I am working on it also. But I didn't got the Uboot menu. Is everything works fine ? DOWNLOAD, STEP, HBR, etc ??
Then what someone explained before:
You do:
> PC 0x1800
> HBR 0xA0000000
> GO
> PC
Result should be 0XA0000000
> download
Now a second person presses for the Uboot menu.
Step through the program using STEP or GO
Each time after executing the command, check with PC command where the program counter is.
When the PC starts with 0X00...... correct it with 0XA0...... (PC 0XA0........) Go further with STEP or GO.
This could bring up the Uboot menu.
Good luck