[U-Boot] [PATCH] tools/kwboot.c: Support UART fallback mode

[Stefan Roese]

Hi Kevin,

On 01.09.2015 14:52, Stefan Roese wrote:
> Hi Kevin,
>
> (Added Luka to Cc, as the Marvell / MVEBU custodian)
>
> On 31.08.2015 22:30, Kevin Smith wrote:
>> On some processors such as Armada 38x, if the hardware-
>> configured boot mode fails, the CPU falls back to booting over
>> UART.  When this happens the chip prints a failure message, waits
>> for the magic sequence and, when it is received, prints a
>> "(boot)" message, then sends a NAK to start the transfer.
>>
>> This breaks the current kwboot behavior because the xmodem
>> transfer only tries to read one character after the magic
>> sequence, looking for the NAK.  Instead it gets the "(boot)"
>> text, and retries the magic sequence.  The CPU thinks the
>> repeated sequence is part of the packet, stops NAKing, and one
>> side or another eventually times out.
>>
>> This patch adds support for a fallback mode which continues to
>> scan for a NAK in the characters received after the sequence,
>> printing out any non-NAK characters.  This allows kwboot to skip
>> the "(boot)" message, find the NAK, and start the transfer
>> successfully.
>>
>> Signed-off-by: Kevin Smith <kevin.smith at elecsyscorp.com>
>
> I've not seen this "(boot)" yet. But the patch looks good. So:
>
> Reviewed-by: Stefan Roese <sr at denx.de>

Is this patch still needed (or helpful)? If yes, please rebase
on top of latest u-boot-marvell/master and send a new version
so that I can pick it up.

Thanks,
Stefan