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Re: ecos w/ arm-thumb


> I know this question has been asked before, but I have never seen a
> specific answer: can the ecos libraries be built in thumb mode (and if
> so, what modifications are necessary)?  I've been able to build the the
> tools (gcc 3.04 & binutils 2.11.2) and configure ecos such that thumb
> interworking is operating properly; however, I still have not been able
> to build the ecos libraries such that they will switch to thumb mode.
> My processor only has a 16-bit bus, so not having two bus accesses for
> each arm instruction would help performance and save space.  Any help
> (with detailed instructions) would be greatly appreciated.
>
> John

Yes I've built them in THUMB mode both with and without interworking.

You've put "-mthumb -mthumb-interwork" in both the link and compile options?

You've enabled the Interworking and Thumb check boxes (if using
configtool) in the HAL settings?

Also with THUMB mode it won't compile with one of the kernel options
turned on, HAL_INTERRUPT something or other, I don't quite recall.

BTW I measured using the dhrystone program a speed increase of 50% and a
code size reduction of 20% w/ the AT91M63200.

I'm not at work now so I can't verify those settings, but it should give
you an idea.

Ryan




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