kernel-yocto: split meta data gathering into patch and config phases

do_kernel_metadata gathers and sanitizes the meta-data that is used
in later steps of the kernel-yocto build process. The processing
takes the form of configuration and patch gathering.

The current single pass of both config and patch gathering means
that patches can't modify in-tree configuration elements (although
this makes tracing configuration changes harder, it is a valid
workflow).

We can divide the routine into a patch and configuration phase, and
call the config variant after patching is done. This keeps the
common parts of the gahering intact, but allows us flexibilty in
when the stages happen.

(From OE-Core rev: 004da4c6c6029bb2bdcea6da8afa70368ddd1bca)

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/kernel-yocto.bbclass

@@ -87,6 +87,13 @@ def get_machine_branch(d, default):
 
 do_kernel_metadata() {
 	set +e
+
+	if [ -n "$1" ]; then
+		mode="$1"
+	else
+		mode="patch"
+	fi
+
 	cd ${S}
 	export KMETA=${KMETA}
 
@@ -120,14 +127,13 @@ do_kernel_metadata() {
 	if [ -n "${KBUILD_DEFCONFIG}" ]; then
 		if [ -f "${S}/arch/${ARCH}/configs/${KBUILD_DEFCONFIG}" ]; then
 			if [ -f "${WORKDIR}/defconfig" ]; then
-				# If the two defconfig's are different, warn that we didn't overwrite the
+				# If the two defconfig's are different, warn that we overwrote the
-				# one already placed in WORKDIR by the fetcher.
+				# one already placed in WORKDIR
 				cmp "${WORKDIR}/defconfig" "${S}/arch/${ARCH}/configs/${KBUILD_DEFCONFIG}"
 				if [ $? -ne 0 ]; then
-					bbwarn "defconfig detected in WORKDIR. ${KBUILD_DEFCONFIG} skipped"
+					bbdebug 1 "detected SRC_URI or unpatched defconfig in WORKDIR. ${KBUILD_DEFCONFIG} copied over it"
-				else
-					cp -f ${S}/arch/${ARCH}/configs/${KBUILD_DEFCONFIG} ${WORKDIR}/defconfig
 				fi
+				cp -f ${S}/arch/${ARCH}/configs/${KBUILD_DEFCONFIG} ${WORKDIR}/defconfig
 			else
 				cp -f ${S}/arch/${ARCH}/configs/${KBUILD_DEFCONFIG} ${WORKDIR}/defconfig
 			fi
@@ -137,6 +143,7 @@ do_kernel_metadata() {
 		fi
 	fi
 
+	if [ "$mode" = "patch" ]; then
 		# was anyone trying to patch the kernel meta data ?, we need to do
 		# this here, since the scc commands migrate the .cfg fragments to the
 		# kernel source tree, where they'll be used later.
@@ -148,6 +155,7 @@ do_kernel_metadata() {
 			git am -s $p
 		    )
 		done
+	fi
 
 	sccs_from_src_uri="${@" ".join(find_sccs(d))}"
 	patches="${@" ".join(find_patches(d,''))}"
@@ -237,6 +245,7 @@ do_kernel_metadata() {
 		done
         fi
 
+	if [ "$mode" = "config" ]; then
 		# run1: pull all the configuration fragments, no matter where they come from
 		elements="`echo -n ${bsp_definition} $sccs_defconfig ${sccs} ${patches} $KERNEL_FEATURES_FINAL`"
 		if [ -n "${elements}" ]; then
@@ -246,6 +255,7 @@ do_kernel_metadata() {
 				bbfatal_log "Could not generate configuration queue for ${KMACHINE}."
 			fi
 		fi
+	fi
 
 	# if KMETA_EXTERNAL_BSPS has been set, or it has been detected from
 	# the bsp definition, then we inject the bsp_definition into the
@@ -254,6 +264,7 @@ do_kernel_metadata() {
 		sccs="${bsp_definition} ${sccs}"
 	fi
 
+	if [ "$mode" = "patch" ]; then
 		# run2: only generate patches for elements that have been passed on the SRC_URI
 		elements="`echo -n ${sccs} ${patches} $KERNEL_FEATURES_FINAL`"
 		if [ -n "${elements}" ]; then
@@ -262,6 +273,7 @@ do_kernel_metadata() {
 				bbfatal_log "Could not generate configuration queue for ${KMACHINE}."
 			fi
 		fi
+	fi
 }
 
 do_patch() {
@@ -363,6 +375,8 @@ do_kernel_configme[depends] += "bc-native:do_populate_sysroot bison-native:do_po
 do_kernel_configme[depends] += "kern-tools-native:do_populate_sysroot"
 do_kernel_configme[dirs] += "${S} ${B}"
 do_kernel_configme() {
+	do_kernel_metadata config
+
 	# translate the kconfig_mode into something that merge_config.sh
 	# understands
 	case ${KCONFIG_MODE} in