Android 7.1 upgrade to Ubuntu using SD card

nhjadhav

While following the instruction here : http://wiki.t-firefly.com/en/Fir ... 1-upgrade-to-ubuntu, I am trying to unpack the image. But when I run unpack.sh, I see the following error :

start to unpack update.img...
./unpack.sh: line 17: ./bin/rkImageMaker: No such file or directory
Press any key to quit:

The file is there :
$ ls -l ./bin/rkImageMaker
-rwxr-xr-x 1 nhjadhav domain^users 325822 Nov 12 16:54 ./bin/rkImageMaker

Is there anything else that is needed to be done to unpack the image?