The SD card bootloader implemented in this application note allows flashing image from an external SD card. The SD card bootloader will be loaded in the Boot Loader flash section.
The user needs to write the image file to be flashed into the SD card and this bootloader will write the image to the Application flash section.
This application note explains how the SD card bootloader is implemented and how it should be used with the Atmel® XMEGA® A1U Xplained Pro.