--- a/Config.in
+++ b/Config.in
@@ -36,7 +36,7 @@
 
 	config TARGET_ROOTFS_TGZ
 		bool "tgz"
-		default y if !USES_SQUASHFS && !USES_JFFS2
+		default y if USES_TGZ
 		depends !TARGET_ROOTFS_INITRAMFS
 		help
 		  Build a compressed tar archive of the the root filesystem

--- a/scripts/metadata.pl
+++ b/scripts/metadata.pl
@@ -253,6 +253,7 @@
 		/squashfs/ and $ret .= "\tselect USES_SQUASHFS\n";
 		/jffs2/ and $ret .= "\tselect USES_JFFS2\n";
 		/ext2/ and $ret .= "\tselect USES_EXT2\n";
+		/tgz/ and $ret .= "\tselect USES_TGZ\n";
 	}
 	return $ret;
 }

--- a/target/Config.in
+++ b/target/Config.in
@@ -33,6 +33,9 @@
 	bool
 
 config USES_EXT2
+	bool
+
+config USES_TGZ
 	bool
 
 config PROFILE_KCONFIG 

--- a/target/linux/adm5120-2.6/profiles/RB1xx.mk
+++ b/target/linux/adm5120-2.6/profiles/RB1xx.mk
@@ -8,6 +8,7 @@
 define Profile/RouterBoard
   NAME:=RouterBoard RB1xx
   PACKAGES:=kmod-madwifi
+  FEATURES+=tgz
 endef
 
 define Profile/RouterBoard/Description