更正一下：
"a31sdk-tools/pack/pctools/linux/mod_update/update_mbr lubuntu-server-nand.img.dump/sys_partition.bin
这里会重新生成dlinfo.fex和sunxi_mbr.fex"
sys_partition.fex应该是前一步生成的sys_partition.bin,如下：
a31sdk-tools/pack/pctools/linux/mod_update/update_mbr lubuntu-server-nand.img.dump/sys_partition.bin
这里会重新生成dlinfo.fex和sunxi_mbr.fex
求帮助，nand的硬盘大小怎么调整。谢谢！！！！
root@cubietruck:~# fdisk -l
Disk /dev/nand: 3.7 GiB, 3984588800 bytes, 7782400 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
root@cubietruck:~# du
12 .
root@cubietruck:~# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 780084 414392 32606456% /
devtmpfs 909424 0 909424 0% /dev
tmpfs 1007840 0 1007840 0% /dev/shm
tmpfs 1007840 8464 999376 1% /run
tmpfs 5120 0 5120 0% /run/lock
tmpfs 1007840 0 1007840 0% /sys/fs/cgroup
tmpfs 20480 0 20480 0% /tmp
tmpfs 201568 0 201568 0% /run/user/0