Short circuit qemu-img convert for raw images

We currently use qemu-img convert with a raw source and dest when
building raw images. We can just mv the file for increased speed.

Change-Id: I3da095cb9ecad7224a121a434a9fb204132bf6df

bin/disk-image-create

@@ -45,7 +45,7 @@ function show_options () {
     echo "Options:"
     echo "    -a i386|amd64|armhf -- set the architecture of the image(default amd64)"
     echo "    -o imagename -- set the imagename of the output image file(default image)"
-    echo "    -t qcow2,tar -- set the image types of the output image files (default qcow2)"
+    echo "    -t qcow2,tar,raw -- set the image types of the output image files (default qcow2)"
     echo "       File types should be comma separated"
     echo "    -x -- turn on tracing"
     echo "    -u -- uncompressed; do not compress the image - larger but faster"
@@ -247,14 +247,24 @@ done
 
 unmount_image
 
+has_raw_type=
 if [ "$IS_RAMDISK" == "0" ]; then
   for IMAGE_TYPE in ${IMAGE_TYPES[@]} ; do
+    # We have to do raw last because it is destructive
+    if [ "$IMAGE_NAME" = "raw" ]; then
+      has_raw_type=1
+    else
       compress_and_save_image $IMAGE_NAME.$IMAGE_TYPE
+    fi
   done
 fi
+if [ -n "$has_raw_type" ]; then
+  IMAGE_TYPE="raw"
+  compress_and_save_image $IMAGE_NAME.$IMAGE_TYPE
+fi
 
 # Always cleanup after ourselves
-rm $TMP_IMAGE_PATH
+rm -f $TMP_IMAGE_PATH
 cleanup_dirs
 
 case "$IMAGE_ELEMENT" in

lib/img-functions

@@ -115,8 +115,12 @@ function compress_and_save_image () {
     else
         EXTRA_OPTIONS=""
     fi
+    if [ "$IMAGE_TYPE" = "raw" ]; then
+        mv $TMP_IMAGE_PATH $1-new
+    else
         echo "Converting image using qemu-img convert"
         qemu-img convert ${COMPRESS_IMAGE:+-c} -f raw $TMP_IMAGE_PATH -O $IMAGE_TYPE $EXTRA_OPTIONS $1-new
+    fi
 
     OUT_IMAGE_PATH=$1-new
     finish_image $1