[SLOF] [Qemu-ppc] [PATCH v4] board-qemu: add private hcall to inform host on "phandle" update

Segher Boessenkool segher at kernel.crashing.org
Fri Sep 29 18:42:07 AEST 2017


On Fri, Sep 29, 2017 at 03:18:41AM -0500, Segher Boessenkool wrote:
> I'm a bit worried about the phandles FDT requires, which are a different
> size than what OF uses (OF uses cell size, which is 64 bit on 64-bit OF;
> the device tree specification uses 32 bit always).
> 
> Now usually everything lives low in memory, so the top 32 bits will all
> be zeroes, but do we guarantee that anywhere (and do we want to restrict
> to that!)

OTOH SLOF currently has similar bugs itself.  Oh well.

> We cannot translate between the two types of phandles, because we do not
> (and CANNOT) know what parts of properties are phandles (for example
> when using FCode on a plugin board).
> 
> Or maybe phandles on flat device trees just are cell size and the spec
> (I looked at devicetree.org) is horribly wrong?  That would be good
> (here and everywhere else).


Segher


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