From dc96269c8ffce46b6ed61ac85a3c6bdc74946692 Mon Sep 17 00:00:00 2001
From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Wed, 16 Feb 2022 14:12:46 +0100
Subject: [PATCH] core/ip/tx: Add broadcast capability.

---
 liteeth/common.py   |  5 +++++
 liteeth/core/arp.py |  2 +-
 liteeth/core/ip.py  | 11 +++++++++--
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/liteeth/common.py b/liteeth/common.py
index 6a5b47d..2c4f88f 100644
--- a/liteeth/common.py
+++ b/liteeth/common.py
@@ -60,6 +60,11 @@ arp_header_fields = {
 }
 arp_header = Header(arp_header_fields, arp_header_length, swap_field_bytes=True)
 
+# Broadcast Constants ------------------------------------------------------------------------------
+
+bcast_ip_mask     = 0xff
+bcast_mac_address = 0xffffffffffff
+
 # Multicast Constants ------------------------------------------------------------------------------
 
 mcast_oui     = C(0x01005e, 24)
diff --git a/liteeth/core/arp.py b/liteeth/core/arp.py
index 99e47a9..18ccfbc 100644
--- a/liteeth/core/arp.py
+++ b/liteeth/core/arp.py
@@ -68,7 +68,7 @@ class LiteEthARPTX(Module):
                 packetizer.sink.target_mac.eq(sink.mac_address),
             ).Elif(sink.request,
                 packetizer.sink.opcode.eq(arp_opcode_request),
-                packetizer.sink.target_mac.eq(0xffffffffffff),
+                packetizer.sink.target_mac.eq(bcast_mac_address),
             )
         ]
         self.comb += [
diff --git a/liteeth/core/ip.py b/liteeth/core/ip.py
index ce89729..e29cde8 100644
--- a/liteeth/core/ip.py
+++ b/liteeth/core/ip.py
@@ -110,7 +110,8 @@ class LiteEthIPTX(Module):
                 "last",
                 "last_be",
                 "protocol",
-                "data"}),
+                "data",
+            }),
             packetizer.sink.valid.eq(sink.valid & checksum.done),
             sink.ready.eq(packetizer.sink.ready & checksum.done),
             packetizer.sink.target_ip.eq(sink.ip_address),
@@ -130,9 +131,15 @@ class LiteEthIPTX(Module):
         self.submodules.fsm = fsm = FSM(reset_state="IDLE")
         fsm.act("IDLE",
             If(packetizer.source.valid,
-                If(sink.ip_address[28:] == mcast_ip_mask,
+                # Broadcast.
+                If(sink.ip_address[0:8] == bcast_ip_mask,
+                    NextValue(target_mac, bcast_mac_address),
+                    NextState("SEND")
+                # Multicast.
+                ).Elif(sink.ip_address[28:] == mcast_ip_mask,
                     NextValue(target_mac, Cat(sink.ip_address[:23], 0, mcast_oui)),
                     NextState("SEND")
+                # Unicast.
                 ).Else(
                     NextState("SEND_MAC_ADDRESS_REQUEST")
                 )