xref: /freebsd/usr.sbin/config/config.8 (revision 23f282aa31e9b6fceacd449020e936e98d6f2298)
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32.\"     @(#)config.8	8.2 (Berkeley) 4/19/94
33.\" $FreeBSD$
34.\"
35.Dd April 19, 1994
36.Dt CONFIG 8
37.Os BSD 4
38.Sh NAME
39.Nm config
40.Nd build system configuration files
41.Sh SYNOPSIS
42.Nm config
43.Op Fl gpr
44.Op Fl d Ar destdir
45.Ar SYSTEM_NAME
46.Sh DESCRIPTION
47This is the old version of the
48.Nm
49program.
50It understands the old autoconfiguration scheme
51used on the HP300, i386, DECstation, and derivative platforms.
52The new version of config is used with the
53SPARC platform.
54Only the version of
55.Nm
56applicable to the architecture that you are running
57will be installed on your machine.
58.Pp
59.Nm Config
60builds a set of system configuration files from the file
61.Ar SYSTEM_NAME
62which describes
63the system to configure.
64A second file
65tells
66.Nm
67what files are needed to generate a system and
68can be augmented by configuration specific set of files
69that give alternate files for a specific machine
70(see the
71.Sx FILES
72section below).
73.Pp
74Available options and operands:
75.Bl -tag -width SYSTEM_NAME
76.It Fl d Ar destdir
77Use
78.Ar destdir
79as the output directory, instead of the default one.
80Note
81that config does not append
82.Ar SYSTEM_NAME
83to the directory given.
84.It Fl g
85Configure a system for debugging.
86.It Fl p
87Configure a system for profiling; for example,
88.Xr kgmon 8
89and
90.Xr gprof 1 .
91If two or more
92.Fl p
93options are supplied,
94.Nm
95configures a system for high resolution profiling.
96.It Fl r
97Remove the old compile directory (see below).
98.It Ar SYSTEM_NAME
99Specify the name of the system configuration file
100containing device specifications, configuration options
101and other system parameters for one system configuration.
102.El
103.Pp
104.Nm Config
105should be run from the
106.Pa conf
107subdirectory of the system source (usually
108.Pa /sys/ARCH/conf ) ,
109where
110.Pa ARCH
111represents one of the architectures supported by FreeBSD.
112.Nm Config
113creates the directory
114.Pa ../../compile/SYSTEM_NAME
115or the one given with the
116.Fl d
117option
118as necessary and places all output files there.
119If the output directory already exists and the
120.Fl r
121flag was specified, it will be removed first.
122The output of
123.Nm
124consists of a number of files; for the
125.Tn i386 ,
126they are:
127.Pa ioconf.c ,
128a description
129of what I/O devices are attached to the system;
130.Pa Makefile ,
131used by
132.Xr make 1
133in building the system;
134header files,
135definitions of
136the number of various devices that will be compiled into the system.
137.Pp
138After running
139.Nm Ns ,
140it is necessary to run
141.Dq Li make depend
142in the directory where the new makefile
143was created.
144.Nm Config
145prints a reminder of this when it completes.
146.Pp
147If any other error messages are produced by
148.Nm Ns ,
149the problems in the configuration file should be corrected and
150.Nm
151should be run again.
152Attempts to compile a system that had configuration errors
153are likely to fail.
154.Pp
155If the option "INCLUDE_CONFIG_FILE" is used in the configuration file the
156entire input file is embedded in the new kernel.  This means that
157.Xr strings 1
158can be used to extract it from a kernel:
159to extract the configuration information, use the command
160.Bd -literal
161strings kernel | grep ___
162.Ed
163.Sh DEBUG KERNELS
164Traditional BSD kernels compiled without symbols due to the heavy load on the
165system when compiling a
166.if n "debug"
167.if t ``debug''
168kernel.  A debug kernel contains complete symbols for all the source files, and
169enables an experienced kernel programmer to analyse the cause of a problem.  The
170debuggers available prior to 4.4BSD-Lite were able to find some information
171from a normal kernel;
172.Xr gdb 1
173provides very little support for normal kernels, and a debug kernel is needed
174for any meaningful analysis.
175.Pp
176For reasons of history, time and space, building a debug kernel is not the
177default with FreeBSD: a debug kernel takes up to 30% longer to build and
178requires about 30 MB of disk storage in the build directory, compared to about 6
179MB for a non-debug kernel.  A debug kernel is about 11 MB in size, compared to
180about 2 MB for a non-debug kernel.  This space is used both in the root file
181system and at run time in memory.  Use the
182.Fl g
183option to build a debug kernel.  With this option,
184.Nm
185causes two kernel files to be built in the kernel build directory:
186.Bl -bullet
187.It
188.Nm kernel.debug
189is the complete debug kernel.
190.It
191.Nm kernel
192is a copy of the kernel with the debug symbols stripped off.  This is equivalent
193to the normal non-debug kernel.
194.El
195.Pp
196There is currently little sense in installing and booting from a debug kernel,
197since the only tools available which use the symbols do not run on-line.  There
198are therefore two options for installing a debug kernel:
199.Bl -bullet
200.It
201.Nm make
202.Ar install
203installs
204.Nm kernel
205in the root file system.
206.It
207.Nm make
208.Ar install.debug
209installs
210.Nm kernel.debug
211in the root file system.
212.El
213.Sh FILES
214.Bl -tag -width /sys/i386/conf/Makefile.i386 -compact
215.It Pa /sys/conf/files
216list of common files system is built from
217.It Pa /sys/i386/conf/Makefile.i386
218generic makefile for the
219.Tn i386
220.It Pa /sys/i386/conf/files.i386
221list of
222.Tn i386
223specific files
224.It Pa /sys/i386/conf/files. Ns Em ERNIE
225list of files specific to
226.Em ERNIE
227system
228.It Pa /sys/compile/SYSTEM_NAME
229default kernel build directory for system
230.Pa SYSTEM_NAME .
231.El
232.Sh SEE ALSO
233The
234.Sx SYNOPSIS
235portion of each device in section 4.
236.Rs
237.%T "Building 4.3 BSD UNIX System with Config"
238.Re
239.Sh BUGS
240The line numbers reported in error messages are usually off by one.
241.Sh HISTORY
242The
243.Nm
244command appeared in
245.Bx 4.1 .
246