diff --git a/common.h b/common.h
index e6e8f85..cba4c86 100644
--- a/common.h
+++ b/common.h
@@ -107,4 +107,23 @@
                               // (that much).
 } Volume;
 
+typedef struct {
+    // number of frames in indeterminate progress bar animation
+    int indeterminate_frames;
+
+    // number of frames per second to try to maintain when animating
+    int update_fps;
+
+    // number of frames in installing animation.  may be zero for a
+    // static installation icon.
+    int installing_frames;
+
+    // the install icon is animated by drawing images containing the
+    // changing part over the base icon.  These specify the
+    // coordinates of the upper-left corner.
+    int install_overlay_offset_x;
+    int install_overlay_offset_y;
+
+} UIParameters;
+
 #endif  // RECOVERY_COMMON_H