scripts: runners: nrf: Add a new --dry-run parameter

In order to allow for users to invoke "west flash" without actual
hardware connected but still running the logic and pregeneration of
commands.

Signed-off-by: Carles Cufi <[email protected]>

Author: carlescufi

scripts/west_commands/runners/nrf_common.py

@@ -118,6 +118,10 @@ def do_add_parser(cls, parser):
                             choices=['none', 'ranges', 'all'],
                             help='Select the type of erase operation for the '
                                  'external non-volatile memory')
+        parser.add_argument('--dry-run', required=False,
+                            action='store_true',
+                            help='''Generate all the commands without actually
+                            executing them''')
 
         parser.set_defaults(reset=True)
 
@@ -139,7 +143,10 @@ def ensure_snr(self):
                 self.dev_id = [d.lstrip("0") for d in dev_id]
                 return
         if not dev_id or "*" in dev_id:
-            dev_id = self.get_board_snr(dev_id or "*")
+            if not self.dry_run:
+                dev_id = self.get_board_snr(dev_id or "*")
+            else:
+                dev_id = "DEVICEID" # for a dry run
         self.dev_id = dev_id.lstrip("0")
 
     @abc.abstractmethod