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NAME    [Toc]    [Back]

     config - build kernel compilation directories  or  modify  a

SYNOPSIS    [Toc]    [Back]

     config [-b builddir] [-p] [-s srcdir] [config-file]
     config -e [-f | -o outfile] [-u] infile

DESCRIPTION    [Toc]    [Back]

     In  the  first  synopsis  form, the config program creates a
kernel build directory
 from the  kernel  configuration  file  specified  by
config-file.  In
     the  second synopsis form, config allows editing of the kernel binary
     specified by infile.

     Furthermore, devices may be enabled, disabled,  or  modified
without recompiling,
  by  editing  the kernel executable using the -e option.  Similarly,
     you can do the same editing at boot-time, using the  in-kernel editor, as
     described in boot_config(8).

     config  is most commonly invoked from the directory containing OpenBSD
     kernel          configuration          files          (i.e.,
/usr/src/sys/arch/i386/conf for i386
     machines).   For instance, the following steps would be followed to configure
 and compile a new GENERIC kernel (assuming a complete
     source tree is available in /usr/src/sys):

           # cd /usr/src/sys/arch/i386/conf
           # config ./GENERIC
           # cd ../compile/GENERIC
           # make depend && make

     Replace ``i386'' with the appropriate architecture name.

     For kernel building, the options are as follows:

     -b builddir
             Create  the build directory in the path specified by
builddir instead
 of the default ../compile/SYSTEMNAME.

     -p      Configure for a system that includes profiling code;
see kgmon(8)
             and gprof(1).  When this option is specified, config
acts as if
             the lines ``makeoptions PROF="-pg"''  and  ``options
GPROF'' appeared
  in  the specified kernel configuration file.
In addition,
             ``.PROF'' is appended to the default compilation directory name.

             The  -p flag is expected to be used for ``one-shot''
profiles of
             existing systems; for regular profiling, it is probably wiser to
             make a separate configuration containing the makeoptions line.

     -s srcdir
             Use srcdir as the top-level kernel source  directory
instead of
             the default (four directories above the build directory).

     For kernel modification, the options are as follows:

     -e      Allows the modification of kernel device  configuration (see
             boot_config(8)).   Temporary  changes can be made to
the running
             kernel's configuration or a new kernel binary may be
written for
             permanent  changes  between system reboots.  See the
section Kernel
             modification below for more details.

     -f      Overwrite the infile kernel binary with the modified
             Otherwise,  -o  should be given to specify an alternate output

     -o outfile
             Write the modified kernel to outfile.

     -u      Check to see if the kernel configuration  was  modified at boottime
  (i.e.,  boot -c was used).  If so, compare the
running kernel
             with the kernel to be edited (infile).  If they seem
to be the
             same,  apply  all configuration changes performed at

     The old -g flag is deprecated and no longer supported.   Instead, add
     ``makeoptions DEBUG="-g"'' to the kernel configuration file,
along with
     (typically) ``options KGDB''.

     The output of config consists of a number of files,  principally ioconf.c
     (a  description  of  I/O devices that may be attached to the
system) and a
     Makefile, used by make(1) when building the kernel.

     After running config it is wise to run  ``make  depend''  in
the new build
     directory.   config  prints  a reminder of this when it completes.

     If config stops due to errors, the problems reported  should
be corrected
     and  config  should  be run again.  config attempts to avoid
changing the
     compilation directory if there are configuration errors, but
this code is
     not  well-tested  and  some problems (such as running out of
disk space) are

     If config-file is not specified, config uses the current directory as the
     build  directory,  and looks in it for a file called CONFIG.
If you run
     config this way, you must specify the location of  the  toplevel kernel
     source  directory  using  the  -s  option  or  by  using the
``source'' directive
     at the beginning of the system configuration file.

     The configuration files consists of various statements which
include the

           machine var
                   Required.  Specifies the machine architecture.

           include file
                   Include another configuration file.

           option NAME
                   Set a kernel option.  Kernel options may  take
either the
                   form  NAME  or the form NAME=value.  These options are passed
                   to the compiler with the -D flag.

           rmoption NAME
                   Delete a previously set option.  This is  useful when including
  another kernel configuration file.  A
typical use
                   is to include the GENERIC kernel provided with
each release
                   and remove options that are unwanted, thus allowing for automatic
 inclusion of new device drivers.

           maxusers number
                   Required.  Used to size various system  tables
and maximum
                   operating  conditions  in an approximate fashion.  Multiple
                   instances of this keyword  may  be  specified.
The number
                   provided  in  the  last instance will be used,
and warnings
                   will be  printed  for  each  duplicate  value.
This is convenient
 when used with the include directive.

           config  bsd  root  on  dev [swap on dev [and dev ...]]
[dumps on dev
                   [and dev ...]]
                   Required.  Specifies the swap and dump devices
which the
                   system should use.

           config bsd swap generic
                   Otherwise, if generic is specified, the system
                   generic routines to decide what should happen.

     Many  other  statements exist, and the file format is fairly
rich; for more
     information see the various configuration files included  in
the system,
     as well as files.conf(5) for the config rules base.

   Kernel modification    [Toc]    [Back]
     When  -e  is  specified, device parameters that are normally
hard-coded into
     the kernel may be changed.  This is useful to avoid the need
for kernel
     recompilation  or  rebooting.  Modifications are made to the
currently running
 kernel and can be written to a  new  kernel  binary  so
changes are preserved
 during subsequent system restarts.

     When invoked, the kernel identification is first shown.

     # config -e -o bsd.new /bsd
     OpenBSD  2.6-beta (GENERIC.rz0) #0: Mon Oct  4 03:57:22 MEST
     Enter 'help' for information

     One or more warnings may be printed before the ukc>  prompt.

           warning: no output file specified

     Neither  the  -f  nor -o option has been specified.  Changes
will be ignored.

           WARNING this kernel doesn't  contain  all  information
           WARNING the commands add and change might not work.

     The  kernel  is too old (pre OpenBSD 2.6) and cannot support
all of the
     functionality needed by the -e option.

           WARNING kernel mismatch. -u ignored.
           WARNING the running kernel version:

     config does not believe the running kernel is  the  same  as
the infile
     specified.   Since  the log of changes (from boot -c) in the
running kernel
     is kernel-specific, the -u option is ignored.

     The commands are as follows:

     add dev                         Add a device through copying

     base  8  | 10 | 16                Change the base of numbers
displayed and
                                     entered, e.g., I/O addresses
in a VAXen
                                     are octal.

     change  devno | dev              Modify one or more devices.

     disable attr val | devno | dev  Disable one or more devices.

     enable  attr val | devno | dev   Enable one or more devices.

     exit                            Exit without saving changes.

     find devno | dev                Find one or more devices.

     help                             Give a short summary of all
commands and
                                     their arguments.

     list                            Show all  known  devices,  a
screen at a

     lines  [count]                    Set the number of rows per

     quit                            Exit and save changes.

     show [attr [val]]               Show all devices  for  which
attribute attr
                                     has the value val.

     timezone  [minuteswest  [dst]]     Change  the  tz  timezone
structure.  Without
 arguments, displays  its
current value.

     cachepct  [number]                Change the BUFCACHEPERCENT
value.  Without
 arguments, displays  its
current value.

     nkmempg [number]                Change the NKMEMPAGES value.
Without arguments,
 displays  its  current value.

     shmseg  [number]                  Change  the  SHMSEG value.
Without arguments,
 displays its  current

     shmmaxpgs  [number]              Change the SHMMAXPGS value.
Without arguments,
 displays  its  current value.

EXAMPLES (First synopsis)    [Toc]    [Back]

     A custom kernel is built in the following way.

     To  compile  your own kernel from a non-writable media (such
as a CD-ROM)
     mounted on /usr/src, do the following:

           # cd /somedir
           # cp /usr/src/sys/arch/somearch/conf/SOMEFILE .
           # vi SOMEFILE   (to make any changes)
           # config -s /usr/src/sys -b . SOMEFILE
           # make

     To compile a kernel inside a writable source  tree,  do  the

           # cd /usr/src/sys/arch/somearch/conf
           # vi SOMEFILE   (to make any changes)
           # config SOMEFILE
           # cd ../compile/SOMEFILE
           # make

     where  somedir  is a writable directory, somearch is the architecture
     (e.g., i386), and SOMEFILE should be a name indicative of  a
     configuration  (often  that  of  the hostname).  config will
warn you if a
     ``make clean'' is required; you can also  do  a  ``make  depend'' so that you
     will have dependencies there the next time you do a compile.

     After either of these two methods, you  can  place  the  new
kernel (called
     bsd)  in  /  (i.e.,  /bsd)  and the system will boot it next
time.  Most people
 save their backup kernels as /bsd.1, /bsd.2, etc.

EXAMPLES (Second synopsis)    [Toc]    [Back]

     The Ethernet card is not detected at boot because the kernel
  does  not  match  the physical hardware configuration,
e.g., wrong IRQ
     in OpenBSD/i386.  The Ethernet card is supposed to  use  the
ne(4) driver.

     ukc> find ne
     24 ne0 at isa0 port 0x240 size 0 iomem 0xd8000 iosiz 0 irq 9
drq -1 drq2 -1 flags 0x0
     25 ne1 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 10 drq
-1 drq2 -1 flags 0x0
     26 ne* at isapnp0 port -1 size 0 iomem -1 iosiz 0 irq -1 drq
-1 flags 0x0
     27 ne* at pci* dev -1 function -1 flags 0x0
     28 ne* at pcmcia* function -1 irq -1 flags 0x0

     ne1 seems to match the configuration except it  uses  IRQ  5
instead of IRQ
     10.  So the irq on ne1 should be changed via the change command.  The device
 can be specified by either name or number.

     ukc> change ne1
     25 ne1 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 10 drq
-1 drq2 -1
     change (y/n) ? y
     port [0x300] ?
     size [0] ?
     iomem [-1] ?
     iosiz [0] ?
     irq [10] ? 5
     drq [-1] ?
     drq2 [-1] ?
     flags [0] ?
     25 ne1 changed
     25  ne1 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 5 drq
-1 drq2 -1 flags 0x0

     Another case is a mistakenly  detected  non-existing  device
instead of another
  device at the probed location.  One known case is the
Mitsumi CDROM
 in OpenBSD/i386.  The simplest thing to solve that problem is to disable

     ukc> find mcd0
      29  mcd0  at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 10
drq -1 drq2 -1 flags 0x0
     ukc> disable mcd0
      29 mcd0 disabled
     ukc> find 29
      29 mcd0 at isa0 disable port 0x300 size 0 iomem -1 iosiz  0
irq 10 drq -1 drq2 -1 flags 0x0

     It's  also possible to disable all devices with a common attribute. e.g.,

     ukc> disable port 0x300
      25 ne1 disabled
      29 mcd0 already disabled
      72 we1 disabled
      75 el0 disabled
      77 ie1 disabled

     The show command is useful for finding which devices have  a
certain attribute.
   It  can also be used to find those devices with a
     value for an attribute.

     ukc> show slot
       2 ahc* at eisa0 slot -1
      10 uha* at eisa0 slot -1
      12 ep0 at eisa0 slot -1
      17 ep* at eisa0 slot -1
     102 ahb* at eisa0 slot -1
     103 fea* at eisa0 slot -1
     ukc> show port 0x300
      25 ne1 at isa0 port 0x300 size 0 iomem -1 iosiz  0  irq  10
drq -1 drq2 -1 flags 0x0
      72  we1 at isa0 port 0x300 size 0 iomem 0xcc000 iosiz 0 irq
10 drq -1 drq2 -1 flags 0x0
      75 el0 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 9 drq
-1 drq2 -1 flags 0x0
      77  ie1  at  isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 10
drq -1 drq2 -1 flags 0x0

     It is possible to add new devices,  but  only  devices  that
were linked into
     the  kernel.   If  a  new device is added, following devices
will be renumbered.

     ukc> find ep
      11 ep0 at isa0 port -1 size 0 iomem -1 iosiz 0 irq  -1  drq
-1 drq2 -1 flags 0x0
      12 ep0 at eisa0 slot -1 flags 0x0
      13 ep0 at pci* dev -1 function -1 flags 0x0
      14  ep*  at  isapnp0 port -1 size 0 iomem -1 iosiz 0 irq -1
drq -1 flags 0x0
      15 ep* at isa0 port -1 size 0 iomem -1 iosiz 0 irq  -1  drq
-1 drq2 -1 flags 0x0
      16 ep* at eisa0 slot -1 flags 0x0
      17 ep* at pci* dev -1 function -1 flags 0x0
      18 ep* at pcmcia* dev -1 irq -1 flags 0x0
     ukc> add ep1
     Clone Device (DevNo, 'q' or '?') ? 13
     Insert before Device (DevNo, 'q' or '?') 14
      14 ep1 at pci* dev -1 function -1
     ukc> change 14
      14 ep1 at pci* dev -1 function -1
     change (y/n) ? y
     dev [-1] ? 14
     function [-1] ?
     flags [0] ? 18
      14 ep1 changed
      14 ep1 at pci* dev 14 function -1 flags 0x12

     When  done, exit the program with the quit or exit commands.
exit will
     ignore any changes while quit writes the changes to  outfile
(if -o or -f
     was given, else ignore changes).

     ukc> quit

SEE ALSO    [Toc]    [Back]

     options(4), files.conf(5), boot_config(8)

     The SYNOPSIS portion of each device in section 4 of the manual.

     Building 4.4 BSD Systems with Config.

HISTORY    [Toc]    [Back]

     The config program appeared in 4.1BSD.   It  was  completely
revised in
     4.4BSD.  The -e option appeared in OpenBSD 2.6.

OpenBSD      3.6                         October     15,     1999
[ Back ]
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