kconfig: implement the `mainmenu' directive

If specified, the directive must be placed at the top of the Kconfig file.

We need to change the grammar to make the mainmenu directive set the
`rootmenu' prompt. This reflect how menu_add_prompt() works internally, ie.
set the prompt of the `current_entry', pointing originally to `rootmenu'.

Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Michal Marek <mmarek@suse.cz>

1 files changed, 2 insertions, 1 deletions

diff --git a/Documentation/kbuild/kconfig-language.txt b/Documentation/kbuild/kconfig-language.txt
index b472e4e0ba67..2fe93ca7c77c 100644
--- a/Documentation/kbuild/kconfig-language.txt
+++ b/Documentation/kbuild/kconfig-language.txt
@@ -322,7 +322,8 @@ mainmenu:
         "mainmenu" <prompt>
 
 This sets the config program's title bar if the config program chooses
-to use it.
+to use it. It should be placed at the top of the configuration, before any
+other statement.
 
 
 Kconfig hints