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Based on kernel version 3.15.4. Page generated on 2014-07-07 09:03 EST.

1	This file contains some assistance for using "make *config".
2	
3	Use "make help" to list all of the possible configuration targets.
4	
5	The xconfig ('qconf') and menuconfig ('mconf') programs also
6	have embedded help text.  Be sure to check it for navigation,
7	search, and other general help text.
8	
9	======================================================================
10	General
11	--------------------------------------------------
12	
13	New kernel releases often introduce new config symbols.  Often more
14	important, new kernel releases may rename config symbols.  When
15	this happens, using a previously working .config file and running
16	"make oldconfig" won't necessarily produce a working new kernel
17	for you, so you may find that you need to see what NEW kernel
18	symbols have been introduced.
19	
20	To see a list of new config symbols when using "make oldconfig", use
21	
22		cp user/some/old.config .config
23		make listnewconfig
24	
25	and the config program will list any new symbols, one per line.
26	
27		scripts/diffconfig .config.old .config | less
28	
29	______________________________________________________________________
30	Environment variables for '*config'
31	
32	KCONFIG_CONFIG
33	--------------------------------------------------
34	This environment variable can be used to specify a default kernel config
35	file name to override the default name of ".config".
36	
37	KCONFIG_OVERWRITECONFIG
38	--------------------------------------------------
39	If you set KCONFIG_OVERWRITECONFIG in the environment, Kconfig will not
40	break symlinks when .config is a symlink to somewhere else.
41	
42	CONFIG_
43	--------------------------------------------------
44	If you set CONFIG_ in the environment, Kconfig will prefix all symbols
45	with its value when saving the configuration, instead of using the default,
46	"CONFIG_".
47	
48	______________________________________________________________________
49	Environment variables for '{allyes/allmod/allno/rand}config'
50	
51	KCONFIG_ALLCONFIG
52	--------------------------------------------------
53	(partially based on lkml email from/by Rob Landley, re: miniconfig)
54	--------------------------------------------------
55	The allyesconfig/allmodconfig/allnoconfig/randconfig variants can also
56	use the environment variable KCONFIG_ALLCONFIG as a flag or a filename
57	that contains config symbols that the user requires to be set to a
58	specific value.  If KCONFIG_ALLCONFIG is used without a filename where
59	KCONFIG_ALLCONFIG == "" or KCONFIG_ALLCONFIG == "1", "make *config"
60	checks for a file named "all{yes/mod/no/def/random}.config"
61	(corresponding to the *config command that was used) for symbol values
62	that are to be forced.  If this file is not found, it checks for a
63	file named "all.config" to contain forced values.
64	
65	This enables you to create "miniature" config (miniconfig) or custom
66	config files containing just the config symbols that you are interested
67	in.  Then the kernel config system generates the full .config file,
68	including symbols of your miniconfig file.
69	
70	This 'KCONFIG_ALLCONFIG' file is a config file which contains
71	(usually a subset of all) preset config symbols.  These variable
72	settings are still subject to normal dependency checks.
73	
74	Examples:
75		KCONFIG_ALLCONFIG=custom-notebook.config make allnoconfig
76	or
77		KCONFIG_ALLCONFIG=mini.config make allnoconfig
78	or
79		make KCONFIG_ALLCONFIG=mini.config allnoconfig
80	
81	These examples will disable most options (allnoconfig) but enable or
82	disable the options that are explicitly listed in the specified
83	mini-config files.
84	
85	______________________________________________________________________
86	Environment variables for 'randconfig'
87	
88	KCONFIG_SEED
89	--------------------------------------------------
90	You can set this to the integer value used to seed the RNG, if you want
91	to somehow debug the behaviour of the kconfig parser/frontends.
92	If not set, the current time will be used.
93	
94	KCONFIG_PROBABILITY
95	--------------------------------------------------
96	This variable can be used to skew the probabilities. This variable can
97	be unset or empty, or set to three different formats:
98		KCONFIG_PROBABILITY     y:n split           y:m:n split
99		-----------------------------------------------------------------
100		unset or empty          50  : 50            33  : 33  : 34
101		N                        N  : 100-N         N/2 : N/2 : 100-N
102	    [1] N:M                     N+M : 100-(N+M)      N  :  M  : 100-(N+M)
103	    [2] N:M:L                    N  : 100-N          M  :  L  : 100-(M+L)
104	
105	where N, M and L are integers (in base 10) in the range [0,100], and so
106	that:
107	    [1] N+M is in the range [0,100]
108	    [2] M+L is in the range [0,100]
109	
110	Examples:
111		KCONFIG_PROBABILITY=10
112			10% of booleans will be set to 'y', 90% to 'n'
113			5% of tristates will be set to 'y', 5% to 'm', 90% to 'n'
114		KCONFIG_PROBABILITY=15:25
115			40% of booleans will be set to 'y', 60% to 'n'
116			15% of tristates will be set to 'y', 25% to 'm', 60% to 'n'
117		KCONFIG_PROBABILITY=10:15:15
118			10% of booleans will be set to 'y', 90% to 'n'
119			15% of tristates will be set to 'y', 15% to 'm', 70% to 'n'
120	
121	______________________________________________________________________
122	Environment variables for 'silentoldconfig'
123	
124	KCONFIG_NOSILENTUPDATE
125	--------------------------------------------------
126	If this variable has a non-blank value, it prevents silent kernel
127	config updates (requires explicit updates).
128	
129	KCONFIG_AUTOCONFIG
130	--------------------------------------------------
131	This environment variable can be set to specify the path & name of the
132	"auto.conf" file.  Its default value is "include/config/auto.conf".
133	
134	KCONFIG_TRISTATE
135	--------------------------------------------------
136	This environment variable can be set to specify the path & name of the
137	"tristate.conf" file.  Its default value is "include/config/tristate.conf".
138	
139	KCONFIG_AUTOHEADER
140	--------------------------------------------------
141	This environment variable can be set to specify the path & name of the
142	"autoconf.h" (header) file.
143	Its default value is "include/generated/autoconf.h".
144	
145	
146	======================================================================
147	menuconfig
148	--------------------------------------------------
149	
150	SEARCHING for CONFIG symbols
151	
152	Searching in menuconfig:
153	
154		The Search function searches for kernel configuration symbol
155		names, so you have to know something close to what you are
156		looking for.
157	
158		Example:
159			/hotplug
160			This lists all config symbols that contain "hotplug",
161			e.g., HOTPLUG_CPU, MEMORY_HOTPLUG.
162	
163		For search help, enter / followed TAB-TAB-TAB (to highlight
164		<Help>) and Enter.  This will tell you that you can also use
165		regular expressions (regexes) in the search string, so if you
166		are not interested in MEMORY_HOTPLUG, you could try
167	
168			/^hotplug
169	
170		When searching, symbols are sorted thus:
171		  - first, exact matches, sorted alphabetically (an exact match
172		    is when the search matches the complete symbol name);
173		  - then, other matches, sorted alphabetically.
174		For example: ^ATH.K matches:
175		    ATH5K ATH9K ATH5K_AHB ATH5K_DEBUG [...] ATH6KL ATH6KL_DEBUG
176		    [...] ATH9K_AHB ATH9K_BTCOEX_SUPPORT ATH9K_COMMON [...]
177		of which only ATH5K and ATH9K match exactly and so are sorted
178		first (and in alphabetical order), then come all other symbols,
179		sorted in alphabetical order.
180	
181	______________________________________________________________________
182	User interface options for 'menuconfig'
183	
184	MENUCONFIG_COLOR
185	--------------------------------------------------
186	It is possible to select different color themes using the variable
187	MENUCONFIG_COLOR.  To select a theme use:
188	
189		make MENUCONFIG_COLOR=<theme> menuconfig
190	
191	Available themes are:
192	  mono       => selects colors suitable for monochrome displays
193	  blackbg    => selects a color scheme with black background
194	  classic    => theme with blue background. The classic look
195	  bluetitle  => a LCD friendly version of classic. (default)
196	
197	MENUCONFIG_MODE
198	--------------------------------------------------
199	This mode shows all sub-menus in one large tree.
200	
201	Example:
202		make MENUCONFIG_MODE=single_menu menuconfig
203	
204	
205	======================================================================
206	xconfig
207	--------------------------------------------------
208	
209	Searching in xconfig:
210	
211		The Search function searches for kernel configuration symbol
212		names, so you have to know something close to what you are
213		looking for.
214	
215		Example:
216			Ctrl-F hotplug
217		or
218			Menu: File, Search, hotplug
219	
220		lists all config symbol entries that contain "hotplug" in
221		the symbol name.  In this Search dialog, you may change the
222		config setting for any of the entries that are not grayed out.
223		You can also enter a different search string without having
224		to return to the main menu.
225	
226	
227	======================================================================
228	gconfig
229	--------------------------------------------------
230	
231	Searching in gconfig:
232	
233		None (gconfig isn't maintained as well as xconfig or menuconfig);
234		however, gconfig does have a few more viewing choices than
235		xconfig does.
236	
237	###
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