I think you need to look at sheeva plug and developments for it. our device has similar board cpu and file system.
http://www.cyrius.com/debian/kirkwoo...g/install.html
not sure if this works on ours:
setenv bootargs_console console=ttyS0,115200
setenv bootcmd_mmc 'mmc init; ext2load mmc 0:1 0x00800000 /uImage; ext2load mmc 0:1 0x01100000 /uInitrd'
setenv bootcmd 'setenv bootargs $(bootargs_console); run bootcmd_mmc; bootm 0x00800000 0x01100000'
saveenv
obviously different offsets. but you may get away from not changing the uboot?