Home.md

@@ -24,6 +24,10 @@ following repositories (branch master).
   - [FMC bus](https://www.ohwr.org/project/fmc-bus) \<- provided by
     SPEC-SW using *git submodule* tool.
 
+In order to ease the usage, the git repository includes those
+dependencies as submodule. The submodule checked out version is the last
+one that has being tested during the development.
+
 ## Download
 
 To download the sources, you should execute the following
@@ -33,9 +37,18 @@ To download the sources, you should execute the following
 
 ## Compile
 
-To compile the sources, you should execute the following command:
+To compile the sources using the submodule dependencies, you should
+execute the following commands:
+
+    $ cd <path-to-fmc-tdc-sw>
+    $ make
+
+If you want to compile the software against other versions of ZIO or
+FMC-BUS, you can use the environment variables like in the following
+example:
 
-    $ SPEC_SW=<path_to_spec_sw> ZIO=<path_to_zio> make
+    $ cd <path-to-fmc-tdc-sw>
+    $ ZIO=<path-to-zio> FMC_BUS=<path-to-fmc> make
 
 ## Loading the drivers