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Diffstat (limited to 'Documentation/kbuild/kconfig-language.rst')
| -rw-r--r-- | Documentation/kbuild/kconfig-language.rst | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/Documentation/kbuild/kconfig-language.rst b/Documentation/kbuild/kconfig-language.rst index 79ac2e8184f6..71b38a7670f3 100644 --- a/Documentation/kbuild/kconfig-language.rst +++ b/Documentation/kbuild/kconfig-language.rst @@ -150,6 +150,12 @@ applicable everywhere (see syntax). That will limit the usefulness but on the other hand avoid the illegal configurations all over. + If "select" <symbol> is followed by "if" <expr>, <symbol> will be + selected by the logical AND of the value of the current menu symbol + and <expr>. This means, the lower limit can be downgraded due to the + presence of "if" <expr>. This behavior may seem weird, but we rely on + it. (The future of this behavior is undecided.) + - weak reverse dependencies: "imply" <symbol> ["if" <expr>] This is similar to "select" as it enforces a lower limit on another @@ -184,7 +190,7 @@ applicable everywhere (see syntax). ability to hook into a secondary subsystem while allowing the user to configure that subsystem out without also having to unset these drivers. - Note: If the combination of FOO=y and BAR=m causes a link error, + Note: If the combination of FOO=y and BAZ=m causes a link error, you can guard the function call with IS_REACHABLE():: foo_init() @@ -202,6 +208,10 @@ applicable everywhere (see syntax). imply BAR imply BAZ + Note: If "imply" <symbol> is followed by "if" <expr>, the default of <symbol> + will be the logical AND of the value of the current menu symbol and <expr>. + (The future of this behavior is undecided.) + - limiting menu display: "visible if" <expr> This attribute is only applicable to menu blocks, if the condition is @@ -399,19 +409,9 @@ choices:: "endchoice" This defines a choice group and accepts any of the above attributes as -options. A choice can only be of type bool or tristate. If no type is -specified for a choice, its type will be determined by the type of -the first choice element in the group or remain unknown if none of the -choice elements have a type specified, as well. - -While a boolean choice only allows a single config entry to be -selected, a tristate choice also allows any number of config entries -to be set to 'm'. This can be used if multiple drivers for a single -hardware exists and only a single driver can be compiled/loaded into -the kernel, but all drivers can be compiled as modules. - -A choice accepts another option "optional", which allows to set the -choice to 'n' and no entry needs to be selected. +options. + +A choice only allows a single config entry to be selected. comment:: |