[U-Boot] [PATCH v7 1/2] armv8: Support loading 32-bit OS in AArch32 execution state

[york sun]

On 11/04/2016 09:32 AM, Ryan Harkin wrote:
>>>
>>> Yes, with the attached patch on top of your original 2 patches,
>>> everything works again.  I tested on FVP Foundation and AEMv8 models
>>> and Juno R0, R1 and R2.
>>>
>>> I don't think it would be good to stack these three patches the way
>>> they are presented in the upstream tree because it would not be
>>> bisect-able.  Some re-work or re-ordering would be needed.
>>>
>>> Note: I haven't attempted to understand what any of this code is
>>> doing, I'm just testing it with my standard boot flow to make sure
>>> nothing is broken for me.
>>
>> Ryan,
>>
>> I support Alison's patch order for her 32-bit patch sets. This feature
>> doesn't exist before her first set. It is functional if you run U-Boot
>> at EL3 after the first patch.
>
> Which I don't do.  I follow the boot flow recommended by ARM and it
> doesn't work for that setup, which I don't think is the right thing to
> do.
>
>
>> It gets EL2 working after the 2nd set. If
>> there is room to clarify in the commit message, please kindly suggest.
>>
>
> Well, I'm not the maintainer of the tree, but I wouldn't want to have
> a tree that wasn't bootable at any point in the patch sequence.
> That's generally unacceptable on most projects I work on.  Keeping the
> tree bisect-able to prove which commit caused a problem is considered
> to be a valuable tool.
>

Ryan,

Thanks for sharing your concern. I support git-bisect. It is valuable, 
no doubt. Let me try to understand the issue here. Without Alison's 
patches, everything boots OK. With her first set, does something break? 
My understanding is 32-bit OS can boot. If existing 64-bit OS fails, 
then she needs to fix it.

York