OpernRD "Ultimate" with two USB hard disks. How to tell uboot which one to boot from?

[Rick Thomas <rbthomas@pobox.com>]

Hi!

I've got a Marvel OpenRD "ultimate" with two USB hard disks  
connected.  One has three partitions: /boot (ext2), root (ext3), and  
swap.  I'll call it the "system" disk.  The other has a large data  
partition (ext4) that I use for archives and backups from other  
computers on the lan.  I'll call it the "data" disk.

A bit more than half the time, when I reboot the machine, uboot tries  
(and fails) to boot from the data disk.  To be sure of a good reboot,  
I need to physically disconnect the data disk and re-plug it after the  
kernel is loaded but before the file system check phase.

How can I make sure that uboot will always use the system disk?


Thanks!

Rick