Add option to force DTS and RTS pins high

This is for development boards like those for the ESP32, where it's
common to use RTS and DTR to control chip resets.

terminal.py

@@ -362,6 +362,9 @@ if __name__ == "__main__":
                         help="Don't use colors in output")
     parser.add_argument("--flow", "-f", action="store_true",
                         help="Enable RTS/CTS flow control")
+    parser.add_argument("--esp", "-e", action="store_true",
+                        help="Force RTS and DTR high, for ESP boards. Note that"
+                        " the lines may still glitch low at startup.")
     parser.add_argument("--bufsize", "-z", metavar="SIZE", type=int,
                         help="Buffer size for reads and writes", default=65536)
 
@@ -395,7 +398,13 @@ if __name__ == "__main__":
             sys.stderr.write("error: %s specified more than once\n" % node)
             raise SystemExit(1)
         try:
-            dev = MySerial(node, baud, rtscts = args.flow)
+            dev = MySerial(None, baud, rtscts = args.flow)
+            dev.port = node
+            if args.esp:
+                # Force DTR and RTS high by setting to false
+                dev.dtr = False
+                dev.rts = False
+            dev.open()
         except serial.serialutil.SerialException:
             sys.stderr.write("error opening %s\n" % node)
             raise SystemExit(1)