Create systemtarball either with bz2 or gz

Change-Id: I64e93872942e8dcad4a894a906be7912bb6da308
Signed-off-by: Bruce Beare <brucex.j.beare@intel.com>

core/Makefile

@@ -720,8 +720,12 @@ define build-systemtarball-target
 		$(INSTALLED_SYSTEMTARBALL_TARGET)
 endef
 
+ifndef SYSTEM_TARBALL_FORMAT
+    SYSTEM_TARBALL_FORMAT := bz2
+endif
+
 system_tar := $(PRODUCT_OUT)/system.tar
-INSTALLED_SYSTEMTARBALL_TARGET := $(system_tar).bz2
+INSTALLED_SYSTEMTARBALL_TARGET := $(system_tar).$(SYSTEM_TARBALL_FORMAT)
 $(INSTALLED_SYSTEMTARBALL_TARGET): PRIVATE_SYSTEM_TAR := $(system_tar)
 $(INSTALLED_SYSTEMTARBALL_TARGET): $(FS_GET_STATS) $(INTERNAL_SYSTEMIMAGE_FILES)
 	$(build-systemtarball-target)

tools/mktarball.sh

@@ -39,7 +39,14 @@ for f in ${subdirs} ${files} ; do
 done
 
 if [ $? -eq 0 ] ; then
-    bzip2 -c ${target_tar} > ${target_tarball}
+    case "${target_tarball}" in
+    *.bz2 )
+        bzip2 -c ${target_tar} > ${target_tarball}
+        ;;
+    *.gz )
+        gzip -c ${target_tar} > ${target_tarball}
+        ;;
+    esac
     success=$?
     [ $success -eq 0 ] || rm -f ${target_tarball}
     rm -f ${target_tar}