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- =================
- NuttX File System
- =================
- **Overview**. NuttX includes an optional, scalable file system.
- This file-system may be omitted altogether; NuttX does not depend
- on the presence of any file system.
- **Pseudo Root File System**. A simple *in-memory*, *pseudo* file
- system can be enabled by default. This is an *in-memory* file
- system because it does not require any storage medium or block
- driver support. Rather, file system contents are generated
- on-the-fly as referenced via standard file system operations
- (open, close, read, write, etc.). In this sense, the file system
- is *pseudo* file system (in the same sense that the Linux
- ``/proc`` file system is also referred to as a pseudo file
- system).
- Any user supplied data or logic can be accessed via the
- pseudo-file system. Built in support is provided for character and
- block `drivers <#DeviceDrivers>`__ in the ``/dev`` pseudo file
- system directory.
- **Mounted File Systems** The simple in-memory file system can be
- extended my mounting block devices that provide access to true
- file systems backed up via some mass storage device. NuttX
- supports the standard ``mount()`` command that allows a block
- driver to be bound to a mountpoint within the pseudo file system
- and to a file system. At present, NuttX supports the standard VFAT
- and ROMFS file systems, a special, wear-leveling NuttX FLASH File
- System (NXFFS), as well as a Network File System client (NFS
- version 3, UDP).
- **Comparison to Linux** From a programming perspective, the NuttX
- file system appears very similar to a Linux file system. However,
- there is a fundamental difference: The NuttX root file system is a
- pseudo file system and true file systems may be mounted in the
- pseudo file system. In the typical Linux installation by
- comparison, the Linux root file system is a true file system and
- pseudo file systems may be mounted in the true, root file system.
- The approach selected by NuttX is intended to support greater
- scalability from the very tiny platform to the moderate platform.
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