Index: kernel/tools/genmap.py
===================================================================
--- kernel/tools/genmap.py	(revision 28f4adbc5088d8d67ea408f56eb3b35838031e6a)
+++ kernel/tools/genmap.py	(revision 71af5a4b8941d5a4dde4b226b1c8d722623f77d8)
@@ -100,8 +100,9 @@
 			for addr, symbol in symbols:
 				value = fname + ':' + symbol
-				data = struct.pack(symtabfmt, addr + offset, value[:MAXSTRING])
+				value_bytes = value.encode('ascii')
+				data = struct.pack(symtabfmt, addr + offset, value_bytes[:MAXSTRING])
 				out.write(data)
 			
-	out.write(struct.pack(symtabfmt, 0, ''))
+	out.write(struct.pack(symtabfmt, 0, b''))
 
 def main():