Well I'm guessing it's a read-only image like squashfs. You could try this command and if it works - well and good otherwise it probably is only an image and there's no way that I know of, that would you let you edit or make changes other than loading a new firmware.
Code:
mount -o remount,rw /
Also try this and do let me know if you are able to pull up a page from htpp://192.168.1.1/ These are just console commands for the router.
Code:
ip iphostname flush
config save
flashfs update
restart
I have attached a Dlink DSL50X utility and a file listing the console commands if it might help. Good luck