asicer 
Step by step example that light on led when poweron. Modify and try it yourself. You will find it is easy. http://blog.csdn.net/asicer/article/details/8562672 ##### FriendlyARM BIOS 2.0 for 2440 ##### [x] format NAND FLASH for Linux [v] Download vivi [k] Download linux kernel [y] Download root_yaffs image [a] Absolute User Application [n] Download Nboot for WinCE [l] Download WinCE boot-logo [w] Download WinCE NK.bin [d] Download & Run [z] Download zImage into RAM [g] Boot linux from RAM [f] Format the nand flash [b] Boot the system [s] Set the boot parameters [u] Backup NAND Flash to HOST through USB(upload) [r] Restore NAND Flash from HOST through USB [q] Goto shell of vivi Enter your selection: q Supervivi> load flash 0 36 u USB host is connected. Waiting a download. Now, Downloading [ADDRESS:30000000h,TOTAL:46] RECEIVED FILE SIZE: 46 (0KB/S, 1S) Downloaded file at 0x30000000, size = 36 bytes Found block size = 0x00020000 Erasing... ... done Writing... ... done Written 36 bytes Supervivi> asicer@localhost:osless$ ls -l total 252 -rwxrwxr-x 1 asicer asicer 36 Feb 1 22:17 led_on.bin -rwxrwxr-x 1 asicer asicer 33979 Feb 1 22:17 led_on_elf -rw-rw-r-- 1 asicer asicer 1336 Feb 1 22:17 led_on.o -rw-rw-r-- 1 asicer asicer 3700 Feb 1 22:17 led_on.S -rw-rw-r-- 1 asicer asicer 20 Feb 1 20:45 main.c -rw-rw-r-- 1 asicer asicer 283 Feb 1 21:48 Makefile -rw------- 1 asicer asicer 180392 Jan 29 23:27 test.bin asicer@localhost:osless$ sudo dnw led_on.bin load address: 0x32000000 Writing data... 100% 0x0000002E bytes (0 K) speed: 0.043869M/S asicer@localhost:osless$