========================= Shared Memory File System ========================= This supports the POSIX shm_open() APIs for shared memory among unrelated apps. It can be enabled with ``CONFIG_FS_SHMFS=y``. To check how it works, please also enable the example app via ``CONFIG_EXMAPLE_SHM=y`` and run ``shm_test`` from NSH command line. This file system doesn't support mount operations though. If comment the line using ``shm_unlink()`` in the example app, we can see a file under ``/var/shm/`` from NSH command line after running the example. We can also remove that file from command line.