kernel: predefine KBUILD_BUILD_USER and KBUILD_BUILD_HOST

By exporting KBUILD_BUILD_USER with a pre-defined value we improve the
reproducibility of the kernel and remove the requirement for whoami in the
HOSTTOOLS.
KBUILD_BUILD_HOST also helps improve the reproducibility of the kernel.

For more kernel reproducibility options see:
https://lwn.net/Articles/437864/

Signed-off-by: Joshua Lock <joshua.g.lock@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

diff --git a/meta/classes/kernel.bbclass b/meta/classes/kernel.bbclass
index 8954b28b2c26d2b2faa37f1bb508be69f448df00..7a134d5c290b4530a577410374963bdb4097fa0b 100644 (file)
--- a/meta/classes/kernel.bbclass
+++ b/meta/classes/kernel.bbclass
@@ -130,6 +130,8 @@ PACKAGES_DYNAMIC += "^kernel-firmware-.*"
 
 export OS = "${TARGET_OS}"
 export CROSS_COMPILE = "${TARGET_PREFIX}"
+export KBUILD_BUILD_USER = "oe-user"
+export KBUILD_BUILD_HOST = "oe-host"
 
 KERNEL_PRIORITY ?= "${@int(d.getVar('PV').split('-')[0].split('+')[0].split('.')[0]) * 10000 + \
                        int(d.getVar('PV').split('-')[0].split('+')[0].split('.')[1]) * 100 + \