[PATCH 2/3] kernel-yocto.bbclass: support modular kernel configs

[Mikko Rapeli <mikko.rapeli@linaro.org>]

Compile many kernel drivers as modules when recipe sets

MODULAR_KERNEL = "true"

This likely requires support for initramfs which includes
kernel modules needed to mount the rootfs.

SCC_OPTS can be used to add arguments to scc kernel config
generation call.

Signed-off-by: Mikko Rapeli <mikko.rapeli@linaro.org>
---
 meta/classes-recipe/kernel-yocto.bbclass | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/meta/classes-recipe/kernel-yocto.bbclass b/meta/classes-recipe/kernel-yocto.bbclass
index cef6b9ec3f..f98720bcec 100644
--- a/meta/classes-recipe/kernel-yocto.bbclass
+++ b/meta/classes-recipe/kernel-yocto.bbclass
@@ -26,6 +26,12 @@ KCONF_BSP_AUDIT_LEVEL ?= "0"
 KMETA_AUDIT ?= "yes"
 KMETA_AUDIT_WERROR ?= ""
 
+# most drivers as built in (default), or as modules
+MODULAR_KERNEL = "false"
+
+# options to scc
+SCC_OPTS ?= "${@bb.utils.contains('MODULAR_KERNEL', 'true', '-DMODULE_OR_Y=m', '', d)}"
+
 # returns local (absolute) path names for all valid patches in the
 # src_uri
 def find_patches(d,subdir):
@@ -298,7 +304,7 @@ do_kernel_metadata() {
 		elements="`echo -n ${bsp_definition} $sccs_defconfig ${sccs} ${patches} $KERNEL_FEATURES_FINAL`"
 		if [ -n "${elements}" ]; then
 			echo "${bsp_definition}" > ${S}/${meta_dir}/bsp_definition
-			scc --force -o ${S}/${meta_dir}:cfg,merge,meta ${includes} $sccs_defconfig $bsp_definition $sccs $patches $KERNEL_FEATURES_FINAL
+			scc ${SCC_OPTS} --force -o ${S}/${meta_dir}:cfg,merge,meta ${includes} $sccs_defconfig $bsp_definition $sccs $patches $KERNEL_FEATURES_FINAL
 			if [ $? -ne 0 ]; then
 				bbfatal_log "Could not generate configuration queue for ${KMACHINE}."
 			fi
-- 
2.43.0