1This file contains some assistance for using "make *config". 2 3Use "make help" to list all of the possible configuration targets. 4 5The xconfig ('qconf') and menuconfig ('mconf') programs also 6have embedded help text. Be sure to check it for navigation, 7search, and other general help text. 8 9====================================================================== 10General 11-------------------------------------------------- 12 13New kernel releases often introduce new config symbols. Often more 14important, new kernel releases may rename config symbols. When 15this happens, using a previously working .config file and running 16"make oldconfig" won't necessarily produce a working new kernel 17for you, so you may find that you need to see what NEW kernel 18symbols have been introduced. 19 20To see a list of new config symbols when using "make oldconfig", use 21 22 cp user/some/old.config .config 23 yes "" | make oldconfig >conf.new 24 25and the config program will list as (NEW) any new symbols that have 26unknown values. Of course, the .config file is also updated with 27new (default) values, so you can use: 28 29 grep "(NEW)" conf.new 30 31to see the new config symbols or you can 'diff' the previous and 32new .config files to see the differences: 33 34 diff .config.old .config | less 35 36(Yes, we need something better here.) 37 38______________________________________________________________________ 39Environment variables for '*config' 40 41KCONFIG_CONFIG 42-------------------------------------------------- 43This environment variable can be used to specify a default kernel config 44file name to override the default name of ".config". 45 46KCONFIG_OVERWRITECONFIG 47-------------------------------------------------- 48If you set KCONFIG_OVERWRITECONFIG in the environment, Kconfig will not 49break symlinks when .config is a symlink to somewhere else. 50 51KCONFIG_NOTIMESTAMP 52-------------------------------------------------- 53If this environment variable exists and is non-null, the timestamp line 54in generated .config files is omitted. 55 56______________________________________________________________________ 57Environment variables for '{allyes/allmod/allno/rand}config' 58 59KCONFIG_ALLCONFIG 60-------------------------------------------------- 61(partially based on lkml email from/by Rob Landley, re: miniconfig) 62-------------------------------------------------- 63The allyesconfig/allmodconfig/allnoconfig/randconfig variants can 64also use the environment variable KCONFIG_ALLCONFIG as a flag or a 65filename that contains config symbols that the user requires to be 66set to a specific value. If KCONFIG_ALLCONFIG is used without a 67filename, "make *config" checks for a file named 68"all{yes/mod/no/random}.config" (corresponding to the *config command 69that was used) for symbol values that are to be forced. If this file 70is not found, it checks for a file named "all.config" to contain forced 71values. 72 73This enables you to create "miniature" config (miniconfig) or custom 74config files containing just the config symbols that you are interested 75in. Then the kernel config system generates the full .config file, 76including symbols of your miniconfig file. 77 78This 'KCONFIG_ALLCONFIG' file is a config file which contains 79(usually a subset of all) preset config symbols. These variable 80settings are still subject to normal dependency checks. 81 82Examples: 83 KCONFIG_ALLCONFIG=custom-notebook.config make allnoconfig 84or 85 KCONFIG_ALLCONFIG=mini.config make allnoconfig 86or 87 make KCONFIG_ALLCONFIG=mini.config allnoconfig 88 89These examples will disable most options (allnoconfig) but enable or 90disable the options that are explicitly listed in the specified 91mini-config files. 92 93______________________________________________________________________ 94Environment variables for 'silentoldconfig' 95 96KCONFIG_NOSILENTUPDATE 97-------------------------------------------------- 98If this variable has a non-blank value, it prevents silent kernel 99config udpates (requires explicit updates). 100 101KCONFIG_AUTOCONFIG 102-------------------------------------------------- 103This environment variable can be set to specify the path & name of the 104"auto.conf" file. Its default value is "include/config/auto.conf". 105 106KCONFIG_AUTOHEADER 107-------------------------------------------------- 108This environment variable can be set to specify the path & name of the 109"autoconf.h" (header) file. Its default value is "include/linux/autoconf.h". 110 111 112====================================================================== 113menuconfig 114-------------------------------------------------- 115 116SEARCHING for CONFIG symbols 117 118Searching in menuconfig: 119 120 The Search function searches for kernel configuration symbol 121 names, so you have to know something close to what you are 122 looking for. 123 124 Example: 125 /hotplug 126 This lists all config symbols that contain "hotplug", 127 e.g., HOTPLUG, HOTPLUG_CPU, MEMORY_HOTPLUG. 128 129 For search help, enter / followed TAB-TAB-TAB (to highlight 130 <Help>) and Enter. This will tell you that you can also use 131 regular expressions (regexes) in the search string, so if you 132 are not interested in MEMORY_HOTPLUG, you could try 133 134 /^hotplug 135 136______________________________________________________________________ 137User interface options for 'menuconfig' 138 139MENUCONFIG_COLOR 140-------------------------------------------------- 141It is possible to select different color themes using the variable 142MENUCONFIG_COLOR. To select a theme use: 143 144 make MENUCONFIG_COLOR=<theme> menuconfig 145 146Available themes are: 147 mono => selects colors suitable for monochrome displays 148 blackbg => selects a color scheme with black background 149 classic => theme with blue background. The classic look 150 bluetitle => a LCD friendly version of classic. (default) 151 152MENUCONFIG_MODE 153-------------------------------------------------- 154This mode shows all sub-menus in one large tree. 155 156Example: 157 make MENUCONFIG_MODE=single_menu menuconfig 158 159 160====================================================================== 161xconfig 162-------------------------------------------------- 163 164Searching in xconfig: 165 166 The Search function searches for kernel configuration symbol 167 names, so you have to know something close to what you are 168 looking for. 169 170 Example: 171 Ctrl-F hotplug 172 or 173 Menu: File, Search, hotplug 174 175 lists all config symbol entries that contain "hotplug" in 176 the symbol name. In this Search dialog, you may change the 177 config setting for any of the entries that are not grayed out. 178 You can also enter a different search string without having 179 to return to the main menu. 180 181 182====================================================================== 183gconfig 184-------------------------------------------------- 185 186Searching in gconfig: 187 188 None (gconfig isn't maintained as well as xconfig or menuconfig); 189 however, gconfig does have a few more viewing choices than 190 xconfig does. 191 192### 193