linux/Documentation/kbuild/kconfig.txt
Linus Torvalds b202c0d520 Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kconfig updates from Michal Marek:
 - dependency solver fix for make defconfig
 - randconfig fixes, one of which had to be reverted again
 - more user-friendly sorting of search results
 - hex and range keywords support longs
 - fix for [mn]conf not to rely on particular behavior of the LINES and
   COLS variables
 - cleanup of magic constants in kconfig/lxdialog
 - [mn]conf formatting fixes
 - fix for scripts/config's help text in out-of-tree usage (under a
   different name)

* 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kconfig: allow "hex" and "range" to support longs
  Revert "kconfig: fix randomising choice entries in presence of KCONFIG_ALLCONFIG"
  kconfig: fix randomising choice entries in presence of KCONFIG_ALLCONFIG
  kconfig: loop as long as we changed some symbols in randconfig
  kconfig/[mn]conf: make it explicit in the search box that a regexp is possible
  kconfig: sort found symbols by relevance
  kconfig/conf: print the seed used to initialise the RNG for randconfig
  kconfig/conf: accept a base-16 seed for randconfig
  kconfig/conf: fix randconfig setting multiple symbols in a choice
  scripts/config: replace hard-coded script name by a dynamic value
  mconf/nconf: mark empty menus/menuconfigs different from non-empty ones
  nconf: use function calls instead of ncurses' variables LINES and COLS
  mconf: use function calls instead of ncurses' variables LINES and COLS
  kconfig/lxdialog: handle newline characters in print_autowrap()
  kconfig/lxdialog: Use new mininimum resize definitions in conf_choice()
  kconfig/lxdialog: Add definitions for mininimum (re)size values
  kconfig: Fix defconfig when one choice menu selects options that another choice menu depends on
2013-07-10 16:06:46 -07:00

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This file contains some assistance for using "make *config".
Use "make help" to list all of the possible configuration targets.
The xconfig ('qconf') and menuconfig ('mconf') programs also
have embedded help text. Be sure to check it for navigation,
search, and other general help text.
======================================================================
General
--------------------------------------------------
New kernel releases often introduce new config symbols. Often more
important, new kernel releases may rename config symbols. When
this happens, using a previously working .config file and running
"make oldconfig" won't necessarily produce a working new kernel
for you, so you may find that you need to see what NEW kernel
symbols have been introduced.
To see a list of new config symbols when using "make oldconfig", use
cp user/some/old.config .config
yes "" | make oldconfig >conf.new
and the config program will list as (NEW) any new symbols that have
unknown values. Of course, the .config file is also updated with
new (default) values, so you can use:
grep "(NEW)" conf.new
to see the new config symbols or you can use diffconfig to see the
differences between the previous and new .config files:
scripts/diffconfig .config.old .config | less
______________________________________________________________________
Environment variables for '*config'
KCONFIG_CONFIG
--------------------------------------------------
This environment variable can be used to specify a default kernel config
file name to override the default name of ".config".
KCONFIG_OVERWRITECONFIG
--------------------------------------------------
If you set KCONFIG_OVERWRITECONFIG in the environment, Kconfig will not
break symlinks when .config is a symlink to somewhere else.
CONFIG_
--------------------------------------------------
If you set CONFIG_ in the environment, Kconfig will prefix all symbols
with its value when saving the configuration, instead of using the default,
"CONFIG_".
______________________________________________________________________
Environment variables for '{allyes/allmod/allno/rand}config'
KCONFIG_ALLCONFIG
--------------------------------------------------
(partially based on lkml email from/by Rob Landley, re: miniconfig)
--------------------------------------------------
The allyesconfig/allmodconfig/allnoconfig/randconfig variants can also
use the environment variable KCONFIG_ALLCONFIG as a flag or a filename
that contains config symbols that the user requires to be set to a
specific value. If KCONFIG_ALLCONFIG is used without a filename where
KCONFIG_ALLCONFIG == "" or KCONFIG_ALLCONFIG == "1", "make *config"
checks for a file named "all{yes/mod/no/def/random}.config"
(corresponding to the *config command that was used) for symbol values
that are to be forced. If this file is not found, it checks for a
file named "all.config" to contain forced values.
This enables you to create "miniature" config (miniconfig) or custom
config files containing just the config symbols that you are interested
in. Then the kernel config system generates the full .config file,
including symbols of your miniconfig file.
This 'KCONFIG_ALLCONFIG' file is a config file which contains
(usually a subset of all) preset config symbols. These variable
settings are still subject to normal dependency checks.
Examples:
KCONFIG_ALLCONFIG=custom-notebook.config make allnoconfig
or
KCONFIG_ALLCONFIG=mini.config make allnoconfig
or
make KCONFIG_ALLCONFIG=mini.config allnoconfig
These examples will disable most options (allnoconfig) but enable or
disable the options that are explicitly listed in the specified
mini-config files.
______________________________________________________________________
Environment variables for 'randconfig'
KCONFIG_SEED
--------------------------------------------------
You can set this to the integer value used to seed the RNG, if you want
to somehow debug the behaviour of the kconfig parser/frontends.
If not set, the current time will be used.
KCONFIG_PROBABILITY
--------------------------------------------------
This variable can be used to skew the probabilities. This variable can
be unset or empty, or set to three different formats:
KCONFIG_PROBABILITY y:n split y:m:n split
-----------------------------------------------------------------
unset or empty 50 : 50 33 : 33 : 34
N N : 100-N N/2 : N/2 : 100-N
[1] N:M N+M : 100-(N+M) N : M : 100-(N+M)
[2] N:M:L N : 100-N M : L : 100-(M+L)
where N, M and L are integers (in base 10) in the range [0,100], and so
that:
[1] N+M is in the range [0,100]
[2] M+L is in the range [0,100]
Examples:
KCONFIG_PROBABILITY=10
10% of booleans will be set to 'y', 90% to 'n'
5% of tristates will be set to 'y', 5% to 'm', 90% to 'n'
KCONFIG_PROBABILITY=15:25
40% of booleans will be set to 'y', 60% to 'n'
15% of tristates will be set to 'y', 25% to 'm', 60% to 'n'
KCONFIG_PROBABILITY=10:15:15
10% of booleans will be set to 'y', 90% to 'n'
15% of tristates will be set to 'y', 15% to 'm', 70% to 'n'
______________________________________________________________________
Environment variables for 'silentoldconfig'
KCONFIG_NOSILENTUPDATE
--------------------------------------------------
If this variable has a non-blank value, it prevents silent kernel
config updates (requires explicit updates).
KCONFIG_AUTOCONFIG
--------------------------------------------------
This environment variable can be set to specify the path & name of the
"auto.conf" file. Its default value is "include/config/auto.conf".
KCONFIG_TRISTATE
--------------------------------------------------
This environment variable can be set to specify the path & name of the
"tristate.conf" file. Its default value is "include/config/tristate.conf".
KCONFIG_AUTOHEADER
--------------------------------------------------
This environment variable can be set to specify the path & name of the
"autoconf.h" (header) file.
Its default value is "include/generated/autoconf.h".
======================================================================
menuconfig
--------------------------------------------------
SEARCHING for CONFIG symbols
Searching in menuconfig:
The Search function searches for kernel configuration symbol
names, so you have to know something close to what you are
looking for.
Example:
/hotplug
This lists all config symbols that contain "hotplug",
e.g., HOTPLUG_CPU, MEMORY_HOTPLUG.
For search help, enter / followed TAB-TAB-TAB (to highlight
<Help>) and Enter. This will tell you that you can also use
regular expressions (regexes) in the search string, so if you
are not interested in MEMORY_HOTPLUG, you could try
/^hotplug
When searching, symbols are sorted thus:
- exact match first: an exact match is when the search matches
the complete symbol name;
- alphabetical order: when two symbols do not match exactly,
they are sorted in alphabetical order (in the user's current
locale).
For example: ^ATH.K matches:
ATH5K ATH9K ATH5K_AHB ATH5K_DEBUG [...] ATH6KL ATH6KL_DEBUG
[...] ATH9K_AHB ATH9K_BTCOEX_SUPPORT ATH9K_COMMON [...]
of which only ATH5K and ATH9K match exactly and so are sorted
first (and in alphabetical order), then come all other symbols,
sorted in alphabetical order.
______________________________________________________________________
User interface options for 'menuconfig'
MENUCONFIG_COLOR
--------------------------------------------------
It is possible to select different color themes using the variable
MENUCONFIG_COLOR. To select a theme use:
make MENUCONFIG_COLOR=<theme> menuconfig
Available themes are:
mono => selects colors suitable for monochrome displays
blackbg => selects a color scheme with black background
classic => theme with blue background. The classic look
bluetitle => a LCD friendly version of classic. (default)
MENUCONFIG_MODE
--------------------------------------------------
This mode shows all sub-menus in one large tree.
Example:
make MENUCONFIG_MODE=single_menu menuconfig
======================================================================
xconfig
--------------------------------------------------
Searching in xconfig:
The Search function searches for kernel configuration symbol
names, so you have to know something close to what you are
looking for.
Example:
Ctrl-F hotplug
or
Menu: File, Search, hotplug
lists all config symbol entries that contain "hotplug" in
the symbol name. In this Search dialog, you may change the
config setting for any of the entries that are not grayed out.
You can also enter a different search string without having
to return to the main menu.
======================================================================
gconfig
--------------------------------------------------
Searching in gconfig:
None (gconfig isn't maintained as well as xconfig or menuconfig);
however, gconfig does have a few more viewing choices than
xconfig does.
###