In my project i already use compiled hex file c5131_mass-storage-NF-2K-1_0_0.hex with shematics from http://www.atmel.com/dyn/resources/prod_documents/doc7516.pdf
. Project works fine with only change a on-board crystal to 16MHz (originally 24MHz). But for my other project I need to now how Atmel firmware do Nand Flash Translation Layer
, therefore I needed the C-source of mass storage. After a week experiments I find a right NFTL and all other necessary data, project work without problems.