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README.md

tpIP a Time-predictable TCP/IP Stack

This folder contains the source code supporting following paper:

Martin Schoeberl and Rasmus Ulslev Pedersen. tpIP: a Time-predictable TCP/IP Stack for Cyber-Physical Systems. Submitted to ISORC 2018.

Most of our evaluation is using the T-CREST/Patmos processor in an FPGA. For the general build instructions of T-CREST please look into the Main README of Patmos.

**************************
Application *  Blaahund,TFTP
**************************
Transport   *  tpip	
Network     *  tpip
**************************
Datalink    * Slip, Ethernet
**************************

A Second Serial Port

We use SLIP as link layer protocol, which means the PC and the FPGA board need a second serial port.

The second port is a USB/TTL cable connected to IO pins on the expansion header. It is connected to the expansion port at the bottom (see Figure 4-15 GPIO Pin Arrangement in the DE2 user manual on page 46).

To build a Patmos configuration with the second port as the project altde2-all. This is best setup by using a local config.mk file (in t-crest/patmos) as follows:

BOARD=altde2-all

Connect the USB/TTL serial cable to the following pins on GP10:

               | * * |  GND
               | * * |
               | * * |
               | * * |
               | * * |
 RX -- 39/AH23 | * * |  40/AG26 -- TX
               +-----+
                GP 10

RX and TX names are from Patmos view. Connect TX from your USB/TTL device to RX of Patmos, and RX to TX.

For information how to test this serial setup see at patmos.

Questions to: [email protected]

tpIP Experiments

The following experiment is a reimplementation of a UDP based protocol used in a railway application on single track lines of the Austrian railway (OEBB).

First, the host pc must listen:

make tpiphost

and then run patmos

make tpippatmos

A flag is set by Patmos, which the host pc reacts to, and clears, and sets a new acknowledge flag.

Note: If make tpiphost results in an error, then try to run tpippatos once to ensure the serial port is enabled.

Using Ethernet as the link layer

For Linux Virtual Machine:

If you are using a Virtual machine like VMware Workstation, first configure the network adaptor setting as 'custom' or 'bridge' mode, I set it as 'custom'. Then choose a virtual network, probably VMnet0. Next, go to the virtual network editor and choose the correct Network Interface Card(NIC) for the virtual network which should be used as a cable connected Ethernet controller. In some linux version, you can set the IP address directly from a GUI, while I couldn't.

Solution:(Ubuntu 20.02)

cd /etc/netplan/

There should be a file called '*.yaml', in my case it is '01-network-manager-all.yaml'

Open it and add the following lines:

 ens33:
            dhcp4: no
            addresses: [192.168.24.5/24] #/num is the number of '1' in netmask
            gateway4: 192.168.24.1
            nameservers:
                addresses: [114.114.114.114,8.8.8.8]

Finally, run command netplan try to see if there are any errors, then apply the changes by netplan apply. Sometimes restart is required, so run systemctl restart system-networkd after.

Now the VM should be able to communicate with the board.

For Windows:

The IP address of patmos board is 192.168.24.50. Set the relative Windows NIC IP in the same domain, like 192.169.24.10.

Monitor

Wireshark works as a monitor to capture UDP packets, netassist is used to send UDP packets through Ethernet.

Compilation

Currently, it is only compiled successfully under patmos/c/ dir.

Note

Basic MAC controller(eth_*, mac.*) is kept unchanged. ICMP, ARP, IPv4, TCP, UDP are merged into tpip, while changes in ARP is writen in tpip_arp.*. No need to use tte and ptp1588.

The test demo is in demo.c temporaly.