查看UBOOT分区
~ # cat /proc/mtd
dev: size erasesize name
mtd0: 00400000 00020000 "param"
mtd1: 02000000 00020000 "rootfs"
mtd2: 00800000 00020000 "data"
mtd3: 00400000 00020000 "sync"
mtd4: 00500000 00020000 "kernel"
mtd5: 0cb00000 00020000 "cust"
mtd6: 00080000 00001000 "u-boot"
删除分区并更新
./flash_eraseall /dev/mtd6
dd if=uboot-img.bin of=/dev/mtd6