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

[Marek Vasut]

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.