early stage debugging on a real product

[Andy Shevchenko]

On Mon, Nov 23, 2020 at 9:08 PM Simon Glass <sjg at chromium.org> wrote:
> On Mon, 23 Nov 2020 at 07:04, Andy Shevchenko <andy.shevchenko at gmail.com> wrote:

Thanks! My comments below.

> > I have been debugging U-Boot on a product (Android-based) device (*)
> > which is not yet supported by U-Boot. It's x86 based.
> >
> > I have stumbled over the couple of things:
> > 1/ it required me to enable TIMER_EARLY and by code analysing I can
> > tell that DM loop fails by some reason
> > 2/ it hangs
> >    reserve_uboot,
> >    reserve_malloc,
> >    reserve_board,
> >    ...here...
> >
> > My suspicion that fastboot does bad things to it (overwritten memory)
> > or something I have missed. Any ideas what to try / where to look into
> > besides the above which I'm on?
>
> #define DEBUG at the top of board_f.c - you might need DEBUG_UART
>
> Make sure that start.S puts the top of memory in a sensible place. If
> something has set up RAM already then you probably want it to be the
> top of RAM, below 2GB.

I wasn't clear, there is no means to debug (See * below).
There is no output except vibra, perhaps I may have (charger) led, but
former I got working, maybe I need to implement morse code.

> > (*) Only I can get is just an approximate place where the code is
> > stuck / hangs. And it's time consuming...
> >
>
> Use a Dediprog SPI emulator and an Intel debugger.

Not sure how it is possible... The only connector I have is micro-B.

-- 
With Best Regards,
Andy Shevchenko