meta-arm: Support firmware building under a multiconfig

To enable building rescue or bootstrap images that can be included into
firmware a "firmware" multiconfig option is required to allow the
building with different options to any mass storage image they may also
be built.

As this multiconfig build will occur under a different TMPDIR, we also
provide a deployment image to allow easy copying of the firmware into
another deploy dir.

Signed-off-by: Drew Reed <Drew.Reed@arm.com>

meta-arm/conf/multiconfig/firmware.conf

@@ -0,0 +1,13 @@
+# Config that can be used to build firmware in a seperate tmp area
+# and with a smaller libc enabled by default
+
+DISTROOVERRIDES = "firmware"
+
+TMPDIR:append = "_${MACHINE}"
+TCLIBC="musl"
+
+# Ignore the testimage flags to include ssh-server-dropbear
+IMAGE_CLASSES:remove = "testimage"
+IMAGE_FEATURES:remove = "ssh-server-dropbear"
+CORE_IMAGE_EXTRA_INSTALL:remove = "ssh-pregen-hostkeys"
+TESTIMAGE_AUTO = "0"

meta-arm/recipes-bsp/images/firmware-deploy-image.bb

@@ -0,0 +1,31 @@
+SUMMARY = "Firmware image deploying multi-config firmware"
+DESCRIPTION = "Image for deploying a firmware set on platforms using multi-config"
+LICENSE = "MIT"
+
+inherit deploy nopackages
+
+PACKAGE_ARCH = "${MACHINE_ARCH}"
+COMPATIBLE_MACHINE ?= "invalid"
+do_configure[noexec] = "1"
+do_compile[noexec] = "1"
+do_install[noexec] = "1"
+
+# Users of this recipe are expected to provide the list of firmware images
+# that need to be deployed by setting this variable.
+FIRMWARE_BINARIES ?= ""
+
+do_deploy() {
+    firmware_loc="${TMPDIR}_${MACHINE}/deploy/images/${MACHINE}"
+    for firmware in ${FIRMWARE_BINARIES}; do
+        echo "cp -av ${firmware_loc}/${firmware} ${DEPLOYDIR}/"
+        cp -av "${firmware_loc}/${firmware}" ${DEPLOYDIR}/
+        if [ -L "${firmware_loc}/${firmware}" ]; then
+            echo "cp -av ${firmware_loc}/$(readlink ${firmware_loc}/${firmware}) ${DEPLOYDIR}/"
+            cp -av "${firmware_loc}/$(readlink ${firmware_loc}/${firmware})" ${DEPLOYDIR}/
+        fi
+    done
+}
+
+do_deploy[umask] = "022"
+
+addtask deploy after do_prepare_recipe_sysroot