kconfig: add *_silentdefconfig feature for config targets

index 8be6a42..fecf5f8 100644
@@ -22,6 +22,7 @@ enum {
 	ask_new,
 	ask_silent,
 	set_default,
+	set_silentdefault,
 	set_yes,
 	set_mod,
 	set_no,

@@ -64,10 +65,11 @@ static void strip(char *str)
 
 static void check_stdin(void)
 {
-	if (!valid_stdin && input_mode == ask_silent) {
+	if (!valid_stdin && (input_mode == ask_silent ||
+			input_mode == set_silentdefault)) {
 		printf(_("aborted!\n\n"));
 		printf(_("Console input/output is redirected. "));
-		printf(_("Run 'make oldconfig' to update configuration.\n\n"));
+		printf(_("Configuration file needs to be updated.\n\n"));
 		exit(1);
 	}
 }

@@ -102,6 +104,7 @@ static void conf_askvalue(struct symbol *sym, const char *def)
 		break;
 	case ask_new:
 	case ask_silent:
+	case set_silentdefault:
 		if (sym_has_value(sym)) {
 			printf("%s\n", def);
 			return;

@@ -349,6 +352,7 @@ static int conf_choice(struct menu *menu)
 		switch (input_mode) {
 		case ask_new:
 		case ask_silent:
+		case set_silentdefault:
 			if (!is_new) {
 				cnt = def;
 				printf("%d\n", cnt);

@@ -420,7 +424,9 @@ static void conf(struct menu *menu)
 
 		switch (prop->type) {
 		case P_MENU:
-			if (input_mode == ask_silent && rootEntry != menu) {
+			if ((input_mode == ask_silent ||
+					input_mode == set_silentdefault) &&
+					rootEntry != menu) {
 				check_conf(menu);
 				return;
 			}

@@ -504,6 +510,16 @@ int main(int ac, char **av)
 			input_mode = ask_silent;
 			valid_stdin = isatty(0) && isatty(1) && isatty(2);
 			break;
+		case 'S':
+			input_mode = set_silentdefault;
+			valid_stdin = isatty(0) && isatty(1) && isatty(2);
+			defconfig_file = av[i++];
+			if (!defconfig_file) {
+				printf("%s: No default config file specified\n",
+					av[0]);
+				exit(1);
+			}
+			break;
 		case 'd':
 			input_mode = set_default;
 			break;

@@ -553,6 +569,14 @@ int main(int ac, char **av)
 			exit(1);
 		}
 		break;
+	case set_silentdefault:
+		if (conf_read(defconfig_file)) {
+			printf("***\n"
+				"*** Can't find default configuration \"%s\"!\n"
+				"***\n", defconfig_file);
+			exit(1);
+		}
+		break;
 	case ask_silent:
 		if (stat(".config", &tmpstat)) {
 			printf(_("***\n"

@@ -593,7 +617,7 @@ int main(int ac, char **av)
 		break;
 	}
 
-	if (input_mode != ask_silent) {
+	if (input_mode != ask_silent && input_mode != set_silentdefault) {
 		rootEntry = &rootmenu;
 		conf(&rootmenu);
 		if (input_mode == ask_all) {

@@ -606,19 +630,21 @@ int main(int ac, char **av)
 			fprintf(stderr, _("\n*** Kernel configuration requires explicit update.\n\n"));
 			return 1;
 		}
-	} else
+	} else if (input_mode != set_silentdefault)
 		goto skip_check;
 
 	do {
 		conf_cnt = 0;
 		check_conf(&rootmenu);
 	} while (conf_cnt);
-	if (conf_write(NULL)) {
+	if (conf_write(NULL, input_mode == ask_silent ||
+			input_mode == set_silentdefault)) {
 		fprintf(stderr, _("\n*** Error during writing of the kernel configuration.\n\n"));
 		return 1;
 	}
 skip_check:
-	if (input_mode == ask_silent && conf_write_autoconf()) {
+	if ((input_mode == ask_silent || input_mode == set_silentdefault) &&
+			conf_write_autoconf()) {
 		fprintf(stderr, _("\n*** Error during writing of the kernel configuration.\n\n"));
 		return 1;
 	}

index b2913e9..5d80e85 100644
@@ -384,7 +384,7 @@ int conf_read(const char *name)
 	return 0;
 }
 
-int conf_write(const char *name)
+int conf_write(const char *name, int quiet)
 {
 	FILE *out;
 	struct symbol *sym;

@@ -539,9 +539,10 @@ int conf_write(const char *name)
 			return 1;
 	}
 
-	printf(_("#\n"
-		 "# configuration written to %s\n"
-		 "#\n"), newname);
+	if (!quiet)
+		printf("#\n"
+			"# configuration written to %s\n"
+			"#\n", newname);
 
 	sym_set_change_count(0);
 

index 262908c..6b883dd 100644
@@ -621,7 +621,7 @@ void on_load1_activate(GtkMenuItem * menuitem, gpointer user_data)
 
 void on_save_activate(GtkMenuItem * menuitem, gpointer user_data)
 {
-	if (conf_write(NULL))
+	if (conf_write(NULL, 0))
 		text_insert_msg(_("Error"), _("Unable to save configuration !"));
 }
 

@@ -634,7 +634,7 @@ store_filename(GtkFileSelection * file_selector, gpointer user_data)
 	fn = gtk_file_selection_get_filename(GTK_FILE_SELECTION
 					     (user_data));
 
-	if (conf_write(fn))
+	if (conf_write(fn, 0))
 		text_insert_msg(_("Error"), _("Unable to save configuration !"));
 
 	gtk_widget_destroy(GTK_WIDGET(user_data));

index 4d09f6d..be29e28 100644
@@ -3,7 +3,7 @@
 P(conf_parse,void,(const char *name));
 P(conf_read,int,(const char *name));
 P(conf_read_simple,int,(const char *name, int));
-P(conf_write,int,(const char *name));
+P(conf_write,int,(const char *name, int));
 P(conf_write_autoconf,int,(void));
 P(conf_get_changed,bool,(void));
 P(conf_set_changed_callback, void,(void (*fn)(void)));

index bc5854e..1f67b18 100644
@@ -869,7 +869,7 @@ static void conf_save(void)
 		case 0:
 			if (!dialog_input_result[0])
 				return;
-			if (!conf_write(dialog_input_result)) {
+			if (!conf_write(dialog_input_result, 0)) {
 				set_config_filename(dialog_input_result);
 				return;
 			}

@@ -929,7 +929,7 @@ int main(int ac, char **av)
 
 	switch (res) {
 	case 0:
-		if (conf_write(filename)) {
+		if (conf_write(filename, 0)) {
 			fprintf(stderr, _("\n\n"
 				"Error during writing of the kernel configuration.\n"
 				"Your kernel configuration changes were NOT saved."