[coreboot-gerrit] Change in coreboot[master]: payloads/LinuxBoot: make linux kernel build reproducible

[Patrick Georgi (Code Review)]

Patrick Georgi has submitted this change. ( https://review.coreboot.org/c/coreboot/+/35393 )

Change subject: payloads/LinuxBoot: make linux kernel build reproducible
......................................................................

payloads/LinuxBoot: make linux kernel build reproducible

Reproducible builds have to be independent from user, host,
domain, time.
Taken from OpenWrt (GPL2).

Change-Id: I420588acc66647051c08e4da6fbedc205cd62877
Signed-off-by: Alexander Couzens 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35393
Reviewed-by: Patrick Georgi 
Tested-by: build bot (Jenkins) 
---
M payloads/external/LinuxBoot/targets/linux.mk
1 file changed, 5 insertions(+), 1 deletion(-)

Approvals:
  build bot (Jenkins): Verified
  Patrick Georgi: Looks good to me, approved

diff --git a/payloads/external/LinuxBoot/targets/linux.mk b/payloads/external/LinuxBoot/targets/linux.mk
index 9906729..c6f4395 100644
--- a/payloads/external/LinuxBoot/targets/linux.mk
+++ b/payloads/external/LinuxBoot/targets/linux.mk
@@ -18,7 +18,11 @@

OBJCOPY:=$(LINUXBOOT_CROSS_COMPILE)objcopy
 KERNEL_MAKE_FLAGS = \
-	ARCH=$(ARCH-y)
+	ARCH=$(ARCH-y) \
+	KBUILD_BUILD_USER="coreboot" \
+	KBUILD_BUILD_HOST="reproducible" \
+	KBUILD_BUILD_TIMESTAMP="$(shell perl -e 'print scalar gmtime($(SOURCE_DATE_EPOCH))')" \
+	KBUILD_BUILD_VERSION="0"

ifeq ($(CONFIG_LINUXBOOT_KERNEL_CUSTOM),y)
    kernel_version:=$(CONFIG_LINUXBOOT_KERNEL_CUSTOM_VERSION)