5 Modify U-Boot to boot from NAND Flash
- Enter the following command to modify
                the
                configurations:
$ make uboot-menuconfigNote that building and opening the U-Boot configuration window will take a few minutes.
 - From the menu, select Boot
                    options and press Enter.
                - In the Boot options
                        window, select Boot media and press Enter. 

 - In the Boot media
                        window, select Support for booting from NAND flash and press
                                ‘Y’.

 - Press ESC twice to exit the menu.
 
 - In the Boot options
                        window, select Boot media and press Enter. 
 - In the Boot Options window,
                select Boot arguments and press Enter.
                - In the Boot arguments
                        window, update the string
                            to:
mtdparts=atmel_nand:256k(bootstrap)ro,512k(uboot)ro,256K(env),256k(env_redundent),256k(spare),512k(dtb),6M(kernel)ro,-(rootfs) rootfstype=ubifs ubi.mtd=7 root=ubi0:rootfsand press Enter.
                         
 - In the Boot arguments
                        window, update the string
                            to:
 - In the Boot Options window,
                select Bootcmd and press Enter.
                - In the Bootcmd value
                        window, update the string
                                to:
nand read 0x21000000 0x00180000 0x00080000; nand read 0x22000000 0x00200000 0x00600000;bootz 0x22000000 – 0x21000000and press Enter.

 - Press ESC twice to exit the menu.
 
 - In the Bootcmd value
                        window, update the string
                                to:
 - Select Exit and press Enter.
- Click Yes.

 
 - Click Yes.
 
