[openwrt/openwrt] mvebu: make boot filesystem reproducible

[LEDE Commits]

dangole pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/44b457168ef7a37533929c4332c86ef084d606a6

commit 44b457168ef7a37533929c4332c86ef084d606a6
Author: Daniel Golle <daniel at makrotopia.org>
AuthorDate: Mon Mar 28 18:25:34 2022 +0100

    mvebu: make boot filesystem reproducible
    
    Set timestamp option for make_ext4fs to make boot filesystem
    reproducible.
    
    Signed-off-by: Daniel Golle <daniel at makrotopia.org>
---
 target/linux/mvebu/image/Makefile | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/target/linux/mvebu/image/Makefile b/target/linux/mvebu/image/Makefile
index 44e66a5f87..b0498d34c9 100644
--- a/target/linux/mvebu/image/Makefile
+++ b/target/linux/mvebu/image/Makefile
@@ -34,7 +34,9 @@ define Build/boot-img-ext4
 	$(foreach dts,$(DEVICE_DTS), $(CP) $(KDIR)/image-$(dts).dtb $@.boot/$(dts).dtb;)
 	$(CP) $(IMAGE_KERNEL) $@.boot/$(KERNEL_NAME)
 	-$(CP) $@-boot.scr $@.boot/boot.scr
-	make_ext4fs -J -L kernel -l $(CONFIG_TARGET_KERNEL_PARTSIZE)M $@.bootimg $@.boot
+	make_ext4fs -J -L kernel -l $(CONFIG_TARGET_KERNEL_PARTSIZE)M \
+		$(if $(SOURCE_DATE_EPOCH),-T $(SOURCE_DATE_EPOCH)) \
+		$@.bootimg $@.boot
 endef
 
 define Build/buffalo-kernel-jffs2