Further to this I have tested the SPI patch and it works beautifully!
This means that in many cases there is no need for a JTAG on a Dreamplug. The patch allows fast, easy display and update of the u-Boot environment.
Using fw_printenv/fw_setenv from u-boot-tools
# apt-get install u-boot-tools
# cat /etc/fw_env.config
# Configuration file for fw_(printenv/saveenv) utility.
# Up to two entries are valid, in this case the redundand
# environment sector is assumed present.
# MTD device name Device offset Env. size Flash sector size
/dev/mtd0 0x30000 0x1000 0x1000
I am not sure why the offset of 0x30000, but it works.
/dev/mtd1 seems to be all 0xFF
I am guessing that this will change depending on your version u-Boot.Versions:
U-Boot 2011.06-02334-g8f495d9-dirty (Mar 28 2011 - 05:21:06)