Re: [Gumstix-users] casting problem and soft-float

[Randy S. <rs...@gm...>]

Nghiem Do <nddo <at> ucdavis.edu> writes:

> 
> Good morning from California:
> 
> Hi Dave,
> 
> Sorry, I forgot to mention that was my attempt at pseudo code.  I'm using
> printf correctly, I believe.  
> 
> I'm using C.  Data is a binary.  
> 
> Here's the weird thing:  Program would run...I add a printf line...data come
> over wrong, but consistently wrong.  That is, the two-byte ID at the
> beginning of the packet changes from 0x55 0x55 to 0x75 0x75.  In binary,
> 01010101 to 
> 01110101
> 
> Regards,
> 
> Nghiem Do
> 

If I'm not mistaken, some of the early softfloat libraries were known to have
problems printing floating point on ARM.  The calculations are correct, but they
print wrong.  This appears to be what's going on with your code.

Are you using the latest buildroot?  I had many problems with floats under 733,
but they all fixed when I upgraded to a 9xx build.  The newer builds have the
corrected libraries.

I posted with a very similar problem a few months back.  You can look in the
archives for more info.  If this doesn't resolve your issues, write me off-list
and I'll try to help.

Randy Steck