1) Make the build of the whole BSP (Build Current BSP and Subproject) in release mode
2) Open release directory in build window
3) Display the characteristics of the file with the command "viewbin firstboot.bin"
4) Convert the file .bin in to .nb0 with "cvrtbin 0x2FF000-to-r-s-w 0x3000 32 FirstBoot. Bin"
6) Open the FIRSTBOOT.nb0 file with notepad++ in hex and cut everything that is before address 0x1000 and everything that's after the address 0x1FFFF so that the new file has dimension equal to 0x1000.
7) Downloading with SAM-BA file thus generated.