Edge1 has an onboard eMMC, so you can install the OS into the eMMC.
You can also choose to install the OS into eMMC via the USB Upgrade Tool1) on a Windows PC.
Please check install-os-into-emmc-on-windows.
You can also choose to install the OS into eMMC via the USB Upgrade Tool on a Ubuntu PC.
Please check install-os-into-emmc-on-ubuntu.
Edge1 also supports to boot from external storage, e.g. TF card, USB storage, etc.
Please check Edge1 Install OS into External Storage.