Readme updated

README.md

@@ -115,6 +115,15 @@ $ ./traceAnalyzer
 
 ### DRAMSys Thermal Simulation 
 
+Before starting make sure you have a **clean repository** without any previous
+automatic generated Makefiles. One way to ensure this is by running the
+command below inside your DRAMSys repository, but keep in mind that **all
+untracked files will be lost**.
+
+``` bash
+$ git clean -fdx
+```
+
 This feature can be enabled via an environment variable.
 
 ``` bash