ip: able to request mac_address if not cached and send an empty ip frame

liteeth/__init__.py

@@ -8,7 +8,7 @@ from liteeth.ip import LiteEthIP
 class LiteEthIPStack(Module, AutoCSR):
 	def __init__(self, phy, mac_address, ip_address):
 		self.phy = phy
-		self.submodules.mac = mac = LiteEthMAC(phy, 8, interface="mac", with_hw_preamble_crc=True)
+		self.submodules.mac = mac = LiteEthMAC(phy, 8, interface="crossbar", with_hw_preamble_crc=True)
 		self.submodules.arp = arp = LiteEthARP(mac, mac_address, ip_address)
 		self.submodules.ip = ip = LiteEthIP(mac, ip_address, arp.table)
 		self.sink, self.source = self.ip.sink, self.ip.source

liteeth/arp/__init__.py

@@ -146,10 +146,12 @@ class LiteEthARPTable(Module):
 		###
 		request_timeout = Timeout(512)	# XXX fix me 100ms?
 		request_pending = FlipFlop()
-		self.submodules += request_timeout, request_pending
+		request_ip_address = FlipFlop(32, reset=0xffffffff) # XXX add cached_valid?
+		self.submodules += request_timeout, request_pending, request_ip_address
 		self.comb += [
 			request_timeout.ce.eq(request_pending.q),
-			request_pending.d.eq(1)
+			request_pending.d.eq(1),
+			request_ip_address.d.eq(request.ip_address)
 		]
 
 		# Note: Store only one ip/mac couple, replace this with
@@ -166,7 +168,7 @@ class LiteEthARPTable(Module):
 			If(sink.stb & sink.request,
 				NextState("SEND_REPLY")
 			).Elif(sink.stb & sink.reply & request_pending.q,
-				NextState("UPDATE_TABLE")
+				NextState("UPDATE_TABLE"),
 			).Elif(request.stb | (request_pending.q & request_timeout.reached),
 				NextState("CHECK_TABLE")
 			)
@@ -193,10 +195,14 @@ class LiteEthARPTable(Module):
 		found = Signal()
 		fsm.act("CHECK_TABLE",
 			# XXX: add a live time for cached_mac_address
-			If(request.ip_address == cached_ip_address,
+			If(request_ip_address.q == cached_ip_address,
+				request_ip_address.reset.eq(1),
+				NextState("PRESENT_RESPONSE"),
+			).Elif(request.ip_address == cached_ip_address,
 				request.ack.eq(request.stb),
-				NextState("PRESENT_RESPONSE")
+				NextState("PRESENT_RESPONSE"),
 			).Else(
+				request_ip_address.ce.eq(1),
 				NextState("SEND_REQUEST")
 			)
 		)

liteeth/common.py

@@ -141,9 +141,9 @@ def eth_udp_description(dw):
 @DecorateModule(InsertReset)
 @DecorateModule(InsertCE)
 class FlipFlop(Module):
-	def __init__(self, **kwargs):
+	def __init__(self, *args, **kwargs):
-		self.d = Signal(**kwargs)
+		self.d = Signal(*args, **kwargs)
-		self.q = Signal(**kwargs)
+		self.q = Signal(*args, **kwargs)
 		self.sync += self.q.eq(self.d)
 
 @DecorateModule(InsertReset)

liteeth/generic/arbiter.py

@@ -10,7 +10,7 @@ class Arbiter(Module):
 			self.grant = Signal()
 			self.comb += Record.connect(sources[0], sink)
 		else:
-			self.rr = RoundRobin(len(sources))
+			self.submodules.rr = RoundRobin(len(sources))
 			self.grant = self.rr.grant
 			cases = {}
 			for i, source in enumerate(sources):

liteeth/ip/__init__.py

@@ -20,12 +20,13 @@ class LiteEthIPV4Packetizer(LiteEthPacketizer):
 
 class LiteEthIPTX(Module):
 	def __init__(self, ip_address, arp_table):
-		self.sink = sink = Sink(eth_ipv4_description(8))
+		self.sink = Sink(eth_ipv4_description(8))
 		self.source = Source(eth_mac_description(8))
 		###
 		packetizer = LiteEthIPV4Packetizer()
 		self.submodules += packetizer
-		source = packetizer.sink
+		self.comb += Record.connect(self.sink, packetizer.sink)
+		sink = packetizer.source
 
 		fsm = FSM(reset_state="IDLE")
 		self.submodules += fsm
@@ -38,7 +39,7 @@ class LiteEthIPTX(Module):
 		)
 		fsm.act("SEND_MAC_ADDRESS_REQUEST",
 			arp_table.request.stb.eq(1),
-			arp_table.request.ip_address.eq(sink.destination_ip_address),
+			arp_table.request.ip_address.eq(self.sink.destination_ip_address),
 			If(arp_table.request.stb & arp_table.request.ack,
 				NextState("WAIT_MAC_ADDRESS_RESPONSE")
 			)
@@ -46,6 +47,7 @@ class LiteEthIPTX(Module):
 		fsm.act("WAIT_MAC_ADDRESS_RESPONSE",
 			# XXX add timeout
 			If(arp_table.response.stb,
+				arp_table.response.ack.eq(1),
 				# XXX manage failed
 				NextState("SEND")
 			)

liteeth/mac/__init__.py

@@ -47,7 +47,7 @@ class LiteEthMAC(Module, AutoCSR):
 		elif interface == "dma":
 			raise NotImplementedError
 		else:
-			raise ValueError(inteface + " not supported by LiteEthMac!")
+			raise ValueError(interface + " not supported by LiteEthMac!")
 
 	def get_csrs(self):
 		return self.csrs

liteeth/test/ip_tb.py

@@ -41,6 +41,8 @@ class TB(Module):
 			yield
 
 		selfp.ip.sink.stb = 1
+		selfp.ip.sink.sop = 1
+		selfp.ip.sink.eop = 1
 		selfp.ip.sink.destination_ip_address = 0x12345678
 		selfp.ip.sink.source_ip_address = ip_address