[U-Boot] SPL Dfu update

[Michael Trimarchi]

Hi

On Wed, Oct 30, 2013 at 9:53 PM, Otavio Salvador
<otavio at ossystems.com.br> wrote:
> Hello Michael,
>
> On Wed, Oct 30, 2013 at 6:35 PM, Michael Trimarchi
> <michael at amarulasolutions.com> wrote:
>> On Wed, Oct 30, 2013 at 9:11 PM, Wolfgang Denk <wd at denx.de> wrote:
>>> Dear Michael Trimarchi,
>>>
>>> In message <CAOf5uw=hCkwPaqogCO3KvM1erhS-dvC5BRT4USU3uqKETtTQ7A at mail.gmail.com> you wrote:
>>>>
>>>> > This does not answer Stefano's question: why do it in SPL, what's
>>>> > wrong with loading the real U-Boot for this purpose?
>>>>
>>>> Because it's not possible, internal memory size of some cpus. You need
>>>> to have a way to load the second stage and I'm discussing a general
>>>> way to do.
>>>
>>> I'm not sure that there are many use cases where you have sufficient
>>> room for all that is needed for DFU (including I/O buffers); and if
>>> you move to RAM early, you have other options as well.
>>>
>>
>> No because you need anyway to have a way to load it and dfu is a way.
>>
>>>> What is your alternative way?
>>>
>>> Depending on your hardware there is a zillion ways to do this.  For
>>> low to medium volumes good old JTAG is still a very powerful tool; for
>>> high volumes you will probably just fit pre-programmed NAND on your
>>> board.  And of course there is the growing number of systems that can
>>> just boot and install from a SDCard or USB MSD.
>>>
>>
>> I accept the lesson even I don't thing that I need a lesson on it. We
>> are talking that we have only otg.
>
> I see your user-case and I think I agree with you.
>
>> BTW Forget about it.
>
> Please don't. I think it is a valuable contribution and I think it is
> good to have a mechanism which work for your user-case in U-Boot; it
> is easy to maintain long term and avoid duplication of work in case
> users has some problem.
>
> I got a little bit lost when Tom gave an example where he 'loads' MLO
> and U-Boot image from OTG; just clarify it for me as it is not clear
> if it works for you or does not.
>
> From what I understand, your use-case would be:
>
> OTG -> SPL -> DFU -> U-Boot Image -> Jump to U-Boot ?
>

My use case is:

OTG->SPL->DFU ----> flash MLO on flash/NAND/eMMC
                            \-----> flash u-boot.img on NAND/flash/eMMC
                            \-----> .....

done? OK so
dfu-util -R

Board should reset and boot from flashed image. One big thing
that I missed (and thanks to Tom Rini) is stack relocation on DDR

Michael






>
> --
> Otavio Salvador                             O.S. Systems
> http://www.ossystems.com.br        http://code.ossystems.com.br
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