[U-Boot-Users] [patch] only update version header as needed

[Mike Frysinger]

Constantly rebuilding the version header will force useless relinking, so we
simply need to compare the new header with the existing one before updating
it.

Signed-off-by: Mike Frysinger <vapier at gentoo.org>
---
diff --git a/Makefile b/Makefile
index 0f6cc59..7655b23 100644
--- a/Makefile
+++ b/Makefile
@@ -337,7 +337,8 @@ $(VERSION_FILE):
 		echo -n "$(U_BOOT_VERSION)" ; \
 		echo -n $(shell $(CONFIG_SHELL) $(TOPDIR)/tools/setlocalversion \
 			 $(TOPDIR)) ; \
-		echo "\"" ) > $(VERSION_FILE)
+		echo "\"" ) > $@.tmp
+		@cmp -s $@ $@.tmp && rm -f $@.tmp || mv -f $@.tmp $@
 
 gdbtools:
 		$(MAKE) -C tools/gdb all || exit 1