gdbserver: server listening callback changes.

- Only subscribe to listening events for the first gdbserver. This
  prevents duplicate echo messages from being printed on multicore
  devices.
- Fix server listening callback for deprecated pyocd-gdbserver.

Author: flit

pyocd/__main__.py

@@ -774,7 +774,10 @@ def do_gdbserver(self):
                     if core_number not in core_list:
                         continue
                     gdb = GDBServer(session, core=core_number)
-                    session.subscribe(self._gdbserver_listening_cb, GDBServer.GDBSERVER_START_LISTENING_EVENT, gdb)
+                    # Only subscribe to the server for the first core, so echo messages aren't printed
+                    # multiple times.
+                    if not gdbs:
+                        session.subscribe(self._gdbserver_listening_cb, GDBServer.GDBSERVER_START_LISTENING_EVENT, gdb)
                     session.gdbservers[core_number] = gdb
                     gdbs.append(gdb)
                     gdb.start()

pyocd/tools/gdb_server.py

@@ -173,7 +173,7 @@ def process_commands(self, commands):
             except IndexError:
                 pass
 
-    def server_listening(self, server):
+    def server_listening(self, note):
         if self.echo_msg is not None:
             print(self.echo_msg, file=sys.stderr)
             sys.stderr.flush()
@@ -294,9 +294,11 @@ def run(self, args=None):
                         if isinstance(session.board.target.cores[core_number], GenericMemAPTarget):
                             continue
 
-                        gdb = GDBServer(session,
-                            core=core_number,
-                            server_listening_callback=self.server_listening)
+                        gdb = GDBServer(session, core=core_number)
+                        # Only subscribe to the server for the first core, so echo messages aren't printed
+                        # multiple times.
+                        if not gdbs:
+                            session.subscribe(self.server_listening, GDBServer.GDBSERVER_START_LISTENING_EVENT, gdb)
                         session.gdbservers[core_number] = gdb
                         gdbs.append(gdb)
                         gdb.start()