From mboxrd@z Thu Jan 1 00:00:00 1970 From: Atharva Lele Date: Sun, 14 Jul 2019 21:53:35 +0530 Subject: [Buildroot] [PATCH 2/2] fs/cpio: make cpio rootfs reproducible In-Reply-To: <20190714162335.12684-1-itsatharva@gmail.com> References: <20190714162335.12684-1-itsatharva@gmail.com> Message-ID: <20190714162335.12684-2-itsatharva@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Pass the recommended argument in the CPIO manual to make cpio archives reproducible. Reference: https://www.gnu.org/software/cpio/manual/cpio.html#Copy_002dpass-mode Pre-patch diffoscope output: https://gitlab.com/snippets/1874745 Post-patch: https://gitlab.com/snippets/1874746 We can see that post-patch, the archive related differences are removed. The differences are arising from utils/bin/getconf. This will have to be investigated further. However, that is unrelated to cpio. Signed-off-by: Atharva Lele --- Changes v1 -> v2: - Added comment - Build host-cpio if we are reproducible, reason is --reproducible option does not exist prior to cpio 2.12. (suggested by Yann, Arnout) --- fs/cpio/cpio.mk | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/cpio/cpio.mk b/fs/cpio/cpio.mk index 1f0cafe62f..521418f950 100644 --- a/fs/cpio/cpio.mk +++ b/fs/cpio/cpio.mk @@ -29,8 +29,16 @@ endif # BR2_ROOTFS_DEVICE_CREATION_STATIC ROOTFS_CPIO_PRE_GEN_HOOKS += ROOTFS_CPIO_ADD_INIT +# --repoducible option was not introduced until cpio v2.12. Some distros +# like Ubuntu 16.04 or Debian oldstable which package v2.11. Hence build +# host-cpio. +ifeq ($(BR2_REPRODUCIBLE), y) +ROOTFS_CPIO_DEPENDENCIES += host-cpio +CPIO_OPTS = --reproducible +endif + define ROOTFS_CPIO_CMD - cd $(TARGET_DIR) && find . | cpio --quiet -o -H newc > $@ + cd $(TARGET_DIR) && find . | cpio $(CPIO_OPTS) --quiet -o -H newc > $@ endef ifeq ($(BR2_TARGET_ROOTFS_CPIO_UIMAGE),y) -- 2.22.0