前言
嵌入式系统中我们常常对flash、SD卡、U盘等进行操作，但我们操作一般是直接操作物理地址，使用起来相对来说比较繁琐，也不能将我们自己写的数据导出到我们的电脑中，这时大名鼎鼎的文件系统fatfs就可以派上用场，fatfs是一小型的可裁剪免费文件系统，移植起来比较方便，移植完文件系统大大缩短开发周期，可以很方便的操作内存，废话不再多说，下面开始介绍移植文件系统步骤：
参考：
https://blog.csdn.net/qq_21475601/article/details/78032854
https://blog.csdn.net/Jun626/article/details/72954494
一、工具
文件系统源码fatfs10b，链接 https://download.csdn.net/download/qq_35257512/12803176是楼主已经移植好的文件系统，运行平台MSP430F5438 IAR工程
二、使用步骤
2.1.解压源码
doc 文档主要是一些参考文档，使用说明、例程等
src文件夹主要是我们的文件系统源码 进入该目录
diskio.c个diskio.h是和存储器读写控制相关的驱动接口，比如SPI_FLASH的读写函数接口，都要映射到这里面。必须的文件
ff.h和ff.h是FATFS的核心文件，必须的文件
ffconf.h是FATFS的配置文件，用来裁剪FATFS，必须的文件
integer.h是FATFS所用到的数据类型定义，用以兼容不同字长CPU，必须的文件
option 目录又是什么呢，下面进入该目录看下
cc936.c /* CP936 (Simplified Chinese GBK)
syscall.c unicode.c 文件名支持长文件名是里面ff_malloc 等ha 函数会用到，需要添加到工程中，具体使用到什么可以不用管他 。
2.1.将源码添加到我们的工程中
2.1.1 修改ffconf.h文件
来裁剪我们的FATFS，通过宏开关来去掉不用的功能，来精简文件系统。想知道每个宏的功能,参考https://blog.csdn.net/xiayufeng520/article/details/8830157
/*---------------------------------------------------------------------------/
/ FatFs - FAT file system module configuration file R0.10b (C)ChaN, 2014
/---------------------------------------------------------------------------*/
#ifndef _FFCONF
#define _FFCONF 29000 /* Revision ID */
/*---------------------------------------------------------------------------/
/ Functions and Buffer Configurations
/---------------------------------------------------------------------------*/
#define _FS_TINY 1 /* 0:Normal or 1:Tiny */ /*文件系统 0 1 微文件系统*/
/* When _FS_TINY is set to 1, it reduces memory consumption _MAX_SS bytes each
/ file object. For file data transfer, FatFs uses the common sector buffer in
/ the file system object (FATFS) instead of private sector buffer eliminated
/ from the file object (FIL). */
#define _FS_READONLY 0 /* 0:Read/Write or 1:Read only */ //0 文件可读可写 1 只读 裁剪
/* Setting _FS_READONLY to 1 defines read only configuration. This removes
/ writing functions, f_write(), f_sync(), f_unlink(), f_mkdir(), f_chmod(),
/ f_rename(), f_truncate() and useless f_getfree(). */
#define _FS_MINIMIZE 0 /* 0 to 3 */ //3个程度进行裁剪 3 裁剪函数最多 0 最少
/* The _FS_MINIMIZE option defines minimization level to remove API functions.
/
/ 0: All basic functions are enabled.
/ 1: f_stat(), f_getfree(), f_unlink(), f_mkdir(), f_chmod(), f_utime(),
/ f_truncate() and f_rename() function 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 1 /* 0:Disable or 1-2:Enable */
/* To enable string functions, set _USE_STRFUNC to 1 or 2. */
#define _USE_MKFS 1 /* 0:Disable or 1:Enable */
/* To enable f_mkfs() function, set _USE_MKFS to 1 and set _FS_READONLY to 0 */
#define _USE_FASTSEEK 1 /* 0:Disable or 1:Enable */ //快速索引 0 取消 1支持
/* To enable fast seek feature, set _USE_FASTSEEK to 1. */
#define _USE_LABEL 1 /* 0:Disable or 1:Enable */ //0 不支持盘符修改 1 支持盘符修改
/* To enable volume label functions, set _USE_LAVEL to 1 */
#define _USE_FORWARD 0 /* 0:Disable or 1:Enable */ //f_forward函数的使能
/* To enable f_forward() function, set _USE_FORWARD to 1 and set _FS_TINY to 1. */
/*---------------------------------------------------------------------------/
/ Locale and Namespace Configurations
/---------------------------------------------------------------------------*/
#define _CODE_PAGE 932 //中文应该选择936
/* The _CODE_PAGE specifies the OEM code page to be used on the target system.
/ Incorrect setting of the code page can cause a file open failure.
/
/ 932 - Japanese Shift_JIS (DBCS, OEM, Windows)
/ 936 - Simplified Chinese GBK (DBCS, OEM, Windows)
/ 949 - Korean (DBCS, OEM, Windows)
/ 950 - Traditional Chinese Big5 (DBCS, OEM, Windows)
/ 1250 - Central Europe (Windows)
/ 1251 - Cyrillic (Windows)
/ 1252 - Latin 1 (Windows)
/ 1253 - Greek (Windows)
/ 1254 - Turkish (Windows)
/ 1255 - Hebrew (Windows)
/ 1256 - Arabic (Windows)
/ 1257 - Baltic (Windows)
/ 1258 - Vietnam (OEM, Windows)
/ 437 - U.S. (OEM)
/ 720 - Arabic (OEM)
/ 737 - Greek (OEM)
/ 775 - Baltic (OEM)
/ 850 - Multilingual Latin 1 (OEM)
/ 858 - Multilingual Latin 1 + Euro (OEM)
/ 852 - Latin 2 (OEM)
/ 855 - Cyrillic (OEM)
/ 866 - Russian (OEM)
/ 857 - Turkish (OEM)
/ 862 - Hebrew (OEM)
/ 874 - Thai (OEM, Windows)
/ 1 - ASCII (Valid for only non-LFN configuration) */
#define _USE_LFN 3 /* 0 to 3 */ //0 不支持长文件名
#define _MAX_LFN 32 /* Maximum LFN length to handle (12 to 255) */ //文件名长度 12 到255
/* The _USE_LFN option switches the LFN feature.
/
/ 0: Disable LFN feature. _MAX_LFN has no effect. //1 2 3 长文件名 分配位置不同
/ 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.
/
/ When enable LFN feature, Unicode handling functions ff_convert() and ff_wtoupper()
/ function must be added to the project.
/ The LFN working buffer occupies (_MAX_LFN + 1) * 2 bytes. 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 /* 0:ANSI/OEM or 1:Unicode */
// FatFs API要切换字符编码形式为Union时，将LEN和LFN_UNICODE为1
/* To switch the character encoding on the FatFs API (TCHAR) to Unicode, enable LFN
/ feature and set _LFN_UNICODE to 1. This option affects behavior of string I/O
/ functions. This option must be 0 when LFN feature is not enabled. */
#define _STRF_ENCODE 0 /* 0:ANSI/OEM, 1:UTF-16LE, 2:UTF-16BE, 3:UTF-8 */
/* When Unicode API is enabled by _LFN_UNICODE option, 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(). This option has no effect when _LFN_UNICODE == 0. Note that
/ FatFs supports only BMP. */
#define _FS_RPATH 0 /* 0 to 2 */
/* The _FS_RPATH option configures relative path feature.
/
/ 0: Disable relative path feature and remove related functions.
/ 1: Enable relative path. f_chdrive() and f_chdir() function are available.
/ 2: f_getcwd() function is available in addition to 1.
/
/ Note that output of the f_readdir() fnction is affected by this option. */
/*---------------------------------------------------------------------------/
/ Drive/Volume Configurations
/---------------------------------------------------------------------------*/
#define _VOLUMES 1 //逻辑桊使用数目
/* Number of volumes (logical drives) to be used. */
#define _STR_VOLUME_ID 0 /* 0:Use only 0-9 for drive ID, 1:Use strings for drive ID */
#define _VOLUME_STRS "RAM","NAND","CF","SD1","SD2","USB1","USB2","USB3"
/* 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: 0-9 and A-Z. */
#define _MULTI_PARTITION 0 /* 0:Single partition, 1:Enable multiple partition */ //0 单分区 1 多分区
/* By default(0), each logical drive number is bound to the same physical drive number
/ and only a FAT volume found on the physical drive is mounted. When it is set to 1,
/ each logical drive number is bound to arbitrary drive/partition listed in VolToPart[].
*/
#define _MIN_SS 4096 // 一个扇区大小4096个字节
#define _MAX_SS 4096
/* These options configure the range of sector size to be supported. (512, 1024, 2048 or
/ 4096) Always set both 512 for most systems, all memory card 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_ERASE 1 /* 0:Disable or 1:Enable */ //是否使能擦除
/* To enable sector erase feature, set _USE_ERASE to 1. Also CTRL_ERASE_SECTOR command
/ should be added to the disk_ioctl() function. */
#define _FS_NOFSINFO 0 /* 0 to 3 */
/* 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 last allocated cluster number as bit 0.
/
/ 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_LOCK 0 /* 0:Disable or >=1:Enable */
//使能文件锁功能，设置FS_LOCK为1或者更大
//定义的大小决定了多少文件能同时打开
/* To enable file lock control feature, set _FS_LOCK to non-zero value.
/ The value defines how many files/sub-directories can be opened simultaneously
/ with file lock control. This feature uses bss _FS_LOCK * 12 bytes. */
#define _FS_REENTRANT 0 /* 0:Disable or 1:Enable */
#define _FS_TIMEOUT 1000 /* Timeout period in unit of time tick */
#define _SYNC_t HANDLE /* O/S dependent sync object type. e.g. HANDLE, OS_EVENT*, ID, SemaphoreHandle_t and etc.. */
/* The _FS_REENTRANT option switches the re-entrancy (thread safe) of the FatFs module.
/
/ 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.
*/
#define _WORD_ACCESS 0 /* 0 or 1 */
/* The _WORD_ACCESS option is an only platform dependent option. It defines
/ which access method is used to the word data on the FAT volume.
/
/ 0: Byte-by-byte access. Always compatible with all platforms.
/ 1: Word access. Do not choose this unless under both the following conditions.
/
/ * Address misaligned memory access is always allowed for ALL instructions.
/ * Byte order on the memory is little-endian.
/
/ If it is the case, _WORD_ACCESS can also be set to 1 to improve performance and
/ reduce code size. Following table shows an example of some processor types.
/
/ ARM7TDMI 0 ColdFire 0 V850E 0
/ Cortex-M3 0 Z80 0/1 V850ES 0/1
/ Cortex-M0 0 RX600(LE) 0/1 TLCS-870 0/1
/ AVR 0/1 RX600(BE) 0 TLCS-900 0/1
/ AVR32 0 RL78 0 R32C 0
/ PIC18 0/1 SH-2 0 M16C 0/1
/ PIC24 0 H8S 0 MSP430 0
/ PIC32 0 H8/300H 0 x86 0/1
*/
#endif /* _FFCONF */
2.1.2 修改diskio.c 来映射我们的存储器读写控制接口
/*-----------------------------------------------------------------------*/
/* Low level disk I/O module skeleton for FatFs (C)ChaN, 2014 */
/*-----------------------------------------------------------------------*/
/* 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 "W25q.h"
#define EX_FLASH 0
#define FLASH_SECTOR_SIZE 4096
#define FLASH_BLOCK_SIZE 1
#define FLASH_SECTOR_COUNT 1024
/*-----------------------------------------------------------------------*/
/* Get Drive Status */
/*-----------------------------------------------------------------------*/
DSTATUS disk_status (
BYTE pdrv /* Physical drive nmuber to identify the drive */
)
{
return RES_OK; //直接返回OK即可
}
/*-----------------------------------------------------------------------*/
/* Inidialize a Drive */
/*-----------------------------------------------------------------------*/
DSTATUS disk_initialize (
BYTE pdrv /* Physical drive nmuber to identify the drive */
)
{
DSTATUS stat =0;
switch (pdrv) {
case EX_FLASH:
W25QXX_Init(); //初始化操作
return stat;
}
return STA_NOINIT;
}
/*-----------------------------------------------------------------------*/
/* Read Sector(s) */
/*-----------------------------------------------------------------------*/
DRESULT disk_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 */
)
{
switch (pdrv) {
case EX_FLASH :
for(;count>0;count--)
{
W25QXX_Read(buff,sector*FLASH_SECTOR_SIZE,FLASH_SECTOR_SIZE);
sector++;
buff+=FLASH_SECTOR_SIZE;
}
return RES_OK;
}
return RES_PARERR;
}
/*-----------------------------------------------------------------------*/
/* Write Sector(s) */
/*-----------------------------------------------------------------------*/
#if _USE_WRITE
DRESULT disk_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 */
)
{
switch (pdrv) {
case EX_FLASH :
for(;count>0;count--)
{
W25QXX_Write((uint8_t*)buff,sector*FLASH_SECTOR_SIZE,FLASH_SECTOR_SIZE);
sector++;
buff+=FLASH_SECTOR_SIZE;
}
return RES_OK;
}
return RES_PARERR;
}
#endif
/*-----------------------------------------------------------------------*/
/* Miscellaneous Functions */
/*-----------------------------------------------------------------------*/
#if _USE_IOCTL
DRESULT disk_ioctl (
BYTE pdrv, /* Physical drive nmuber (0..) */
BYTE cmd, /* Control code */
void *buff /* Buffer to send/receive control data */
)
{
DRESULT res;
switch (pdrv) {
case EX_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_COUNT;
res = RES_OK;
break;
default:
res = RES_PARERR;
break;
}
}
return res;
}
#endif
/*
*获取时间
*/
DWORD get_fattime (void)
{
return 0;
} 3 测试文件系统
测试实利：
#if 1
FATFS fs; /* Filesystem object */
FIL fil; /* File object */
FRESULT res; /* API result code */
UINT bw; /* Bytes written */
BYTE mm[50];
UINT i;
uint16_t f_size;
#endif
#if 0
uint8_t w25qWrite[512] ={0x55};
uint8_t w25qRead[512] ={0};
#endif
#if 1
void fs_test(void)
{
/* 挂载文件系统 */
res = f_mount(&fs, "0:", 0);
if (res)
{
}
else
{
}
#if 1
/* 格式化文件系统 */
res = f_mkfs("0:", 0 ,4096);//"0:"是卷标，来自于 #define SPI_FLASH 0
if (res)
{
return ;
}
else
{
}
#endif
res = f_mount(&fs, "0:", 0);
if (res)
{
}
else
{
}
/* Create a file as new */
res = f_open(&fil, "0:/test.txt", FA_CREATE_NEW|FA_WRITE|FA_READ);
if (res)
{
}
else
{
}
/* Write a message */
res = f_write(&fil, "Hello,World!", 12, &bw);
if (bw == 12)
{
}
else
{
}
//res = f_size(&fil);
memset(mm,0x0,50);
f_lseek(&fil,0);
f_size = f_read(&fil,mm,12,&i);
if (res == FR_OK)
{
}
else
{
}
/* Close the file */
f_close(&fil);
/*卸载文件系统*/
f_mount(0, "0:", 0);
}
#endif
int main(void)
{
W25QXX_Init();
//系统主频初始化
W25Q_Enable();
#if 0
memset(w25qWrite,0x55,512);
W25QXX_Write(w25qWrite,0x00,512);
W25QXX_Read(w25qRead,0x00,512);
#endif
fs_test();
while(1);
} 总结
在移植的过程中也是遇到了很多问题，前期准备非常重要，准备工作全了，其他的也就很容易解决，flash W25Q一个扇区是4K 对RAM要求至少是4K 空间大小缓存，如果对SD卡扇区512 字节，RAM 要求512字节做为缓存大小
移植之前，一定先要对flash 进行读写操作下，向flash 中写入4K字节，并读取出来做下对比
MSP430 读数据前要先写一个时钟，然后再读寄存器，这一点与STM32 存在点区别
如：
W25QXX_WriteByte(0xFF);
Temp = USCI_B_SPI_receiveData(USCI_B3_BASE);
写数据时，调用完一个写函数，做一个时钟的延时，否则容易写入失败
USCI_B_SPI_transmitData(USCI_B3_BASE, byte);
__delay_cycles(1); //延时1个时钟，否则写入失败