I know,in the our github(GitHub - gl-inet/imagebuilder: Warning!Please look at 'GL.iNET Imagebuilder Introduction' section.),there is a command to generate firmware,like this:

To make an image for the Mifi with some extra packages included:
./gl_image -p mifi -e “openssh-sftp-server nano htop”

what command do you use?tell me, I will test it.