[U-Boot] [PATCH] tools: kwboot: Make kwboot more robust on a38x

[Chris Packham]

On Thu, Aug 16, 2018 at 8:38 PM Baruch Siach <baruch at tkos.co.il> wrote:
>
> Hi Chris,
>
> Chris Packham writes:
> > On Tue, Aug 14, 2018 at 3:25 AM Baruch Siach <baruch at tkos.co.il> wrote:
> >> From: Jon Nettleton <jon at solid-run.com>
> >>
> >> This patch accomplishes 2 things to make the kwboot procedure
> >> on the a38x more reliable.
> >>
> >> 1)  We fill the tty with 1K of the magic bootparam.  This helps
> >> with the timing of where the microcode picks up in the read of
> >> the line to ensure we actually catch the break to go into recovery
> >> mode
> >>
> >> 2)  Before starting the xmodem transfer we sleep for 2 seconds
> >> and then flush the line.  This allows all the magic bootparam
> >> to be flushed from the line and makes the xmodem transfer reliable
> >> and removes the Bad message failures.
> >>
> >> Signed-off-by: Jon Nettleton <jon at solid-run.com>
> >> Signed-off-by: Baruch Siach <baruch at tkos.co.il>
> >> ---
> >
> > Reviewed-by: Chris Packham <judge.packham at gmail.com>
>
> Thanks.
>
> > Lately I haven't had much luck with using kwboot on a38x. I seem to be
> > able to get the spl to boot from uart (even better now thanks to this
> > patch) but the next stage still loads from SPI. I haven't been brave
> > enough to blank a board to see if that changes behaviour. Are your
> > experiences any different? I'm wondering if there is something we need
> > to do in the SPL to figure out that we need to load the next stage via
> > xmodem.
>
> It works for me here on the Clearfog.
>
> The code that determines the seconds stage load device is in
> arch/arm/mach-mvebu/spl.c:get_boot_device(). Does the code there get it
> right? What do you read from CONFIG_BOOTROM_ERR_REG?
>

I get the following from enabling the debug

BOOTROM_REG=0x63001000 boot_device=0x0
SAR_REG=0xcb20b342 boot_device=0x34
BOOTROM_REG=0x63001000 boot_device=0x0
SAR_REG=0xcb20b342 boot_device=0x34

The strapping is for SPI so the second part isn't surprising.