File System Interfaces
LVGL has a File system module to provide an abstraction layer for various file system drivers.
LVG has built in support for:
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 FATFS, STDIO, POSIX, WIN32 and LVGL.
Usage
In lv_conf.h enable LV_USE_FS_... and assign an upper cased
letter to LV_FS_..._LETTER (e.g. 'S'). After that you can access
files using that driver letter. E.g. "S:path/to/file.txt".
The work directory can be set with LV_FS_..._PATH. E.g.
"/home/joe/projects/" The actual file/directory paths will be
appended to it.
Cached reading is also supported if LV_FS_..._CACHE_SIZE is set to
not 0 value. lv_fs_read() caches this size of data to lower the
number of actual reads from the storage.
To use the memory-mapped file emulation an lv_fs_path_ex_t object must be
created and initialized. This object can be passed to lv_fs_open() as
the file name:
lv_fs_path_ex_t mempath;
lv_fs_file_t file;
uint8_t *buffer;
uint32_t size;
/*Initialize buffer*/
...
lv_fs_make_path_from_buffer(&mempath, LV_FS_MEMFS_LETTER, (void*)buffer, size);
lv_fs_res_t res = lv_fs_open(&file, (const char *)&mempath, LV_FS_MODE_RD);