Re: Differences between MPC823 powerpc & any other powerpc

Re: Differences between MPC823 powerpc & any other powerpc

[clark]

At 11:48 AM 5/12/00 +0100, you wrote:
>
>Hello,
>
>I would like to know what are the basic difference between the MPC823
>PowerPC and any other PowerPC , say, the G4? Why dont the binaries running
>on G4 not work correctly on the MPC823?
>
>Thank you,
>Navin.
>
>
>

        For starters the MPC823 has no FPU. I think you could compile FPU
emulation into the kernel to remedy this but I'm not sure. G4 compiled
programs may use alti-vec instructions but I'm not sure on this either.

        Good luck,

        Conn Clark


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Re: Differences between MPC823 powerpc & any other powerpc

[Mark Hatle]

clark@esteem.com wrote:
>
> At 11:48 AM 5/12/00 +0100, you wrote:
> >
> >Hello,
> >
> >I would like to know what are the basic difference between the MPC823
> >PowerPC and any other PowerPC , say, the G4? Why dont the binaries running
> >on G4 not work correctly on the MPC823?
>
>         For starters the MPC823 has no FPU. I think you could compile FPU
> emulation into the kernel to remedy this but I'm not sure. G4 compiled
> programs may use alti-vec instructions but I'm not sure on this either.
>

In addition to no FPU, the 8xx series also has half of the cachelines
that all
of the other PPC's have.  (4xx, 6xx, 7xx, 74xx, 82xx)  This causes a
problem
with glibc [and possibly other things] which expect a certain line size
to do
fast memset's, memcpy's etc.  (The result of having the wrong cacheline
size
is to miss area's of memory in the previous listed functions.)

Also w/ the no FPU comes ABI issues including (especially?) var args
issues.

--Mark

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Differences between MPC823 powerpc & any other powerpc

[Navin Boppuri]

Hello,

I would like to know what are the basic difference between the MPC823
PowerPC and any other PowerPC , say, the G4? Why dont the binaries running
on G4 not work correctly on the MPC823?

Thank you,
Navin.


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Re: Differences between MPC823 powerpc & any other powerpc

[Dan Malek]

Navin Boppuri wrote:

> ..... Why dont the binaries running
> on G4 not work correctly on the MPC823?

You received two replies with some details, but I want to ask a question
from the other direction.  Explain what your applications are trying
to do, and maybe we can help.  The PowerPC integer core is binary
compatible, but as you move through the libraries and into other
features, the details can be quite complex and hard to list just exactly
what may be causing your difficulties.


	-- Dan

>
> Thank you,
> Navin.
>

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