[U-Boot] SPL Dfu update

[Eric Nelson <eric.nelson@boundarydevices.com>]

On 10/30/2013 07:24 AM, Stefano Babic wrote:
> Hi Otavio,
>
> On 30/10/2013 15:19, Otavio Salvador wrote:
>
>>> OMAP4/3 can boot over the otg, so you can send MLO and let it wait for the
>>> second stage boot. We have already SPL USBETH in u-boot but in production
>>> otg flashing can be very useful. Think SPL as a differently configured U-BOOT
>>> doesn't change the problem but yes it's a nice idea.
>>
>> But you'd usually want to have an 'upgrade mode' which allows DFU to
>> run. In this case, this could be done using complete U-Boot instead of
>> SPL, no? In case customer needs a slim version of it, it could be
>> accomplished using a specific config and having:
>>
>> SPL
>> Update mode U-Boot (normal U-Boot with less features)
>> Complete U-Boot (interactive and like)
>>
>> or am I missing something?
>
>
> Right, I agree completely with you.
>
> That's the reason I do not understand why we have to push DFU into SPL.
> Maybe we both are missing something.
>

If I understand Tom's comment, I think the question surrounds
a "bare metal" use case, when a full U-Boot isn't available in
the normal place.

In the case of our i.MX boards that boot to SPI-NOR, it would be
nice to simply load an SPL image over the i.MX downloader
and have immediate access to DFU so we can use it to
program the SPI-NOR.

Regards,


Eric