Re: powerpc/405ex: Support cuImage for PPC405EX

[Josh Boyer <jwboyer@linux.vnet.ibm.com>]

On Wed, Aug 19, 2009 at 09:45:13AM +0800, tiejun.chen wrote:
>Josh Boyer wrote:
>> On Tue, Aug 18, 2009 at 10:28:02AM +0800, Tiejun Chen wrote:
>>> Summary: powerpc/405ex: Support cuImage for PPC405EX
>>> Reviewers: Benjmain and linux-ppc
>>> ----------------------------------------------------
>>> These patch series are used to support cuImage on the kilauea board based on PPC405ex.
>>>
>>> Tested on the amcc kilauea board:
>> 
>> Hm.  The U-Boot version that ships on the AMCC Kilauea board is FDT aware, so
>> cuImage shouldn't be needed at all.  I'm slightly confused why we need this.
>
>That the newer u-boot can aware extra on Kilauea is really as you said. But I
>think I/we need to consider some other requirements for 405EX, such as only
>using one image for convenient on embedded system, and u-boot don't pass dtb for
>kernel since it will be isolated with one customer software layer.
>
>And actually to support old U-boot compatibility is original *goal* of
>implementing cuImage in kernel as we know. Right?

Yes.  Supporting _old_ U-Boot compatibility.  Not FDT aware U-Boot :).


>As Documentation/powerpc/bootwrapper.txt I think the kernel should support more
>image variant to satisfy different requirement. Sometimes that is also beyond we
>can discuss here.
>
>> Are you using it for some other board derived from 405EX that doesn't have
>> an FDT aware U-Boot?
>> 
>
>Yes, this is really another factor. Anyway thinks your comments.

That's fine then.  I have no real problems with having a cuImage that works
on Kilauea.  I just wouldn't want to promote it as the default because the
cuImage wrapper is a bit of a hack.

Anyway, I'll review the patches soon.  Thanks for the explanation.

josh