Re: [Qemu-devel] [PATCH v2 2/2] fw_cfg: document MMIO registers for arm, sun4*, and ppc/mac_*

[Gabriel L. Somlo]

On Thu, Aug 06, 2015 at 02:15:11PM +0100, Peter Maydell wrote:
> On 6 August 2015 at 10:14, Laszlo Ersek <address@hidden> wrote:
> > On 08/06/15 01:47, Gabriel L. Somlo wrote:
> 
> >> +=== arm Register Locations ===
> >> +
> >> +Selector Register MMIO addr: 0x9020008 (16-bit, big-endian)
> >> +Data Register MMIO addr:     0x9020000 (64-bit)
> >
> > Suggestions:
> > - maybe mention that this is specific to the "virt" machtype
> > - mention that the exact location comes from the DTB,
> >   and hint at "Documentation/devicetree/bindings/arm/fw-cfg.txt" in the
> >   kernel tree
> > - for the data register, rather than just "(64-bit)", consider saying
> >   "(64-bit, endianless, string-preserving)"
> 
> We shouldn't be documenting the specific locations at all --
> the guest *must* look at the DTB or ACPI table to find the
> device.

I see how that may work on x86 (acpi) or arm (dtb). But would either of
those also work for sun4 and ppc/mac ? Do we even care ? ;)

Thanks,
--Gabriel