[PATCH] kconfig: preset config during all*config

Allow to force setting of config variables during all{no,mod,yes,random}config
to a specific value.  For that conf first checks the KCONFIG_ALLCONFIG
environment variable for a file name, otherwise it checks for
all{no,mod,yes,random}.config and all.config.  The file is a normal config
file, which presets the config variables, but they are still subject to normal
dependency checks.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 02f670c..4bba620 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -69,15 +69,13 @@
 	return name;
 }
 
-int conf_read(const char *name)
+int conf_read_simple(const char *name)
 {
 	FILE *in = NULL;
 	char line[1024];
 	char *p, *p2;
 	int lineno = 0;
 	struct symbol *sym;
-	struct property *prop;
-	struct expr *e;
 	int i;
 
 	if (name) {
@@ -232,6 +230,19 @@
 
 	if (modules_sym)
 		sym_calc_value(modules_sym);
+	return 0;
+}
+
+int conf_read(const char *name)
+{
+	struct symbol *sym;
+	struct property *prop;
+	struct expr *e;
+	int i;
+
+	if (conf_read_simple(name))
+		return 1;
+
 	for_all_symbols(i, sym) {
 		sym_calc_value(sym);
 		if (sym_has_value(sym) && !sym_is_choice_value(sym)) {