[PATCH] Revert "Fix data abort caused by mis-aligning FIT data"

[Marek Vasut]

On 10/20/20 12:58 AM, Tom Rini wrote:
> On Tue, Oct 20, 2020 at 12:54:35AM +0200, Marek Vasut wrote:
>> On 10/20/20 12:45 AM, Tom Rini wrote:
>>> On Mon, Oct 19, 2020 at 11:59:22PM +0200, Marek Vasut wrote:
>>>> On 10/19/20 11:50 PM, Reuben Dowle wrote:
>>>>> The alignment of 8 bytes would also work if code was expecting 4 byte alignment. So the explanation you give for reverting this does not make sense to me.
>>>>
>>>> Well, since U-Boot 2020.10-rc5, any STM32MP1 board does no longer boot
>>>> and if I revert this patch, it works again (per git bisect). But this
>>>> also applies to any other arm32 boards which load fitImage in SPL, all
>>>> of those boards are broken in U-Boot 2020.10.
>>>>
>>>> It seems that the end of the U-Boot image is at 4-byte aligned offset on
>>>> arm32, and that is where the DT is also loaded ; but your patch forces
>>>> the alignment to 8-bytes, so suddenly the DT location is 4-bytes off.
>>>
>>> I think this needs some more investigation to figure out what's going
>>> on and where the underlying bugs are.  This section of the code is where
>>> U-Boot is saying it will copy the device tree to.  If we're using a
>>> device tree in place that's NOT being copied (and someone else has
>>> ensured 8 byte alignment of) we need to set the address of where the
>>> device tree is, at that time.
>>
>> The problem is that the previous alignment was 4 byte, now it is 8 byte
>> and that breaks all the other assumptions. So, this patch should be
>> reverted to fix the platforms which used to work (or use ALIGN(...4),
>> which is the same as reverting it really).
>>
>> And likely the signed image which caused the breakage should be
>> generated with mkimage -E / -B 8, which would insure the alignment, so
>> then there is no need to change anything in the code itself.
> 
> 4 byte alignment is wrong.

Please elaborate why is 4 byte alignment wrong? 8 byte alignment
obviously breaks existing boards which are in-tree and worked for
multiple releases.