CONFIG(8) BSD System Manager's Manual CONFIG(8)NAMEconfig — build system configuration files
SYNOPSISconfig [-gpr] [-d destdir] SYSTEM_NAME
DESCRIPTION
The config utility builds a set of system configuration files from the
file SYSTEM_NAME which describes the system to configure. A second file
tells config what files are needed to generate a system and can be aug‐
mented by configuration specific set of files that give alternate files
for a specific machine (see the FILES section below).
Available options and operands:
-d destdir Use destdir as the output directory, instead of the default
one. Note that config does not append SYSTEM_NAME to the
directory given.
-g Configure a system for debugging.
-p Configure a system for profiling; for example, kgmon(8) and
gprof(1). If two or more -p options are supplied, config
configures a system for high resolution profiling.
-r Remove the old compile directory (see below).
SYSTEM_NAME Specify the name of the system configuration file containing
device specifications, configuration options and other sys‐
tem parameters for one system configuration.
config should be run from the config subdirectory of the system source
(usually /sys/config). config creates the directory
../compile/SYSTEM_NAME or the one given with the -d option as necessary
and places all output files there. If the output directory already
exists and the -r flag was specified, it will be removed first. The out‐
put of config consists of a number of files; for the i386, they are:
ioconf.c, a description of what I/O devices are attached to the system;
Makefile, used by make(1) in building the system; header files, defini‐
tions of the number of various devices that will be compiled into the
system.
After running config, it is necessary to run “make depend” in the direc‐
tory where the new makefile was created.
If any other error messages are produced by config, the problems in the
configuration file should be corrected and config should be run again.
Attempts to compile a system that had configuration errors are likely to
fail.
If the options INCLUDE_CONFIG_FILE is used in the configuration file the
entire input file is embedded in the new kernel. This means that
strings(1) can be used to extract it from a kernel: to extract the con‐
figuration information, use the command
strings -n 3 kernel | sed -n 's/^___//p'
DEBUG KERNELS
Traditional BSD kernels are compiled without symbols due to the heavy
load on the system when compiling a “debug” kernel. A debug kernel con‐
tains complete symbols for all the source files, and enables an experi‐
enced kernel programmer to analyse the cause of a problem. The debuggers
available prior to 4.4BSD-Lite were able to find some information from a
normal kernel; kgdb(1) provides very little support for normal kernels,
and a debug kernel is needed for any meaningful analysis.
In order to ease posting bug reports for inexperienced users and make the
debugging environment more uniform, DragonFly installs kernel and modules
unstripped. Debug information is not loaded into memory, so the only
impact is a growth in root file-system consumption by 60MB. Those wish‐
ing to install stripped down kernel and modules can specify two new
makeoptions in their kernel config file or when they run the kernel-
related targets to make:
INSTALLSTRIPPED=1 The installed kernel and modules will be
stripped of debug info.
INSTALLSTRIPPEDMODULES=1 The installed modules will be stripped of debug
info. The kernel will be left with debug info
intact.
Backup copies of the kernel and modules are automatically stripped of
their debug information by objcopy(1).
FILES
/sys/conf/files list of common files system is
built from
/sys/config/SYSTEM_NAME default location for kernel config‐
uration file
/sys/config/GENERIC default i386 kernel configuration
file
/sys/config/LINT kernel configuration file for
checking all the sources, includes
description of kernel configuration
options
/sys/config/SOEKRIS kernel configuration file for the
Soekris Engineering net5501 board
/sys/config/VKERNEL default 32 bit vkernel(7) kernel
configuration file
/sys/config/VKERNEL64 default 64 bit vkernel(7) kernel
configuration file
/sys/config/X86_64_GENERIC default x86_64 kernel configuration
file
/sys/compile/SYSTEM_NAME default kernel build directory for
system SYSTEM_NAME
/sys/platform/PLATFORM/conf/Makefile generic makefile for the PLATFORM
/sys/platform/PLATFORM/conf/files list of PLATFORM specific files
SEE ALSOgprof(1), kgdb(1), make(1), kernconf(5), build(7), vkernel(7), kgmon(8)
The SYNOPSIS portion of each device in section 4.
Building 4.3 BSD UNIX System with Config.
HISTORY
The config utility appeared in 4.1BSD.
BUGS
The line numbers reported in error messages are usually off by one.
BSD March 28, 2010 BSD
