尝试EFM32下的fatfs的使用

主芯片为EFM32WG360F256，使用的SPIflash为W25Q256。
关于SPIflash的驱动部分不再说明。
移植的fatfs为官方的最新版本：http://elm-chan.org/fsw/ff/00index_e.html，Download: FatFs R0.12a | Updates | Latest Patch July 23, 2016
用不到长文件名，直接删掉源码的option文件夹下所有文件，接下来开始配置ffconf.h，配置如下：

/*---------------------------------------------------------------------------//  FatFs - FAT file system module configuration file/---------------------------------------------------------------------------*/#define _FFCONF 80186   /* Revision ID *//*---------------------------------------------------------------------------// Function Configurations/---------------------------------------------------------------------------*/#define _FS_READONLY    0/* This option switches read-only configuration. (0:Read/Write or 1:Read-only)/  Read-only configuration removes writing API functions, f_write(), f_sync(),/  f_unlink(), f_mkdir(), f_chmod(), f_rename(), f_truncate(), f_getfree()/  and optional writing functions as well. */#define _FS_MINIMIZE    0/* This option defines minimization level to remove some basic API functions.//   0: All basic functions are enabled./   1: f_stat(), f_getfree(), f_unlink(), f_mkdir(), f_truncate() and f_rename()/      are removed./   2: f_opendir(), f_readdir() and f_closedir() are removed in addition to 1./   3: f_lseek() function is removed in addition to 2. */#define _USE_STRFUNC    0/* This option switches string functions, f_gets(), f_putc(), f_puts() and/  f_printf().//  0: Disable string functions./  1: Enable without LF-CRLF conversion./  2: Enable with LF-CRLF conversion. */#define _USE_FIND       0/* This option switches filtered directory read functions, f_findfirst() and/  f_findnext(). (0:Disable, 1:Enable 2:Enable with matching altname[] too) */#define _USE_MKFS       1/* This option switches f_mkfs() function. (0:Disable or 1:Enable) */#define _USE_FASTSEEK   0/* This option switches fast seek function. (0:Disable or 1:Enable) */#define _USE_EXPAND     0/* This option switches f_expand function. (0:Disable or 1:Enable) */#define _USE_CHMOD      0/* This option switches attribute manipulation functions, f_chmod() and f_utime()./  (0:Disable or 1:Enable) Also _FS_READONLY needs to be 0 to enable this option. */#define _USE_LABEL      0/* This option switches volume label functions, f_getlabel() and f_setlabel()./  (0:Disable or 1:Enable) */#define _USE_FORWARD    0/* This option switches f_forward() function. (0:Disable or 1:Enable) *//*---------------------------------------------------------------------------// Locale and Namespace Configurations/---------------------------------------------------------------------------*/#define _CODE_PAGE  936/* This option specifies the OEM code page to be used on the target system./  Incorrect setting of the code page can cause a file open failure.//   1   - ASCII (No extended character. Non-LFN cfg. only)/   437 - U.S./   720 - Arabic/   737 - Greek/   771 - KBL/   775 - Baltic/   850 - Latin 1/   852 - Latin 2/   855 - Cyrillic/   857 - Turkish/   860 - Portuguese/   861 - Icelandic/   862 - Hebrew/   863 - Canadian French/   864 - Arabic/   865 - Nordic/   866 - Russian/   869 - Greek 2/   932 - Japanese (DBCS)/   936 - Simplified Chinese (DBCS)/   949 - Korean (DBCS)/   950 - Traditional Chinese (DBCS)*/#define _USE_LFN    0#define _MAX_LFN    255/* The _USE_LFN switches the support of long file name (LFN).//   0: Disable support of LFN. _MAX_LFN has no effect./   1: Enable LFN with static working buffer on the BSS. Always NOT thread-safe./   2: Enable LFN with dynamic working buffer on the STACK./   3: Enable LFN with dynamic working buffer on the HEAP.//  To enable the LFN, Unicode handling functions (option/unicode.c) must be added/  to the project. The working buffer occupies (_MAX_LFN + 1) * 2 bytes and/  additional 608 bytes at exFAT enabled. _MAX_LFN can be in range from 12 to 255./  It should be set 255 to support full featured LFN operations./  When use stack for the working buffer, take care on stack overflow. When use heap/  memory for the working buffer, memory management functions, ff_memalloc() and/  ff_memfree(), must be added to the project. */#define _LFN_UNICODE    0/* This option switches character encoding on the API. (0:ANSI/OEM or 1:UTF-16)/  To use Unicode string for the path name, enable LFN and set _LFN_UNICODE = 1./  This option also affects behavior of string I/O functions. */#define _STRF_ENCODE    3/* When _LFN_UNICODE == 1, this option selects the character encoding ON THE FILE to/  be read/written via string I/O functions, f_gets(), f_putc(), f_puts and f_printf().//  0: ANSI/OEM/  1: UTF-16LE/  2: UTF-16BE/  3: UTF-8//  This option has no effect when _LFN_UNICODE == 0. */#define _FS_RPATH   0/* This option configures support of relative path.//   0: Disable relative path and remove related functions./   1: Enable relative path. f_chdir() and f_chdrive() are available./   2: f_getcwd() function is available in addition to 1.*//*---------------------------------------------------------------------------// Drive/Volume Configurations/---------------------------------------------------------------------------*/#define _VOLUMES    1/* Number of volumes (logical drives) to be used. */#define _STR_VOLUME_ID  0#define _VOLUME_STRS    "RAM","NAND","CF","SD","SD2","USB","USB2","USB3"/* _STR_VOLUME_ID switches string support of volume ID./  When _STR_VOLUME_ID is set to 1, also pre-defined strings can be used as drive/  number in the path name. _VOLUME_STRS defines the drive ID strings for each/  logical drives. Number of items must be equal to _VOLUMES. Valid characters for/  the drive ID strings are: A-Z and 0-9. */#define _MULTI_PARTITION    0/* This option switches support of multi-partition on a physical drive./  By default (0), each logical drive number is bound to the same physical drive/  number and only an FAT volume found on the physical drive will be mounted./  When multi-partition is enabled (1), each logical drive number can be bound to/  arbitrary physical drive and partition listed in the VolToPart[]. Also f_fdisk()/  funciton will be available. */#define _MIN_SS     512#define _MAX_SS     512/* These options configure the range of sector size to be supported. (512, 1024,/  2048 or 4096) Always set both 512 for most systems, all type of memory cards and/  harddisk. But a larger value may be required for on-board flash memory and some/  type of optical media. When _MAX_SS is larger than _MIN_SS, FatFs is configured/  to variable sector size and GET_SECTOR_SIZE command must be implemented to the/  disk_ioctl() function. */#define _USE_TRIM   0/* This option switches support of ATA-TRIM. (0:Disable or 1:Enable)/  To enable Trim function, also CTRL_TRIM command should be implemented to the/  disk_ioctl() function. */#define _FS_NOFSINFO    0/* If you need to know correct free space on the FAT32 volume, set bit 0 of this/  option, and f_getfree() function at first time after volume mount will force/  a full FAT scan. Bit 1 controls the use of last allocated cluster number.//  bit0=0: Use free cluster count in the FSINFO if available./  bit0=1: Do not trust free cluster count in the FSINFO./  bit1=0: Use last allocated cluster number in the FSINFO if available./  bit1=1: Do not trust last allocated cluster number in the FSINFO.*//*---------------------------------------------------------------------------// System Configurations/---------------------------------------------------------------------------*/#define _FS_TINY    1/* This option switches tiny buffer configuration. (0:Normal or 1:Tiny)/  At the tiny configuration, size of the file object (FIL) is reduced _MAX_SS bytes./  Instead of private sector buffer eliminated from the file object, common sector/  buffer in the file system object (FATFS) is used for the file data transfer. */#define _FS_EXFAT   0/* This option switches support of exFAT file system in addition to the traditional/  FAT file system. (0:Disable or 1:Enable) To enable exFAT, also LFN must be enabled./  Note that enabling exFAT discards C89 compatibility. */#define _FS_NORTC   1#define _NORTC_MON  1#define _NORTC_MDAY 1#define _NORTC_YEAR 2016/* The option _FS_NORTC switches timestamp functiton. If the system does not have/  any RTC function or valid timestamp is not needed, set _FS_NORTC = 1 to disable/  the timestamp function. All objects modified by FatFs will have a fixed timestamp/  defined by _NORTC_MON, _NORTC_MDAY and _NORTC_YEAR in local time./  To enable timestamp function (_FS_NORTC = 0), get_fattime() function need to be/  added to the project to get current time form real-time clock. _NORTC_MON,/  _NORTC_MDAY and _NORTC_YEAR have no effect. /  These options have no effect at read-only configuration (_FS_READONLY = 1). */#define _FS_LOCK    0/* The option _FS_LOCK switches file lock function to control duplicated file open/  and illegal operation to open objects. This option must be 0 when _FS_READONLY/  is 1.//  0:  Disable file lock function. To avoid volume corruption, application program/      should avoid illegal open, remove and rename to the open objects./  >0: Enable file lock function. The value defines how many files/sub-directories/      can be opened simultaneously under file lock control. Note that the file/      lock control is independent of re-entrancy. */#define _FS_REENTRANT   0#define _FS_TIMEOUT     1000#define _SYNC_t         HANDLE/* The option _FS_REENTRANT switches the re-entrancy (thread safe) of the FatFs/  module itself. Note that regardless of this option, file access to different/  volume is always re-entrant and volume control functions, f_mount(), f_mkfs()/  and f_fdisk() function, are always not re-entrant. Only file/directory access/  to the same volume is under control of this function.//   0: Disable re-entrancy. _FS_TIMEOUT and _SYNC_t have no effect./   1: Enable re-entrancy. Also user provided synchronization handlers,/      ff_req_grant(), ff_rel_grant(), ff_del_syncobj() and ff_cre_syncobj()/      function, must be added to the project. Samples are available in/      option/syscall.c.//  The _FS_TIMEOUT defines timeout period in unit of time tick./  The _SYNC_t defines O/S dependent sync object type. e.g. HANDLE, ID, OS_EVENT*,/  SemaphoreHandle_t and etc.. A header file for O/S definitions needs to be/  included somewhere in the scope of ff.c. *//*--- End of configuration options ---*/

配置为TINY精简模式。之后开始完善diskio.c的底层接口函数，代码如下：

/*-----------------------------------------------------------------------*//* Low level disk I/O module skeleton for FatFs     (C)ChaN, 2016        *//*-----------------------------------------------------------------------*//* If a working storage control module is available, it should be        *//* attached to the FatFs via a glue function rather than modifying it.   *//* This is an example of glue functions to attach various exsisting      *//* storage control modules to the FatFs module with a defined API.       *//*-----------------------------------------------------------------------*/#include "diskio.h"     /* FatFs lower layer API */#include "bsp_gps.h"/* Definitions of physical drive number for each drive */#define EX_FLASH 0  //外部flash,卷标为0#define FLASH_SECTOR_SIZE   4096#define FLASH_BLOCK_SIZE    16      //每个BLOCK有16个扇区#define FLASH_SECTOR_NUM    (32*1024*1024)//flash的总容量/*-----------------------------------------------------------------------*//* Get Drive Status                                                      *//*-----------------------------------------------------------------------*///获得磁盘状态DSTATUS disk_status (    BYTE pdrv       /* Physical drive nmuber (0..) */){    return 0;}/*-----------------------------------------------------------------------*//* Inidialize a Drive                                                    *//*-----------------------------------------------------------------------*///初始化磁盘DSTATUS disk_initialize (    BYTE pdrv               /* Physical drive nmuber (0..) */){    BYTE res=0;    switch(pdrv)    {        case EX_FLASH://外部flash            W25QXX_Init();            break;        default:            res=1;    }    if(res)return  STA_NOINIT;    else return 0; //初始化成功}/*-----------------------------------------------------------------------*//* Read Sector(s)                                                        *//*-----------------------------------------------------------------------*///读扇区//drv:磁盘编号0~9//*buff:数据接收缓冲首地址//sector:扇区地址//count:需要读取的扇区数DRESULT disk_read (    BYTE pdrv,      /* Physical drive nmuber (0..) */    BYTE *buff,     /* Data buffer to store read data */    DWORD sector,   /* Sector address (LBA) */    UINT count      /* Number of sectors to read (1..128) */){    BYTE res=0;    if (!count)return RES_PARERR;//count不能等于0，否则返回参数错误    switch(pdrv)    {        case EX_FLASH://外部flash            for(;count>0;count--)            {                W25QXX_Read(buff,sector*FLASH_SECTOR_SIZE,FLASH_SECTOR_SIZE);                sector++;                buff+=FLASH_SECTOR_SIZE;            }            res=0;            break;        default:            res=1;    }   //处理返回值，将SPI_SD_driver.c的返回值转成ff.c的返回值    if(res==0x00)return RES_OK;    else return RES_ERROR;}/*-----------------------------------------------------------------------*//* Write Sector(s)                                                       *//*-----------------------------------------------------------------------*///写扇区//drv:磁盘编号0~9//*buff:发送数据首地址//sector:扇区地址//count:需要写入的扇区数DRESULT disk_write (    BYTE pdrv,          /* Physical drive nmuber (0..) */    const BYTE *buff,   /* Data to be written */    DWORD sector,       /* Sector address (LBA) */    UINT count          /* Number of sectors to write (1..128) */){    BYTE res=0;    if (!count)return RES_PARERR;//count不能等于0，否则返回参数错误    switch(pdrv)    {        case EX_FLASH://外部flash            for(;count>0;count--)            {                W25QXX_Write((BYTE*)buff,sector*FLASH_SECTOR_SIZE,FLASH_SECTOR_SIZE);                sector++;                buff+=FLASH_SECTOR_SIZE;            }            res=0;            break;        default:            res=1;    }    //处理返回值，将SPI_SD_driver.c的返回值转成ff.c的返回值    if(res == 0x00)return RES_OK;    else return RES_ERROR;}/*-----------------------------------------------------------------------*//* Miscellaneous Functions                                               *//*-----------------------------------------------------------------------*///其他表参数的获得 //drv:磁盘编号0~9 //ctrl:控制代码 //*buff:发送/接收缓冲区指针DRESULT disk_ioctl (    BYTE pdrv,      /* Physical drive nmuber (0..) */    BYTE cmd,       /* Control code */    void *buff      /* Buffer to send/receive control data */){    DRESULT res;    if(pdrv==EX_FLASH)  //外部FLASH    {        switch(cmd)        {            case CTRL_SYNC:                res = RES_OK;                break;            case GET_SECTOR_SIZE:                *(WORD*)buff = FLASH_SECTOR_SIZE;                res = RES_OK;                break;            case GET_BLOCK_SIZE:                *(WORD*)buff = FLASH_BLOCK_SIZE;                res = RES_OK;                break;            case GET_SECTOR_COUNT:                *(DWORD*)buff = FLASH_SECTOR_NUM;                res = RES_OK;                break;            default:                res = RES_PARERR;                break;        }    }else res=RES_ERROR;//其他的不支持    return res;}//获得时间//User defined function to give a current time to fatfs module      *///31-25: Year(0-127 org.1980), 24-21: Month(1-12), 20-16: Day(1-31) *///15-11: Hour(0-23), 10-5: Minute(0-59), 4-0: Second(0-29 *2) */DWORD get_fattime (void){    u32 time=0;    if((pGPS_Data.Year+2000)<1980)return 0;    time=(pGPS_Data.Year+2000-1980)<<25;//年份    time|=(pGPS_Data.Mouth)<<21;    //月份    time|=(pGPS_Data.Day)<<16;  //日期    time|=(pGPS_Data.Hour)<<11;     //时    time|=(pGPS_Data.Min)<<5;       //分    time|=(pGPS_Data.Sec/2);            //秒    return time;}

将spiflash的读写函数嵌入fatfs的读写函数中，用GPS的全局时间结构体作为fatfs的时间，之后编写一个fatfs的初始化函数：

//fatfs初始化函数，检测无文件系统的时候会自动格式化//成功返回剩余容量(一个0~1之间的小数)，失败返回0FATFS FatFs;float fatfs_init(void){    FRESULT res;    /* FatFs return code */    DWORD fre_clust, fre_sect, tot_sect;    BYTE line[512];    //检查SPI FLASH的文件系统    f_mount(&FatFs, "0:", 0);       //挂载FLASH.    //W25Q256检测,如果不存在文件系统,则先创建.    res=f_getfree("0:", &fre_clust, &FatFs);//得到FLASH剩余容量和总容量    /* Get total sectors and free sectors */    tot_sect = (FatFs.n_fatent - 2) * FatFs.csize;    fre_sect = fre_clust * FatFs.csize;    if(res == FR_NO_FILESYSTEM)//文件系统不存在    {        res=f_mkfs("0:", FM_FAT32, 0, line, sizeof line);//格式化FLASH        if(res==FR_OK)        {            res=f_getfree("0:", &fre_clust, &FatFs);//重新获取容量            /* Get total sectors and free sectors */            tot_sect = (FatFs.n_fatent - 2) * FatFs.csize;            fre_sect = fre_clust * FatFs.csize;        }    }    if(res==FR_OK)//得到FLASH卡剩余容量和总容量        return ((float)fre_sect/(float)tot_sect);    else        return 0;}

编写一个fatfs 的测试函数：

void fatfs_text (void){    printf("Flash text begin...\r\n");    FIL fil;       /* File object */    UINT bw;    UINT br;    BYTE buff[64];    FRESULT fr;    /* FatFs return code */    float fre_sect;    f_mount(&FatFs, "0:", 0);       //挂载FLASH.    /* Open a text file */    fr = f_open(&fil, "0:text.txt", FA_OPEN_ALWAYS|FA_READ|FA_WRITE);    printf ("open fill is %d\r\n",fr);    /* write str in to the file */    sprintf (buff,"%2d%2d%2d %2d%2d%2d %2d %2d\r\n",pGPS_Data.Year,pGPS_Data.Mouth,pGPS_Data.Day,pGPS_Data.Hour,pGPS_Data.Min,pGPS_Data.Sec,pGPS_Data.sum_satellite,pGPS_Data.PUBX_data.num);    fr = f_write(&fil,buff,64,&bw);    printf ("write fill is %d\r\n",fr);    /* Pointer to */    fr = f_lseek(&fil,0);    printf (buff,"lseek fill is %d\r\n",fr);    /* read str from the file */    BYTE data[64] = "no data!\r\n";    fr = f_read(&fil,data,64,&br);    printf (data);    printf ("read fill is %d\r\n",fr);    /* Close the file */    f_close(&fil);    fre_sect = fatfs_init();    printf ("free sectors is %d.0\r\n",(WORD)(fre_sect*100));    printf ("Finish.\r\n");}

测试函数将一个动态的GPS数据打印出来，每次调用这个测试函数应该会提示不一样的数据，测试打印结果如下所示：

---

open fill is 0
write fill is 0
lseek fill is 0
16 8 8 11211 0 12
read fill is 0
free sectors is 99.0
Finish.

---

0代表运行成功，创建text.txt，将GPS的数据写入文件，并读取从串口打印出来。至此fatfs的移植测试成功完成。