Split rootfs-overlay target from rootfs-init

Author: gsingh93

Makefile

@@ -252,9 +252,13 @@ $(ROOTFS_DIR):
 .PHONY: rootfs-init
 rootfs-init: | $(ROOTFS_DIR)
 	tar -xf $(ROOTFS_PARENT_DIR)/alpine-minirootfs-*-$(ARCH).tar.gz -C $(ROOTFS_DIR)
+	$(MAKE) rootfs-overlay
+
+.PHONY: rootfs-overlay
+rootfs-overlay: | $(ROOTFS_DIR)
 	cp -f -r $(CONFIG_DIR)/rootfs-overlay/. $(ROOTFS_DIR)
 	$(SCRIPT_DIR)/arch_specific.sh $(ARCH) $(ROOTFS_DIR)
-	$(MAKE) ext4
+	$(MAKE) rootfs
 
 .PHONY: ext4
 ext4: | $(ROOTFS_DIR)