hai every one...

I decided to do my pg project in RTLinux platform,and i am very new to rtlinux,
so can anybody help me

1)regarding rtlinux licencing,ie whether the kernal is free to downloadable or not..or how can i get rtlinux installation cd..? ?
2)rtlinux supporting os platforms for installation..
3)which are the basic configuration requirement of my pc.both software and hardware?

pls help me...

What reasons do you have for choosing RTLinux specifically, rather than PREEMPT_RT, Xenomai, or RTAI? RTLinux is no longer supported, and most Linux-based RTOS users are using one of the latter three options now.

Would it be possible for you to explain your intended application? What are you doing in realtime? What latiencies do you need, and is it hard realtime (can never miss its deadlines) or soft realtime (may occasionally miss deadlines)?

To answer your questions specifically:

1) IIRC, at one time, RTLinux was not open source. Wikipedia suggests that it may be now, however -- but it was discontinued a couple of years ago. I'm not sure if it's still available.

2) Depends on the download you find. Since it looks like it's probably patched kernel sources, then it would work for almost any Linux distribution.

3) I'm not sure what RTLinux's hardware support is like, nor what its userspace libraries are like (assuming those exist), so I cannot answer this question accurately.

1 members found this post helpful.

thank u for ur valuable info,

actually..i have read one ieee paper regarding comparison between various rtos,among that i came to know that vxworks is better one.
and rt linux is better among opensource/linux based rtos,
so i planned to work over rtlinux,before doing my project i was actually interested to know about all these..
and so tried to download rtlinux...but failed..

You need to define "better" here.

From what I have researched, here are the three main Linux-based RTOSs, ranked from lowest latency to highest latency:

1. RTAI
2. Xenomai
3. PREEMPT_RT

Here are the same three RTOSs, ranked from easiest to use to hardest to use (in terms of setup, hardware support, and software development):

1. PREEMPT_RT
2. Xenomai
3. RTAI

Now do you see why knowing what latencies you need is necessary? If PREEMPT_RT offers sufficiently low latencies, than you should probably use it (because it has the best hardware support and is the easiest to work with). If not, try Xenomai. If Xenomai doesn't work for you, then it is likely that RTAI won't be good enough either (they are very close to each other in performance).

For cyclic applications up to 1 kHz, PREEMPT_RT is typically "good enough". Above 1 kHz, it becomes hardware-specific. Often, you can achieve maximum latencies under 100µs under PREEMPT_RT -- is this good enough for your application?