distrodata: Add documentation about usage distrodata/checkpkg.

index 9625894..ab6d3d3 100644
@@ -728,6 +728,25 @@
      INHERIT+= "distrodata"
         </literallayout>
     </para>
+
+    <para>
+	Two tasks are provided for the distrodata class distrodata and checkpkg,
+	this two tasks can be used against a simple recipe or a image one for
+	get all the recipes information of an image.
+
+	The task distrodata provides information about the recipe and the checkpkg
+	provides the same information as distrodata plus upstream version/status that
+	means what version of the software exists in upstream and if is un-updated/updated/
+	unknown.
+    </para>
+
+    <para>
+        For execute distrodata/checkpkg over an image:
+
+	$ bitbake core-image-minimal -c distrodata
+
+	The results are stored in $LOG_DIR by default $BUILD_DIR/tmp/log.
+    </para>
 </section>
 
 <section id='ref-classes-distutils'>