Kernel and kernel modules contain hard coded paths referencing the host
build system. This is usually because the source code contains __FILE__
at some place. This prevents binary reproducibility. However, some compilers
allow remapping of the __FILE__ value. If we detect the compiler is capable
of doing this, we replace the source path $(S) part of __FILE__ by a string
"/kernel-source".
For example:
/data/master/build-repro/tmp/work-shared/qemux86/kernel-source/drivers/media/v4l2-core/videobuf2-core.c
will be replaced by a reproducible value:
/kernel-source/drivers/media/v4l2-core/videobuf2-core.c.
Signed-off-by: Juro Bystricky <juro.bystri...@intel.com>
---
meta/classes/kernel.bbclass | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/meta/classes/kernel.bbclass b/meta/classes/kernel.bbclass
index 8954b28..0a2cd3d 100644
--- a/meta/classes/kernel.bbclass
+++ b/meta/classes/kernel.bbclass
@@ -249,6 +249,18 @@ python do_devshell_prepend () {
addtask bundle_initramfs after do_install before do_deploy
+get_cc_option () {
+ # Check if KERNEL_CC supports the option "file-prefix-map".
+ # This option allows us to build images with __FILE__ values
that do not
+ # contain the host build path.
+ cc_option_supported=`${KERNEL_CC} -Q --help=joined | grep
ffile-prefix-map`
+ cc_extra=""
+ if [ $cc_option_supported = "-ffile-prefix-map=<old=new>" ];
then
+ cc_extra=-ffile-prefix-map=${S}=/kernel-source/
+ fi
+ echo $cc_extra
+}
+
kernel_do_compile() {
unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS MACHINE
# The $use_alternate_initrd is only set from
@@ -264,8 +276,9 @@ kernel_do_compile() {
copy_initramfs
use_alternate_initrd=CONFIG_INITRAMFS_SOURCE=${B}/usr/${INITRAMFS_IMAGE_NAME}.cpio
fi
+ cc_extra=$(get_cc_option)
for typeformake in ${KERNEL_IMAGETYPE_FOR_MAKE} ; do
- oe_runmake ${typeformake} CC="${KERNEL_CC}" LD="${KERNEL_LD}"
${KERNEL_EXTRA_ARGS} $use_alternate_initrd
+ oe_runmake ${typeformake} CC="${KERNEL_CC} $cc_extra "
LD="${KERNEL_LD}" ${KERNEL_EXTRA_ARGS} $use_alternate_initrd
for type in ${KERNEL_IMAGETYPES} ; do
if test "${typeformake}.gz" = "${type}"; then
mkdir -p "${KERNEL_OUTPUT_DIR}"
@@ -279,7 +292,8 @@ kernel_do_compile() {
do_compile_kernelmodules() {
unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS MACHINE
if (grep -q -i -e '^CONFIG_MODULES=y$' ${B}/.config); then
- oe_runmake -C ${B} ${PARALLEL_MAKE} modules CC="${KERNEL_CC}"
LD="${KERNEL_LD}" ${KERNEL_EXTRA_ARGS}
+ cc_extra=$(get_cc_option)
+ oe_runmake -C ${B} ${PARALLEL_MAKE} modules CC="${KERNEL_CC}
$cc_extra " LD="${KERNEL_LD}" ${KERNEL_EXTRA_ARGS}
# Module.symvers gets updated during the
# building of the kernel modules. We need to
--
2.7.4
--
_______________________________________________
Openembedded-core mailing list
Openembedded-core@lists.openembedded.org
http://lists.openembedded.org/mailman/listinfo/openembedded-core
