tools/comm_udp/litex_server: add --udp-scan args to scan network for …

…available Etherbone/UDP devices.

litex_server --udp --udp-scan --udp-ip=192.168.1.x --udp-port=1234
Etherbone scan on 192.168.1.x network:
- 192.168.1.20
- 192.168.1.50

litex/tools/litex_server.py

@@ -178,6 +178,7 @@ def main():
     parser.add_argument("--udp",             action="store_true",    help="Select UDP interface")
     parser.add_argument("--udp-ip",          default="192.168.1.50", help="Set UDP remote IP address")
     parser.add_argument("--udp-port",        default=1234,           help="Set UDP remote port")
+    parser.add_argument("--udp-scan",        action="store_true",    help="Scan network for available UDP devices.")
 
     # PCIe arguments
     parser.add_argument("--pcie",            action="store_true",    help="Select PCIe interface")
@@ -205,10 +206,21 @@ def main():
     # UDP mode
     elif args.udp:
         from litex.tools.remote.comm_udp import CommUDP
-        udp_ip = args.udp_ip
+        udp_ip   = args.udp_ip
         udp_port = int(args.udp_port)
-        print("[CommUDP] ip: {} / port: {} / ".format(udp_ip, udp_port), end="")
-        comm = CommUDP(udp_ip, udp_port, debug=args.debug)
+        if args.udp_scan:
+            udp_ip = udp_ip.split(".")
+            assert len(udp_ip) == 4
+            udp_ip[3] = "x"
+            udp_ip = ".".join(udp_ip)
+            comm = CommUDP(udp_ip, udp_port, debug=args.debug)
+            comm.open(probe=False)
+            comm.scan(udp_ip)
+            comm.close()
+            exit()
+        else:
+            print("[CommUDP] ip: {} / port: {} / ".format(udp_ip, udp_port), end="")
+            comm = CommUDP(udp_ip, udp_port, debug=args.debug)
 
     # PCIe mode
     elif args.pcie:

litex/tools/remote/comm_udp.py

@@ -1,7 +1,7 @@
 #
 # This file is part of LiteX.
 #
-# Copyright (c) 2015-2019 Florent Kermarrec <[email protected]>
+# Copyright (c) 2015-2020 Florent Kermarrec <[email protected]>
 # Copyright (c) 2016 Tim 'mithro' Ansell <[email protected]>
 # SPDX-License-Identifier: BSD-2-Clause
 
@@ -21,36 +21,49 @@ def __init__(self, server="192.168.1.50", port=1234, csr_csv=None, debug=False):
         self.port   = port
         self.debug  = debug
 
-    def open(self):
+    def open(self, probe=True):
         if hasattr(self, "socket"):
             return
         self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
         self.socket.bind(("", self.port))
         self.socket.settimeout(1)
-        self.probe()
+        if probe:
+            self.probe(self.server, self.port)
 
     def close(self):
         if not hasattr(self, "socket"):
             return
         self.socket.close()
         del self.socket
 
-    def probe(self):
-        # Send probe request to server...
-        packet = EtherbonePacket()
-        packet.pf = 1
-        packet.encode()
-        self.socket.sendto(packet.bytes, (self.server, self.port))
-
-        # ...and get/check server's response.
+    def probe(self, ip, port, loose=False):
         try:
+            # Send probe request to server...
+            packet = EtherbonePacket()
+            packet.pf = 1
+            packet.encode()
+            self.socket.sendto(packet.bytes, (ip, port))
+
+            # ...and get/check server's response.
             datas, dummy = self.socket.recvfrom(8192)
             packet = EtherbonePacket(datas)
             packet.decode()
             assert packet.pr == 1
+            return 1
         except:
-            self.close()
-            raise Exception(f"Unable to probe Etherbone server at {self.server}.")
+            if not loose:
+                self.close()
+                raise Exception(f"Unable to probe Etherbone server at {self.server}.")
+        return 0
+
+    def scan(self, ip="192.168.1.x"):
+        print(f"Etherbone scan on {ip} network:")
+        ip = ip.replace("x", "{}")
+        self.socket.settimeout(0.01)
+        for i in range(1, 255):
+            if self.probe(ip=ip.format(str(i)), port=self.port, loose=True):
+                print("- {}".format(ip.format(i)))
+        self.socket.settimeout(1)
 
     def read(self, addr, length=None, burst="incr"):
         assert burst == "incr"