kconfig.rst 9.1 KB

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