In this video:
adding micro SD card support to the project,
using common SPI type module for the SD card,
configuring FatFs to enable needed functions,
adding missing sd_mmc_mem.c and sd_mmc_mem.h files.
UPDATE
To generate sd_mmc_mem in ASF menu unfold SD/MMC stack(component) and you will see SD/MMC Memory Control Access(component) and chose enable, if it still does not generate the files use the second option.
To generate a example project which has the missing two files simply select File -- New -- Example Project -- SD/MMC/SDIO Card FatFs example - SAM3-EK.
Link to the repo with projects:
https://github.com/E-exp/Arduino-Due-...