Hi Phil
Unfortunately Global Scale's response to me via New-It is that the Openrd only uses the SD card as a data storage device and not a a bootable device
I have been corresponding with New-it for some time regarding what I regard as a cop out by Globalscale regarding this matter.
I would appreciate it if you would email Jason at New-IT stating your concerns.
Have a look at the other forum
www.open-rd.org, you will find several very acrimonious threads regarding this matter.
One user does post a location to a git repository where the sources for his modified uboot are located.
The various unidentifiable versions of uboot are a disgrace , this has been raised with einfochips, (the original designers and support people for the open-rd), on several occasions, and on the Google Code open issues list, but einfochips have vanished, from the scene leaving the support to the ineffectual GlobalScale who now manufacture the device, but have no presence in the forums
regards
P