[U-Boot] db-88f6820-amc board fails to boot with latest u-boot master

[Chris Packham]

On Wed, Feb 15, 2017 at 11:56 AM, Chris Packham <judge.packham at gmail.com> wrote:
> On Tue, Feb 14, 2017 at 11:01 PM, Mario Six <mario.six at gdsys.cc> wrote:
>> On Tue, Feb 14, 2017 at 10:26 AM, Chris Packham <judge.packham at gmail.com> wrote:
>>> On Tue, Feb 14, 2017 at 7:56 PM, Mario Six <mario.six at gdsys.cc> wrote:
>>>> On Tue, Feb 14, 2017 at 7:36 AM, Stefan Roese <sr at denx.de> wrote:
>>>>> Hi Chris,
>>>>>
>>>>> On 14.02.2017 02:48, Chris Packham wrote:
>>>>>>
>>>>>> I just tried UART booting db-88f6820-amc with the latest u-boot master
>>>>>> and it fails to reach the normal u-boot prompt. I don't know if this
>>>>>> affects the normal SPI booting.
>>>>>>
>>>>>> I've bisected down to commit 94084eea3bd3 ("tools: kwbimage: Fix dest
>>>>>> addr").
>>>>>
>>>>>
>>>>> Thanks for checking and reporting.
>>>>>
>>>>>> Reverting this gets things working again, but I'm guessing it'll break
>>>>>> secure boot. Should the size adjustment be conditional on something?
>>>>>
>>>>>
>>>>> Might be, not sure.
>>>>>
>>>>>> Does db-88f6820-amc_defconfig need something that the other armada
>>>>>> configs have enabled?
>>>>>
>>>>>
>>>>> I don't think so.
>>>>>
>>>>> Mario, could you please take a look at this so that we find a solution
>>>>> for the upcoming release?
>>>>>
>>>>
>>>> I'll take a look. The quick-fix solution would be to only do the
>>>> address adjustment if secure boot is active.
>>>>
>>>> But the weird thing is that the address should not matter for the
>>>> non-secure boot images, since for them the SPL (which is run from a
>>>> BIN header) directly loads and starts the main U-Boot, hence the
>>>> BootROM's image loading process is completely bypassed, and the
>>>> destination address from the header is never used. Does the
>>>> db-88f6820-amc do anything different in that regard?
>>>>
>>>
>>> No the amc board is pretty standard. Just doesn't have the extra SATA
>>> and PCI-e stuff you get on the bigger GP board.
>>>
>>
>> OK, thanks for clarifying.
>>
>> Well, I just tried it with our GP board, and it works with and without
>> the address adjustment, as expected.
>>
>> Caveat: I'm booting from an SD card (I changed the U-Boot config
>> around to build a suitable image). There definitely are *some*
>> differences between the boot flows on different boot mediums (I never
>> got the jump back into the BootROM to work on SD boot, for example).
>> So if you boot from another medium, this might be the problem.
>
> For the AMC board my only option is SPI (still haven't tried that with
> a "broken" build) and UART. UART definitely fails for me.
>

And now I have tried SPI and that works. So this is indeed UART specific.

>>> I notice in that commit series you talk about the .img file. But the
>>> default build target is u-boot-spl.kwb[1]. That's what I've always
>>> loaded onto the armada boards.
>>
>> The u-boot-spl.kwb is the correct image. But this image contains the
>> u-boot.img as a payload. And since this image has the header
>> prepended, we have to subtract the header size from the destination
>> address, so that the entry point lines up correctly if we want to jump
>> back into the BootROM (which is necessary for secure boot to work).
>> But for boards that don't jump back into the BootROM, this doesn't
>> matter, since the BootROM doesn't actually load the main U-Boot in
>> this case, but the SPL does (and the SPL doesn't care about some
>> address in a SoC-specific header; hence my consternation).
>
> Maybe this is UART boot specific. The addressing is probably a bit
> special and secure boot probably does not apply. Up to now it's been
> neat trick that kwboot can patch the image on the fly. Maybe it needs
> to be a bit smarter. I note that Marvell's build process actually
> produces a separate -uart version of the image, maybe this is why.