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[FreeRTOS Home] [Live FreeRTOS Forum] [FAQ] [Archive Top] [May 2008 Threads] what is the real difference?Posted by robot_gary on May 4, 2008 Can anybody here give a detail description of the real difference of using freeRTOS and ucOSII, I want to know the pros and cons, please!
Thanks!
RE: what is the real difference?Posted by ikram on May 4, 2008 follow the link. Hope fully it helps you.
http://www.streambag.se/files/rtproj.pdf
-ikram
RE: what is the real difference?Posted by robot_gary on May 5, 2008 but that is not what I want to know, I want to know the difference between FreeRTOS and ucOSII.
RE: what is the real difference?Posted by Neil Bradley on May 5, 2008 I have extensive experience with uCOS-II and definite familiarity with FreeRTOS. I am not attempting to pass judgement on which is "better" or "worse". Value judgement on these issues is in the eye of the beholder. Whether or not a bullet point is an issue or not depends upon one's requirements in an RTOS:
uCOS-II -
* All threads are their own priority (no round robining on the same priorities) * Costs ~$5K for a "single end product" or around $25K for a "product family" * Mature (roughly 15+ years old) * Other stacks available, like USB and TCP/IP (for fees) and are mature as well * Timer support * Event flags support * Message mailboxes * Highly configurable (on a per OS API perspective) * 100+ ports to various CPUs and architectures * FAA Certified * Very tiny (can reduce to ~2K and 256 bytes of memory in minimalist configuration
FreeRTOS -
* Almost completely free (modified GPL with exceptions - see the FreeRTOS web site for restrictions) * Supports different thread priorities and round robining on threads of the same priority * No timer support * No event flag support * Co-routine feature (very useful!) * Roughly ~25 ports (not sure how many exactly) * Fairly young (circa 2004) * Very configurable (on a subsection basis)
I've used both in various configurations/applications. I've chosen uCOS-II in a couple of instances where FreeRTOS wasn't sufficient (porting existing code that used event flags, and at the time, lack of counting semaphores). However, starting a new project, I can't see much (if any) of a reason to consider uCOS-II over FreeRTOS. OS "Overhead" on uCOS-II vs. FreeRTOS is insignificant/unmeasurable on the architectures I've worked with both.
RE: what is the real difference?Posted by robot_gary on May 5, 2008 Neil,
That is a really nice summary, is there more?
Thanks, Gary
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