linux-raspberrypi: Enable kernel cache mechanism

Enable kernel cache based configuration of the linux-raspberrypi kernel.

Signed-off-by: Martin Borg <martin.borg@enea.com>
Signed-off-by: Adrian Dudau <adrian.dudau@enea.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/recipes-kernel/linux/linux-raspberrypi_4.9.bbappend b/recipes-kernel/linux/linux-raspberrypi_4.9.bbappend
new file mode 100644
index 0000000..41e9c50
--- /dev/null
+++ b/recipes-kernel/linux/linux-raspberrypi_4.9.bbappend
@@ -0,0 +1,21 @@
+require recipes-kernel/linux/linux-deploy-kconfig.inc
+
+# The meta-raspberrypi layer generates the kernel configuration using
+# "yes '' | make oldconfig", so we need to instruct the Yocto kernel
+# mechanism to use KCONFIG_MODE "--alldefconfig" to produce a similar
+# end result.
+KCONFIG_MODE = "--alldefconfig"
+
+# The .config file generated using the kernel cache mechanism will be
+# cleaned up by meta-raspberrypi layer (see do_configure_prepend()
+# in meta-raspberrypi/recipes-kernel/linux/linux-rpi.inc).
+# As a workaround, we copy the kernel cache generated .config file to
+# ${WORKDIR}/defconfig, which will then be used as default configuration
+# by meta-raspberrypi.
+do_configure_prepend() {
+  cp ${B}/.config ${WORKDIR}/defconfig
+}
+
+SRCREV_metaenea ?= "43e34f5a4b6e0f6e68c64525728412952add9c84"
+KENEABRANCH = "raspberrypi-4.9"
+SRC_URI_append = " git://git@git.enea.com/linux/enea-kernel-cache.git;protocol=ssh;type=kmeta;name=metaenea;branch=${KENEABRANCH};destsuffix=enea-kernel-cache"