Received the board, tried to run the command line Fedora .. but decided to install Ubuntu (from the supported OS page - www.tecmint.com/ubuntu-15-04-installation-on-uefi-firmware/)
During the install, I might have used the option 'Erase disk' and believe this has scratched some of the original (UEFi) partition.
The install from USB goes fine, but when rebooting, I end with an EFU shell prompt. No OS starts.
In the BIOS, I can see only' built-in EFI shell ' in the boot options.

Is there an image available to recover the eMMC in it's original state ? Or how to assure I can boot again in a valid OS

*** SOLVED ***
Did a reinstall of UBUNTU to the ext4 partition from the same USB as the last install (that failed)(and all the others like fedora before)
Install completed and system is booting correctly.
Unclear what happened - real work can start now

Hi Sir,
Maybe the uefi partition is not handled well in the first time, the jaguarboard only supports UEFI boot, so make sure the UEFI bootloader is installed correctly everytime you reinstall the system.