For people blocked at usb boot 'attached scsi removable disk'
try to :
1) unplug ethernet and re-plug it. 'eth0 down, eth0 up' will be displayed
2) Your server should appear in the network by using your computer with synology assistant.
3) follow instructions.
Look like 'Booting Kernel' message is not mandatory to detect and install xopenology.
Thank you very much. i try right now
Edit : block at setup : attached scsi removable disk