File content as of revision 0:f1015c4245f6:

#include "mbed.h"
#include "MemFileSystem.h"
#include "SDFileSystem.h"

SDFileSystem sd(P8_5, P8_6, P8_3, P8_4, "sd");

namespace {
const char *mem_file_path = "/ram/out.txt";
const char *sd_file_path = "/sd/fatdump";
const int DATA_SIZE = 10 * 1024;
}

int main()
{
    uint8_t data_written[DATA_SIZE] = { 0 };
    bool result = true;
    
    MemFileSystem *ramfs1 = new MemFileSystem("ram");
    ramfs1->format();
    {
        FILE *f = fopen(mem_file_path, "w");
 
        printf("Mem: Writing ... ");
        for (int i = 0; i < DATA_SIZE; i++) {
            data_written[i] = rand() % 0XFF;
            fprintf(f, "%c", data_written[i]);
        }
        printf("[OK]\r\n");
        fclose(f);
    }
 
    {
        FILE *f = fopen(mem_file_path, "r");
        printf("Mem: Reading data ... ");
        for (int i = 0; i < DATA_SIZE; i++) {
            uint8_t data = fgetc(f);
            if (data != data_written[i]) {
                result = false;
                break;
            }
        }
        printf("[%s]\r\n", result ? "OK" : "FAIL");
        fclose(f);
    }

    {
        FILE *f = fopen(sd_file_path, "w");
        printf("Dump from MemFs to SDFs ... ");
        ramfs1->dump(f);
        printf("[OK]\r\n");
        fclose(f);
    }

    delete ramfs1;
    MemFileSystem *ramfs2 = new MemFileSystem("ram");

    {
        FILE *f = fopen(sd_file_path, "r");
        printf("Load from SDFs to MemFs ... ");
        ramfs2->load(f);
        printf("[OK]\r\n");
        fclose(f);
    }

    {
        FILE *f = fopen(mem_file_path, "r");
        printf("Mem: Reading data ... ");
        for (int i = 0; i < DATA_SIZE; i++) {
            uint8_t data = fgetc(f);
            if (data != data_written[i]) {
                result = false;
                break;
            }
        }
        printf("[%s]\r\n", result ? "OK" : "FAIL");
        fclose(f);
    }
}