Re: [Xen-devel] [PATCH 04/12] arm: parse modules from DT during early boot.

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Thu, 2012-11-29 at 17:05 +0000, Tim Deegan wrote:
> > +            cell = (const u32 *)prop->data;
> > +            device_tree_get_reg(&cell, address_cells, size_cells,
> > +                                &mod->start, &size);
> 
> This get_reg returns a start + size -- can/should we encode the module
> as one of these rather than encdong start + end separately and
> discarding the 'size' fields?

Interesting thought, I'm not enough of a DTB guru to know what the right
way to express this is (CCing Stefano :-))

This is trying to parse
/ {
        chosen { 
                module@1 {
                        start = 0x80000000;
                        end = 0x2000;
                }
        }
which is roughtly equivalent to how Linux bootloaders pass in initrds
(although the name etc differ)

I suspect using device_tree_get_reg as things stands is just plain
wrong, since the above things are not actually regs.

However you might be right that this should be expressed as

/ {
        chosen { 
                module@1 {
                        address = <0x80000000 0x2000>;
                }
        }

and then I think using device_tree_get_reg would be correct.

Stefano -- does that make sense? is "address = < ... >" allowed or does
the thing have to be called reg?

Ian.



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