Xenomai RTNet

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TODO: {{#todo: NotStarted (03.03.2016-13:06->MW+)|Michael Welling|OE 5.0,MW,NotStarted}}

General Information

Xenomai uses the RTNet stack to provide real-time Ethernet. RTNet provides deterministic versions of various protocols (UDP/IP, IMCP, ARP). Xenomai provides several real-time Ethernet drivers, the stack, and various tools. This document explains how to load a real-time Ethernet driver and perform basic tests. The links below will help augment this information as well as discuss programming using the RTnet stack.

Xenomai RTNet

Loading a RTNet driver

As with the other real-time drivers, the Linux driver must be detached the interface before loading that real-time driver.

For example on IMX6 target the fec device must be unbound from the Linux driver and attached to the real-time driver.

root@somimx6-xenomai:~# echo 2188000.ethernet > /sys/bus/platform/drivers/fec/unbind 
root@somimx6-xenomai:~# echo 2188000.ethernet > /sys/bus/platform/drivers/rt_fec/bind
[   86.762295] libphy: fec_enet_mii_bus: probed
[   86.766586] RTnet: registered rteth0

Xenomai provides a script make launching rtnet easier. This will load the appropriate modules and bring up the interface.

root@somimx6-xenomai:~# rtnet -cf /etc/rtnet.conf start
[  645.330848] initializing loopback...
[  645.334487] RTnet: registered rtlo[  645.355662] RTcfg: init real-time configuration distribution protocol
[  645.375986] RTmac: init realtime media access control[  645.400419] RTmac/TDMA: init time division multiple access control mechanism
[  645.499423] rteth0: Freescale FEC PHY driver [Micrel KSZ9031 Gigabit PHY] (mii_bus:phy_addr=2188000.ethernet:01, irq=-1)
[  645.551954] rteth0: tx link down!.
[  652.497075] rt_fec 2188000.ethernet (unnamed net_device) (uninitialized): Link is Up - 1Gbps/Full - flow control rx/tx

The rtnet helper script is configured with /etc/rtnet.conf which determines the IP address of the interface and the slave devices.

root@somimx6-xenomai:/# rtifconfig
 rteth0    Medium: Ethernet  Hardware address: 00:00:00:00:00:00
          IP address:  Broadcast address:
          RX packets:14 errors:0 dropped:0 overruns:0 frame:0
          TX packets:164476 errors:0 dropped:0 overruns:0 carrier:0
          RX bytes:896 (896.0 b)  TX bytes:7031954 (6.7 Mb)

rtlo      Medium: Local Loopback
          IP address:  
          UP LOOPBACK RUNNING  MTU: 1500

External Links