[U-Boot] [PATCH] build: create time and date independent binary

[Heiko Schocher]

With this option enabled each compilation creates the exact
same binary. There are no timestamps, with which a U-Boot
binary can be identified.

This option is disabled by default.

Signed-off-by: Heiko Schocher <hs at denx.de>
---

 Kconfig  | 9 +++++++++
 Makefile | 8 ++++++++
 2 files changed, 17 insertions(+)

diff --git a/Kconfig b/Kconfig
index 15e15af..c0c7eb8 100644
--- a/Kconfig
+++ b/Kconfig
@@ -81,6 +81,15 @@ menuconfig EXPERT
 	  Only use this if you really know what you are doing.
 
 if EXPERT
+	config SYS_EXACT_BINARY
+	bool "Create time and date independent binary"
+	default n
+	help
+	  With this option enabled each compilation creates the exact
+	  same binary. There are no timestamps, with which a U-Boot
+	  binary can be identified.
+	  This option is disabled by default.
+
 	config SYS_MALLOC_CLEAR_ON_INIT
 	bool "Init with zeros the memory reserved for malloc (slow)"
 	default y
diff --git a/Makefile b/Makefile
index 0a674bf..4ae2701 100644
--- a/Makefile
+++ b/Makefile
@@ -1230,11 +1230,19 @@ define filechk_version.h
 	echo \#define LD_VERSION_STRING \"$$($(LD) --version | head -n 1)\"; )
 endef
 
+ifeq ($(CONFIG_SYS_EXACT_BINARY),y)
+define filechk_timestamp.h
+	(LC_ALL=C date +'#define U_BOOT_DATE "NODATE"'; \
+	LC_ALL=C date +'#define U_BOOT_TIME "NOTIME"'; \
+	LC_ALL=C date +'#define U_BOOT_TZ "NOTZ"')
+endef
+else
 define filechk_timestamp.h
 	(LC_ALL=C date +'#define U_BOOT_DATE "%b %d %C%y"'; \
 	LC_ALL=C date +'#define U_BOOT_TIME "%T"'; \
 	LC_ALL=C date +'#define U_BOOT_TZ "%z"')
 endef
+endif
 
 $(version_h): include/config/uboot.release FORCE
 	$(call filechk,version.h)
-- 
2.1.0