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diff --git a/Documentation/kbuild/kconfig.txt b/Documentation/kbuild/kconfig.txt new file mode 100644 index 000000000000..26a7c0a93193 --- /dev/null +++ b/Documentation/kbuild/kconfig.txt @@ -0,0 +1,188 @@ +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 'diff' the previous and +new .config files to see the differences: + + diff .config.old .config | less + +(Yes, we need something better here.) + + +====================================================================== +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, 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 + + +______________________________________________________________________ +Color Themes for 'menuconfig' + +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) + +______________________________________________________________________ +Environment variables in 'menuconfig' + +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, "make *config" checks for a file named +"all{yes/mod/no/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 dependencies of your miniconfig file, based on the 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. + +KCONFIG_NOSILENTUPDATE +-------------------------------------------------- +If this variable has a non-blank value, it prevents silent kernel +config udpates (requires explicit updates). + +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. + +KCONFIG_NOTIMESTAMP +-------------------------------------------------- +If this environment variable exists and is non-null, the timestamp line +in generated .config files is omitted. + +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_AUTOHEADER +-------------------------------------------------- +This environment variable can be set to specify the path & name of the +"autoconf.h" (header) file. Its default value is "include/linux/autoconf.h". + +______________________________________________________________________ +menuconfig User Interface Options +---------------------------------------------------------------------- +MENUCONFIG_MODE +-------------------------------------------------- +This mode shows all sub-menus in one large tree. + +Example: + MENUCONFIG_MODE=single_menu make 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. + +### |