Re: [patches] E500 port

["Joseph S. Myers" <joseph@xxxxxxxxxxxxxxxx>]

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).

> 3. some additional patches for gcc-4.1.x for e500?

Yes, as detailed in my message.

> 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.

-- 
Joseph S. Myers
joseph@xxxxxxxxxxxxxxxx