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Code Issues Releases Wiki Activity

Improvements to Ethernet receiver; packets usually make it through unscathed. Still random cases of a single word being dropped randomly in the middle of packets.

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This commit is contained in:
Josh Dersch
2019-03-13 23:53:59 -07:00
parent 8356fca5ab
commit 63c3ddd8a7
3 changed files with 239 additions and 75 deletions
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229
D/Ethernet/EthernetController.cs
View File

@@ -32,6 +32,7 @@ using D.Logging;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Threading;
namespace D.Ethernet
@@ -40,19 +41,9 @@ namespace D.Ethernet
/// EthernetController implements the Star's Ethernet controller.
/// At this time, no official documentation exists; only microcode listings and the schematic drawings.
/// The code is implemented based on study of the schematics and diagnostic microcode.
/// As such there is a lot of handwavy stuff in here, especially around loopback. At this time enough
/// is implemented to get boot diagnostics to pass.
///
/// Questions remaining to be answered:
/// - What is the distinction between Loopback and LocalLoopback? Initially it looked like LocalLoopback only
/// looped back through the FIFO, but it appears to invoke CRC generation and microcode comments make it look
/// like transmission actually takes place? At this time both are treated identically.
/// - How is the FIFO actually controlled during loopback? (How does the transmit hardware know when to stop
/// transmitting when the FIFO is (apparently) being used for both transmit and receive at the same time during
/// a loopback operation?)
///
/// - Why is CRC calculation not working the way I expect? The residual sum does not appear to work out to
/// the expected value for Ethernet CRC32.
/// As such there is a lot of handwavy stuff in here. This implmentation should be revamped based
/// on a closer study of the microcode and schematics, and dumps of the various control PROMs.
/// In particular the Receive logic is extremely bad.
///
/// </summary>
public class EthernetController
@@ -113,7 +104,9 @@ namespace D.Ethernet
_tickElapsed = false;
_outAttn = false;
_inAttn = false;
_lastRWord = false;
_transmitterRunning = false;
_evenPacketLength = false;
_outputData = 0;
_outputDataLatched = false;
@@ -242,6 +235,7 @@ namespace D.Ethernet
_rxMode_ = true;
_receiverState = ReceiverState.Preamble;
_inAttn = false;
_lastRWord = false;
_rxGoodCRC = true;
_rxGoodAlign = true;
@@ -319,9 +313,10 @@ namespace D.Ethernet
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "EStrobe: (cycle 2) flushing received data.");
// Throw out input data and stop the receiver
_fifo.Clear();
_inputPacket.Clear();
_fifo.Clear();
_inAttn = false;
_lastRWord = false;
_rxMode_ = true;
StopReceiver();
UpdateWakeup();
@@ -330,7 +325,7 @@ namespace D.Ethernet
public ushort EIData(int cycle)
{
ushort value = 0;
ushort value = 0;
//
// Read from the input/output FIFO.
@@ -338,19 +333,102 @@ namespace D.Ethernet
if (_fifo.Count > 0)
{
value = _fifo.Dequeue();
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "<-EIData: Returning FIFO word 0x{0:x4}. FIFO count is now {1}",
if (Log.Enabled) Log.Write(LogComponent.EthernetReceive, " <-EIData: Returning FIFO word 0x{0:x4}. FIFO count is now {1}",
value, _fifo.Count);
_debugPacket.Add(value);
Console.WriteLine("addr 0x{0:x4} count {1} char {2}{3}",
_system.CP.TPC[(int)_system.CP.CurrentTask],
_fifo.Count + 1,
GetPrintableChar((byte)(value >> 8)),
GetPrintableChar((byte)(value))
);
}
else
{
if (Log.Enabled) Log.Write(LogType.Error, LogComponent.EthernetControl, "<-EIData: FIFO empty.");
if (Log.Enabled) Log.Write(LogType.Error, LogComponent.EthernetReceive, " <-EIData: FIFO empty.");
// TODO: does this cause an underrun?
}
if (_fifo.Count == 0 && (_lastRWord || _loopBack || _localLoop))
{
_readerLock.EnterWriteLock();
_receiverRunning = false;
_readerLock.ExitWriteLock();
_lastRWord = false;
//
// Let microcode know the packet is done.
//
_inAttn = true;
//
// Update CRC and other final status flags.
//
_rxMode_ = false;
_rxGoodCRC = _loopBack || _localLoop ? _crc32.Checksum == _goodCRC : true;
_rxEvenLen = _loopBack || _localLoop ? true : _evenPacketLength;
if (Log.Enabled) Log.Write(LogComponent.EthernetReceive, " <-EIData: completing transfer.");
if (Log.Enabled)
{
StringBuilder sb = new StringBuilder();
int byteNum = 0;
StringBuilder dataLine = new StringBuilder();
StringBuilder asciiLine = new StringBuilder();
dataLine.AppendFormat("000: ");
for (int i = 0; i < _debugPacket.Count; i++)
{
dataLine.AppendFormat("{0:x2} {1:x2}", (_debugPacket[i] >> 8), _debugPacket[i] & 0xff);
asciiLine.Append(GetPrintableChar((byte)(_debugPacket[i] >> 8)));
asciiLine.Append(GetPrintableChar((byte)_debugPacket[i]));
byteNum++;
if ((byteNum % 16) == 0)
{
Log.Write(LogComponent.EthernetPacket, "{0} {1}", dataLine.ToString(), asciiLine.ToString());
dataLine.Clear();
asciiLine.Clear();
dataLine.AppendFormat("{0:x3}: ", i + 1);
byteNum = 0;
}
}
if (byteNum > 0)
{
Log.Write(LogComponent.EthernetPacket, "{0} {1}", dataLine.ToString(), asciiLine.ToString());
}
Log.Write(LogComponent.EthernetPacket, "");
}
_debugPacket.Clear();
}
UpdateWakeup();
return value;
}
private static char GetPrintableChar(byte b)
{
char c = (char)b;
if (char.IsLetterOrDigit(c) ||
char.IsPunctuation(c) ||
char.IsSymbol(c))
{
return c;
}
else
{
return '.';
}
}
private void DeferCallback(ulong skewNsec, object context)
{
_tickElapsed = true;
@@ -443,7 +521,7 @@ namespace D.Ethernet
//
if (_outputPacket.Count < 4)
{
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Malformed packet: too short.");
if (Log.Enabled) Log.Write(LogComponent.EthernetTransmit, "Malformed packet: too short.");
return;
}
@@ -464,13 +542,13 @@ namespace D.Ethernet
if (badSfd)
{
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Malformed packet: Invalid SFD.");
if (Log.Enabled) Log.Write(LogComponent.EthernetTransmit, "Malformed packet: Invalid SFD.");
return;
}
if (_outputPacket.Count > 0 && _hostInterface != null)
{
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Transmitting completed packet.");
if (Log.Enabled) Log.Write(LogComponent.EthernetTransmit, "Transmitting completed packet.");
_hostInterface.Send(_outputPacket.ToArray());
}
}
@@ -483,7 +561,7 @@ namespace D.Ethernet
if (_fifo.Count > 0)
{
ushort nextWord = _fifo.Dequeue();
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Transmitting word 0x{0:x4}", nextWord);
if (Log.Enabled) Log.Write(LogComponent.EthernetTransmit, "Transmitting word 0x{0:x4}", nextWord);
TransmitWord(nextWord);
}
else if (!_lastWord)
@@ -493,7 +571,7 @@ namespace D.Ethernet
// Raise txUnderrun to signal an error.
//
_txUnderrun = true;
if (Log.Enabled) Log.Write(LogType.Error, LogComponent.EthernetControl, "Transmit underrun.");
if (Log.Enabled) Log.Write(LogType.Error, LogComponent.EthernetTransmit, "Transmit underrun.");
}
if (_lastWord && _fifo.Count == 0)
@@ -503,7 +581,7 @@ namespace D.Ethernet
//
_transmitterRunning = false;
_outAttn = true;
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Last word. Stopping transmission.");
if (Log.Enabled) Log.Write(LogComponent.EthernetTransmit, "Last word. Stopping transmission.");
//
// Transmit completed packet over real ethernet.
@@ -513,7 +591,7 @@ namespace D.Ethernet
else if (_txUnderrun)
{
_transmitterRunning = false;
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Underrun. Stopping transmission.");
if (Log.Enabled) Log.Write(LogComponent.EthernetTransmit, "Underrun. Stopping transmission.");
}
else
{
@@ -549,13 +627,13 @@ namespace D.Ethernet
//
// Receiver is off, just drop the packet on the floor.
//
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Ethernet receiver is off; dropping this packet.");
if (Log.Enabled) Log.Write(LogComponent.EthernetReceive, "Ethernet receiver is off; dropping this packet.");
_readerLock.EnterWriteLock();
_pendingPackets.Clear();
_readerLock.ExitWriteLock();
}
else if (_pendingPackets.Count < 32)
else if (_pendingPackets.Count < 1)
{
//
// Place the packet into the queue; this will be picked up by the receiver poll thread
@@ -565,14 +643,14 @@ namespace D.Ethernet
_pendingPackets.Enqueue(data);
_readerLock.ExitWriteLock();
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Packet (length {0}) added to pending buffer.", data.Length);
if (Log.Enabled) Log.Write(LogComponent.EthernetReceive, "Packet (length {0}) added to pending buffer.", data.Length);
}
else
{
//
// Too many queued-up packets, drop this one.
//
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Pending buffer full; dropping this packet.");
if (Log.Enabled) Log.Write(LogComponent.EthernetReceive, "Pending buffer full; dropping this packet.");
}
_readerLock.ExitUpgradeableReadLock();
}
@@ -580,7 +658,10 @@ namespace D.Ethernet
private void StopReceiver()
{
_system.Scheduler.Cancel(_receiveEvent);
_receiverRunning = false;
_readerLock.EnterWriteLock();
_receiverRunning = false;
_readerLock.ExitWriteLock();
}
private void RunReceiver()
@@ -602,8 +683,10 @@ namespace D.Ethernet
_receiveEvent = _system.Scheduler.Schedule(
_localLoop || _loopBack ? _receiveIntervalLoopback : _receiveInterval,
ReceiveCallback);
_receiverRunning = true;
_readerLock.EnterWriteLock();
_receiverRunning = true;
_readerLock.ExitWriteLock();
}
}
@@ -637,22 +720,44 @@ namespace D.Ethernet
//
packetStream.Seek(0, SeekOrigin.Begin);
while (packetStream.Position < packetStream.Length)
//
// We have to handle cases where the packet length is odd specially because
// ReadByte() returns -1 if we read past the end of the stream.
// Read in an even count of bytes to start....
//
int evenLength = (int)(packetStream.Length - (packetStream.Length % 2));
while (packetStream.Position < evenLength)
{
_inputPacket.Enqueue((ushort)((packetStream.ReadByte() << 8) | packetStream.ReadByte()));
}
//
// If we have a byte left, enqueue it now.
//
if (packetStream.Position < packetStream.Length)
{
_inputPacket.Enqueue((ushort)(packetStream.ReadByte() << 8));
}
_fifo.Clear();
//
// Skip the preamble state (only used in loopback)
//
_receiverState = ReceiverState.Data;
//
// Set the packet even/odd byte length flag
//
_evenPacketLength = (packetStream.Length % 2) == 0;
//
// Alert the microcode to the presence of input data and start processing.
//
RunReceiver();
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Receive: Incoming packet queued into input buffer.");
if (Log.Enabled) Log.Write(LogComponent.EthernetReceive, "Receive: Incoming packet queued into input buffer.");
}
}
@@ -669,14 +774,12 @@ namespace D.Ethernet
//
if (_inputPacket.Count > 0)
{
ushort nextWord = _inputPacket.Dequeue();
switch (_receiverState)
{
case ReceiverState.Preamble:
if (nextWord == 0x55d5) // end of preamble
if (_inputPacket.Dequeue() == 0x55d5) // end of preamble
{
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Receive: end of preamble, switching to Data state.");
if (Log.Enabled) Log.Write(LogComponent.EthernetReceive, "Receive: end of preamble, switching to Data state.");
_receiverState = ReceiverState.Data;
}
break;
@@ -685,11 +788,20 @@ namespace D.Ethernet
//
// Stuff into FIFO.
//
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Receive: Enqueuing Data word 0x{0:x4} onto FIFO, {1} words left.", nextWord, _inputPacket.Count);
_fifo.Enqueue(nextWord);
_crc32.AddToChecksum(nextWord);
UpdateWakeup();
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Packet CRC is now 0x{0:x8}", _crc32.Checksum);
if (_fifo.Count < 16)
{
ushort nextWord = _inputPacket.Dequeue();
if (Log.Enabled) Log.Write(LogComponent.EthernetReceive, "Receive: Enqueuing Data word 0x{0:x4} onto FIFO, {1} words left.", nextWord, _inputPacket.Count);
_fifo.Enqueue(nextWord);
_crc32.AddToChecksum(nextWord);
UpdateWakeup();
if (Log.Enabled) Log.Write(LogComponent.EthernetReceive, "Packet CRC is now 0x{0:x8}", _crc32.Checksum);
}
else
{
if (Log.Enabled) Log.Write(LogComponent.EthernetReceive, "Input FIFO full. Waiting.");
// TODO: This should likely cause an underrun and the operation should be aborted.
}
break;
}
}
@@ -699,30 +811,23 @@ namespace D.Ethernet
//
// Post next event if there are still words left.
//
_receiveEvent = _system.Scheduler.Schedule(_transmitInterval, ReceiveCallback);
_receiveEvent = _system.Scheduler.Schedule(_receiveInterval, ReceiveCallback);
}
else
{
//
// End of packet.
//
_receiverRunning = false;
//
_lastRWord = true;
//
// Let microcode know the packet is done.
// When the last word is read from the FIFO,
// we will update the final status.
//
_inAttn = true;
//
// Update CRC and other flags.
//
_rxMode_ = false;
_rxGoodCRC = _loopBack || _localLoop ? _crc32.Checksum == _goodCRC : true;
UpdateWakeup();
if (Log.Enabled) Log.Write(LogComponent.EthernetControl, "Final Packet CRC is 0x{0:x8}", _crc32.Checksum);
if (Log.Enabled) Log.Write(LogComponent.EthernetReceive, "Final Packet CRC is 0x{0:x8}", _crc32.Checksum);
}
}
@@ -733,11 +838,12 @@ namespace D.Ethernet
// TxMode & BufIR & Defer' & LastWord' (i.e.transmit on, fifo buffer not full, not deferring, not the last word)
// OR
// Defer & TickElapsed (microcode asked for the transmission to be deferred, and that deferral time has elapsed)
// OR
// OR
// RcvMode & BufOR & Purge' (i.e. rcv on, fifo data ready, not purging fifo)
// OR
// Attn (i.e.hardware has a a status to report)
//
//
bool txWakeup = _enableTx && _fifo.Count < 16 && !_defer && !_lastWord;
bool deferWakeup = _defer & _tickElapsed;
bool rxWakeup = !_rxMode_ && (_fifo.Count > 2 || _lastRWord) && !_purge;
@@ -765,6 +871,10 @@ namespace D.Ethernet
private Queue<ushort> _inputPacket;
private Queue<MemoryStream> _pendingPackets;
// Defer timings
private bool _tickElapsed;
// Attention flags
private bool _outAttn;
private bool _inAttn;
@@ -822,7 +932,7 @@ namespace D.Ethernet
// LocalLoop 13
// LoopBack 12
// (See above)
//
// Defer event & timing -- 51.2uS
//
@@ -846,5 +956,6 @@ namespace D.Ethernet
private ReceiverState _receiverState;
private Event _receiveEvent;
private readonly ulong _receiverPollInterval = (ulong)(51000.2 * Conversion.UsecToNsec);
private ReaderWriterLockSlim _readerLock;

72
D/Ethernet/HostEthernet.cs
View File

@@ -148,8 +148,7 @@ namespace D.Ethernet
public void Send(ushort[] packet)
{
byte[] packetBytes = new byte[packet.Length * 2];
// StringBuilder sb = new StringBuilder();
//
// Do this annoying dance to stuff the ushorts into bytes because this is C#.
//
@@ -157,8 +156,6 @@ namespace D.Ethernet
{
packetBytes[i * 2] = (byte)(packet[i] >> 8);
packetBytes[i * 2 + 1] = (byte)(packet[i]);
// sb.AppendFormat("{0:x2} {1:x2} ", packetBytes[i * 2], packetBytes[i * 2 + 1]);
}
ByteArraySegment seg = new ByteArraySegment(packetBytes);
@@ -169,7 +166,7 @@ namespace D.Ethernet
_interface.SendPacket(p);
Log.Write(LogComponent.HostEthernet, "Ethernet packet (length {0}) sent.", packetBytes.Length);
// Log.Write(LogComponent.HostEthernet, "Contents: {0}", sb.ToString());
}
private void ReceiveCallback(object sender, CaptureEventArgs e)
@@ -197,11 +194,48 @@ namespace D.Ethernet
if (packet != null)
{
if (!packet.SourceHwAddress.Equals(_10mbitSourceAddress) &&
packet.PayloadData != null) // Don't recieve packets sent by this emulator.
if (!packet.SourceHwAddress.Equals(_10mbitSourceAddress) && // Don't recieve packets sent by this emulator.
(packet.DestinationHwAddress.Equals(_10mbitSourceAddress) || // Filter on packets destined for us or broadcast.
packet.DestinationHwAddress.Equals(_10mbitBroadcastAddress)))
{
Log.Write(LogComponent.HostEthernet, "Received 10mbit packet.");
_callback(new System.IO.MemoryStream(packet.PayloadData));
Log.Write(LogType.Verbose, LogComponent.EthernetReceive, "Packet received: dst {0} src {1}",
packet.DestinationHwAddress, packet.SourceHwAddress);
Log.Write(LogComponent.HostEthernet, "Received ethernet packet.");
_callback(new System.IO.MemoryStream(e.Packet.Data));
/*
if (Log.Enabled)
{
StringBuilder sb = new StringBuilder();
int byteNum = 0;
StringBuilder dataLine = new StringBuilder();
StringBuilder asciiLine = new StringBuilder();
dataLine.AppendFormat("000: ");
for (int i = 0; i < e.Packet.Data.Length; i++)
{
dataLine.AppendFormat("{0:x2} ", e.Packet.Data[i]);
asciiLine.Append(GetPrintableChar(e.Packet.Data[i]));
byteNum++;
if ((byteNum % 16) == 0)
{
Log.Write(LogComponent.EthernetPacket, "{0} {1}", dataLine.ToString(), asciiLine.ToString());
dataLine.Clear();
asciiLine.Clear();
dataLine.AppendFormat("{0:x3}: ", i + 1);
byteNum = 0;
}
}
if (byteNum > 0)
{
Log.Write(LogComponent.EthernetPacket, "{0} {1}", dataLine.ToString(), asciiLine.ToString());
}
Log.Write(LogComponent.EthernetPacket, "");
} */
}
else
{
@@ -211,17 +245,32 @@ namespace D.Ethernet
}
}
private static char GetPrintableChar(byte b)
{
char c = (char)b;
if (char.IsLetterOrDigit(c) ||
char.IsPunctuation(c) ||
char.IsSymbol(c))
{
return c;
}
else
{
return '.';
}
}
private void UpdateSourceAddress()
{
byte[] macBytes = new byte[6];
for (int i = 0; i < 6; i++)
{
macBytes[i] = (byte)((Configuration.HostID >> (i * 8)));
macBytes[i] = (byte)((Configuration.HostID >> ((5 - i) * 8)));
}
_10mbitSourceAddress = new PhysicalAddress(macBytes);
_10mbitBroadcastAddress = new PhysicalAddress(new byte[] { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff });
}
private void AttachInterface(ICaptureDevice iface)
@@ -268,5 +317,6 @@ namespace D.Ethernet
private ReceivePacketDelegate _callback;
private PhysicalAddress _10mbitSourceAddress;
private PhysicalAddress _10mbitBroadcastAddress;
}
}

13
D/Logging/Log.cs
View File

@@ -76,10 +76,13 @@ namespace D.Logging
// Ethernet
EthernetControl = 0x1000000,
HostEthernet = 0x2000000,
HostEthernet = 0x2000000,
EthernetTransmit = 0x4000000,
EthernetReceive = 0x8000000,
EthernetPacket = 0x10000000,
// Configuration
Configuration = 0x4000000,
Configuration = 0x40000000,
All = 0x7fffffff
}
@@ -105,9 +108,9 @@ namespace D.Logging
{
static Log()
{
Enabled = false;
_components = LogComponent.None;
_type = LogType.None;
Enabled = true;
_components = LogComponent.EthernetPacket;
_type = LogType.All;
_logIndex = 0;
}