Re: cirrus ep93xx support (was: Re: Debian ARM success story: Debian desktop on a TS-7300)

[Lennert Buytenhek <buytenh@wantstofly.org>]

On Mon, Jul 31, 2006 at 05:54:31PM +0300, Petko Manolov wrote:

> > The current advantage of Maverick over something like iWMMXt, 
> > considering that Debian is still hardfpa, is that Maverick is on 
> > coprocessors 4,5,6 so it doesn't conflict with FPA, whereas if you want 
> > to use iWMMXt at all, you have to use either softfloat or EABI for 
> > everything because it conflicts with FPA.
> 
> Even though FPA and Maverick doesn't conflict in hardware aspect, it is 
> still impossible to mix both in the same dynamically linked executable. 
> The problems are numerous, but think about the data representation in the 
> memory (and within the FPUs), C argument passing, return values (as per 
> current GCC convention), etc.

If you want to emit Crunch assembly from C code, it indeed won't work
without a bunch of hacking.  (I have successfully used inline Crunch
assembly in FPA binaries, though.)


> The only sane way of using Maverick code is by having it in a
> statically linked executable.

Or by using EABI?


> This, however, implies that the corresponding libc has been built
> with Maverick support.

Why can't we use a Crunch app on top of a, say, VFP soft-float libc?
As long as the calling conventions are the same (which they are, in
this case), I don't see why it would be a problem that the app uses
Crunch while the C library does not..


cheers,
Lennert