SPIFFS Example (Base On STM32L4 DISCO)

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Advantage:

• Small (embedded) targets, sparse RAM without heap
• Only big areas of data (blocks) can be erased
• An erase will reset all bits in block to ones
• Writing pulls one to zeroes
• Zeroes can only be pulled to ones by erase
• Wear leveling
• Cache
• Garbage Collecting

Disadvantages:

• Non-Support For PC
• Execution time uncertainty
• Maximum partition only support up to 128MByte

[How to Build]

• Keil UV5.24.2.0 or later
• STM32L476 DISCO
• Jlink-OB for RTT Debugger (It is free.)

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My configuration

• Debug method:Segger RTT
• Cache For Read
• Cache For Write[Unexpected power-lost has an impact on this.]
• Cache Statistics
• Garbage Collecting
• Flash Magic signature[Easy to detect new Flash]
• Mutex[You can migrate the operating system Mutex API.It is so easy.]
• Single partition
• Flash Size:16MB
• Flash Sector:64K
• Flash SubSector:4KB
• Flash Page:256Bytes
• SPIFFS Cache:(256 + 32) * 4 Bytes

Main Code

void SPIFFS_Main(void)
{
    SEGGER_RTT_Init();

    BSP_QSPI_Init();

    cfg.hal_erase_f = _spiffs_erase;
    cfg.hal_read_f = _spiffs_read;
    cfg.hal_write_f = _spiffs_write;

    if ((res = SPIFFS_mount(&fs,
                            &cfg,
                            FS_Work_Buf,
                            FS_FDS, sizeof(FS_FDS),
                            FS_Cache_Buf, sizeof(FS_Cache_Buf),
                            NULL)) != SPIFFS_OK &&
            SPIFFS_errno(&fs) == SPIFFS_ERR_NOT_A_FS)
    {
        SEGGER_RTT_printf("formatting spiffs...\n");
        if (SPIFFS_format(&fs) != SPIFFS_OK)
        {
            SEGGER_RTT_printf("SPIFFS format failed: %d\n", SPIFFS_errno(&fs));
        }
        SEGGER_RTT_printf("ok\n");
        SEGGER_RTT_printf("mounting\n");
        res = SPIFFS_mount(&fs,
                           &cfg,
                           FS_Work_Buf,
                           FS_FDS, sizeof(FS_FDS),
                           FS_Cache_Buf, sizeof(FS_Cache_Buf),
                           NULL);
    }
    if (res != SPIFFS_OK)
    {
        SEGGER_RTT_printf("SPIFFS mount failed: %d\n", SPIFFS_errno(&fs));
    }
    else
    {
        SEGGER_RTT_printf("SPIFFS mounted\n");
    }
    SEGGER_RTT_printf("errno %d\n", SPIFFS_errno(&fs));



    for(;;)
    {
        spiffs_file fd = SPIFFS_open(&fs, "my_file", SPIFFS_CREAT | SPIFFS_TRUNC | SPIFFS_RDWR, 0);
        SEGGER_RTT_printf("errno %d\n", SPIFFS_errno(&fs));
        if (SPIFFS_write(&fs, fd, WriteBuf, sizeof(WriteBuf)) < 0)
            SEGGER_RTT_printf("errno %d\n", SPIFFS_errno(&fs));
        SPIFFS_close(&fs, fd);

        fd = SPIFFS_open(&fs, "my_file", SPIFFS_RDWR, 0);
        if (SPIFFS_read(&fs, fd, ReadBuf, sizeof(WriteBuf)) < 0)
            SEGGER_RTT_printf("errno %d\n", SPIFFS_errno(&fs));
        SPIFFS_close(&fs, fd);
        LL_mDelay(1000);
        SPIFFS_info(&fs, &total, &used_space);
        SEGGER_RTT_printf("mybuf = %s\n", ReadBuf);
    }
}