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From: Josh Boyer <jwboyer@jdub.homelinux.org>
To: Matt Porter <mporter@kernel.crashing.org>
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Date: Wed, 09 Nov 2005 10:50:33 -0600
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Cc: linuxppc-dev@ozlabs.org, Stefan Roese <sr@denx.de>,
	linuxppc64-dev@ozlabs.org
Subject: Re: 440EP FPU support missing
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On Tue, 2005-11-08 at 16:02 -0700, Matt Porter wrote:
> On Tue, Nov 08, 2005 at 04:32:54PM -0600, Josh Boyer wrote:
> > On Tue, 2005-11-08 at 15:30 -0700, Matt Porter wrote:
> > > On Tue, Nov 08, 2005 at 06:38:11PM +0100, Stefan Roese wrote:
> > > > In the current linux version, Bamboo (440EP) won't compile anymore, because of 
> > > > missing fpu support:
> > > > 
> > > > make uImage
> > > > ...
> > > >   LD      init/built-in.o
> > > >   LD      .tmp_vmlinux1
> > > > arch/ppc/kernel/head_44x.o(.text+0x868): In function `_start':
> > > > : undefined reference to `KernelFP'
> > > > make: *** [.tmp_vmlinux1] Error 1
> > > > 
> > > > Somehow arch/ppc/kernel/fpu.S has disappeared. :-( I assume, this happened in 
> > > > the ppc/ppc64 -> powerpc merge. Any thoughts, why this file disappeared and 
> > > > how to solve this problem (just restore the original file)?
> > > 
> > > arch/powerpc/kernel/fpu.S is being used now which doesn't have KernelFP.
> > > I don't know why the 44x fpu support wasn't using
> > > kernel_fp_unavailable_exception() before but I must have missed that
> > > reviewing it.
> > > 
> > > Try this patch.
> > 
> > Doesn't this render the 440EP's FPU useless?
>  
> Does what render the 440EP's FPU useless? The supplied patch? I
> don't think so, the path should be the same as classic PPC.
> 
> The patch simply replaces the KernelFP routine that used to be in
> arch/ppc/kernel/fpu.S (and was removed inadvertently in the arch/powerpc/
> merge) with a kernel_fp_unavailable_exception() call which does the
> equivalent and is shared by others.
> 
> The exception still loads up the fpu is coming from userspace and
> only goes down this path when getting an FP unavailable exception from
> kernel space.

Yes, you're obviously right.  I blame my idiocy on lack of coffee.
Sorry for the noise.

josh