add --show_text option to recovery

Change-Id: Ie6c6c920260dfa759fbb15b1f352d6bb0fa7146c
diff --git a/common.h b/common.h
index 1182d77..a767b58 100644
--- a/common.h
+++ b/common.h
@@ -26,6 +26,7 @@
 int ui_wait_key();            // waits for a key/button press, returns the code
 int ui_key_pressed(int key);  // returns >0 if the code is currently pressed
 int ui_text_visible();        // returns >0 if text log is currently visible
+void ui_show_text(int visible);
 void ui_clear_key_queue();
 
 // Write a message to the on-screen log shown with Alt-L (also to stderr).