NAME
config —
build system configuration
files
SYNOPSIS
config |
[-gr] [-d
destdir] SYSTEM_NAME |
DESCRIPTION
Theconfig 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 augmented by configuration
specific set of files that give alternate files for a specific machine (see
the FILES section below).
Available options and operands:
-ddestdir- Use destdir as the output directory, instead of the
default one. Note that
configdoes not append SYSTEM_NAME to the directory given. -g- Configure a system for debugging.
-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 system 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
output of config consists of a number of files; for
the x86_64 architecture, 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, definitions 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 directory
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
configuration 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 contains complete symbols for all the source files, and enables an experienced 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 wishing 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), unless NO_KERNEL_OLD_STRIP is set in make.conf(5).
FILES
- /sys/conf/files
- list of common files system is built from
- /sys/config/SYSTEM_NAME
- default location for kernel configuration file
- /sys/config/LINT64
- kernel configuration file for checking all the sources, includes description of kernel configuration options
- /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 ALSO
gprof(1), kgdb(1), make(1), kernconf(5), build(7), vkernel(7)
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.