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Date: Sat, 28 Feb 2009 17:58:35 +0200
Message-ID: <f43fc5580902280758j26b3ddf2l4451d7489bf20a52@mail.gmail.com>
Subject: Re: [Qemu-devel] [PATCH] Make the ELF loader aware of backwards
	compatibility
From: Blue Swirl <blauwirbel@gmail.com>
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To: qemu-devel@nongnu.org
Cc: Alexander Graf <alex@csgraf.de>

On 2/28/09, Andreas F=C3=A4rber <andreas.faerber@web.de> wrote:
>
>  Am 28.02.2009 um 16:30 schrieb Blue Swirl:
>
>
> > On 2/28/09, Alexander Graf <agraf@suse.de> wrote:
> >
> > > Most 64 bit architectures I'm aware of support running 32 bit code
> > > of the same architecture as well.
> > >
> >
> > For Sparc64 this is only true for userland, kernel level code is not
> > compatible at all. Sparc64 kernel can run Sparc64 and Sparc32
> > binaries, but a Sparc32 kernel will crash on Sparc64.
> >
>
>  Same for ppc. To install Linux, you need to type "install64" at the prom=
pt,
> the default "install" crashes on a G5.

Not exactly. I guess it's possible to construct a dual PPC32/PPC64
kernel for 32 bit mode because even though the MMUs are not
compatible, instruction sets are. But Sparc32 supervisor instructions
do wildly different things on a Sparc64.