finally move buildroot-ng to trunk

include/prereq.mk

@@ -0,0 +1,54 @@
+# 
+# Copyright (C) 2006 OpenWrt.org
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+$(TMP_DIR):
+	mkdir -p $@
+
+prereq:
+	if [ -f $(TMP_DIR)/.prereq-error ]; then \
+		echo; \
+		cat $(TMP_DIR)/.prereq-error; \
+		echo; \
+		rm -rf $(TMP_DIR); \
+		false; \
+	fi
+	rm -rf $(TMP_DIR)
+	mkdir -p $(TMP_DIR)
+
+.SILENT: $(TMP_DIR) prereq
+
+define Require
+  export PREREQ_CHECK=1
+  ifeq ($$(CHECK_$(1)),)
+    prereq: prereq-$(1)
+
+    prereq-$(1): $(TMP_DIR) FORCE
+		echo -n "Checking '$(1)'... "
+		if $(NO_TRACE_MAKE) -f $(firstword $(MAKEFILE_LIST)) check-$(1) >/dev/null 2>/dev/null; then \
+			echo 'ok.'; \
+		else \
+			echo 'failed.'; \
+			echo -e "$(strip $(2))" >> $(TMP_DIR)/.prereq-error; \
+		fi
+
+    check-$(1): FORCE
+	  $(call Require/$(1))
+    CHECK_$(1):=1
+
+    .SILENT: prereq-$(1) check-$(1)
+  endif
+endef
+
+
+define RequireCommand
+  define Require/$(1)
+    which $(1)
+  endef
+
+  $$(eval $$(call Require,$(1),$(2)))
+endef
+