Re: embedding dtb file into kernel

[Tim Bird <tim.bird@sonymobile.com>]

On 02/12/2015 02:30 PM, K Richard Pixley wrote:
> On 2/12/15 14:01 , Tim Bird wrote:
>> On 02/12/2015 11:33 AM, K Richard Pixley wrote:
>>> I'm having trouble figuring out how to embed a dtb file into my kernel.
>>> I'm thinking that there should be a standard, architecture independent
>>> facility for this akin to initramfs, yes?
>>>
>>> Could someone please either point me to the standard facility, relevant
>>> doc, a currently building board that uses the standard facility, or
>>> outline what needs to be done to do this with a new board?
>>>
>>> If it matters, (I can't think why it would), I'm working with powerpc on
>>> a 3.10 kernel.  But if there are better facilities in other versions I'd
>>> appreciate hearing about that too.
>> The normal method is just to cat the two files together, like so:
>>   $ cat zImage <filename>.dtb > zImage_w_dtb
>>
>> See https://community.freescale.com/thread/315543 for one example, on ARM.
>> I'm not sure what the status is for appended DTBs on powerpc, but it's
>> easy enough you can just try it and see what happens.
>>   -- Tim
> 
> Thanks!
> 
> How do I tell the kernel where to find that dtb?  Is there a relevant 
> config option?

Usually you make the dtb from sources in the kernel.
I don't know how it works on powerpc, but on arm, the .dts
files are located in arch/arm/boot/dts, and you would make
the dtb for the corresponding "foo.dts" source
by typing:
$ make foo.dtb

   -- Tim