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Date: Thu, 10 Jun 2004 18:02:07 +0200
From: Ralf Baechle <ralf@linux-mips.org>
To: juli mallett <jmallett@FreeBSD.org>
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cc: Gheorghe Ardelean <ardelean@ww.uni-erlangen.de>
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Subject: Re: Some MIPS status goodies.
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On Wed, Jun 09, 2004 at 11:07:12PM -1000, juli mallett wrote:

> R10K and IP28 support are probably a ways away, but I'm interested
> in supporting these systems and more.  Right now it's easiest to start
> with the, much simpler, R4400 Indigo2 I have here, and get a good base
> of this stuff, then move into supporting the more modern and complex
> CPUs and machines - but be assured I am taking them into account!

R10000 in non-coherent systems (Indigo 2 R10000, O2) is a rather hard to
use processor due to unwanted behaviour of speculative execution that
leads to memory corruption.  The workarounds are fairly complex; efficient
solutions involve compiler modifications.

That said, the R10000's is resolving all hazards in hardware and does
almost the entire coherency in software so in a saner system such as
the Origin it's a breeze.

  Ralf