[OpenBIOS] [PATCH 3/6] escc: Fix legacy addresses

Benjamin Herrenschmidt benh at kernel.crashing.org
Tue Aug 2 11:15:45 CEST 2016

On Tue, 2016-08-02 at 08:51 +0000, Alyssa Milburn wrote:
> The attached patch is probably the one you mean. I never posted it to the
> qemu list, I think, but in any case it deliberately doesn't change these
> values because I think I worked out it wasn't necessary.. it's been too long
> > for me to remember.

Nothing uses them anyway at this point. I have done a slightly different
patch that adds comments too, I'll send it to the qemu list later.

> >>  om memory, the current mappings match *some* hardware, and this new patch
> matches other hardware. So they're both "right". I kind of gave up trying to
> work out what on earth Apple was thinking (see also the errata mentioned in
> the patch).

The register mapping for the base set is fine, and is what everything
uses. The extended registers as described by your patch and my patch
is correct for any MacRISC machine.

I don't know whether more ancient (read: pre-PCI) macs use some
different kind of mapping but I doubt it and in any case it wouldn't
have a macio ASIC so we don't care.


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