diff --git a/BaseTools/ReadMe.txt b/BaseTools/ReadMe.txt
index fb098902da..e50ac82c99 100644
--- a/BaseTools/ReadMe.txt
+++ b/BaseTools/ReadMe.txt
@@ -21,18 +21,17 @@ BaseTools Simple Usage:
    *.inf file is
 
 Notes:
-1) Only *.efi files can be generated. Flash image cannot be generated at present.
-2) Only "clean" and "cleanall" build target are supported, in both top level 
-   makefile and module's makefile. 
-3) Not all tool chains and target architectures are tested. Due to both tools 
-   and source code limitations, ther must be bugs in it. Please report any issue 
-	 ASAP so we can fix it soon.
-4) The tree structure generated by build tools is similar to Ant build system.
-5) Makefile can be called directly by nmake for both top level platform and module. But
+1) The tree structure generated by build tools is similar to Ant build system.
+2) Makefile can be called directly by nmake for both top level platform and module. But
    after you call "nmake cleanall", you have to call "build" command to rebuild platform
 	 or modules because the AutoGen.* files have been be removed. The "makefile" itself
 	 cannot generate AutoGen.* files. Only "build" command can.
-
+3) build.exe in %WORKSPACE%\BaseTools\Bin\Win32 is generated from following revision of
+   Python source code:
+        r601 <buildtools_project>\BaseTools\Source\Python\Autogen
+        r601 <buildtools_project>\BaseTools\Source\Python\Python\build
+        r569 <buildtools_project>\BaseTools\Source\Python\Python\Common
+        r564 <buildtools_project>\BaseTools\Source\Python\Python\CommonDataClass
 
 Brief usage for Migration Tool MigrationMsa2Inf.exe:
 1. Command line format:
@@ -92,4 +91,4 @@ Brief usage for Migration Tool MigrationMsa2Inf.exe:
  
 
           
-13-August-2007
+20-August-2007