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Re: Adding xscale support to my eCos config
C B wrote:
>
> Yes, I believe it should just be a compiler issue.
>
> I'll have to look into the 'march' flag but I had tried to compile my application with -mcpu=xscale and I got an error message saying that libtarget.a uses FPA instructions where as my app uses VFP instructions. So, I assumed I need to similarly modify how I build eCos but it's not clear to me at the moment where to make that change (at least within the configtool).
Did you rebuild eCos using these same settings?
>> Date: Wed, 14 Nov 2007 14:30:44 +0100
>> From: andrew@lunn.ch
>> To: csb_80@hotmail.com
>> CC: ecos-discuss@ecos.sourceware.org
>> Subject: Re: [ECOS] Adding xscale support to my eCos config
>>
>> On Wed, Nov 14, 2007 at 08:19:46AM -0500, C B wrote:
>>>
>>> Coming from a long background developing Applications in Java to the
>>> embedded world is quite a switch so please bear with me. I've got
>>> an eCos configuration working based on the latest from CVS for an
>>> ARM9 based target from Atmel. I've written simple applications in
>>> C, linked against the eCos libs and successfully executed them on my
>>> target. So, my question: My target supports an extended DSP
>>> instruction set (xscale). I see an xscale package in the eCos I've
>>> checked out but it is not clear to me how I get from my current eCos
>>> configuration to one in which I can make calls from my C application
>>> to make use of the xscale instruction set. I would appreciate any
>>> hints. Thanks!
>> Isn't this just a compiler issue? So long as the compile knows you are
>> using an xscale with these extra instructions, it should use them.
>>
>> Look what flags are passed to the compiler, in particular march.
>>
>> If you want to explicitly call these xscale instructions, you will
>> need to do inline/out of line assembly language programming, or find a
>> library from somewhere which has wrapped them up in something easier
>> to use.
>>
>> Andrew
--
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Gary Thomas | Consulting for the
MLB Associates | Embedded world
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