivalent
209to the normal non-debug kernel.
210.El
211.Pp
212There is currently little sense in installing and booting from a debug kernel,
213since the only tools available which use the symbols do not run on-line.
214There
215are therefore two options for installing a debug kernel:
216.Bl -bullet
217.It
218.Dq Li "make install"
219installs
220.Pa kernel
221in the root file system.
222.It
223.Dq Li "make install.debug"
224installs
225.Pa kernel.debug
226in the root file system.
227.El
228.Sh FILES
229.Bl -tag -width ".Pa /sys/ Ns Va ARCH Ns Pa /compile/ Ns Ar SYSTEM_NAME" -compact
230.It Pa /sys/conf/files
231list of common files system is built from
232.It Pa /sys/conf/Makefile. Ns Va ARCH
233generic makefile for the
234.Va ARCH
235.It Pa /sys/conf/files. Ns Va ARCH
236list of
237.Va ARCH
238specific files
239.It Pa /sys/ Ns Va ARCH Ns Pa /compile/ Ns Ar SYSTEM_NAME
240default kernel build directory for system
241.Ar SYSTEM_NAME
242on
243.Va ARCH .
244.El
245.Sh SEE ALSO
246.Xr config 5
247.Pp
248The
249.Sx SYNOPSIS
250portion of each device in section 4.
251.Rs
252.%T "Building 4.3 BSD UNIX System with Config"
253.Re
254.Sh HISTORY
255The
256.Nm
257utility appeared in
258.Bx 4.1 .
259.Pp
260Before support for
261.Fl x
262was introduced,
263.Cd "options INCLUDE_CONFIG_FILE"
264included entire configuration file that used to be embedded in
265the new kernel.
266This meant that
267.Xr strings 1
268could be used to extract it from a kernel:
269to extract the configuration information, you had to use
270the command:
271.Pp
272.Dl "strings -n 3 kernel | sed -n 's/^___//p'"
273.Sh BUGS
274The line numbers reported in error messages are usually off by one.
275