Can't flash smaller root-fs through dfu-util?

[John Seghers]

Dr. H. Nikolaus Schaller wrote:
> After unsuccessfully flashing different root-filesystems, I finally
> found this note:
> > If you upload rootfs image that is smaller that previous one it
> > won't work - you need to attach to bootloader, erase NAND and then
> > upload your rootfs first:
> >
> > cu -l /dev/ttyACM0
> > GTA01Bv3 # nand erase rootfs
> This *should* help but I am trying to understand why dfu-util can't
> do that? And what do I do if I have no serial interface? Does this
> mean I can't ever again flash a (smaller) rootfs?

I have no info on the first question, but about the serial interface.
The commands above actually run over USB.  Simply boot the Neo into uBoot
(hold the Aux button while powering on) and select the option to use the
console over USB (Move selection using Aux, invoke the selection by pressing
power).  Then plug in the USB cable and run the "cu" command.

- John