Re: [patches] E500 port

[Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>]

On Dec 10, 2006, at 3:47 PM, Joseph S. Myers wrote:

> On Fri, 8 Dec 2006, Kumar Gala wrote:
>
> > 2. need patches for long double ?? is this just an eglibc  
> > requirement?
>
> glibc 2.4 and later for PowerPC requires 128-bit IBM long double  
> support.
> This was added to GCC 4.1 branch for 6xx hard float at a very late  
> stage
> before 4.1 was released, but the soft float support is not yet on GCC
> trunk because of FSF policies (it requires a soft-fp patch, and  
> soft-fp
> can only be imported into FSF GCC unmodified from FSF glibc, and  
> FSF glibc
> maintainers have no interest in applying soft-fp patches), so the  
> EGLIBC
> prerequisites page points to the required soft float patches (which in
> turn are needed by the E500 long double support patches).

Hmm, what exactly is the requirement in glibc?  I know I've built a  
glibc-2.5 for a ppc32 system w/o hardware long double support.

> > 3. some additional patches for gcc-4.1.x for e500?
>
> Yes, as detailed in my message.

Would a recent gcc-4.1.x branch + the patch you referenced be enough  
or are there more patches on top of that for e500?

> > Any help in getting this going would be appreciated.  I'd be happy  
> > to look
> > into implementing the kernel side trap handling and fixup if I can  
> > get an
> > environment working to show the issues.  [Wasn't sure if you aware  
> > there isn't
> > any code today that does this]
>
> I was told some time ago that Freescale might be implementing this  
> some
> time this year, but I do not know the current status.
>
> If the trap handling uses the kernel's copy of glibc's soft-fp,  
> note that
> I found and fixed many bugs in glibc's soft-fp (and some more are  
> fixed in
> EGLIBC as part of the PowerPC soft-float work) and these many fixes  
> need
> merging into the kernel's copy if they haven't already been merged.

I know we haven't merged any recent changes into the fp emulation  
code in the kernel.  Have you been using a particular test suite to  
find these issues?

- k