Re: [ECOS] Current state of SMP in eCos

["David Brennan" <ecos at brennanhome dot com>]

On Thu, Dec 18, 2008 at 10:12 AM, Andrew Lunn <andrew@lunn.ch> wrote:
> On Wed, Dec 17, 2008 at 08:13:44PM -0800, David Brennan wrote:
>> I was wondering about the current state of SMP in eCos. Specifically,
>> has any progress been made on running it on a dual core Intel chip
>> yet? Or failing that, can it run on a SMP linux synthetic target?
>>
>> If either of those have not been done, I might consider tackling one
>> or the other, if someone would give me some guidance as to what the
>> process would be.
>
> An SMP synth would be interesting. It does not need a SMP host
> underneath, just multiple threads. However such a system would be a
> good test and development platform for SMP development.
>
> I think part of the problem with SMP is that so few people actually
> have SMP hardware. The other problem is its a very specialized area. I
> guess there are very few applications which need SMP and RTOS which
> cannot use Linux.
>
>       Andrew
>
I was actually recently playing with "another operating system's"
simulator on an SMP linux box and thought exactly what you did. I
think it would be great for testing SMP code without hardware. My
current project is UP, but we use COTS VME boards and they are mostly
going to Core Duo chips (for Intel architecture). So we would like to
consider how difficult it would be to make our code SMP aware. We
don't currently need the horsepower. But who knows what the future
requirements are going to be. And the hardware vendors are "throwing
it in for free" (if you neglect the extra power, and heat).

But if it is possible to get the SMP eCos running on a Core Duo
laptop, they are also getting cheap enough to testing/development. But
I don't understand what the actual steps are for identifying
processors, and initializing them. I'd be willing to try and learn to
try and get it working under eCos.

For running it on linux synth with mulitple threads, would that just
require starting a second thread somewhere in the synthetic startup
code? Will the threads be able to share memory? I've never done
multi-threaded programming on anything other than a flat memory model
RTOS.

Thanks for your input
David

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