Ebony development board

Hi,

I've recently got an Ebony board (440GP) with the original bootloader 
(440GP 1.18 ROM Monitor) which I would like to replace with U-boot. Is 
there a way to boot an U-boot image via TFTP to replace the bootloader, 
or is it possible only with using a JTAG? I've googled through the 
mailing list, but most of the related hits are dated back in 2004-2005, 
they say no, one have to use JTAG, but some time passed since then, and 
I would like to know if there is a way for this.

Thanks in advance,
Zoltan HERPAI