Dear All,

I am new to the Linux.
I Have a Doubt regarding the RTLinux. Previously I was developing my code in the Linux using the pthread library. recently I have seen a similar code for the RTLinux which has include the following two header files with them

#include <rtl.h>
#include <rtl_time.h>

can anyone please suggest what is that library and how can I include it to my programme. What are the changes need to be done in my system to make the system real time.

Thank you.

Hello,

you are referring to Victor Yodaiken & Michael Barabanov's modifications to the kernel started in the late 90ies, which was GPL for some time, then became proprietary with FSMLabs, with a GPL version spun out by Nicholas McGuire and now maintained by http://rtportal.upv.es/ . FSMLab's RTLinux is now owned and maintained by WindRiver as http://www.rtlinuxfree.com/ . You can find many papers on RTLinux and its usage following the links on http://www.realtimelinuxfoundation.o...ts/events.html

RTLinux requires you to write your application in kernel space. You may want to split your application into a real real-time and a less real-time part that can run in user space, both communicating through RT FIFOs or shared memory. If you application was based on POSIX threads, you should be able to port parts of it straight to RTLinux. If it is still relevent, take a look at http://www.osadl.org/fileadmin/event...-peterw.tar.gz for a simple example of an RTLinux application (based on RTLinux 0.6 many years ago).

Hope this helps,
peter

Thanks Peter,

I have a doubt regarding the RTLinux, can we develop it in normal Linux Environment(Ubuntu or Fedora) or I need to change my environment to real time using the RT Patch.

and Again if I need to develop the code in the normal Environment then how to get and use the rtl.h, rtl_time.c and rtl_sched.h
and further how to test the developed code.

Thanks and regards,
Zafar

Hi Peter,

Can You Please Comment on Elinos(Embedded Linux) and its usage in Embedded PCs.

Thanks and regards,
Zafar

Hello,

I cannot comment on Elinos as I do not know it.

In general I would tend to stay away from "proprietary" linux based real-time solutions. First you are locked in with the supplier; second, many suppliers run sooner or later in the situation where they cannot keep up with the kernel development speed with their modifications, with the result is that their real-time version is discontinued. This could be observed a lot in the past 10 years.

In my opinion it's better to stay with a community. Companies go out of business and a user is left with nothing, no support, no code, no contacts; communities stay alive as long as there are users and contributors, communities might dissolve, but at least you have some code and email addresses of real people.

As far as RTLinux is concerned, I have to mention that I used it several years ago. Then, one used to download a vanilla kernel for which an RT patch existed, patched that kernel, compile and install. The patch created rtl.h and other header files. All you needed to do is write your application as one or several kernel modules, compile them, then ismod rtl.o and other things you might need, then insmod your application's modules.

There are two things to consider. First, if you write your application in kernel code, you are bound to the GPL, keep that in mind. Second, it is much harder to debug an application in kernel. That said, perhaps a "modern" Linux kernel compiled with high resolution timers and with the PREEMPT patch applied would do the job. More information on https://rt.wiki.kernel.org/index.php/Main_Page . Perhaps rethink you real-time requirements.

If you really want RTLinux/GPL, then get in contact with Nicholas McGuire (www.opentech.at) or one of the poeple at http://rtportal.upv.es/

Cheers,
peter