RT-Thread-ART-Pi 外部 SPI Flash 使用 elmfatfs 文件系统RT-Thread问答社区

ART-Pi 外部 SPI Flash 使用 elmfatfs 文件系统

发布于 2023-06-16 16:34:23 浏览：727 订阅该版

[tocm]

# 有关技术背景

## SPI 介绍

https://www.rt-thread.org/document/site/#/rt-thread-version/rt-thread-standard/programming-manual/device/spi/spi

SPI 原理：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/f8d48bfced9496743dc027bc46c8cb27.png)

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/4f7d71282b9aa37ce845d29c56212723.png)

## FAL (Flash Abstraction Layer) Flash 抽象层

https://www.rt-thread.org/document/site/#/rt-thread-version/rt-thread-standard/programming-manual/fal/fal?id=fal-%e7%bb%84%e4%bb%b6

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/067a5aaa36753aac1194b1e64d704aa2.png.webp)

## DFS (Device File System) 设备虚拟文件系统

https://www.rt-thread.org/document/site/#/rt-thread-version/rt-thread-standard/programming-manual/filesystem/filesystem?id=dfs-%e7%ae%80%e4%bb%8b

DFS 的层次架构图：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/882501c07eb0f86089e2df931a8112e5.png.webp)

## ROMFS

https://www.rt-thread.org/document/site/#/rt-thread-version/rt-thread-standard/tutorial/qemu-network/filesystems/filesystems?id=%e4%bd%bf%e7%94%a8-romfs

## ARTPI 外部 SPI Flash

ARTPI 有一个外部 SPI Flash，空间为 16-Mbytes，使用的是 ARTPI 的 SPI1 接口。

查阅 Flash 的数据手册可知，扇区大小为 4KB，也就是 4096B：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/52f35f6f1e9466cbc055baa212551385.png.webp)

# 整体思路

在 meunconfig 中开启 DFS，本教程使用 elmfatfs 文件系统，需要将 elmfatfs 挂载到 RT-Thread 的 DFS 上，所以 elmfatfs 也要开启：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/85071d2be15e53b57000313babd1f12c.png.webp)

注意要把扇区大小改成上面查阅的 4096：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/5fee2679852b86c016ce2aca063688af.png)

当然，不要忘记在 meunconfig 中开启 SPI Flash filesystem：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/f11c4e87a2d2e18dca867aa83703ca47.png)

此时 `scons --target=mdk5` 然后编译下载，运行结果会是这样：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/5dcf67f3f03398ccc76cda107acfc6d8.png)

显示两个报错：
一是 Flash 上面的 filesystem 分区（在上方输出的 FAL 分区表种可以找到，对应的定义在 `fal_cfg.h` 文件中）挂载到 /flash 上失败了；二是 lfs 文件系统没有找到

我们在 `filesystem.c` 中找到了报错对应的代码：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/ac8a5638619c62929b541fbca2b20812.png.webp)

可以看出来这部分代码是挂载 lfs 文件系统，于是上面报错的原因找到了：我们使用的是 elm-FATFS 系统，需要手动修改一下挂载代码。

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/14fa845146c857cb3efe8a7cc3913b25.png.webp)

我们创建设备的时候是 BLK 设备，要用 `fal_blk_device_create` 这个函数。

代码修改之后是这样：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/860bd0319ec20e81f8357b44e8a0a254.png.webp)

照葫芦画瓢写个 elm 系统的挂载，主要的区别有：

1.注册设备用的 `fal_blk_device_create` 而非 `fal_mtd_nor_device_create`
2.挂载到 / 而非 /flash
3.文件系统使用 elm 而非 rom

修改完之后重新编译下载，发现依旧报错，运行 ls 查看一下情况，发现是这样：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/f8c43c5dc817395e949a63b5a21d86d6.png)

再次返回查看代码，原来是这里导致的：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/0b6f893829af36afedaa130eac91a74b.png)

使用了 romfs，然后开启了 flash 和 sdcard 两块区域。这里我们需要默认不使用 ROMFS，改成这样：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/f761bffb7f10c595912b606534967691.png.webp)

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/6bb98307c1079179ee90ff058315134c.png)

另外在 menuconfig 中查看，发现这个宏是默认开启的，找到是在 `boards/Kconfig` 中默认选择了，需要注释掉：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/28c844e1c4981d14ff72c7d54e4c5333.png)

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/f2ee8773c3a4cc3a7d84d5795d2160f1.png)

到对应的选项取消掉这个宏：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/598f779d2e8ce7aae85d7497dd7c634e.png.webp)

最终，filesystem.c 的代码完整版如下：

```
/*
 * Copyright (c) 2006-2022, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author        Notes
 * 2018-12-13     balanceTWK    add sdcard port file
 * 2019-06-11     WillianChan   Add SD card hot plug detection
 */

#include <rtthread.h>

#ifdef BSP_USING_FS
#if DFS_FILESYSTEMS_MAX < 4
    #error "Please define DFS_FILESYSTEMS_MAX more than 4"
#endif
#if DFS_FILESYSTEM_TYPES_MAX < 4
    #error "Please define DFS_FILESYSTEM_TYPES_MAX more than 4"
#endif

#include <dfs_fs.h>
#ifdef BSP_USING_SDCARD_FS
    #include <board.h>
    #include "drv_sdio.h"
#endif
#ifdef BSP_USING_SPI_FLASH_FS
    #include "fal.h"
#endif
#define DBG_TAG "app.filesystem"
#define DBG_LVL DBG_INFO
#include <rtdbg.h>

#ifdef RT_USING_DFS_ROMFS   /* 默认不使用 ROMFS */
#include "dfs_romfs.h"
static const struct romfs_dirent _romfs_root[] =
{
    {ROMFS_DIRENT_DIR, "flash", RT_NULL, 0},
    {ROMFS_DIRENT_DIR, "sdcard", RT_NULL, 0}
};

const struct romfs_dirent romfs_root =
{
    ROMFS_DIRENT_DIR, "/", (rt_uint8_t *)_romfs_root, sizeof(_romfs_root) / sizeof(_romfs_root[0])
};
#endif

#ifdef BSP_USING_SDCARD_FS

/* SD Card hot plug detection pin */
#define SD_CHECK_PIN GET_PIN(D, 5)

static void _sdcard_mount(void)
{
    rt_device_t device;

device = rt_device_find("sd0");

if (device == NULL)
    {
        mmcsd_wait_cd_changed(0);
        sdcard_change();
        mmcsd_wait_cd_changed(RT_WAITING_FOREVER);
        device = rt_device_find("sd0");
    }

if (device != RT_NULL)
    {
        if (dfs_mount("sd0", "/sdcard", "elm", 0, 0) == RT_EOK)
        {
            LOG_I("sd card mount to '/sdcard'");
        }
        else
        {
            LOG_W("sd card mount to '/sdcard' failed!");
        }
    }
}

static void _sdcard_unmount(void)
{
    rt_thread_mdelay(200);
    dfs_unmount("/sdcard");
    LOG_I("Unmount \"/sdcard\"");

mmcsd_wait_cd_changed(0);
    sdcard_change();
    mmcsd_wait_cd_changed(RT_WAITING_FOREVER);
}

static void sd_mount(void *parameter)
{
    rt_uint8_t re_sd_check_pin = 1;
    rt_thread_mdelay(200);

if (rt_pin_read(SD_CHECK_PIN))
    {
        _sdcard_mount();
    }

while (1)
    {
        rt_thread_mdelay(200);

if (!re_sd_check_pin && (re_sd_check_pin = rt_pin_read(SD_CHECK_PIN)) != 0)
        {
            _sdcard_mount();
        }

if (re_sd_check_pin && (re_sd_check_pin = rt_pin_read(SD_CHECK_PIN)) == 0)
        {
            _sdcard_unmount();
        }
    }
}

#endif /* BSP_USING_SDCARD_FS */

int mnt_spi_flash_init(void)
{
    struct rt_device *flash_dev = RT_NULL;

#ifndef RT_USING_WIFI
    fal_init();
    #endif

flash_dev = fal_blk_device_create("filesystem");

if (flash_dev)
    {
        //mount filesystem
        if (dfs_mount(flash_dev->parent.name, "/", "elm", 0, 0) != 0)
        {
            LOG_W("mount to '/' failed! try to mkfs %s", flash_dev->parent.name);
            dfs_mkfs("elm", flash_dev->parent.name);

if (dfs_mount(flash_dev->parent.name, "/", "elm", 0, 0) == 0)
            {
                LOG_I("mount to '/' success!");
            }
        }
        else
        {
            LOG_I("mount to '/' success!");
        }
    }
    else
    {
        LOG_E("Can't create block device  filesystem or bt_image partition.");
    }
}

int mount_init(void)
{
    #ifdef RT_USING_DFS_ROMFS /* 默认不使用ROMFS */
    if (dfs_mount(RT_NULL, "/", "rom", 0, &(romfs_root)) != 0)
    {
        LOG_E("rom mount to '/' failed!");
    }
    #endif

#ifdef BSP_USING_SPI_FLASH_FS

mnt_spi_flash_init();

#if 0
    struct rt_device *flash_dev = RT_NULL;

#ifndef RT_USING_WIFI
    fal_init();
    #endif

flash_dev = fal_mtd_nor_device_create("filesystem");

if (flash_dev)
    {
        //mount filesystem
        if (dfs_mount(flash_dev->parent.name, "/flash", "lfs", 0, 0) != 0)
        {
            LOG_W("mount to '/flash' failed! try to mkfs %s", flash_dev->parent.name);
            dfs_mkfs("lfs", flash_dev->parent.name);

if (dfs_mount(flash_dev->parent.name, "/flash", "lfs", 0, 0) == 0)
            {
                LOG_I("mount to '/flash' success!");
            }
        }
        else
        {
            LOG_I("mount to '/flash' success!");
        }
    }
    else
    {
        LOG_E("Can't create  block device  filesystem or bt_image partition.");
    }

#endif
    #endif

#ifdef BSP_USING_SDCARD_FS
    rt_thread_t tid;

rt_pin_mode(SD_CHECK_PIN, PIN_MODE_INPUT_PULLUP);

tid = rt_thread_create("sd_mount", sd_mount, RT_NULL,
                           2048, RT_THREAD_PRIORITY_MAX - 2, 20);

if (tid != RT_NULL)
    {
        rt_thread_startup(tid);
    }
    else
    {
        LOG_E("create sd_mount thread err!");
    }

#endif
    return RT_EOK;
}
INIT_APP_EXPORT(mount_init);

#endif /* BSP_USING_FS */
```

重新生成、编译、下载，运行结果如下：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230616/6bf020f9c97c3f278ab7112fff3c0e01.png)

大功告成！