Which Linux RTOS solution should I choose?

Question

I'm preparing myself to build RTOS solution on top of Linux this going to work on embedded device. I've done some investigation by myself but still I'm a bit confused. Those are my criteria:

• Easy to run on Samsung s3c2440 ARM9 machine

• Open Source

• Works together with Linux

• Good community support

I've seen RTLinux and Xenomai. Xenomai looks more like thing for me, but still I'm confused.

Any good advice, pro's and cons?

Answer 1

If you need free and absolutely stable out of the box with the lowest latencies, consider something like RTEMS (not Linux based, but does provide POSIX functions).

If you can afford it and want something absolutely stable out of the box with very low latencies and have a general purpose OS with all the bells and whistles, check out QNX - its got the same GNU userland/toolchains you're used to and is POSIX compliant.

RTLinux is best avoided - very buggy. Xenomai/RTAI can have decent success, although it has more limitations than QNX. Everything else is going to bleed you for large sums of money so you might as well choose the best option :-).

Answer 2

With the aid of FCSE enabled by Xenomai, Linux with the real-time extension can work pretty weel on ARM9 based boards like S3C2440.

This presentation covers some concepts: http://www.slideshare.net/jserv/realtime-linux

Answer 3

If you have decided on a processor, I suggest you find a development board or kit and use the recommended operating environment. Including development tools and OS.

Answer 4

Check out montavista if you need commercial support.

Answer 5

The question is do you really need hard RTOS?

You may be able to get away with something like uClinux http://www.uclinux.org/

Answer 6

I have not done any work with Real Time systems, but I know if this and this. I hope it helps or that it can at least put you in the right track.