1This file contains some assistance for using "make *config".
2
3Use "make help" to list all of the possible configuration targets.
4
5The xconfig ('qconf') and menuconfig ('mconf') programs also
6have embedded help text.  Be sure to check it for navigation,
7search, and other general help text.
8
9======================================================================
10General
11--------------------------------------------------
12
13New kernel releases often introduce new config symbols.  Often more
14important, new kernel releases may rename config symbols.  When
15this happens, using a previously working .config file and running
16"make oldconfig" won't necessarily produce a working new kernel
17for you, so you may find that you need to see what NEW kernel
18symbols have been introduced.
19
20To see a list of new config symbols when using "make oldconfig", use
21
22	cp user/some/old.config .config
23	yes "" | make oldconfig >conf.new
24
25and the config program will list as (NEW) any new symbols that have
26unknown values.  Of course, the .config file is also updated with
27new (default) values, so you can use:
28
29	grep "(NEW)" conf.new
30
31to see the new config symbols or you can 'diff' the previous and
32new .config files to see the differences:
33
34	diff .config.old .config | less
35
36(Yes, we need something better here.)
37
38______________________________________________________________________
39Environment variables for '*config'
40
41KCONFIG_CONFIG
42--------------------------------------------------
43This environment variable can be used to specify a default kernel config
44file name to override the default name of ".config".
45
46KCONFIG_OVERWRITECONFIG
47--------------------------------------------------
48If you set KCONFIG_OVERWRITECONFIG in the environment, Kconfig will not
49break symlinks when .config is a symlink to somewhere else.
50
51______________________________________________________________________
52Environment variables for '{allyes/allmod/allno/rand}config'
53
54KCONFIG_ALLCONFIG
55--------------------------------------------------
56(partially based on lkml email from/by Rob Landley, re: miniconfig)
57--------------------------------------------------
58The allyesconfig/allmodconfig/allnoconfig/randconfig variants can
59also use the environment variable KCONFIG_ALLCONFIG as a flag or a
60filename that contains config symbols that the user requires to be
61set to a specific value.  If KCONFIG_ALLCONFIG is used without a
62filename, "make *config" checks for a file named
63"all{yes/mod/no/def/random}.config" (corresponding to the *config command
64that was used) for symbol values that are to be forced.  If this file
65is not found, it checks for a file named "all.config" to contain forced
66values.
67
68This enables you to create "miniature" config (miniconfig) or custom
69config files containing just the config symbols that you are interested
70in.  Then the kernel config system generates the full .config file,
71including symbols of your miniconfig file.
72
73This 'KCONFIG_ALLCONFIG' file is a config file which contains
74(usually a subset of all) preset config symbols.  These variable
75settings are still subject to normal dependency checks.
76
77Examples:
78	KCONFIG_ALLCONFIG=custom-notebook.config make allnoconfig
79or
80	KCONFIG_ALLCONFIG=mini.config make allnoconfig
81or
82	make KCONFIG_ALLCONFIG=mini.config allnoconfig
83
84These examples will disable most options (allnoconfig) but enable or
85disable the options that are explicitly listed in the specified
86mini-config files.
87
88______________________________________________________________________
89Environment variables for 'silentoldconfig'
90
91KCONFIG_NOSILENTUPDATE
92--------------------------------------------------
93If this variable has a non-blank value, it prevents silent kernel
94config updates (requires explicit updates).
95
96KCONFIG_AUTOCONFIG
97--------------------------------------------------
98This environment variable can be set to specify the path & name of the
99"auto.conf" file.  Its default value is "include/config/auto.conf".
100
101KCONFIG_TRISTATE
102--------------------------------------------------
103This environment variable can be set to specify the path & name of the
104"tristate.conf" file.  Its default value is "include/config/tristate.conf".
105
106KCONFIG_AUTOHEADER
107--------------------------------------------------
108This environment variable can be set to specify the path & name of the
109"autoconf.h" (header) file.
110Its default value is "include/generated/autoconf.h".
111
112
113======================================================================
114menuconfig
115--------------------------------------------------
116
117SEARCHING for CONFIG symbols
118
119Searching in menuconfig:
120
121	The Search function searches for kernel configuration symbol
122	names, so you have to know something close to what you are
123	looking for.
124
125	Example:
126		/hotplug
127		This lists all config symbols that contain "hotplug",
128		e.g., HOTPLUG, HOTPLUG_CPU, MEMORY_HOTPLUG.
129
130	For search help, enter / followed TAB-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
135		/^hotplug
136
137______________________________________________________________________
138User interface options for 'menuconfig'
139
140MENUCONFIG_COLOR
141--------------------------------------------------
142It is possible to select different color themes using the variable
143MENUCONFIG_COLOR.  To select a theme use:
144
145	make MENUCONFIG_COLOR=<theme> menuconfig
146
147Available themes are:
148  mono       => selects colors suitable for monochrome displays
149  blackbg    => selects a color scheme with black background
150  classic    => theme with blue background. The classic look
151  bluetitle  => a LCD friendly version of classic. (default)
152
153MENUCONFIG_MODE
154--------------------------------------------------
155This mode shows all sub-menus in one large tree.
156
157Example:
158	make MENUCONFIG_MODE=single_menu menuconfig
159
160
161======================================================================
162xconfig
163--------------------------------------------------
164
165Searching in xconfig:
166
167	The Search function searches for kernel configuration symbol
168	names, so you have to know something close to what you are
169	looking for.
170
171	Example:
172		Ctrl-F hotplug
173	or
174		Menu: File, Search, hotplug
175
176	lists all config symbol entries that contain "hotplug" in
177	the symbol name.  In this Search dialog, you may change the
178	config setting for any of the entries that are not grayed out.
179	You can also enter a different search string without having
180	to return to the main menu.
181
182
183======================================================================
184gconfig
185--------------------------------------------------
186
187Searching in gconfig:
188
189	None (gconfig isn't maintained as well as xconfig or menuconfig);
190	however, gconfig does have a few more viewing choices than
191	xconfig does.
192
193###
194