[U-Boot] [PATCH] Revert "arm: mvebu: fix boot from UART when in fallback mode"

[Chris Packham]

On Fri, Aug 17, 2018 at 5:41 PM Sean Nyekjær <sean.nyekjaer at prevas.dk> wrote:
>
>
>
> On 17/08/2018 01.30, Chris Packham wrote:
> > This reverts commit e83e2b390038c9075642cb243a6292241beb8d73. This
> > prevents kwboot from overriding the hardware strapped boot source.
> >
> > Signed-off-by: Chris Packham <judge.packham at gmail.com>
> > ---
> > Sean,
> >
> > I take it your use case was for when the default boot source doesn't
> > have a valid image and it falls back to UART? If that's the case I think
> > we need something in addition to the existing code not instead of.
>
> Hi,
>
> My use case was exactly what you are describing. If the default boot
> source doesn't have a valid image it falls back til UART and without
> this patch the SPL will try default boot source which in most cases are
> the old image or non existing. What kind of use case do you have?
> It's really hard to read in the datasheet as it's not entirely accurate
> on this.

Yeah for some reason Marvell deemed it unnecessary to document the
fields of that particular register.

I can confirm from experience that bits 31:28 do reflect the current
boot source when using kwboot to override the HW strapped boot source.
I can also confirm your observation that if you manage to kill the
boot header but not the final stage u-boot you end up booting the spl
over UART but then the next stage boots from SPI.

I'll see if I can come up with something that covers both cases.