early stage debugging on a real product

[Andy Shevchenko]

On Wed, Nov 25, 2020 at 5:23 PM Simon Glass <sjg at chromium.org> wrote:
> On Wed, 25 Nov 2020 at 08:07, Andy Shevchenko <andy.shevchenko at gmail.com> wrote:
> > On Wed, Nov 25, 2020 at 4:50 PM Simon Glass <sjg at chromium.org> wrote:
> > > On Wed, 25 Nov 2020 at 06:26, Andy Shevchenko <andy.shevchenko at gmail.com> wrote:

...

> > > I think you should be more worried about the UART!
> >
> > How? There is no UART (there are ports, but all of them are occupied
> > by real devices wired up). The only connector is microB and getting
> > USB to work in a gadget mode seems to me a harder task to achieve.
>
> The board designers should be severely punished. Do you have post codes?
>
> Some boards have an FTDI chip to do the USB/serial conversion but I
> guess your one does not.

It's not a board. As I stated in the subject line it's a real product
(tablet / phone).

...

> > > Note that graphics uses lazy init, like everything else in U-Boot, so
> > > unless you have 'vidconsole' in your stdout it won't actually init it.
> >
> > I have no environment for now (ENV_IS_NO_WHERE) and I have provided
> >
> > #define CONFIG_STD_DEVICES_SETTINGS     "stdin=serial\0" \
> >                                        "stdout=vidconsole\0" \
> >                                        "stderr=vidconsole\0"
> >
> > in the configuration header. Not sure if it's correct and/or enough.
>
> Should be fine.

Thanks. But the question is still open why DM PCI et al. is not
getting initialized.

...

> > > You can use something like this to force probing video:
> > >
> > > struct udevice *dev;
> > > int ret = uclass_first_device_err(UCLASS_VIDEO, &dev);
> >
> > I will try this, thanks!
>
> But you'll need to select the driver, or write one that finds the
> frame buffer. Is video already set up by the earlier loader?

Yes, there is an initialized framebuffer by bootloader (droidboot). I
need a glue driver that will find FB parameters and set up a graphical
console on it.
So far I have a custom code.

-- 
With Best Regards,
Andy Shevchenko