Hi, all > Hi, > > we are happy to welcome a new developer to the RTnet project: > Yuchen has contributed a real-time port of the Linux > IEEE-1394 layer, and he will continue to work on a smooth > integration of this layer into the main RTnet branch. > Thank you, Jan. The current port is based on the Ethernet Emulation on Firewire (eth1394), so if you use "rtifconfig" when the Firewire stack has been loaded, you will see a normal "rteth". The Firewrie stack consists of rt_ohci1394, rt_ieee1394 and rt_eth1394. But you will also find another module: rtos_tasklet_scheduler. As the name implies, this module schedules/executes the Linux tasklet in a realtime manner(FIFO). Since in Linux, the task of fetching the incoming Firewire packet is done in a tasklet that is seen as the bottomhalf of interrupt handler, the rtos_tasklet_scheduler is used here to treat the "Linux tasklet" realtimely. Because the RT task in rtos_tasklet_scheduler has a higher priority than the RT task in stack_mgr, the original priority of RT task in stack_mgr is lowed by 1. Also, some other slight change is made in rtifconfig. I suggest that the whole branch of rtnet-1394 is downloaded, and configured with "--enable-firewire".
> Currently you can find his work only in the SVN branch > svn://svn.berlios.de/rtnet/branches/rtnet-1394 under > drivers/experimental/firewire. It's actually so experimental > that I still haven't tried it on my own (I'm just organising > some FireWire > cards...) ;)! But Yuchen can likely add some more details > about his successful experiments... > Actually, I only did the round_trip_test on eth1394/Firewire. Compared with 10/100Mbit ethernet, Firewire is, in average, 100us faster with a high data payload (>1400 byte). But with a low payload, they have almost the same average latency. Note that, eth1394 uses the asynchronous tranmission of Firewire, on which the data payload can be as high as 2048 bytes. > FireWire will open interesting new application domains for > RTnet. There is an increasing number of projects working with > this media, and you can also find more and more industrial > field devices supporting 1394. The extension of RTnet by > FireWire underlines that RTnet has real potentials to be more > than "just" hard real-time Ethernet, in fact it can be hard > real-time networking! > > Jan > Currently, I am working on the integration of Firewire's isochronous transmission into RTnet. The iso feature is a undeniable highlight of Firewire, and is quite suitable for Time-Triggered Multicasting communication in distributed realtime control system. So, if anyone interested/experienced in this topic (Time-Triggerd Multicasting, not specific to Firewire) is invited to have a discussion here:) Yuchen > ------------------------------------------------------- > This SF.Net email is sponsored by: IntelliVIEW -- Interactive > Reporting Tool for open source databases. Create drag-&-drop > reports. Save time by over 75%! Publish reports on the web. > Export to DOC, XLS, RTF, etc. > Download a FREE copy at http://www.intelliview.com/go/osdn_nl > _______________________________________________ > RTnet-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/rtnet-users > ------------------------------------------------------- This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting Tool for open source databases. Create drag-&-drop reports. Save time by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc. Download a FREE copy at http://www.intelliview.com/go/osdn_nl _______________________________________________ RTnet-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/rtnet-users
