Re: [PATCH] x86/platform: sta2x11: add platform code

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Tue, 2012-05-29 at 00:39 -0700, H. Peter Anvin wrote:
> > So, it seems I must go device-tree for the chipset-like mounting.
> And
> > what about plug in boards? I may arrange a firmware-loader mechanism
> > as an alternative, so the vendor of each board can provide the the
> > platform data for all the sub devices. Actually, if firmware loader
> is
> > acceptable, I'd try it first, to avoid changing the boot procedure;
> > maybe I can save myself from the device tree.
> > 
> 
> If you're going to use a binary blob for the loader, use either ACPI 5
> SSDT or device tree format.  This is *not* something where
> (re)invention is encouraged.

Right, a device-tree blob could easily be passed an x86 has the
infrastructure to use it already afaik.

It then becomes a matter of the bootloader to carry it over to the
kernel a way or another. If the "vendor" boards don't do the right
thing, you can always do like powerpc for those cases and "package" the
device-tree blob in the zImage wrapper.

That way, distribution install tools etc.... can stick the right
device-tree before doing whatever "flashing" of the image is needed for
booting etc... and the main kernel image remains agnostic.

That or the ACPI way but I know nothing about it and thus naturally
assume it's harder :-)

Cheers,
Ben.