VNC: Add an allocated (local) framebuffer

graphics/vnc/server/vnc_server.h

@@ -90,7 +90,9 @@ struct vnc_session_s
   /* Display geometry and color characteristics */
 
   uint8_t colorfmt;            /* See include/nuttx/fb.h */
+  uint8_t bpp;                 /* Bits per pixel */
   struct nxgl_size_s screen;   /* Size of the screen in pixels x rows */
+  FAR uint8_t *fb;             /* Allocated local frame buffer */
 };
 
 /****************************************************************************

graphics/vnc/server/vnc_session.c

@@ -216,5 +216,12 @@ void vnc_release_session(FAR struct vnc_session_s *session)
       psock_close(&session->listen);
     }
 
+  /* Free the allocated framebuffer */
+
+  if (session->fb)
+    {
+      kmm_free(session->fb);
+    }
+
   vnc_initialize_session(session);
 }