1=================== 2Kconfig make config 3=================== 4 5This file contains some assistance for using `make *config`. 6 7Use "make help" to list all of the possible configuration targets. 8 9The xconfig ('qconf'), menuconfig ('mconf'), and nconfig ('nconf') 10programs also have embedded help text. Be sure to check that for 11navigation, search, and other general help text. 12 13General 14------- 15 16New kernel releases often introduce new config symbols. Often more 17important, new kernel releases may rename config symbols. When 18this happens, using a previously working .config file and running 19"make oldconfig" won't necessarily produce a working new kernel 20for you, so you may find that you need to see what NEW kernel 21symbols have been introduced. 22 23To see a list of new config symbols, use:: 24 25 cp user/some/old.config .config 26 make listnewconfig 27 28and the config program will list any new symbols, one per line. 29 30Alternatively, you can use the brute force method:: 31 32 make oldconfig 33 scripts/diffconfig .config.old .config | less 34 35---------------------------------------------------------------------- 36 37Environment variables for `*config` 38 39KCONFIG_CONFIG 40-------------- 41This environment variable can be used to specify a default kernel config 42file name to override the default name of ".config". 43 44KCONFIG_OVERWRITECONFIG 45----------------------- 46If you set KCONFIG_OVERWRITECONFIG in the environment, Kconfig will not 47break symlinks when .config is a symlink to somewhere else. 48 49`CONFIG_` 50--------- 51If you set `CONFIG_` in the environment, Kconfig will prefix all symbols 52with its value when saving the configuration, instead of using the default, 53`CONFIG_`. 54 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 63-------------------------------------------------- 64 65The allyesconfig/allmodconfig/allnoconfig/randconfig variants can also 66use the environment variable KCONFIG_ALLCONFIG as a flag or a filename 67that contains config symbols that the user requires to be set to a 68specific value. If KCONFIG_ALLCONFIG is used without a filename where 69KCONFIG_ALLCONFIG == "" or KCONFIG_ALLCONFIG == "1", `make *config` 70checks for a file named "all{yes/mod/no/def/random}.config" 71(corresponding to the `*config` command that was used) for symbol values 72that are to be forced. If this file is not found, it checks for a 73file named "all.config" to contain forced values. 74 75This enables you to create "miniature" config (miniconfig) or custom 76config files containing just the config symbols that you are interested 77in. Then the kernel config system generates the full .config file, 78including symbols of your miniconfig file. 79 80This 'KCONFIG_ALLCONFIG' file is a config file which contains 81(usually a subset of all) preset config symbols. These variable 82settings are still subject to normal dependency checks. 83 84Examples:: 85 86 KCONFIG_ALLCONFIG=custom-notebook.config make allnoconfig 87 88or:: 89 90 KCONFIG_ALLCONFIG=mini.config make allnoconfig 91 92or:: 93 94 make KCONFIG_ALLCONFIG=mini.config allnoconfig 95 96These examples will disable most options (allnoconfig) but enable or 97disable the options that are explicitly listed in the specified 98mini-config files. 99 100---------------------------------------------------------------------- 101 102Environment variables for 'randconfig' 103 104KCONFIG_SEED 105------------ 106You can set this to the integer value used to seed the RNG, if you want 107to somehow debug the behaviour of the kconfig parser/frontends. 108If not set, the current time will be used. 109 110KCONFIG_PROBABILITY 111------------------- 112This variable can be used to skew the probabilities. This variable can 113be unset or empty, or set to three different formats: 114 115 ======================= ================== ===================== 116 KCONFIG_PROBABILITY y:n split y:m:n split 117 ======================= ================== ===================== 118 unset or empty 50 : 50 33 : 33 : 34 119 N N : 100-N N/2 : N/2 : 100-N 120 [1] N:M N+M : 100-(N+M) N : M : 100-(N+M) 121 [2] N:M:L N : 100-N M : L : 100-(M+L) 122 ======================= ================== ===================== 123 124where N, M and L are integers (in base 10) in the range [0,100], and so 125that: 126 127 [1] N+M is in the range [0,100] 128 129 [2] M+L is in the range [0,100] 130 131Examples:: 132 133 KCONFIG_PROBABILITY=10 134 10% of booleans will be set to 'y', 90% to 'n' 135 5% of tristates will be set to 'y', 5% to 'm', 90% to 'n' 136 KCONFIG_PROBABILITY=15:25 137 40% of booleans will be set to 'y', 60% to 'n' 138 15% of tristates will be set to 'y', 25% to 'm', 60% to 'n' 139 KCONFIG_PROBABILITY=10:15:15 140 10% of booleans will be set to 'y', 90% to 'n' 141 15% of tristates will be set to 'y', 15% to 'm', 70% to 'n' 142 143---------------------------------------------------------------------- 144 145Environment variables for 'syncconfig' 146 147KCONFIG_NOSILENTUPDATE 148---------------------- 149If this variable has a non-blank value, it prevents silent kernel 150config updates (requires explicit updates). 151 152KCONFIG_AUTOCONFIG 153------------------ 154This environment variable can be set to specify the path & name of the 155"auto.conf" file. Its default value is "include/config/auto.conf". 156 157KCONFIG_TRISTATE 158---------------- 159This environment variable can be set to specify the path & name of the 160"tristate.conf" file. Its default value is "include/config/tristate.conf". 161 162KCONFIG_AUTOHEADER 163------------------ 164This environment variable can be set to specify the path & name of the 165"autoconf.h" (header) file. 166Its default value is "include/generated/autoconf.h". 167 168 169---------------------------------------------------------------------- 170 171menuconfig 172---------- 173 174SEARCHING for CONFIG symbols 175 176Searching in menuconfig: 177 178 The Search function searches for kernel configuration symbol 179 names, so you have to know something close to what you are 180 looking for. 181 182 Example:: 183 184 /hotplug 185 This lists all config symbols that contain "hotplug", 186 e.g., HOTPLUG_CPU, MEMORY_HOTPLUG. 187 188 For search help, enter / followed by TAB-TAB (to highlight 189 <Help>) and Enter. This will tell you that you can also use 190 regular expressions (regexes) in the search string, so if you 191 are not interested in MEMORY_HOTPLUG, you could try:: 192 193 /^hotplug 194 195 When searching, symbols are sorted thus: 196 197 - first, exact matches, sorted alphabetically (an exact match 198 is when the search matches the complete symbol name); 199 - then, other matches, sorted alphabetically. 200 201 For example: ^ATH.K matches: 202 203 ATH5K ATH9K ATH5K_AHB ATH5K_DEBUG [...] ATH6KL ATH6KL_DEBUG 204 [...] ATH9K_AHB ATH9K_BTCOEX_SUPPORT ATH9K_COMMON [...] 205 206 of which only ATH5K and ATH9K match exactly and so are sorted 207 first (and in alphabetical order), then come all other symbols, 208 sorted in alphabetical order. 209 210---------------------------------------------------------------------- 211 212User interface options for 'menuconfig' 213 214MENUCONFIG_COLOR 215---------------- 216It is possible to select different color themes using the variable 217MENUCONFIG_COLOR. To select a theme use:: 218 219 make MENUCONFIG_COLOR=<theme> menuconfig 220 221Available themes are:: 222 223 - mono => selects colors suitable for monochrome displays 224 - blackbg => selects a color scheme with black background 225 - classic => theme with blue background. The classic look 226 - bluetitle => a LCD friendly version of classic. (default) 227 228MENUCONFIG_MODE 229--------------- 230This mode shows all sub-menus in one large tree. 231 232Example:: 233 234 make MENUCONFIG_MODE=single_menu menuconfig 235 236---------------------------------------------------------------------- 237 238nconfig 239------- 240 241nconfig is an alternate text-based configurator. It lists function 242keys across the bottom of the terminal (window) that execute commands. 243You can also just use the corresponding numeric key to execute the 244commands unless you are in a data entry window. E.g., instead of F6 245for Save, you can just press 6. 246 247Use F1 for Global help or F3 for the Short help menu. 248 249Searching in nconfig: 250 251 You can search either in the menu entry "prompt" strings 252 or in the configuration symbols. 253 254 Use / to begin a search through the menu entries. This does 255 not support regular expressions. Use <Down> or <Up> for 256 Next hit and Previous hit, respectively. Use <Esc> to 257 terminate the search mode. 258 259 F8 (SymSearch) searches the configuration symbols for the 260 given string or regular expression (regex). 261 262NCONFIG_MODE 263------------ 264This mode shows all sub-menus in one large tree. 265 266Example:: 267 268 make NCONFIG_MODE=single_menu nconfig 269 270---------------------------------------------------------------------- 271 272xconfig 273------- 274 275Searching in xconfig: 276 277 The Search function searches for kernel configuration symbol 278 names, so you have to know something close to what you are 279 looking for. 280 281 Example:: 282 283 Ctrl-F hotplug 284 285 or:: 286 287 Menu: File, Search, hotplug 288 289 lists all config symbol entries that contain "hotplug" in 290 the symbol name. In this Search dialog, you may change the 291 config setting for any of the entries that are not grayed out. 292 You can also enter a different search string without having 293 to return to the main menu. 294 295 296---------------------------------------------------------------------- 297 298gconfig 299------- 300 301Searching in gconfig: 302 303 There is no search command in gconfig. However, gconfig does 304 have several different viewing choices, modes, and options. 305