patch to allow for avrdude to erase by not appending -D

ino/commands/upload.py

@@ -32,6 +32,9 @@ def setup_arg_parser(self, parser):
         parser.add_argument('-p', '--serial-port', metavar='PORT',
                             help='Serial port to upload firmware to\nTry to guess if not specified')
 
+        parser.add_argument('-e', '--auto-erase', metavar='<0|1>', default='0',
+                            help='Enable auto-erase of firmware\npass 1 for yes, 0 (default) for no')
+
         self.e.add_board_model_arg(parser)
         self.e.add_arduino_dist_arg(parser)
 
@@ -126,13 +129,17 @@ def run(self, args):
             port = new_port
 
         # call avrdude to upload .hex
-        subprocess.call([
+        avrargs = [
             self.e['avrdude'],
             '-C', self.e['avrdude.conf'],
             '-p', board['build']['mcu'],
             '-P', port,
             '-c', protocol,
             '-b', board['upload']['speed'],
-            '-D',
-            '-U', 'flash:w:%s:i' % self.e['hex_path'],
-        ])
+            '-U', 'flash:w:%s:i' % self.e['hex_path']
+        ]
+
+        if (args.auto_erase == '0'):
+            avrargs.append('-D')
+
+        subprocess.call(avrargs)