Subject: Re: [PATCH 07/17] bootwrapper: Add dt_set_memory(), to fill in the /memory node.

From: Segher Boessenkool <[email-masked]>
Date: Thu, 22 Mar 2007 12:02:56 +0100

>>> However, #address-cells=2, #size-cells=1 is common enough that we
>>> really need to support that case.
>>
>> On the root node?!?  Who would do such a strange thing?
>
> Ebony, for one, it works nicely for a 32-bit system with >32-bit bus.

It means you cannot have a 4GB-or-bigger region below your
root node.  Dunno if Ebony ever needs one, for I/O mapping
perhaps?

> Apple G5s do it too.

And they do a an awful workaround for their memory node
because of this.

Is their any reason why you couldn't use #a=#s=2 on 32-bit
systems?  The root node is one contiguous hunk of address
space, so the biggest (theoretically) possible size is equal
to the biggest address (+1).  It's not hard to come up with
an example where you need a size of 4GB or more.

Segher