From 2af238e455ef5fd31c2f7a06c2db3f13d843b9bf Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Fri, 29 Feb 2008 14:21:53 -0800 Subject: kbuild: make *config usage docs Create a kconfig user assistance guide, with a few tips and hints about using menuconfig, xconfig, and gconfig. Mostly contains user interface, environment variables, and search topics, along with mini.config/custom.config usage. Signed-off-by: Randy Dunlap Signed-off-by: Sam Ravnborg --- Documentation/kbuild/00-INDEX | 2 + Documentation/kbuild/kconfig.txt | 188 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 190 insertions(+) create mode 100644 Documentation/kbuild/kconfig.txt (limited to 'Documentation') diff --git a/Documentation/kbuild/00-INDEX b/Documentation/kbuild/00-INDEX index 11464428545..54a118a20f2 100644 --- a/Documentation/kbuild/00-INDEX +++ b/Documentation/kbuild/00-INDEX @@ -4,5 +4,7 @@ kconfig-language.txt - specification of Config Language, the language in Kconfig files makefiles.txt - developer information for linux kernel makefiles +kconfig.txt + - usage help for make *config modules.txt - how to build modules and to install them diff --git a/Documentation/kbuild/kconfig.txt b/Documentation/kbuild/kconfig.txt new file mode 100644 index 00000000000..26a7c0a9319 --- /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 + ) 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= 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. + +### -- cgit v1.2.3 From acc08b516f25b79cfcff310e51d95048bfcf7b0d Mon Sep 17 00:00:00 2001 From: Sam Ravnborg Date: Mon, 29 Dec 2008 13:45:52 +0100 Subject: kbuild: document environment variables Add kbuild.txt to Documentation/kbuild More stuff can be added later - at least we have som of the varous environment variables documented now. Signed-off-by: Sam Ravnborg --- Documentation/kbuild/00-INDEX | 8 ++- Documentation/kbuild/kbuild.txt | 126 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 131 insertions(+), 3 deletions(-) create mode 100644 Documentation/kbuild/kbuild.txt (limited to 'Documentation') diff --git a/Documentation/kbuild/00-INDEX b/Documentation/kbuild/00-INDEX index 54a118a20f2..e8d2b6d83a3 100644 --- a/Documentation/kbuild/00-INDEX +++ b/Documentation/kbuild/00-INDEX @@ -1,10 +1,12 @@ 00-INDEX - - this file: info on the kernel build process + - this file: info on the kernel build process +kbuild.txt + - developer information on kbuild +kconfig.txt + - usage help for make *config kconfig-language.txt - specification of Config Language, the language in Kconfig files makefiles.txt - developer information for linux kernel makefiles -kconfig.txt - - usage help for make *config modules.txt - how to build modules and to install them diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt new file mode 100644 index 00000000000..51771847e81 --- /dev/null +++ b/Documentation/kbuild/kbuild.txt @@ -0,0 +1,126 @@ +Environment variables + +KCPPFLAGS +-------------------------------------------------- +Additional options to pass when preprocessing. The preprocessing options +will be used in all cases where kbuild do preprocessing including +building C files and assembler files. + +KAFLAGS +-------------------------------------------------- +Additional options to the assembler. + +KCFLAGS +-------------------------------------------------- +Additional options to the C compiler. + +KBUILD_VERBOSE +-------------------------------------------------- +Set the kbuild verbosity. Can be assinged same values as "V=...". +See make help for the full list. +Setting "V=..." takes precedence over KBUILD_VERBOSE. + +KBUILD_EXTMOD +-------------------------------------------------- +Set the directory to look for the kernel source when building external +modules. +The directory can be specified in several ways: +1) Use "M=..." on the command line +2) Environmnet variable KBUILD_EXTMOD +3) Environmnet variable SUBDIRS +The possibilities are listed in the order they take precedence. +Using "M=..." will always override the others. + +KBUILD_OUTPUT +-------------------------------------------------- +Specify the output directory when building the kernel. +The output directory can also be specificed using "O=...". +Setting "O=..." takes precedence over KBUILD_OUTPUT + +ARCH +-------------------------------------------------- +Set ARCH to the architecture to be built. +In most cases the name of the architecture is the same as the +directory name found in the arch/ directory. +But some architectures suach as x86 and sparc has aliases. +x86: i386 for 32 bit, x86_64 for 64 bit +sparc: sparc for 32 bit, sparc64 for 64 bit + +CROSS_COMPILE +-------------------------------------------------- +Specify an optional fixed part of the binutils filename. +CROSS_COMPILE can be a part of the filename or the full path. + +CROSS_COMPILE is also used for ccache is some setups. + +CF +-------------------------------------------------- +Additional options for sparse. +CF is often used on the command-line like this: + + make CF=-Wbitwise C=2 + +INSTALL_PATH +-------------------------------------------------- +INSTALL_PATH specifies where to place the updated kernel and system map +images. Default is /boot, but you can set it to other values + + +MODLIB +-------------------------------------------------- +Specify where to install modules. +The default value is: + + $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE) + +The value can be overridden in which case the default value is ignored. + +INSTALL_MOD_PATH +-------------------------------------------------- +INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory +relocations required by build roots. This is not defined in the +makefile but the argument can be passed to make if needed. + +INSTALL_MOD_STRIP +-------------------------------------------------- +INSTALL_MOD_STRIP, if defined, will cause modules to be +stripped after they are installed. If INSTALL_MOD_STRIP is '1', then +the default option --strip-debug will be used. Otherwise, +INSTALL_MOD_STRIP will used as the options to the strip command. + +INSTALL_FW_PATH +-------------------------------------------------- +INSTALL_FW_PATH specify where to install the firmware blobs. +The default value is: + + $(INSTALL_MOD_PATH)/lib/firmware + +The value can be overridden in which case the default value is ignored. + +INSTALL_HDR_PATH +-------------------------------------------------- +INSTALL_HDR_PATH specify where to install user space headers when +executing "make headers_*". +The default value is: + + $(objtree)/usr + +$(objtree) is the directory where output files are saved. +The output directory is often set using "O=..." on the commandline. + +The value can be overridden in which case the default value is ignored. + +KBUILD_MODPOST_WARN +-------------------------------------------------- +KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined +symbols in the final module linking stage. + +KBUILD_MODPOST_FINAL +-------------------------------------------------- +KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. +This is solely usefull to speed up test compiles. + +KBUILD_EXTRA_SYMBOLS +-------------------------------------------------- +For modules use symbols from another modules. +See more details in modules.txt. -- cgit v1.2.3