AGIF IKANOS fusiv v160 jboot image memory dump

Hi All
I am going to work on this kind of ADSL wifi modem. Telecom Alice Gate 2 Plus from Dialface

It is possible to work on by serial and i would like to try to put an openwrt image on it.
I found sagem modem with this kind of hardware
The system has got already U-boot boot loader and it has two image on it jboot 0 and jboot 1 that are based on linux kernel

What I would like to know is how to know the hex location of the images through printenv in uboot in order to try to:
First of all dump the two images as recovery and
Second try to install an openwrt image
thank you all for your help