Where can I find infos to create the image?
You can try generating the image using RootFS Build Factory https://github.com/mndar/rbf If it works please let me know so that I can add Bananapi to the list of tested boards.
I have added support for bananapi but I don't have one. The support if based on information available here http://fedoraproject.org/wiki/Architectures/ARM/F21/Installation
Refer README.md It has everything to get you started. You need Linux running on armv7 hardware or Qemu to use RootFS Build Factory. You can generate image for Qemu using the build factory.
For Bananapi 1. Clone the repo 2. run the command ./rbf.py build templates/bananapi.xml 3. Write image bananapi-centos-image.img to sd card
Regards Mandar Joshi