Flashing the device
Natively the board only supports booting from the eMMC or microSD card, see boot order. There doesn’t seem to be a way to boot from USB devices or SATA yet.
The board can be booted by flashing your favorite operating system to a microSD card using another device and to insert the microSD card into the Quartz64, see the article Getting started. Flashing the eMMC is possible by booting an operating system from the microSD card and to overwrite the eMMC from within the booted operating system.
The hardware boot order of the Quartz64 is:
SPI NOR flash
SPI NAND flash