The following is the list of the characteristics of a mount point:
The mount point must be a directory. It may have files and other
directories under it. These files and directories will be hidden when the
filesystem is mounted.
The task must have read/write/execute permissions to the mount point
or the mount attempt will be rejected.
Only one filesystem can be mounted to a single mount point.
The Root of the mountable filesystem will be referenced by the name
of the mount point after the mount is complete.
RTEMS Filesystem Design Guide