SDBootloader is a bootloader that can read the firmware from an SD card, decode it (from an encrypted form intel hex) and flash your Atmega328 microcontroller
Based on:
Simple FAT and SD Tutorial (http://codeandlife.com/2012/04/02/simple-fat-and-sd-tutorial-part-1/)
and
AVR FERRET BOOTLOADER(http://www.mlodedrwale.pl/2013/06/09/bootlader-avr-ferret/)
More info in doc/ folder