xref: /freebsd/usr.sbin/config/config.8 (revision a14a0223ae1b172e96dd2a1d849e22026a98b692)
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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.Pp
76.Bl -tag -width SYSTEM_NAME
77.It Fl d Ar destdir
78Use
79.Ar destdir
80as the output directory, instead of the default one. Note
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
99Specifies 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 vector.h ,
131definitions of
132macros related to counting interrupts;
133.Pa Makefile ,
134used by
135.Xr make 1
136in building the system;
137header files,
138definitions of
139the number of various devices that will be compiled into the system;
140so-called swap configuration files,
141definitions for
142the disk areas to be used for the root file system
143and system dumps.
144.Pp
145After running
146.Nm config ,
147it is necessary to run
148.Dq Li make depend
149in the directory where the new makefile
150was created.
151.Nm Config
152prints a reminder of this when it completes.
153.Pp
154If any other error messages are produced by
155.Nm config ,
156the problems in the configuration file should be corrected and
157.Nm
158should be run again.
159Attempts to compile a system that had configuration errors
160are likely to fail.
161.Pp
162If the option "INCLUDE_CONFIG_FILE" is used in the configuration file the
163entire input file is embedded in the new kernel.  This means that
164.Xr strings 1
165can be used to extract it from a kernel:
166to extract the configuration information, use the command
167.Bd -literal
168strings kernel | grep ___
169.Ed
170.Sh DEBUG KERNELS
171Traditional BSD kernels compiled without symbols due to the heavy load on the
172system when compiling a
173.if n "debug"
174.if t ``debug''
175kernel.  A debug kernel contains complete symbols for all the source files, and
176enables an experienced kernel programmer to analyse the cause of a problem.  The
177debuggers available prior to 4.4BSD-Lite were able to find some information
178from a normal kernel;
179.Xr gdb 1
180provides very little support for normal kernels, and a debug kernel is needed
181for any meaningful analysis.
182.Pp
183For reasons of history, time and space, building a debug kernel is not the
184default with FreeBSD: a debug kernel takes up to 30% longer to build and
185requires about 30 MB of disk storage in the build directory, compared to about 6
186MB for a non-debug kernel.  A debug kernel is about 11 MB in size, compared to
187about 2 MB for a non-debug kernel.  This space is used both in the root file
188system and at run time in memory.  Use the
189.Fl g
190option to build a debug kernel.  With this option,
191.Nm
192causes two kernel files to be built in the kernel build directory:
193.Bl -bullet
194.It
195.Nm kernel.debug
196is the complete debug kernel.
197.It
198.Nm kernel
199is a copy of the kernel with the debug symbols stripped off.  This is equivalent
200to the normal non-debug kernel.
201.El
202.Pp
203There is currently little sense in installing and booting from a debug kernel,
204since the only tools available which use the symbols do not run on-line.  There
205are therefore two options for installing a debug kernel:
206.Bl -bullet
207.It
208.Nm make
209.Ar install
210installs
211.Nm kernel
212in the root file system.
213.It
214.Nm make
215.Ar install.debug
216installs
217.Nm kernel.debug
218in the root file system.
219.El
220.Sh FILES
221.Bl -tag -width /sys/i386/conf/Makefile.i386 -compact
222.It Pa /sys/conf/files
223list of common files system is built from
224.It Pa /sys/i386/conf/Makefile.i386
225generic makefile for the
226.Tn i386
227.It Pa /sys/i386/conf/files.i386
228list of
229.Tn i386
230specific files
231.It Pa /sys/i386/conf/files. Ns Em ERNIE
232list of files specific to
233.Em ERNIE
234system
235.It Pa /sys/compile/SYSTEM_NAME
236default kernel build directory for system
237.Pa SYSTEM_NAME .
238.El
239.Sh SEE ALSO
240The SYNOPSIS portion of each device in section 4.
241.Rs
242.%T "Building 4.3 BSD UNIX System with Config"
243.Re
244.Sh BUGS
245The line numbers reported in error messages are usually off by one.
246.Sh HISTORY
247The
248.Nm
249command appeared in
250.Bx 4.1 .
251