nc -lk 4000
root@OpenWrt:~# mount
rootfs on / type rootfs (rw)
/dev/root on /rom type squashfs (ro,relatime)
proc on /proc type proc (rw,noatime)
sysfs on /sys type sysfs (rw,noatime)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,noatime)
/dev/mtdblock3 on /overlay type jffs2 (rw,noatime)
overlayfs:/overlay on / type overlayfs (rw,noatime,lowerdir=/,upperdir=/overlay)
tmpfs on /dev type tmpfs (rw,relatime,size=512k,mode=755)
devpts on /dev/pts type devpts (rw,relatime,mode=600)
debugfs on /sys/kernel/debug type debugfs (rw,noatime)
tmpfs on /dev/shm type tmpfs (rw,relatime)
/dev/sda1 on /www/record type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro)
root@OpenWrt:~#
mount -t jffs2 /dev/mtdblock3 /overlay
mount -t overlayfs overlayfs:/overlay / -oupperdir=/overlay,lowerdir=/,rw,noatime
overlayfs:/overlay on / type overlayfs (rw,noatime,lowerdir=/,upperdir=/overlay)
overlayfs:/overlay on / type overlayfs (rw,noatime,lowerdir=/,upperdir=/overlay)