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Linux kernel mirror (for testing)
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kernel
os
linux
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_AUTOHEADER
158------------------
159This environment variable can be set to specify the path & name of the
160"autoconf.h" (header) file.
161Its default value is "include/generated/autoconf.h".
162
163
164----------------------------------------------------------------------
165
166menuconfig
167----------
168
169SEARCHING for CONFIG symbols
170
171Searching in menuconfig:
172
173 The Search function searches for kernel configuration symbol
174 names, so you have to know something close to what you are
175 looking for.
176
177 Example::
178
179 /hotplug
180 This lists all config symbols that contain "hotplug",
181 e.g., HOTPLUG_CPU, MEMORY_HOTPLUG.
182
183 For search help, enter / followed by TAB-TAB (to highlight
184 <Help>) and Enter. This will tell you that you can also use
185 regular expressions (regexes) in the search string, so if you
186 are not interested in MEMORY_HOTPLUG, you could try::
187
188 /^hotplug
189
190 When searching, symbols are sorted thus:
191
192 - first, exact matches, sorted alphabetically (an exact match
193 is when the search matches the complete symbol name);
194 - then, other matches, sorted alphabetically.
195
196 For example: ^ATH.K matches:
197
198 ATH5K ATH9K ATH5K_AHB ATH5K_DEBUG [...] ATH6KL ATH6KL_DEBUG
199 [...] ATH9K_AHB ATH9K_BTCOEX_SUPPORT ATH9K_COMMON [...]
200
201 of which only ATH5K and ATH9K match exactly and so are sorted
202 first (and in alphabetical order), then come all other symbols,
203 sorted in alphabetical order.
204
205----------------------------------------------------------------------
206
207User interface options for 'menuconfig'
208
209MENUCONFIG_COLOR
210----------------
211It is possible to select different color themes using the variable
212MENUCONFIG_COLOR. To select a theme use::
213
214 make MENUCONFIG_COLOR=<theme> menuconfig
215
216Available themes are::
217
218 - mono => selects colors suitable for monochrome displays
219 - blackbg => selects a color scheme with black background
220 - classic => theme with blue background. The classic look
221 - bluetitle => a LCD friendly version of classic. (default)
222
223MENUCONFIG_MODE
224---------------
225This mode shows all sub-menus in one large tree.
226
227Example::
228
229 make MENUCONFIG_MODE=single_menu menuconfig
230
231----------------------------------------------------------------------
232
233nconfig
234-------
235
236nconfig is an alternate text-based configurator. It lists function
237keys across the bottom of the terminal (window) that execute commands.
238You can also just use the corresponding numeric key to execute the
239commands unless you are in a data entry window. E.g., instead of F6
240for Save, you can just press 6.
241
242Use F1 for Global help or F3 for the Short help menu.
243
244Searching in nconfig:
245
246 You can search either in the menu entry "prompt" strings
247 or in the configuration symbols.
248
249 Use / to begin a search through the menu entries. This does
250 not support regular expressions. Use <Down> or <Up> for
251 Next hit and Previous hit, respectively. Use <Esc> to
252 terminate the search mode.
253
254 F8 (SymSearch) searches the configuration symbols for the
255 given string or regular expression (regex).
256
257NCONFIG_MODE
258------------
259This mode shows all sub-menus in one large tree.
260
261Example::
262
263 make NCONFIG_MODE=single_menu nconfig
264
265----------------------------------------------------------------------
266
267xconfig
268-------
269
270Searching in xconfig:
271
272 The Search function searches for kernel configuration symbol
273 names, so you have to know something close to what you are
274 looking for.
275
276 Example::
277
278 Ctrl-F hotplug
279
280 or::
281
282 Menu: File, Search, hotplug
283
284 lists all config symbol entries that contain "hotplug" in
285 the symbol name. In this Search dialog, you may change the
286 config setting for any of the entries that are not grayed out.
287 You can also enter a different search string without having
288 to return to the main menu.
289
290
291----------------------------------------------------------------------
292
293gconfig
294-------
295
296Searching in gconfig:
297
298 There is no search command in gconfig. However, gconfig does
299 have several different viewing choices, modes, and options.