kernel/linux-kernel-base: Fix kernel build artefact determinism issues

With the 6.1 kernel we've seen reproducibility/determinism issues where the kernel
seems to rebuild headers referencing the hostname or local user. kernel-devsrc
building after the kernel seemed to trigger it in some cases.

Moving the definitions to the bbclass used by all the kernel recipe code including
kernel-devsrc seems to be the best way to ensure this doesn't happen.

(From OE-Core rev: 60681baa97daf4f3856453c34d6be08b6771a81b)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 4 insertions, 3 deletions

diff --git a/meta/classes-recipe/kernel.bbclass b/meta/classes-recipe/kernel.bbclass
index bd3b6471c6..4fbe84c4e4 100644
--- a/meta/classes-recipe/kernel.bbclass
+++ b/meta/classes-recipe/kernel.bbclass
@@ -210,9 +210,6 @@ PACKAGES_DYNAMIC += "^${KERNEL_PACKAGE_NAME}-firmware-.*"
 
 export OS = "${TARGET_OS}"
 export CROSS_COMPILE = "${TARGET_PREFIX}"
-export KBUILD_BUILD_VERSION = "1"
-export KBUILD_BUILD_USER ?= "oe-user"
-export KBUILD_BUILD_HOST ?= "oe-host"
 
 KERNEL_RELEASE ?= "${KERNEL_VERSION}"
 
diff --git a/meta/classes-recipe/linux-kernel-base.bbclass b/meta/classes-recipe/linux-kernel-base.bbclass
index cb2212c948..65cc48f304 100644
--- a/meta/classes-recipe/linux-kernel-base.bbclass
+++ b/meta/classes-recipe/linux-kernel-base.bbclass
@@ -43,5 +43,9 @@ def linux_module_packages(s, d):
     suffix = ""
     return " ".join(map(lambda s: "kernel-module-%s%s" % (s.lower().replace('_', '-').replace('@', '+'), suffix), s.split()))
 
+export KBUILD_BUILD_VERSION = "1"
+export KBUILD_BUILD_USER ?= "oe-user"
+export KBUILD_BUILD_HOST ?= "oe-host"
+
 # that's all