[ECOS] eCos info

[ECOS] eCos info

[Meiring, H, Mnr <meiring@sun.ac.za>]

Hi all,

What protection does eCos provide for MMU-less micro controllers, for example when a process want to do memory altering outside its permitted allocation area, and for that matter to protect itself (the OS)

I have some simple questions regarding the HAL layer of eCos after reading A Massa’s book on eCos. Redboot and eCos use the same HAL. If redboot is compiled for ROM mode it produces a binary image that is structured as defined on page 187, which include a HAL layer and device drivers. Now if you compile the eCos default template, it results in a library that contains the HAL and device drivers as well? Resulting in 2 identical sets of HAL’s and device drivers? Is this correct, or do I have the integration of it incorrect? And is it possible to end with one HAL and device driver set? 

According to the my interpretation and the Example application chapter in the book the libraries produces by compiling the eCos default template are implemented(imported) into the example programs and can then be copied onto the chip via redboot and the ymodem. I want to know if something similar to the following is possible and how.
I want to load ecos and a couple of applications and be allowed at a later stage to upgrade 1 or more of the applications without having to load eCos with it again as shown in the example provided (I will have very limited bandwidth and connection time to do upgrade). 

I want to use reboot(purely as a bootloader), what optimization can be done (with regards to Compiler settings and feature removal) once the development is done and the system is to be built for production purposes – ie no debug.
I removed the –g option from the compiler options and it reduced the image size significantly, any other recommendations?

Thanks in advance, any advice welcome. 
 
Regards,
Hendrik Meiring

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Re: [ECOS] eCos info

[Andrew Lunn]

On Sun, Sep 02, 2007 at 11:35:47PM +0200, Meiring, H, Mnr <meiring@sun.ac.za> wrote:
> 
> Hi all,
> 

> What protection does eCos provide for MMU-less micro controllers,
> for example when a process want to do memory altering outside its
> permitted allocation area, and for that matter to protect itself
> (the OS)

eCos performance no memory protection at all. For deeply embedded
systems, which eCos is target at, it is considered unnecessary
overhead.
 
> I have some simple questions regarding the HAL layer of eCos after
> reading A Massa?s book on eCos. Redboot and eCos use the same
> HAL. If redboot is compiled for ROM mode it produces a binary image
> that is structured as defined on page 187, which include a HAL layer
> and device drivers. Now if you compile the eCos default template, it
> results in a library that contains the HAL and device drivers as
> well? Resulting in 2 identical sets of HAL?s and device drivers? Is
> this correct, or do I have the integration of it incorrect? And is
> it possible to end with one HAL and device driver set?

The ROM mode application and the RAM mode application each are
complete. Each has its own eCos.

> I want to load ecos and a couple of applications and be allowed at a
> later stage to upgrade 1 or more of the applications without having
> to load eCos with it again as shown in the example provided (I will
> have very limited bandwidth and connection time to do upgrade).

> I want to use reboot(purely as a bootloader), what optimization can
> be done (with regards to Compiler settings and feature removal) once
> the development is done and the system is to be built for production
> purposes ? ie no debug.  I removed the ?g option from the compiler
> options and it reduced the image size significantly, any other
> recommendations?

Take a read of the man page for size, arm-elf-size. My guess is you
are looking at the size of the elf, not the size of the image. -g
should only make a small difference.

You should be able to remove the GDB stubs.

    Andrew

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