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1=================================
2Configuration targets and editors
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
13The gconfig ('gconf') program has limited help text.
14
15
16General
17=======
18
19New kernel releases often introduce new config symbols. Often more
20important, new kernel releases may rename config symbols. When
21this happens, using a previously working .config file and running
22"make oldconfig" won't necessarily produce a working new kernel
23for you, so you may find that you need to see what NEW kernel
24symbols have been introduced.
25
26To see a list of new config symbols, use::
27
28 cp user/some/old.config .config
29 make listnewconfig
30
31and the config program will list any new symbols, one per line.
32
33Alternatively, you can use the brute force method::
34
35 make oldconfig
36 scripts/diffconfig .config.old .config | less
37
38
39Environment variables
40=====================
41
42Environment variables for ``*config``:
43
44``KCONFIG_CONFIG``
45 This environment variable can be used to specify a default kernel config
46 file name to override the default name of ".config".
47
48``KCONFIG_DEFCONFIG_LIST``
49 This environment variable specifies a list of config files which can be
50 used as a base configuration in case the .config does not exist yet.
51 Entries in the list are separated with whitespaces to each other, and
52 the first one that exists is used.
53
54``KCONFIG_OVERWRITECONFIG``
55 If you set KCONFIG_OVERWRITECONFIG in the environment, Kconfig will not
56 break symlinks when .config is a symlink to somewhere else.
57
58``KCONFIG_WARN_UNKNOWN_SYMBOLS``
59 This environment variable makes Kconfig warn about all unrecognized
60 symbols in the config input.
61
62``KCONFIG_WERROR``
63 If set, Kconfig treats warnings as errors.
64
65``CONFIG_``
66 If you set ``CONFIG_`` in the environment, Kconfig will prefix all symbols
67 with its value when saving the configuration, instead of using the
68 default, ``CONFIG_``.
69
70Environment variables for ``{allyes/allmod/allno/rand}config``:
71
72``KCONFIG_ALLCONFIG``
73 The allyesconfig/allmodconfig/allnoconfig/randconfig variants can also
74 use the environment variable KCONFIG_ALLCONFIG as a flag or a filename
75 that contains config symbols that the user requires to be set to a
76 specific value. If KCONFIG_ALLCONFIG is used without a filename where
77 KCONFIG_ALLCONFIG == "" or KCONFIG_ALLCONFIG == "1", ``make *config``
78 checks for a file named "all{yes/mod/no/def/random}.config"
79 (corresponding to the ``*config`` command that was used) for symbol values
80 that are to be forced. If this file is not found, it checks for a
81 file named "all.config" to contain forced values.
82
83 This enables you to create "miniature" config (miniconfig) or custom
84 config files containing just the config symbols that you are interested
85 in. Then the kernel config system generates the full .config file,
86 including symbols of your miniconfig file.
87
88 This ``KCONFIG_ALLCONFIG`` file is a config file which contains
89 (usually a subset of all) preset config symbols. These variable
90 settings are still subject to normal dependency checks.
91
92 Examples::
93
94 KCONFIG_ALLCONFIG=custom-notebook.config make allnoconfig
95
96 or::
97
98 KCONFIG_ALLCONFIG=mini.config make allnoconfig
99
100 or::
101
102 make KCONFIG_ALLCONFIG=mini.config allnoconfig
103
104 These examples will disable most options (allnoconfig) but enable or
105 disable the options that are explicitly listed in the specified
106 mini-config files.
107
108Environment variables for ``randconfig``:
109
110``KCONFIG_SEED``
111 You can set this to the integer value used to seed the RNG, if you want
112 to somehow debug the behaviour of the kconfig parser/frontends.
113 If not set, the current time will be used.
114
115``KCONFIG_PROBABILITY``
116 This variable can be used to skew the probabilities. This variable can
117 be unset or empty, or set to three different formats:
118
119 ======================= ================== =====================
120 KCONFIG_PROBABILITY y:n split y:m:n split
121 ======================= ================== =====================
122 unset or empty 50 : 50 33 : 33 : 34
123 N N : 100-N N/2 : N/2 : 100-N
124 [1] N:M N+M : 100-(N+M) N : M : 100-(N+M)
125 [2] N:M:L N : 100-N M : L : 100-(M+L)
126 ======================= ================== =====================
127
128where N, M and L are integers (in base 10) in the range [0,100], and so
129that:
130
131 [1] N+M is in the range [0,100]
132
133 [2] M+L is in the range [0,100]
134
135Examples::
136
137 KCONFIG_PROBABILITY=10
138 10% of booleans will be set to 'y', 90% to 'n'
139 5% of tristates will be set to 'y', 5% to 'm', 90% to 'n'
140 KCONFIG_PROBABILITY=15:25
141 40% of booleans will be set to 'y', 60% to 'n'
142 15% of tristates will be set to 'y', 25% to 'm', 60% to 'n'
143 KCONFIG_PROBABILITY=10:15:15
144 10% of booleans will be set to 'y', 90% to 'n'
145 15% of tristates will be set to 'y', 15% to 'm', 70% to 'n'
146
147Environment variables for ``syncconfig``:
148
149``KCONFIG_NOSILENTUPDATE``
150 If this variable has a non-blank value, it prevents silent kernel
151 config updates (requires explicit updates).
152
153``KCONFIG_AUTOCONFIG``
154 This 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
157``KCONFIG_AUTOHEADER``
158 This environment variable can be set to specify the path & name of the
159 "autoconf.h" (header) file.
160 Its default value is "include/generated/autoconf.h".
161
162
163menuconfig
164==========
165
166Searching in menuconfig:
167
168 The Search function searches for kernel configuration symbol
169 names, so you have to know something close to what you are
170 looking for.
171
172 Example::
173
174 /hotplug
175 This lists all config symbols that contain "hotplug",
176 e.g., HOTPLUG_CPU, MEMORY_HOTPLUG.
177
178 For search help, enter / followed by TAB-TAB (to highlight
179 <Help>) and Enter. This will tell you that you can also use
180 regular expressions (regexes) in the search string, so if you
181 are not interested in MEMORY_HOTPLUG, you could try::
182
183 /^hotplug
184
185 When searching, symbols are sorted thus:
186
187 - first, exact matches, sorted alphabetically (an exact match
188 is when the search matches the complete symbol name);
189 - then, other matches, sorted alphabetically.
190
191 For example, ^ATH.K matches:
192
193 ATH5K ATH9K ATH5K_AHB ATH5K_DEBUG [...] ATH6KL ATH6KL_DEBUG
194 [...] ATH9K_AHB ATH9K_BTCOEX_SUPPORT ATH9K_COMMON [...]
195
196 of which only ATH5K and ATH9K match exactly and so are sorted
197 first (and in alphabetical order), then come all other symbols,
198 sorted in alphabetical order.
199
200 In this menu, pressing the key in the (#) prefix will jump
201 directly to that location. You will be returned to the current
202 search results after exiting this new menu.
203
204User interface options for 'menuconfig':
205
206``MENUCONFIG_COLOR``
207 It is possible to select different color themes using the variable
208 MENUCONFIG_COLOR. To select a theme use::
209
210 make MENUCONFIG_COLOR=<theme> menuconfig
211
212 Available themes are::
213
214 - mono => selects colors suitable for monochrome displays
215 - blackbg => selects a color scheme with black background
216 - classic => theme with blue background. The classic look
217 - bluetitle => a LCD friendly version of classic. (default)
218
219``MENUCONFIG_MODE``
220 This mode shows all sub-menus in one large tree.
221
222 Example::
223
224 make MENUCONFIG_MODE=single_menu menuconfig
225
226
227nconfig
228=======
229
230nconfig is an alternate text-based configurator. It lists function
231keys across the bottom of the terminal (window) that execute commands.
232You can also just use the corresponding numeric key to execute the
233commands unless you are in a data entry window. E.g., instead of F6
234for Save, you can just press 6.
235
236Use F1 for Global help or F3 for the Short help menu.
237
238Searching in nconfig:
239
240 You can search either in the menu entry "prompt" strings
241 or in the configuration symbols.
242
243 Use / to begin a search through the menu entries. This does
244 not support regular expressions. Use <Down> or <Up> for
245 Next hit and Previous hit, respectively. Use <Esc> to
246 terminate the search mode.
247
248 F8 (SymSearch) searches the configuration symbols for the
249 given string or regular expression (regex).
250
251 In the SymSearch, pressing the key in the (#) prefix will
252 jump directly to that location. You will be returned to the
253 current search results after exiting this new menu.
254
255Environment variables:
256
257``NCONFIG_MODE``
258 This mode shows all sub-menus in one large tree.
259
260 Example::
261
262 make NCONFIG_MODE=single_menu nconfig
263
264
265xconfig
266=======
267
268Searching in xconfig:
269
270 The Search function searches for kernel configuration symbol
271 names, so you have to know something close to what you are
272 looking for.
273
274 Example::
275
276 Ctrl-F hotplug
277
278 or::
279
280 Menu: File, Search, hotplug
281
282 lists all config symbol entries that contain "hotplug" in
283 the symbol name. In this Search dialog, you may change the
284 config setting for any of the entries that are not grayed out.
285 You can also enter a different search string without having
286 to return to the main menu.
287
288
289gconfig
290=======
291
292Searching in gconfig:
293
294 There is no search command in gconfig. However, gconfig does
295 have several different viewing choices, modes, and options.
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.