Re: [Qemu-devel] [PATCH 3/3] target-arm: Add the GICv2m to the virt board

[Christoffer Dall <christoffer.dall@linaro.org>]

On Tue, Apr 21, 2015 at 03:47:13PM +0100, Peter Maydell wrote:

[...]

> > @@ -340,9 +357,31 @@ static void fdt_add_gic_node(VirtBoardInfo *vbi)
> >                                       2, vbi->memmap[VIRT_GIC_DIST].size,
> >                                       2, vbi->memmap[VIRT_GIC_CPU].base,
> >                                       2, vbi->memmap[VIRT_GIC_CPU].size);
> > +    qemu_fdt_setprop_cell(vbi->fdt, "/intc", "#address-cells", 0x2);
> > +    qemu_fdt_setprop_cell(vbi->fdt, "/intc", "#size-cells", 0x2);
> > +    qemu_fdt_setprop(vbi->fdt, "/intc", "ranges", NULL, 0);
> >
> 
> Why do we need an empty ranges attribute?
> 

Without it, Linux fails to make things work.  I suspect this is related
to specifically setting the #address-cells and #size-cells.

I forgot by now, but I think when I originally wrote this patch I traced
through the Linux code and found out that it was required somewhere.

I also think the AMD GICv2m FDT has the empty ranges property.

-Christoffer