On 10/20/20 4:07 PM, Tom Rini wrote:
> On Tue, Oct 20, 2020 at 11:05:40AM +0200, Marek Vasut wrote:
>> On 10/20/20 2:27 AM, Reuben Dowle wrote:
>>>>> What assumptions? Any code that assumes 4 byte alignment will also work
>>>> on 8 byte alignment.
>>>>>
>>>>> Reverting is not the same as assuming ALIGN(...4) if incoming data is not
>>>> already aligned to 4 bytes (as was the case when I saw crashes).
>>>>
>>>> Can the incoming data _not_ be 4 byte aligned ?
>>>> How can this be replicated ?
>>>
>>> In my case I have an offline signing process (separate from build server to
>>> keep secure boot keys safe), and this runs a script which also patches the
>>> main uboot device tree with some extra properties, then updates main uboot
>>> dtb with kernel signature, then finally updates the spl dtb with the uboot
>>> signature. I think when mkimage patches the dtb with the signatures, this
>>> results in the alignment issues (the unsigned bootloader direct from the
>>> uboot make process does not experience this issue).
>>>
>>> Possibly using mkimage to add padding would also fix the alignment issue I
>>> see at boot time.
>>>
>>>>> Interesting. I had not noticed the -B parameter previously. I had
>>>>> originally
>>>> fixed this issue on an older version of uboot that did not have that
>>>> option,
>>>> and later rebased the fix to newer uboot. I would need to do some testing
>>>> to
>>>> see if this would fix it as well.
>>>>
>>>> I believe this is the way to handle this if you are building a custom DT
>>>> for U-
>>>> Boot -- just make sure it has the correct parameters. I think this is also
>>>> related
>>>> to:
>>>> 20a154f95b ("mkimage: fit: Do not tail-pad fitImage with external data")
>>>
>>> I will look into this, although unfortunately I am very busy with other
>>> projects right now so can't retest th
>>
>> In that case, I would propose to revert this to fix existing boards in
>> mainline, and if your tests are not successful, revisit this issue.
>>
>> I am rather sure what you are hitting is related to the mkimage patch
>> above, there was a lengthy discussion on that topic before.
>
> This gets back to what I was saying earlier in this thread. But to
> expand on it, we have been, but cannot, use the same variable for both
> "this is where we have the DTB at runtime to use" and "this is where the
> DTB happens to exist when we get here". For the case of "we copy the
> device tree to $address", $address must be 8 bytes aligned. For the
> case of "we use an externally provided DTB in place" I don't like the
> idea of, and worry a lot about, assuming it's going to be 8 byte
> aligned. But I can set that aside for the moment. That said, in that
> second case we need to set $address to where the device tree is.
I don't think I understand this paragraph at all ?
> That all said, I'm still not quite sure how you're ending up in the
> place you're ending up. Which if/else paths in spl_fit_append_fdt() is
> your exact platform hitting, and where is what in memory?
Is this a question for me or for Reuben ?
