diff --git a/guide/source/chapter1/0intro.rst b/guide/source/chapter1/0intro.rst
index dd767ae..244cf9a 100644
--- a/guide/source/chapter1/0intro.rst
+++ b/guide/source/chapter1/0intro.rst
@@ -59,10 +59,6 @@
 
 获取本章代码：
 
-.. code-block:: console
-
-获取本章代码：
-
 .. code-block:: console
 
    $ git clone ``gitaddr of github-classroom-build-lab0-0``
diff --git a/os7-ref/src/link_app.S b/os7-ref/src/link_app.S
new file mode 100644
index 0000000..e69de29
diff --git a/os8-ref/src/link_app.S b/os8-ref/src/link_app.S
new file mode 100644
index 0000000..e69de29