+# Convert file names to SCons File objects. This takes care of the
+# path relative to the top of the directory tree.
+sources = [File(s) for s in sources]
+
+# Add in files generated by the ISA description.
+isa_desc_files = env.ISADesc('isa/main.isa')
+# Only non-header files need to be compiled.
+isa_desc_sources = [f for f in isa_desc_files if not f.path.endswith('.hh')]
+sources += isa_desc_sources