LLFS (Linked List File System)

Introduction

The llfs filesystem can be generated using the mkllfss utility. It is a simple filesystem that uses a linked list to store files. The filesystem is stored in a single c file (llfs_data.c), which can be compiled and read by the llfs library. The llfs filesystem is a flat filesystem, meaning that it does not support directories.

Usage of the llfs API

Getting a list of files

#include "llfs.h"

void main(void) {
    // Allocate space for 10 files
    llfs_file_t file_list[10];
    
    // Get the file list
    size_t file_count = llfs_file_list(file_list, 10, NULL);
    
    // Loop through the files and print their names and sizes
    for (int i = 0; i < file_count; i++) {
        LOG_INFO(TAG, "File: %s, size: %d", file_list[i].name, file_list[i].len);
    }
}

Result:

[Info]      (2009) [main]: File: image.bmp, size: 9270
[Info]      (2013) [main]: File: python_file.py, size: 645
[Info]      (2019) [main]: File: image2.bmp, size: 7738
[Info]      (2024) [main]: File: filename with a space.txt, size: 61
[Info]      (2031) [main]: File: file1.txt, size: 77

Reading a file

#include "llfs.h"

void main(void) {
    // Get a file by name
    llfs_file_t *file = llfs_file_open("filename with a space.txt");
    
    if (file != NULL) {
        // Print the file name, size and data
        LOG_INFO(TAG, "File found: %s, size: %d", file->name, file->len);
        LOG_INFO(TAG, "File data: %s", file->data);
    } else {
        LOG_WARN(TAG, "File not found");
    }
}