Re: generating a phandle w/libfdt?

[Jimi Xenidis <jimix-aZOuKsOsJu3MbYB6QlFGEg@public.gmane.org>]

On Oct 24, 2008, at 9:18 AM, Kumar Gala wrote:

>
> On Oct 24, 2008, at 8:11 AM, Kumar Gala wrote:
>
>> In some work I'm doing I noticed we don't have any APIs to generate  
>> a phandle via libfdt.
>>
>> was wondering if anyone had ideas on this.
>>
>> In first thought it seems we have to scan through the whole blob  
>> looking for the largest phandle id and than +1 it to generate the  
>> next "valid" id.  Any other ideas on how to do this more efficiently?
>
> The other question is there a way today to create a phandle even if  
> there isn't a reference to it elsewhere in a .dts?
>

Well, then by definition, it is not a phandle, right?
If nothing references it then I'm not sure how you can reconcile the  
number when some SW layer builds the next version of it to pass on up.

It sounds like you need a separate numerical space.

Just a shot in that dark to see if your actual problem is similar...

I'm expecting us to hit something like this _hard_ when we try to fit  
runtime FW into ePAPR, like IBM's RTAS layer, where the devtree can go  
through several generations but we need to hang on to the _original_  
phandle for a node from the time that the RTAS was instantiated.  In  
server we use "ibm,phandle" for this.

-JX