RE: [ECOS] eCos API

RE: [ECOS] eCos API

[Nielsen Linus]

>       Hi, many RTOS e.g. WinCE, Paml, etc. allow user to use 
> it's API to
> develop applications and download it to it's system. Now I 
> want to support
> it. but don't know how to do it.

As far as I know there is no support for dynamic loading of
applications in eCOS.

(But I do think it's kind of unfair to call WinCE and PalmOS
RTOS'es. They do not play in the same league as eCOS, and are
not targetted at the same type of applications. They could
surely be called "embedded OS" but certainly not RTOS.)

I an earlier project, not with eCOS though, we developed a
separate API that wrapped the OS functionality using a
jump table on a fixed address. Using that, we could load
applications on the fly that called our functions via the
jump table.

/Linus

[ECOS] eCos API

[james chen]

      Hi, many RTOS e.g. WinCE, Paml, etc. allow user to use it's API to
develop applications and download it to it's system. Now I want to support
it. but don't know how to do it.  in eCos install/lib directory, there are
two libraries. but it is used to link whole system. if we use it to link
user applications, the applications is very large and we will have many eCos
Kernels in platform, and it will won't run correctly( I think so :-) ). so
another library is needed, this library only contains C library API and
kernel API(not the kernel core). Will anyone tell me how to do it? thanks in
advance.

Regards,
james chen

Re: [ECOS] eCos API

[Lewin A.R.W. Edwards]

>      Hi, many RTOS e.g. WinCE, Paml, etc. allow user to use it's API to
>develop applications and download it to it's system. Now I want to support

eCos does not support user-installable applications. It is a monolithic, 
statically-linked OS+application.

There are various proprietary ways to solve this, depending on your needs. 
For instance, we have developed a _very_ simple executable file format for 
our platform to allow third parties to develop "plugins" for the OS. 
However these plugins have no access to the eCos APIs and in fact the same 
plugin API is implemented both on the eCos and non-eCos products. We have a 
jump table at a known location in ROM, and a few system variables at known 
locations in RAM, and that's how "plugins" access APIs (filesystem stuff 
mostly) in our application. It is all very modal - our application runs 
entirely in a single thread, and when a "plugin" is executed, control of 
the system is surrendered entirely to that plugin - i.e. the application 
jumps into the plugin.

=== Lewin A.R.W. Edwards (Embedded Engineer)
Work: http://www.digi-frame.com/
Personal: http://www.zws.com/ and http://www.larwe.com/

"... a man who is endowed with real qualities of leadership will be tempted 
to refrain from taking part in political life; because [...] the situation 
does not call for a man who has a capacity for constructive statesmanship 
but rather for a man who is capable of bargaining for the favour of the 
majority. Thus the situation will appeal to small minds and will attract 
them accordingly."

Re: [ECOS] eCos API

[Grant Edwards]

> >      Hi, many RTOS e.g. WinCE, Paml, etc. allow user to use it's API to
> >develop applications and download it to it's system. Now I want to support
> 
> eCos does not support user-installable applications. It is a
> monolithic, statically-linked OS+application.

Exactly.  If you need to support the dynamic loading of
applications, then eCos is probably not a good choice for OS.
You might want to look at uCLinux -- I presume it does dynamic
loading of applications.

Developing a dynamic linker/loader for eCos would take a fair
amount of work -- especially if you wanted applications to
share run-time libraries.  If all you wanted was a
position-independant way to make system calls, that wouldn't be
quite as bad.

-- 
Grant Edwards
grante@visi.com

Re: [ECOS] eCos API

[Fredrik Hederstierna]

We have developed a dynamical loader for applications in the ELF file format. It
works very well I think!

Best Regards,
Fredrik Hederstierna
WeSpot AB
SWEDEN

Grant Edwards wrote:

> > >      Hi, many RTOS e.g. WinCE, Paml, etc. allow user to use it's API to
> > >develop applications and download it to it's system. Now I want to support
> >
> > eCos does not support user-installable applications. It is a
> > monolithic, statically-linked OS+application.
>
> Exactly.  If you need to support the dynamic loading of
> applications, then eCos is probably not a good choice for OS.
> You might want to look at uCLinux -- I presume it does dynamic
> loading of applications.
>
> Developing a dynamic linker/loader for eCos would take a fair
> amount of work -- especially if you wanted applications to
> share run-time libraries.  If all you wanted was a
> position-independant way to make system calls, that wouldn't be
> quite as bad.
>
> --
> Grant Edwards
> grante@visi.com

Re: [ECOS] eCos API

[Chris Gray]

"Lewin A.R.W. Edwards" wrote:

> >      Hi, many RTOS e.g. WinCE, Paml, etc. allow user to use it's API to
> >develop applications and download it to it's system. Now I want to support
>
> eCos does not support user-installable applications. It is a monolithic,
> statically-linked OS+application.
>
> There are various proprietary ways to solve this, depending on your needs.
>

One interesting case is the one where the application includes a Java(TM)
compatible Virtual Machine (I think that's the approved formula; doubtless
Sun's lawyers will tell me if it isn't).  Is anyone doing this with eCos, or
would be interested in doing so?

Chris Gray

VM Architect, ACUNIA
(draw your own conclusions)

Re: [ECOS] eCos API

[Jonathan Larmour]

Chris Gray wrote:
> 
> One interesting case is the one where the application includes a Java(TM)
> compatible Virtual Machine (I think that's the approved formula; doubtless
> Sun's lawyers will tell me if it isn't).  Is anyone doing this with eCos, or
> would be interested in doing so?

We've been wanting to hook up with GCJ's bytecode interpreter for a while
now, but noone has sponsored the work :-/. That would be the ideal way to
go though.

Jifl
-- 
Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223) 271062
Maybe this world is another planet's Hell -Aldous Huxley || Opinions==mine

Re: [ECOS] eCos API

[Lewin A.R.W. Edwards]

> > eCos does not support user-installable applications. It is a monolithic,
> > statically-linked OS+application.
>
>One interesting case is the one where the application includes a Java(TM)
>compatible Virtual Machine (I think that's the approved formula; doubtless

Question: If the only reason you want to support dynamic executable loading 
is to load a JVM, then why don't you just roll the JVM into the 
"monolithic, statically-linked OS+application"?

>VM Architect, ACUNIA
>(draw your own conclusions)

(sotto voce) concludes: "This person works for an acronym I don't know" :)

=== Lewin A.R.W. Edwards (Embedded Engineer)
Work: http://www.digi-frame.com/
Personal: http://www.zws.com/ and http://www.larwe.com/

"... a man who is endowed with real qualities of leadership will be tempted 
to refrain from taking part in political life; because [...] the situation 
does not call for a man who has a capacity for constructive statesmanship 
but rather for a man who is capable of bargaining for the favour of the 
majority. Thus the situation will appeal to small minds and will attract 
them accordingly."