early stage debugging on a real product

[Simon Glass]

Hi Andy,

On Wed, 25 Nov 2020 at 10:33, Andy Shevchenko <andy.shevchenko at gmail.com> wrote:
>
> On Wed, Nov 25, 2020 at 7:11 PM Siarhei Siamashka
> <siarhei.siamashka at gmail.com> wrote:
> > On Wed, Nov 25, 2020 at 5:36 PM Andy Shevchenko
> > <andy.shevchenko at gmail.com> wrote:
>
> ...
>
> > Does this tablet / phone have an MMC slot?
>
> In fact it does.
>
> > For example, on all
> > Allwinner tablets it is technically possible to use MMC pins for UART
> > via a different non-standard pin mux setup and a breakout board:
> >
> >   https://linux-sunxi.org/MicroSD_Breakout
> >   https://linux-sunxi.org/File:MSI_Primo81_and_MicroSD_breakout.jpg
> >
> > Also are you sure that there are really no UART pads on the PCB to
> > solder some wires if you disassemble your tablet / phone?
>
> There are UARTs which are soldered with real devices connected. MMC
> can be switched to GPIO, so it would be rather bitbanging with some
> non-standard speed.
> Does U-Boot have a bitbang UART driver?

I don't think so.

Regards,
Simon