Developping a configurable RTOS

Hi everybody,

I am a new member on this group. I want help because i wanna develop a
new modular rtos but i don't really have an idea how to begin?? A
modular RTOS is a configurable RTOS based on components such as SHaRK
and others..

Please help me....


Thanks


Moctar

Moctar wrote:

> I am a new member on this group. I want help because i wanna develop a
> new modular rtos but i don't really have an idea how to begin?? A
> modular RTOS is a configurable RTOS based on components such as SHaRK
> and others..
> 
> Please help me....

First, this sounds like a misguided venture.  But if you want to do it 
for the thrill and learning experience, go ahead.  It's fun.  Years I 
wrote two simple RTOSs from scratch and it was a nice exercise.  I even 
got paid for it.

You might start by learning what you can about existing RTOSs.  There 
are several low-cost or free versions, such as uC-OS, and eCOS.  I first 
learned a lot by studying the internals of TIP-MX, a nice commercial 
realtime OS for the TI-9900 uP decades ago.  Determine the tradeoffs and 
what features that are most important to you.  Here are some issues off 
the top of my head:

fast context switch
minimum value for maximum interrupt latency
small memory footprint
compatibility with existing tools and languages
memory protection between tasks
dynamic (vs static) configuration
network support
multiple processor support
good error detection and reporting
good development tools for the user
good documentation
easy to expand

-- 
Thad

Thanks a lot Thad,

It is not for fun (a little bit). I have a 5 persons team and we have
to make a project in embedded systems but we have not an idea how to
develop a RTOS (do you have some references or examples of small RTOSs
that could be understoud easily).



Thanks

Moctar


Thad Smith wrote:
> Moctar wrote:
>
> > I am a new member on this group. I want help because i wanna develop a
> > new modular rtos but i don't really have an idea how to begin?? A
> > modular RTOS is a configurable RTOS based on components such as SHaRK
> > and others..
> >
> > Please help me....
>
> First, this sounds like a misguided venture.  But if you want to do it
> for the thrill and learning experience, go ahead.  It's fun.  Years I
> wrote two simple RTOSs from scratch and it was a nice exercise.  I even
> got paid for it.
>
> You might start by learning what you can about existing RTOSs.  There
> are several low-cost or free versions, such as uC-OS, and eCOS.  I first
> learned a lot by studying the internals of TIP-MX, a nice commercial
> realtime OS for the TI-9900 uP decades ago.  Determine the tradeoffs and
> what features that are most important to you.  Here are some issues off
> the top of my head:
>
> fast context switch
> minimum value for maximum interrupt latency
> small memory footprint
> compatibility with existing tools and languages
> memory protection between tasks
> dynamic (vs static) configuration
> network support
> multiple processor support
> good error detection and reporting
> good development tools for the user
> good documentation
> easy to expand
> 
> -- 
> Thad

Moctar wrote:

> Thanks a lot Thad,
> 
> It is not for fun (a little bit). I have a 5 persons team and we have
> to make a project in embedded systems but we have not an idea how to
> develop a RTOS (do you have some references or examples of small RTOSs
> that could be understoud easily).
> 

The development of a basic RTOS kernel and services from the scratch is 
a one man one week project.

Start with the uC/OS book by Jean Labrosse. It is a good tutorial on the 
general principles of any RTOS, not just mucos.


Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com

On 2006-12-16, Moctar <ouldm8@gmail.com> wrote:
> Thanks a lot Thad,
>
> It is not for fun (a little bit). I have a 5 persons team and we have
> to make a project in embedded systems but we have not an idea how to
> develop a RTOS (do you have some references or examples of small RTOSs
> that could be understoud easily).

He already gave you two very good examples.  I suggest you
study them.

-- 
Grant Edwards                   grante             Yow!  I want a WESSON
                                  at               OIL lease!!
                               visi.com            

ok i will study them and will give the result later.


Thnks a lot!!


Moctar
Grant Edwards wrote:
> On 2006-12-16, Moctar <ouldm8@gmail.com> wrote:
> > Thanks a lot Thad,
> >
> > It is not for fun (a little bit). I have a 5 persons team and we have
> > to make a project in embedded systems but we have not an idea how to
> > develop a RTOS (do you have some references or examples of small RTOSs
> > that could be understoud easily).
>
> He already gave you two very good examples.  I suggest you
> study them.
>
> --
> Grant Edwards                   grante             Yow!  I want a WESSON
>                                   at               OIL lease!!
>                                visi.com

Moctar wrote:
> 
> ok i will study them and will give the result later.

When you do, please don't top-post.  Read the following links.

-- 
 Some informative links:
   <news:news.announce.newusers
   <http://www.geocities.com/nnqweb/>
   <http://www.catb.org/~esr/faqs/smart-questions.html>
   <http://www.caliburn.nl/topposting.html>
   <http://www.netmeister.org/news/learn2quote.html>
   <http://cfaj.freeshell.org/google/>

"Moctar" <ouldm8@gmail.com> wrote in message 
news:1166271797.731167.191160@79g2000cws.googlegroups.com...
> Thanks a lot Thad,
>
> It is not for fun (a little bit). I have a 5 persons team and we have
> to make a project in embedded systems but we have not an idea how to
> develop a RTOS (do you have some references or examples of small RTOSs
> that could be understoud easily).


http://www.freertos.org/implementation/


Regards,
Richard.

+ http://www.FreeRTOS.org
+ http://www.SafeRTOS.com
for Cortex-M3, ARM7, ARM9, HCS12, H8S, MSP430
Microblaze, Coldfire, AVR, x86, 8051, PIC24 & dsPIC

Vladimir Vassilevsky <antispam_bogus@hotmail.com> writes:

> The development of a basic RTOS kernel and services from the scratch
> is a one man one week project.
> 

But maintaining it, and adding a lot of "necessary" features may cost
considerably more time.  ;-)

Don't reinvent the wheel, unless your requirements are very special.

-- 
mdc at manbw dk  -  MAN Diesel A/S, Copenhagen
www.manbw.com    -  Electronics & software dept.
      -  Speaking for myself only. -