examples: add initial examples for RFC

Add hello_world and random(generate UUID) examples

Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: Igor Opaniuk <igor.opaniuk@linaro.org>
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..8b0adc0
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,36 @@
+export V?=0
+
+OUTPUT_DIR := $(CURDIR)/out
+EXAMPLE_LIST := hello_world random
+
+.PHONY: all
+all: examples prepare-for-rootfs
+
+.PHONY: clean
+clean: examples-clean prepare-for-rootfs-clean
+
+examples:
+	for example in $(EXAMPLE_LIST); do \
+		$(MAKE) -C $$example CROSS_COMPILE="$(HOST_CROSS_COMPILE)"; \
+	done
+
+examples-clean:
+	for example in $(EXAMPLE_LIST); do \
+		$(MAKE) -C $$example clean; \
+	done
+
+prepare-for-rootfs: examples
+	echo "Copying example CA and TA binaries to $(OUTPUT_DIR)..."
+	@mkdir -p $(OUTPUT_DIR)
+	@mkdir -p $(OUTPUT_DIR)/ta
+	@mkdir -p $(OUTPUT_DIR)/ca
+	@for example in $(EXAMPLE_LIST); do \
+		if [ -e $$example/host/$$example ]; then \
+			cp -p $$example/host/optee_$$example $(OUTPUT_DIR)/ca/; \
+		fi; \
+		cp -pr $$example/ta/*.ta $(OUTPUT_DIR)/ta/; \
+	done
+
+prepare-for-rootfs-clean:
+	rm -rf $(OUTPUT_DIR)/ta/*
+	rm -rf $(OUTPUT_DIR)/ca/*