From c5bf930fb8d4c76e3f0d3f82ba37407ec02648ab Mon Sep 17 00:00:00 2001
From: MatthijsMu <93450301+MatthijsMu@users.noreply.github.com>
Date: Sun, 2 Jun 2024 23:35:48 +0200
Subject: [PATCH] Implement IP +ARP + Eth Stack

---
 src/Clash/Cores/Ethernet/Examples/IPStack.hs | 63 ++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 src/Clash/Cores/Ethernet/Examples/IPStack.hs

diff --git a/src/Clash/Cores/Ethernet/Examples/IPStack.hs b/src/Clash/Cores/Ethernet/Examples/IPStack.hs
new file mode 100644
index 00000000..91b41fd8
--- /dev/null
+++ b/src/Clash/Cores/Ethernet/Examples/IPStack.hs
@@ -0,0 +1,63 @@
+{-|
+Module      : Clash.Cores.Ethernet.Examples.ArpStack
+Description : Fully functional ARP stack.
+-}
+
+{-# language FlexibleContexts #-}
+
+module Clash.Cores.Ethernet.Examples.IPStack
+( ipStackC
+) where
+
+import Clash.Prelude
+
+import Clash.Cores.Crc
+import Clash.Cores.Crc.Catalog
+import Clash.Cores.Ethernet.Arp
+import Clash.Cores.Ethernet.Arp.ArpTypes
+import Clash.Cores.Ethernet.Examples.RxStack
+import Clash.Cores.Ethernet.Examples.TxStack
+import Clash.Cores.Ethernet.IP.IPv4Types
+import Clash.Cores.Ethernet.Mac.EthernetTypes
+
+import Protocols
+import Protocols.Extra.PacketStream
+import Protocols.Extra.PacketStream.Routing
+
+-- | TODO replace this by the IPv4 -> Ethernet stream transformer
+constArpLookup :: Circuit () (ArpLookup dom)
+constArpLookup = Circuit $ \((), _bwdIn) -> ((), fwdOut)
+  where
+    fwdOut = pure (Just (IPv4Address (192 :> 168 :> 1 :> 254 :> Nil)))
+
+-- | Fully functional ARP stack.
+ipStack
+  :: forall
+       (dom :: Domain)
+       (domEthRx :: Domain)
+       (domEthTx :: Domain)
+   . KnownDomain dom
+  => KnownDomain domEthRx
+  => KnownDomain domEthTx
+  => KnownNat (DomainPeriod dom)
+  => DomainPeriod dom <= 5 * 10^11
+  => 1 <= DomainPeriod dom
+  => HardwareCrc Crc32_ethernet 8 4
+  => HiddenClockResetEnable dom
+  => Clock domEthRx
+  -> Reset domEthRx
+  -> Enable domEthRx
+  -> Clock domEthTx
+  -> Reset domEthTx
+  -> Enable domEthTx
+  -> Signal dom MacAddress
+  -> Signal dom IPv4Address
+  -> Circuit (PacketStream domEthRx 1 ()) (PacketStream domEthTx 1 ())
+ipStack rxClk rxRst rxEn txClk txRst txEn ourMacS ourIPv4S =
+  circuit $ \stream -> do
+    ethStream <- rxStack @4 rxClk rxRst rxEn ourMacS -< stream
+    [arpStream] <- packetDispatcherC (singleton $ \hdr -> _etherType hdr == arpEtherType) -< ethStream
+    lookupIn <- constArpLookup -< ()
+    arpOtp <- arpC d10 d5 ourMacS ourIPv4S -< (arpStream, lookupIn)
+    ethOtp <- packetArbiterC RoundRobin -< [arpOtp]
+    txStack txClk txRst txEn -< ethOtp