Re: qemu/powernv: coreboot support?

[David Gibson]

On Mon, Oct 21, 2019 at 09:17:55PM -0500, Marty E. Plummer wrote:
> On Tue, Oct 22, 2019 at 12:40:32PM +1100, David Gibson wrote:
> > On Mon, Oct 21, 2019 at 07:32:09PM -0500, Marty E. Plummer wrote:
> > > On that note, is qemu-ppc64 currently capable of running LE
> > > firmware?
> > 
> > Well.. "qemu-ppc64" as such isn't capable of running either LE or
> > firmware, since that's the Linux userspace emulator.
> > qemu-system-ppc64 *is* capable of running both LE and BE firmwares though.
> > 
> Ah. yeah, that's what I meant. Good to know.

Paul Mackerras came up with some magic code that can get you from an
unknown endian state to a known state.

> > Your firmware will, however, need a tiny BE shim to switch the cpu
> > into LE mode.
> > 
> Yeah, I figured as much, and was planning to have a shim available for
> 'real' hardware in the event a user wants to run coreboot in LE mode
> after both work properly (though somewhere in the OpenPOWER spec it is
> stated firmware must be BE).

TBH, it makes no sense to specify the endianness of the firmware -
it's an internal detail.  The endianness of the firmware *interfaces*
needs to be fixed of course, but not the endianness of the
implementation.

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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