[1/2] make rootfs rebuild ondemand

Currently it is based on directory dependencies so that not all changes could be detected.

README.md

@@ -66,8 +66,6 @@ Build a single rootfs target:
 make openEuler-24.03-LTS-SP1-base-rootfs
 ```
 
-> Once a rootfs target is created, it will never be created again and will be used to build all related BSP targets.
-
 Build all rootfs targets one by one, under a different directory `/tmp/build`:
 
 ```shell
@@ -80,7 +78,7 @@ Build all available BSP targets, parallelly:
 make -j$(nproc) all_bsp
 ```
 
-> BSP target will be rebuilt each time
+> BSP target will be rebuilt each time even if no configuration is changed
 
 Cleanup:
 

functions.mk

@@ -97,11 +97,11 @@ $(STAGING_DIR)/$$(DISTRO_NAME)/$$(RELEASE_NAME)/receipes/$$(RECEIPE_NAME): $$(fo
 .PHONY: $$(DISTRO_NAME)-$$(RELEASE_NAME)-$$(RECEIPE_NAME)-rootfs
 $$(DISTRO_NAME)-$$(RELEASE_NAME)-$$(RECEIPE_NAME)-rootfs: $$($$(DISTRO_NAME)_$$(RELEASE_NAME)_$$(RECEIPE_NAME)_ARTIFACT)
 define GENERATE_TAR_TARGET
-$$($$(DISTRO_NAME)_$$(RELEASE_NAME)_$$(RECEIPE_NAME)_ARTIFACT): | $(STAGING_DIR)/$$(DISTRO_NAME)/$$(RELEASE_NAME)/receipes/$$(RECEIPE_NAME)
+$$($$(DISTRO_NAME)_$$(RELEASE_NAME)_$$(RECEIPE_NAME)_ARTIFACT): $(STAGING_DIR)/$$(DISTRO_NAME)/$$(RELEASE_NAME)/receipes/$$(RECEIPE_NAME)
 	$$$$(dir_guard)
 	$(CONTAINER_CMD) run --rm \
 		-v $(ROOT_DIR)/tools:/image-builder/tools:ro \
-		-v $$$$|:/image-builder/receipe:ro \
+		-v $$$$<:/image-builder/receipe:ro \
 		-v $$$$(dir $$$$@):/image-builder/output \
 		$(CONTAINER_IMAGE_TAG) \
 		/bin/sh -c ' \