xtensa-build-zephyr.sh: build rimage later, just before it's needed.

We care about other build errors more.

This also makes it easier to test locally that "west build" does not
depend on rimage to create zephyr.elf

Signed-off-by: Marc Herbert <marc.herbert@intel.com>

scripts/xtensa-build-zephyr.sh

@@ -107,14 +107,6 @@ build()
 	    # https://github.com/zephyrproject-rtos/west/issues/419
 	}
 
-	# Build rimage
-	RIMAGE_DIR=build-rimage
-	mkdir -p "$RIMAGE_DIR"
-	cd "$RIMAGE_DIR"
-	cmake ../modules/audio/sof/rimage
-	make -j"$BUILD_JOBS"
-	cd -
-
 	local STAGING=build-sof-staging
 	mkdir -p ${STAGING}/sof/ # smex does not use 'install -D'
 
@@ -189,6 +181,11 @@ build()
 			       -l "$STAGING"/sof/sof-"$platform".ldc \
 			       "$bdir"/zephyr/zephyr.elf
 
+			# Build rimage
+			RIMAGE_DIR=build-rimage
+			cmake -B "$RIMAGE_DIR" -S modules/audio/sof/rimage
+			make -C "$RIMAGE_DIR" -j"$BUILD_JOBS"
+
 			west sign  --build-dir "$bdir" \
 				--tool rimage --tool-path "$RIMAGE_DIR"/rimage \
 				--tool-data modules/audio/sof/rimage/config -- -k "$RIMAGE_KEY"
@@ -271,8 +268,9 @@ main()
 		    ln -s "$SOF_TOP" "${WEST_TOP}"/modules/audio/sof
 		}
 
-		# Support for submodules in west is too recent, cannot
+		# FIXME: remove this hack. Downloading and building
-		# rely on it
+		# should be kept separate but support for submodules in
+		# west is too recent, cannot rely on it yet.
 		test -e "${WEST_TOP}"/modules/audio/sof/rimage/CMakeLists.txt || (
 		    cd "${WEST_TOP}"/modules/audio/sof
 		    git submodule update --init --recursive