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authorRoman Zippel <zippel@linux-m68k.org>2008-01-13 22:50:54 -0500
committerSam Ravnborg <sam@ravnborg.org>2008-01-28 17:14:39 -0500
commit93449082e905ce73d0346d617dd67c4b668b58af (patch)
treeeba7030f32ce18fa71562224ee2e0d8ddda33421 /Documentation/kbuild
parent7a962923359768e04137125bd479fd0dfa6117d3 (diff)
kconfig: environment symbol support
Add the possibility to import a value from the environment into kconfig via the option syntax. Beside flexibility this has the advantage providing proper dependencies. Documented the options syntax. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Diffstat (limited to 'Documentation/kbuild')
-rw-r--r--Documentation/kbuild/kconfig-language.txt21
1 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/kbuild/kconfig-language.txt b/Documentation/kbuild/kconfig-language.txt
index 53ca12f7999f..a43fcc68e171 100644
--- a/Documentation/kbuild/kconfig-language.txt
+++ b/Documentation/kbuild/kconfig-language.txt
@@ -127,6 +127,27 @@ applicable everywhere (see syntax).
127 used to help visually separate configuration logic from help within 127 used to help visually separate configuration logic from help within
128 the file as an aid to developers. 128 the file as an aid to developers.
129 129
130- misc options: "option" <symbol>[=<value>]
131 Various less common options can be defined via this option syntax,
132 which can modify the behaviour of the menu entry and its config
133 symbol. These options are currently possible:
134
135 - "defconfig_list"
136 This declares a list of default entries which can be used when
137 looking for the default configuration (which is used when the main
138 .config doesn't exists yet.)
139
140 - "modules"
141 This declares the symbol to be used as the MODULES symbol, which
142 enables the third modular state for all config symbols.
143
144 - "env"=<value>
145 This imports the environment variable into Kconfig. It behaves like
146 a default, except that the value comes from the environment, this
147 also means that the behaviour when mixing it with normal defaults is
148 undefined at this point. The symbol is currently not exported back
149 to the build environment (if this is desired, it can be done via
150 another symbol).
130 151
131Menu dependencies 152Menu dependencies
132----------------- 153-----------------