Re: Could the DTS experts look at this?

[David Gibson <david@gibson.dropbear.id.au>]

On Tue, Feb 12, 2008 at 01:21:44AM +0100, Arnd Bergmann wrote:
> On Tuesday 12 February 2008, David Gibson wrote:
> > Or to expand.  It's relatively easy now to just include multiple nodes
> > in the tree and either delete or nop some of them out conditionally
> > using libfdt.  But the conditional logic should be in the manipulating
> > agent (u-boot or bootwrapper or whatever), there's no way we're going
> > to require a conditional expression parser to interpret the device
> > tree blob itself.
> 
> How about making the logic to nop out nodes a little more generic
> without changes to the binary format?
> E.g. you could have a "linux,conditional-node" property in the device
> tree whose value is compared to a HW configuration specific string.
> In Sean's example, you can have linux,conditional-node="Rev.A" in
> some nodes and linux,conditional-node="Rev.B" in others, then
> knock out all devices that have a non-matching linux,conditional-node
> property, and finally remove the properties themselves before starting
> the kernel.

Well, that's basically a u-boot issue.  If they want to do their input
trees that way, and have helper functions that deal with it...

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson