[RTEMS] How do you like RTEMS ?

[Joel Sherrill]

Jeffrey wrote:
> 
> Hi Jake:
> 
> Thank you very much.
> 
> We want to get rid of pSOS and VxWorks because of the Loyalty(a lot) and
> no source codes( need a lot of time to debug if "down" inside kernel).

Loyalty or Royalty? <grin>  Nice slip either way. <grin>

Seriously what we now call the Classic API is essentially pSOS+.  There
is a long story that goes back to the RTEID and ORKID specifications
from the VMEbus Industry Trade Association.  These were an effort 
by Motorola and Software Component Groups (later ISI, now WRS) to 
promote the pSOS+/VMEexec API as a standard.  This all predates
the POSIX threads standardization.  RTEMS was originally implemented
based on the RTEID standard.  The short, cryptic names like
"t_create" were replaced with more meaningful names like 
"rtems_task_create".  But the API is to this day very similar
and mappings from the short name style could be done with 
a simple .h file and macros.

The VxWorks API is another matter.  There is the NRAO library providing
POSIX API wrappers that give some VxWorks services.  But this is a
limited
subset and wrappers always have a performance cost.  This is still
a good alternative for many applications.

As I have privately discussed with Jeffrey, it is possible to implement
any RTOS API on top of the RTEMS SuperCore.  The SuperCore was designed
with this in mind.  You could migrate from an in-house or alternative
RTOS
by implementing its API on top of the RTEMS SuperCore.  The advantage
here is that the various APIs all benefit from SuperCore optimizations.

Eric Norum and others have encouraged the addition of features/behaviors
that map closely to the VxWorks API (task variables, simple semaphores).
This makes it easier to port VxWorks applications to RTEMS but you
are still porting.  A compatable API would be an alternative.

If there is sufficient interest in providing a VxWorks compatable API
on RTEMS, then it is distinctly possible for multiple companies to
co-sponsor
and cooperate on the effort.  

I would like to point out that I personally and OAR as a company have
great respect for intellectual property rights.  We would want to ensure
that every effort is made to honor those and would encourage everyone
else to do the same.

> Sincerely,
> 
> Jeffrey Wui

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
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