Okay followed the commands you gave me and ran into an error on the run command (wanted an env variable) so I just dropped the word run from the commands. I put the rootfs.tar.gz onto a usb stick that was formatted to ext2 and it was happy with that except it gave me an error about not finding uImage and modules.tar.gz. I reset and was greeted by a login prompt (Yeah!). I logged in and I have a working Plug again. Now onto MisterHouse (home automation). I'll have to load a few modules but that's later.
Thanks!
Edit: 04/11/202
The Sheeva has been running well and I now have
Misterhouse working on the plug. I did notice that while booting the Sheeva complains about the following:
NAND device: Manufacturer ID: 0xec, Chip ID: 0xdc (Samsung NAND 512MiB 3,3V 8-bit)
Scanning device for bad blocks
Bad eraseblock 2122 at 0x000010940000
Bad eraseblock 2500 at 0x000013880000
I think explains the trouble with using the JTAG from the command line. So is this permanent or something that can be fixed?