Re: Design doc of adding ACPI support for arm64 on Xen - version 3

[Ian Campbell <ian.campbell@citrix.com>]

On Tue, 2015-08-18 at 12:00 -0700, Julien Grall wrote:
> Hi,
> 
> On 18/08/2015 02:34, Shannon Zhao wrote:
> > IIUC, this is a requirement for Linux. Because when Linux parses the
> > minimal DT, it uses below dt_params to match the DT properties. If it
> > doesn't match any of them, it will fial.
> > See efi_get_fdt_params in drivers/firmware/efi/efi.c.
> 
> This is *not* a requirement for Linux. All those properties are internal 
> to Linux so it's not exposed to anyone else. We have room to change it 
> while we standardize the property.

This thread is not the correct forum for such standardisation, since we
(Xen) cannot do so in isolation. I've not yet seen any discussion in the
appropriate places and we really should be doing so before we
build/finalise a design based upon it (otherwise we get to the end and the
rest of the world says "no").

AFAICT the correct place to discuss would be the devicetree-spec ML[0], and
perhaps also some or all of:
      * Some appropriate UEFI forum?
      * Linux (~=devicetree-spec?) since we are building on their internal
        spec?
      * BSD, since we would like them to support it?

Is someone going to make such a proposal?

Ian.

[0] http://vger.kernel.org/vger-lists.html#devicetree-spec