使用STM32CUBEMX生成FatFS代码，操作SPI FLASH

首先配置SPI，我的板子是SPI2连接到SPI FLASH 上，我的flash是W25Q64， PB12用来当CSN。

接下来配置FATFS，这里选择用户定义的。

配置FATFS的时候要注意，由于SPI FLASH 的sector是4096字节的，故需要设置sector的大小为4096，其余选项根据自己情况配置。

配置好了生成代码和工程。记得把堆栈尺寸调大一些。我用IAR这样配置：

接着把SPI FLASH的读写操作实现：读一个sector和写一个sector。我写好的函数叫做W25_WriteSector和W25_ReadSector. 然后定义好常量：

#define PAGE_SIZE       256

#define SECTOR_SIZE     4096

#define SECTOR_COUNT 200

#define BLOCK_SIZE 65536

#define FLASH_PAGES_PER_SECTOR SECTOR_SIZE/PAGE_SIZE

下一步打开user_diskio.c 文件，填充几个函数。

/**

  * @brief  Reads Sector(s) 

  * @param  pdrv: Physical drive number (0..)

  * @param  *buff: Data buffer to store read data

  * @param  sector: Sector address (LBA)

  * @param  count: Number of sectors to read (1..128)

  * @retval DRESULT: Operation result

  */

DRESULT USER_read (

BYTE pdrv,      /* Physical drive nmuber to identify the drive */

BYTE *buff,     /* Data buffer to store read data */

DWORD sector,   /* Sector address in LBA */

UINT count      /* Number of sectors to read */

)

{

  /* USER CODE HERE */

  UINT i = 0;

  for(i = 0; i < count; i ++)

  {

    W25_ReadSector(sector, buff);

    sector ++;

    buff += SECTOR_SIZE;

  }

  return RES_OK;

}

/**

  * @brief  Writes Sector(s)  

  * @param  pdrv: Physical drive number (0..)

  * @param  *buff: Data to be written

  * @param  sector: Sector address (LBA)

  * @param  count: Number of sectors to write (1..128)

  * @retval DRESULT: Operation result

  */

#if _USE_WRITE == 1

DRESULT USER_write (

BYTE pdrv,          /* Physical drive nmuber to identify the drive */

const BYTE *buff,   /* Data to be written */

DWORD sector,       /* Sector address in LBA */

UINT count          /* Number of sectors to write */

)

{ 

  /* USER CODE HERE */

  UINT i = 0;

  for(i = 0; i < count; i ++)

  {

    W25_WriteSector(sector, buff);

    sector ++;

    buff += SECTOR_SIZE;

  }

  return RES_OK;

}

#endif /* _USE_WRITE == 1 */

/**

  * @brief  I/O control operation  

  * @param  pdrv: Physical drive number (0..)

  * @param  cmd: Control code

  * @param  *buff: Buffer to send/receive control data

  * @retval DRESULT: Operation result

  */

#if _USE_IOCTL == 1

DRESULT USER_ioctl (

BYTE pdrv,      /* Physical drive nmuber (0..) */

BYTE cmd,       /* Control code */

void *buff      /* Buffer to send/receive control data */

)

{

  DRESULT res = RES_OK;

  switch(cmd)

  {

    case CTRL_SYNC :

        break;

    case CTRL_TRIM:

        break;

    case GET_BLOCK_SIZE:

*(DWORD*)buff = BLOCK_SIZE;

break;

    case GET_SECTOR_SIZE:

*(DWORD*)buff = SECTOR_SIZE;

        break;

    case GET_SECTOR_COUNT:

*(DWORD*)buff = SECTOR_COUNT;

break;

    default:

res = RES_PARERR;

break;

    }

  return res;

}

#endif /* _USE_IOCTL == 1 */

这些函数填充好，就可以用FATFS了。对于一个新的SPI FLASH，先挂载f_mount，再格式化文件系统f_mkfs，之后就可以做各种新建文件、读写操作了。

补充一个，在fatfs.c 文件中，定义了这样一个：

char USER_Path[4];  /* USER logical drive path */

之后我们可以在main或者其他文件里用extern声明它，mount和mkfs时的USER_Path都是它。

附上我的测试代码

void mount_disk(void)

{

  uint8_t res = f_mount(&fs, USER_Path, 0);

  if (res != FR_OK)

  {

    printf("FAILED: %d\n",res);

   return;

 }

  printf("MOUNT OK\n");

}

void format_disk(void)

{

  uint8_t res = 0;

  printf("PROCESSING...\n");

  res = f_mkfs(USER_Path, 1, 4096);

  if (res == FR_OK)

  {

    printf("OK!\n");

  }

  else

  {

    printf("failed with: %d\n",res);

  }

}

void create_file(void)

{

  FIL file;

  FIL *pf = &file;

  uint8_t res;

  res = f_open(pf, "0:/test.txt", FA_OPEN_ALWAYS | FA_WRITE);

  if (res == FR_OK)

  {

    printf("creat ok\n");

  }

  else

  {

    printf("creat failed\n");

    printf("error code: %d\n",res);

  }

  f_printf(pf, "hello fatfs!\n");

  res = f_close(pf);

    if (res != FR_OK)

    {

      printf("close file error\n");

      printf("error code: %d\n",res);

    }

}

void get_disk_info(void)

{

FATFS fs;

FATFS *fls = &fs;

FRESULT res;

DWORD fre_clust;

res = f_getfree("/",&fre_clust,&fls);         /* Get Number of Free Clusters */

if (res == FR_OK) 

{

                                            /* Print free space in unit of MB (assuming 4096 bytes/sector) */

        printf("%d KB Total Drive Space.\n"

               "%d KB Available Space.\n",

               ((fls->n_fatent-2)*fls->csize)*4,(fre_clust*fls->csize)*4);

}

else

{

printf("get disk info error\n");

printf("error code: %d\n",res);

}   

}

void read_file(void)

{

  FIL file;

  FRESULT res;

  UINT bw;

  uint8_t rbuf[100] = {0};

  res = f_open(&file, "0:/test.txt", FA_READ);

  if (res != FR_OK)

  {

    printf("open error: %d\n",res);

    return;

  }

  f_read(&file, rbuf, 20, &bw);

  printf("%s\n", rbuf);

  res = f_close(&file);

  if (res != FR_OK)

  {

     printf("close file error\n");

     printf("error code: %d\n",res);

  }

}