build system: have tar use $SOURCE_DATE_EPOCH for --mtime

The --mtime argument to 'tar' sets the modification time for all files within
the archive, which determines the timestamp files will get when they are
extracted. In this case, rootfs and other tarballs will get mtimes which
correspond to the last commit timestamp of the build system, as reported by
git/subversion.

This is a step towards reproducible image builds.

Signed-off-by: bryan newbold <bnewbold@robocracy.org>
Signed-off-by: Alexander Couzens <lynxis@fe80.eu>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@48586 3c298f89-4303-0410-b956-a3cf2f4a3e73

diff --git a/include/image.mk b/include/image.mk
index 4eee4ad..8f81861 100644 (file)
--- a/include/image.mk
+++ b/include/image.mk
@@ -186,7 +186,8 @@ ifneq ($(CONFIG_NAND_SUPPORT),)
        [ -z "$(2)" ] || $(CP) "$(KDIR)/root.$(2)" "$(KDIR_TMP)/sysupgrade-$(1)/root"
        [ -z "$(3)" ] || $(CP) "$(3)" "$(KDIR_TMP)/sysupgrade-$(1)/kernel"
        (cd "$(KDIR_TMP)"; $(TAR) cvf \
-               "$(BIN_DIR)/$(IMG_PREFIX)-$(1)-$(2)-sysupgrade.tar" sysupgrade-$(1))
+               "$(BIN_DIR)/$(IMG_PREFIX)-$(1)-$(2)-sysupgrade.tar" sysupgrade-$(1) \
+                       $(if $(SOURCE_DATE_EPOCH),--mtime="@$(SOURCE_DATE_EPOCH)")
    endef
 
 # $(1) board name
@@ -248,7 +249,10 @@ define Image/mkfs/cpiogz
 endef
 
 define Image/mkfs/targz
-       $(TAR) -czpf $(BIN_DIR)/$(IMG_PREFIX)$(if $(PROFILE_SANITIZED),-$(PROFILE_SANITIZED))-rootfs.tar.gz --numeric-owner --owner=0 --group=0 --sort=name -C $(TARGET_DIR)/ .
+       $(TAR) -czpf $(BIN_DIR)/$(IMG_PREFIX)$(if $(PROFILE_SANITIZED),-$(PROFILE_SANITIZED))-rootfs.tar.gz \
+               --numeric-owner --owner=0 --group=0 --sort=name \
+               $(if $(SOURCE_DATE_EPOCH),--mtime="@$(SOURCE_DATE_EPOCH)") \
+               -C $(TARGET_DIR)/ .
 endef
 
 E2SIZE=$(shell echo $$(($(CONFIG_TARGET_ROOTFS_PARTSIZE)*1024*1024)))

diff --git a/include/kernel-build.mk b/include/kernel-build.mk
index 8bfd9c8..a52c90d 100644 (file)
--- a/include/kernel-build.mk
+++ b/include/kernel-build.mk
@@ -54,7 +54,9 @@ ifdef CONFIG_COLLECT_KERNEL_DEBUG
                $(STAGING_DIR_ROOT)/lib/modules/$(LINUX_VERSION)/* \
                $(KERNEL_BUILD_DIR)/debug/modules/
        $(FIND) $(KERNEL_BUILD_DIR)/debug -type f | $(XARGS) $(KERNEL_CROSS)strip --only-keep-debug
-       $(TAR) c -C $(KERNEL_BUILD_DIR) debug | bzip2 -c -9 > $(BIN_DIR)/kernel-debug.tar.bz2
+       $(TAR) c -C $(KERNEL_BUILD_DIR) debug \
+               $(if $(SOURCE_DATE_EPOCH),--mtime="@$(SOURCE_DATE_EPOCH)") \
+               | bzip2 -c -9 > $(BIN_DIR)/kernel-debug.tar.bz2
   endef
 endif
 

diff --git a/scripts/sysupgrade-nand.sh b/scripts/sysupgrade-nand.sh
index 92b326c..45b17da 100755 (executable)
--- a/scripts/sysupgrade-nand.sh
+++ b/scripts/sysupgrade-nand.sh
@@ -56,7 +56,12 @@ echo "BOARD=${board}" > "${tmpdir}/sysupgrade-${board}/CONTROL"
 [ -z "${rootfs}" ] || cp "${rootfs}" "${tmpdir}/sysupgrade-${board}/root"
 [ -z "${kernel}" ] || cp "${kernel}" "${tmpdir}/sysupgrade-${board}/kernel"
 
-(cd "$tmpdir"; tar cvf sysupgrade.tar sysupgrade-${board})
+mtime=""
+if [ -n "$SOURCE_DATE_EPOCH" ]; then
+       mtime="--mtime=@${SOURCE_DATE_EPOCH}"
+fi
+
+(cd "$tmpdir"; tar cvf sysupgrade.tar sysupgrade-${board} ${mtime})
 err="$?"
 if [ -e "$tmpdir/sysupgrade.tar" ]; then
        cp "$tmpdir/sysupgrade.tar" "$outfile"