clean up a bit

scripts/zynq7000-ps-pl-init.py

@@ -33,9 +33,7 @@ def main():
         required=True,
         help="Path to the ps7 initialization TCL file to prepare the processing system.",
     )
-    parser.add_argument(
-        "-a", "--app", required=True, dest="app", help="Path to the app to program"
-    )
+    parser.add_argument("-a", "--app", dest="app", help="Path to the app to program")
     parser.add_argument(
         "-i",
         "--ip",
@@ -70,12 +68,13 @@ def main():
         print("Error: 'xsct' could not be found after sourcing settings64.sh.")
         sys.exit(1)
 
-    if not os.path.isfile(args.app):
+    if args.app and not os.path.isfile(args.app):
         print(f"The app '{args.app}' does not exist")
         sys.exit(1)
 
     # Export environment variables
-    os.environ["APP"] = args.app
+    if args.app:
+        os.environ["APP"] = args.app
     os.environ["IP_ADDRESS_HW_SERVER"] = args.ip
     if args.bit:
         os.environ["BITSTREAM"] = args.bit