[U-Boot] Using U-boot command to write NAND flash

[Lyn.Tran at L-3com.com]

Please help,
I am new to u-boot. The processor that we are using is AVR32
(AT32AP7000).
U-Boot is a Boot Loader, its primary purpose is to load some operating
system. Can we use the U-Boot to load our small application before
loading the operating system (Linux)? Our small application will read a
FPGA bit file from the NAND flash and configure the FPGA.
U-Boot includes a basic interactive command interpreter, support for
download over Ethernet and the capability to program the flash. Can we
update the FPGA bit file (by programming NAND flash using U-boot
command)?  If yes, then which flash file system that U-boot uses to
program the flash? and does that flasf file system take care of wear
leveling in the NAND flash?

Thank you so much,