Re: embedding dtb file into kernel

[Hugh Blemings <hugh@blemings.org>]

On 13/02/2015 17:10, Rob Landley wrote:
> On 02/12/2015 06:56 PM, Tim Bird wrote:
>>
>>
>> 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
>
> It's probably somewhere in:
>
> https://www.kernel.org/doc/Documentation/devicetree/booting-without-of.txt

Worth pointing out the folk over in linuxppc-dev are usually pretty 
friendly, may be able to help out with this too. 
https://lists.ozlabs.org/listinfo/linuxppc-dev

Cheers,
Hugh