.. _libs_filesystem:

====================== File System Interfaces

LVGL's :ref:file_system module provides an abstraction that enables you to attach any type of file system for LVGL's use. File systems already supported are:

FATFS <https://elm-chan.org/fsw/ff/>__
STDIO (Linux and Windows using C standard function .e.g fopen, fread)
POSIX (Linux and Windows using POSIX function .e.g open, read)
WIN32 (Windows using Win32 API function .e.g CreateFileA, ReadFile)
MEMFS (read a file from a memory buffer)
LITTLEFS (a little fail-safe filesystem designed for microcontrollers)
Arduino ESP LITTLEFS (a little fail-safe filesystem designed for Arduino ESP)
Arduino SD (allows for reading from and writing to SD cards)

You still need to provide the drivers and libraries, this extension provides only the bridge between LVGL and these file systems.

.. _libs_filesystem_usage:

Usage

In lv_conf.h enable LV_USE_FS_... (by setting its value to 1) and assign an upper cased letter to LV_FS_..._DRIVER_LETTER (e.g. 'S'). If more than one file system is enabled, each driver will need to have a unique driver-identifier letter. After that you can access files using that driver letter. Example with driver identifier letter 'S':

:Linux-like relative path: "S:path/to/file.txt" :Linux-like absolute path: "S:/path/to/file.txt" :Windows-like relative path: "S:C:path/to/file.txt" :Windows-like absolute path: "S:C:/path/to/file.txt"

Do not confuse the driver-identifier letter with the Windows/DOS/FAT "drive letter", which is part of the path passed to the OS-level functions. For more details, see :ref:lv_fs_identifier_letters.

:ref:Cached reading <file_system_cache> is also supported if LV_FS_..._CACHE_SIZE is set to a non-zero value.

For further details, including how to create support for your own file system, see :ref:file_system.