Added support for multiple systems to Makefile

Makefile.common

 current_dir := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
 
+default:
+	if [[ ! -z "$(BOARD)" ]] ; then \
+	    $(MAKE) $(BOARD) ; \
+	else \
+	    $(MAKE) packages ; \
+	fi
+
 PACKAGES = $(TEMPORARY_PACKAGES) $(BASE_PACKAGES) $(BOOT_PACKAGES)
 
 .PHONY: packages set-version set-hostname $(PACKAGES) cleanup success

common.xml

@@ -462,13 +462,14 @@ VERSION="${VERSION}"
 BUILD_ID=${BUILD_ID}
 ARTIFACT_NAME=${ARTIFACT_NAME}
 DEVICE_TYPE=${DEVICE_TYPE}
+BOARD="${BOARD}"
 CONSOLE="${CONSOLE}"
 ROOT_DEVICE="${ROOT_DEVICE}"
 DISK="${DISK}"
 SECONDARY="${SECONDARY}"
 SHUTDOWN_WATCHDOG="${SHUTDOWN_WATCHDOG}"
 RUNTIME_WATCHDOG="${RUNTIME_WATCHDOG}"
-export LC_ALL PATH PROJECT_NAME ID PRETTY_NAME HOSTNAME VERSION BUILD_ID ARTIFACT_NAME DEVICE_TYPE CONSOLE ROOT_DEVICE DISK SECONDARY SHUTDOWN_WATCHDOG RUNTIME_WATCHDOG HOSTTYPE
+export LC_ALL PATH PROJECT_NAME ID PRETTY_NAME HOSTNAME VERSION BUILD_ID ARTIFACT_NAME DEVICE_TYPE BOARD CONSOLE ROOT_DEVICE DISK SECONDARY SHUTDOWN_WATCHDOG RUNTIME_WATCHDOG HOSTTYPE
 
 mount -o remount,rw /