1 files changed, 78 insertions, 0 deletions
diff --git a/build/cache.mk b/build/cache.mk
new file mode 100644
index 00000000..fdfd0034
--- /dev/null
+++ b/build/cache.mk
@@ -0,0 +1,78 @@
+##############################################################################
+# Copyright (c) 2015 Ericsson AB and others.
+# stefan.k.berg@ericsson.com
+# jonas.bjurel@ericsson.com
+# All rights reserved. This program and the accompanying materials
+# are made available under the terms of the Apache License, Version 2.0
+# which accompanies this distribution, and is available at
+# http://www.apache.org/licenses/LICENSE-2.0
+##############################################################################
+
+SHELL = /bin/bash
+CACHEVALIDATE := $(addsuffix .validate,$(SUBDIRS))
+CACHECLEAN := $(addsuffix .clean,$(CACHEFILES) $(CACHEDIRS))
+
+############################################################################
+# BEGIN of variables to customize
+#
+CACHEFILES += .versions
+CACHEFILES += $(shell basename $(ISOSRC))
+#
+# END of variables to customize
+############################################################################
+
+.PHONY: prepare-cache
+prepare-cache: make-cache-dir $(CACHEDIRS) $(CACHEFILES)
+
+.PHONY: make-cache-dir
+make-cache-dir:
+	@rm -rf ${CACHE_DIR}
+	@mkdir ${CACHE_DIR}
+
+.PHONY: clean-cache
+clean-cache: $(CACHECLEAN)
+	@rm -rf ${CACHE_DIR}
+
+.PHONY: $(CACHEDIRS)
+$(CACHEDIRS):
+	@mkdir -p $(dir $(CACHE_DIR)/$@)
+	@if [ ! -d $(BUILD_BASE)/$@ ]; then\
+	   mkdir -p $(BUILD_BASE)/$@;\
+	fi
+	@ln -s $(BUILD_BASE)/$@ $(CACHE_DIR)/$@
+
+.PHONY: $(CACHEFILES)
+$(CACHEFILES):
+	@mkdir -p $(dir $(CACHE_DIR)/$@)
+	@if [ ! -d $(dir $(BUILD_BASE)/$@) ]; then\
+	   mkdir -p $(dir $(BUILD_BASE)/$@);\
+	fi
+
+	@if [ ! -f $(BUILD_BASE)/$@ ]; then\
+	   echo " " > $(BUILD_BASE)/$@;\
+ 	   ln -s $(BUILD_BASE)/$@ $(CACHE_DIR)/$@;\
+	   rm -f $(BUILD_BASE)/$@;\
+	else\
+	   ln -s $(BUILD_BASE)/$@ $(CACHE_DIR)/$@;\
+	fi
+
+.PHONY: validate-cache
+validate-cache: $(CACHEVALIDATE)
+	@if [[ $(shell md5sum $(BUILD_BASE)/config.mk | cut -f1 -d " ") != $(shell cat $(VERSION_FILE) | grep config.mk | awk '{print $$NF}') ]]; then\
+	   echo "Cache does not match current config.mk definition, cache must be rebuilt";\
+	   exit 1;\
+	fi;
+
+	@if [[ $(shell md5sum $(BUILD_BASE)/cache.mk | cut -f1 -d " ") != $(shell cat $(VERSION_FILE) | grep cache.mk | awk '{print $$NF}') ]]; then\
+	   echo "Cache does not match current cache.mk definition, cache must be rebuilt";\
+	   exit 1;\
+	fi;
+
+.PHONY: $(CACHEVALIDATE)
+$(CACHEVALIDATE): %.validate:
+	@echo VALIDATE $(CACHEVALIDATE)
+	$(MAKE) -C $* -f Makefile validate-cache
+
+.PHONY: $(CACHECLEAN)
+$(CACHECLEAN): %.clean:
+	rm -rf ${CACHE_DIR}/$*