开发板 jz2440
下载uboot.bin
tftp 0x30000000 u-boot.bin
nand erase bootloader
nand write bootloader
下载内核
tftp 0x30000000 uImage
nand erase kernel
nand write.jffs2 0x30000000 kernel
下载文件系统
tftpboot fsroot.yaffs2
nand erase root
nand write.yaffs 0x30000000 root $(filesize)