embedding dtb file into kernel

embedding dtb file into kernel

[K Richard Pixley]

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.

Thank you in advance.

--rich

Re: embedding dtb file into kernel

[christophe leroy]

Le 13/02/2015 18:41, K Richard Pixley a écrit :
> 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.
>
> Thank you in advance.
>

Hi,

The device tree (DTB file) is not supposed to be embedded into the 
kernel but loaded independently by the boot loader (for instance Uboot).
Then a pointer to the device tree is handed over by Uboot to the kernel 
when calling the _start function.

You also have in arch/powerpc/boot/ a facility called cuboot which 
allows to create a ppcboot image with kernel and device tree bound together.

Christophe

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Re: embedding dtb file into kernel

[Stefano Babic]

Hi Richard,

On 13/02/2015 18:41, 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.
> 

Maybe it is worth to take a look at the fitImage, which can embed pretty
much anything (including DTB).

Best regards,
Stefano Babic

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