The
utility builds a set of system configuration files from the file
SYSTEM_NAME
which describes
the system to configure.
A second file
tells
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
Sx FILES
section below).
Available options and operands:
-V
Print the
version number.
-C
If the INCLUDE_CONFIG_FILE is present in a configuration file,
kernel image will contain full configuration files included
literally (preserving comments).
This flag is kept for backward compatibility.
-d destdir
Use
destdir
as the output directory, instead of the default one.
Note that
does not append
SYSTEM_NAME
to the directory given.
-g
Configure a system for debugging.
-x kernel
Print kernel configuration file embedded into a kernel
file.
This option makes sense only if
options INCLUDE_CONFIG_FILE
entry was present in your configuration file.
-p
Configure a system for profiling; for example,
kgmon(8)
and
gprof(1).
If two or more
-p
options are supplied,
configures a system for high resolution profiling.
SYSTEM_NAME
Specify the name of the system configuration file
containing device specifications, configuration options
and other system parameters for one system configuration.
The
utility should be run from the
conf
subdirectory of the system source (usually
/sys/ ARCH /conf
where
ARCH
represents one of the architectures supported by
Fx .
The
utility creates the directory
../compile/ SYSTEM_NAME
or the one given with the
-d
option
as necessary and places all output files there.
The output of
consists of a number of files; for the
i386
they are:
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
,
it is necessary to run
``make depend
''
in the directory where the new makefile
was created.
The
utility prints a reminder of this when it completes.
If any other error messages are produced by
,
the problems in the configuration file should be corrected and
should be run again.
Attempts to compile a system that had configuration errors
are likely to fail.
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
BSD 4.4 Lite
were able to find some information
from a normal kernel;
gdb(1)
provides very little support for normal kernels, and a debug kernel is needed
for any meaningful analysis.
For reasons of history, time and space, building a debug kernel is not the
default with
Fx :
a debug kernel takes up to 30% longer to build and
requires about 30 MB of disk storage in the build directory, compared to about 6
MB for a non-debug kernel.
A debug kernel is about 11 MB in size, compared to
about 2 MB for a non-debug kernel.
This space is used both in the root file
system and at run time in memory.
Use the
-g
option to build a debug kernel.
With this option,
causes two kernel files to be built in the kernel build directory:
kernel.debug
is the complete debug kernel.
kernel
is a copy of the kernel with the debug symbols stripped off.
This is equivalent
to the normal non-debug kernel.
There is currently little sense in installing and booting from a debug kernel,
since the only tools available which use the symbols do not run on-line.
There
are therefore two options for installing a debug kernel:
``make install
''
installs
kernel
in the root file system.
``make install.debug
''
installs
kernel.debug
in the root file system.
FILES
/sys/conf/files
list of common files system is built from
/sys/conf/Makefile. ARCH
generic makefile for the
ARCH
/sys/conf/files. ARCH
list of
ARCH
specific files
/sys/ ARCH /compile/ SYSTEM_NAME
default kernel build directory for system
SYSTEM_NAME
on
ARCH
The
Sx SYNOPSIS
portion of each device in section 4.
"Building 4.3 BSD UNIX System with Config"
HISTORY
The
utility appeared in
BSD 4.1
Before support for
-x
was introduced,
options INCLUDE_CONFIG_FILE
included entire configuration file that used to be embedded in
the new kernel.
This meant that
strings(1)
could be used to extract it from a kernel:
to extract the configuration information, you had to use
the command:
"strings -n 3 kernel | sed -n 's/^___//p'"
BUGS
The line numbers reported in error messages are usually off by one.
