[U-Boot] Uboot NAND sub system and it's commands

[Swapnali C. Patil]

Hello All,
I am using DM6446 (TI DaVinci) customized board. 
1. I am not able to understand meaning of NAND Sub system U boot commands, e.g. nand write, nand read, nand erase etc. 
2. I want to use the NAND sub system U boot command in Linux (ARM side of DM6446 core), is it possible ? may be some utiliy to export these commands or some paralle command which have similar functionality (such as writting on specific location of RAM (87000000) from nand(0X1000000)).?

Thanks in advance
-swapnali
Thanks and regards
-swapnali