kconfig: add helper to set config symbol from environment variable

Add conf_set_env_sym() that can set an already defined symbol
based on the value of an environment variable.

Unknown symbols are silently ignored.
A warning is printed if the value of the environment variable
is unexpected.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Roman Zippel <zippel@linux-m68k.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h
index 4d09f6ddefe3..dca294e90cc3 100644
--- a/scripts/kconfig/lkc_proto.h
+++ b/scripts/kconfig/lkc_proto.h
@@ -1,6 +1,7 @@
 
 /* confdata.c */
 P(conf_parse,void,(const char *name));
+P(conf_set_env_sym,int,(const char *envname, const char *symname, int def));
 P(conf_read,int,(const char *name));
 P(conf_read_simple,int,(const char *name, int));
 P(conf_write,int,(const char *name));