[package] add usbreset - a small simple utility to send port rests to selected usb...

[openwrt.git] / include / prereq.mk

diff --git a/include/prereq.mk b/include/prereq.mk
index 660f67c..4a55c89 100644 (file)
--- a/include/prereq.mk
+++ b/include/prereq.mk
@@ -5,6 +5,9 @@
 # See /LICENSE for more information.
 #
 
+ifneq ($(__prereq_inc),1)
+__prereq_inc:=1
+
 prereq:
        if [ -f $(TMP_DIR)/.prereq-error ]; then \
                echo; \
@@ -15,6 +18,7 @@ prereq:
        fi
 
 .SILENT: prereq
+endif
 
 define Require
   export PREREQ_CHECK=1
@@ -47,4 +51,12 @@ define RequireCommand
   $$(eval $$(call Require,$(1),$(2)))
 endef
 
+define RequireHeader
+  define Require/$(1)
+    [ -e "$(1)" ]
+  endef
+  
+  $$(eval $$(call Require,$(1),$(2)))
+endef
+
 .NOTPARALLEL: