runners: stlink_gdbserver: make it possible to disable SWD mode

The "--swd" argument had both an action='store_true' and default value of
True so it wasn't possible to disable it: providing the argument would set
its value to True, and not providing it would use the default=True!

Add a new argument "--no-swd" which shares its destination variable with
"--swd", but with action='store_false', such that either can be provided
to enable/disable SWD mode. Both arguments are placed in a mutually
exclusive group and use a common help message.

Signed-off-by: Mathieu Choplain <[email protected]>

Author: mathieuchopstm

scripts/west_commands/runners/stlink_gdbserver.py

@@ -100,7 +100,10 @@ def extload_help(cls) -> str:
     def do_add_parser(cls, parser: argparse.ArgumentParser):
         # Expose a subset of the ST-LINK GDB server arguments
         parser.add_argument(
-            "--swd", action='store_true', default=True, help="Enable SWD debug mode"
+            "--swd",
+            default=True,
+            action=argparse.BooleanOptionalAction,
+            help="Enable SWD debug mode (default: %(default)s)\nUse --no-swd to disable.",
         )
         parser.add_argument("--apid", type=int, default=0, help="Target DAP ID")
         parser.add_argument(