Pulling out image from GateWorks 5400 Ventana SBC

Dear Friends,

I have GateWorks 5400 Ventana SBC that I made a lot of changes on it, I would like to duplicate the firmware with all changes that made on it.

I've tried and succeeded to get the env and rootfs from the SBC with this manual:

In order to get the SPL & u-boot.img I downloaded a fresh OpwnWRT and get it from there ( I still don't know if that's the right way to do it but in other hand there is no instruction to make those files, if its the wrong way please let me know).

After that I made this command :
$sudo ./mkimage_jtag -e SPL@0 u-boot.img@14M env@16M ubi@17M > image.bin
I got a 253MB file that I flash into a fresh GateWorks 5400 Ventana SBC.

It took 42 Min to flash it and at the end I saw that it flashed a fresh OpenWRT without all the changes that we made.

Please assist if you can because I really don't know what should I do to fix it,

Thanks in advance,