在完善dev目录时出现mount: invalid option

yaffs: dev is 32505859 name is "mtdblock3"
yaffs: passed flags ""
yaffs: Attempting MTD mount on 31.3, "mtdblock3"
yaffs: auto selecting yaffs2
block 1981 is bad
VFS: Mounted root (yaffs filesystem).
Freeing init memory: 140K
init started: BusyBox v1.7.0 (2018-03-13 17:36:36 CST)
starting pid 764, tty '': '/etc/init.d/rcS'
mount: invalid option --
BusyBox v1.7.0 (2018-03-13 17:36:36 CST) multi-call binary

Usage: mount [flags] DEVICE NODE [-o options,more-options]

Mount a filesystem. Filesystem autodetection requires /proc be mounted.

Options:
        -a              Mount all filesystems in fstab
        -o option       One of many filesystem options, listed below
        -r              Mount the filesystem read-only
        -t fs-type      Specify the filesystem type
        -w              Mount for reading and writing (default)

Options for use with the "-o" flag:
        loop            Ignored (loop devices are autodetected)
        [a]sync         Writes are asynchronous / synchronous
        [no]atime       Disable / enable updates to inode access times
        [no]diratime    Disable / enable atime updates to directories
        [no]dev         Allow use of special device files / disallow them
        [no]exec        Allow use of executable files / disallow them
        [no]suid        Allow set-user-id-root programs / disallow them
        [r]shared       Convert [recursively] to a shared subtree
        [r]slave        Convert [recursively] to a slave subtree
        [r]private      Convert [recursively] to a private subtree
        [un]bindable    Make mount point [un]able to be bind mounted
        bind            Bind a directory to an additional location
        move            Relocate an existing mount point
        remount         Remount a mounted filesystem, changing its flags
        ro/rw           Mount for read-only / read-write

There are EVEN MORE flags that are specific to each filesystem
You'll have to see the written documentation for those filesystems

: nonexistent directory: cannot create /proc/sys/kernel/hotplug
BusyBox v1.7.0 (2018-03-13 17:36:36 CST) multi-call binary

Usage: mdev [-s]

        -s      Scan /sys and populate /dev during system boot

Called with no options (via hotplug) it uses environment variables
to determine which device to add/remove.


Please press Enter to activate this console.
starting pid 769, tty '/dev/console': '/bin/sh'
#
#
#
#
# ps
  PID  Uid        VSZ Stat Command
# ls
bin         etc         linuxrc     proc        sys
dev         lib         lost+found  ***in        usr
#
#
#
# ls dev
console  null     pts
#


dev目录下没有自动创建的设备节点