> > I accidently erased it, so my journey for unbricking the device began.
> > at91bootstrap, openocd, barebox - they all once supported A9G20, but
> > nowadays all of them were broken. Well, I fixed openocd and barebox
> > mostly so far, the bootstrap is still the missing piece.
> 
> You may be hit by the newer gcc optimize the delays in
> the sdram init code in at91bootstrap.

The issue was something else: SAM-BA failed to flash the bootstrap
because it couldn't get the SDRAM initialized before. I still didn't
figure out why. Flashing the bootstrap with barebox never got it
executed. I now found out that SAM-BA is modifying one vector at runtime
before flashing. What is 'endaddress of blob in RAM' becomes 'filesize
of blob'. If I modify my binary bootstrap like this, I can flash it with
barebox and finally have a working device again. Phew!