STM32Cube MX USB虚拟U盘+FATFS+W25Q128

第一次写CSDN，把这两天做的一个小实验记个笔记。写的不好请见谅，有错误欢迎指正，欢迎讨论。在做之前也参考其他博主的一些文章Carry_王的博客
USB基本概念不做介绍，不懂的可以先去了解，主要说明实现过程。

一、硬件

STM32F407 开发板，包括外部FLASH w25q128 （16MB）
通过USB数据线连接板子USB SLAVE接口与PC端

二、实现内容

片外FLASH虚拟U盘，利用文件系统对FLASH芯片进行读写操作，同时PC端也可对U盘内文件进行操作。后面测试结果会有详细说明。下面直接上具体操作。

三、CubeMX配置

STM32CubeMX版本6.3.0

1.选择芯片

STM32F407ZGTX

2.RCC和SYS

3.时钟树配置
4.SPI

5.USB_OTG_FS(默认即可）
模式选择 Device_Only

6.FATFS
修改过的地方已经标出，按照图配置即可

7.USB_DEVICE

8.生成代码

四、代码修改

CubeMX创建基础工程生成代码，直接打开。
1.首先添加Flash芯片的驱动文件，直接把我的贴出来，注释比较详细
w25qxx.c

#include "w25qxx.h"
#include "spi.h"
#include "stm32f4xx_hal_gpio.h"
#include "stm32f4xx_hal_def.h"uint16_t W25QXX_TYPE=W25Q128;  //默认是W25Q128
uint8_t SPI1_ReadWriteByte(uint8_t TxData);
//4Kbytes为一个Sector
//16个扇区为1个Block
//W25Q128
//容量为16M字节,共有512个Block,4096个Sector //初始化SPI FLASH的IO口
HAL_StatusTypeDef W25QXX_Init(void)
{ HAL_StatusTypeDef r = HAL_ERROR;uint8_t temp;  W25QXX_CS_H();                              //SPI FLASH不选中
//  MX_SPI1_Init();                             //初始化SPI
//  SPI1_SetSpeed(SPI_BAUDRATEPRESCALER_4); //设置为21M时钟,高速模式W25QXX_TYPE=W25QXX_ReadID();            //读取FLASH ID.if(W25QXX_TYPE==W25Q128)                //SPI FLASH为W25Q256{temp=W25QXX_ReadSR(3);              //读取状态寄存器3，判断地址模式if((temp&0X01)==0)                      //如果不是4字节地址模式,则进入4字节地址模式{W25QXX_CS_L();                           //选中SPI1_ReadWriteByte(W25X_Enable4ByteAddr);//发送进入4字节地址模式指令   W25QXX_CS_H();                       //取消片选   }r = HAL_OK;;}return r;
}  //读取W25QXX的状态寄存器，W25QXX一共有3个状态寄存器
//状态寄存器1：
//BIT7  6   5   4   3   2   1   0
//SPR   RV  TB BP2 BP1 BP0 WEL BUSY
//SPR:默认0,状态寄存器保护位,配合WP使用
//TB,BP2,BP1,BP0:FLASH区域写保护设置
//WEL:写使能锁定
//BUSY:忙标记位(1,忙;0,空闲)
//默认:0x00
//状态寄存器2：
//BIT7  6   5   4   3   2   1   0
//SUS   CMP LB3 LB2 LB1 (R) QE  SRP1
//状态寄存器3：
//BIT7      6    5    4   3   2   1   0
//HOLD/RST  DRV1 DRV0 (R) (R) WPS ADP ADS
//regno:状态寄存器号，范:1~3
//返回值:状态寄存器值
uint8_t W25QXX_ReadSR(uint8_t regno)
{  uint8_t byte=0,command=0; switch(regno){case 1:command=W25X_ReadStatusReg1;    //读状态寄存器1指令break;case 2:command=W25X_ReadStatusReg2;    //读状态寄存器2指令break;case 3:command=W25X_ReadStatusReg3;    //读状态寄存器3指令break;default:command=W25X_ReadStatusReg1;    break;}    W25QXX_CS_L();                            //使能器件   SPI1_ReadWriteByte(command);            //发送读取状态寄存器命令    byte=SPI1_ReadWriteByte(0Xff);          //读取一个字节  W25QXX_CS_H();                            //取消片选     return byte;
}
//写W25QXX状态寄存器
void W25QXX_Write_SR(uint8_t regno,uint8_t sr)
{   uint8_t command=0;switch(regno){case 1:command=W25X_WriteStatusReg1;    //写状态寄存器1指令break;case 2:command=W25X_WriteStatusReg2;    //写状态寄存器2指令break;case 3:command=W25X_WriteStatusReg3;    //写状态寄存器3指令break;default:command=W25X_WriteStatusReg1;    break;}   W25QXX_CS_L();                            //使能器件   SPI1_ReadWriteByte(command);            //发送写取状态寄存器命令    SPI1_ReadWriteByte(sr);                 //写入一个字节  W25QXX_CS_H();                            //取消片选
}
//W25QXX写使能
//将WEL置位
void W25QXX_Write_Enable(void)
{W25QXX_CS_L();                            //使能器件   SPI1_ReadWriteByte(W25X_WriteEnable);   //发送写使能  W25QXX_CS_H();                            //取消片选
}
//W25QXX写禁止
//将WEL清零
void W25QXX_Write_Disable(void)
{  W25QXX_CS_L();                            //使能器件   SPI1_ReadWriteByte(W25X_WriteDisable);  //发送写禁止指令    W25QXX_CS_H();                            //取消片选
} //读取芯片ID
//返回值如下:
//0XEF13,表示芯片型号为W25Q80
//0XEF14,表示芯片型号为W25Q16
//0XEF15,表示芯片型号为W25Q32
//0XEF16,表示芯片型号为W25Q64
//0XEF17,表示芯片型号为W25Q128
//0XEF18,表示芯片型号为W25Q256
uint16_t W25QXX_ReadID(void)
{uint16_t Temp = 0;      W25QXX_CS_L();                    SPI1_ReadWriteByte(0x90);//发送读取ID命令     SPI1_ReadWriteByte(0x00);       SPI1_ReadWriteByte(0x00);       SPI1_ReadWriteByte(0x00);                  Temp|=SPI1_ReadWriteByte(0xFF)<<8;  Temp|=SPI1_ReadWriteByte(0xFF);   W25QXX_CS_H();                 return Temp;
}
//读取SPI FLASH
//在指定地址开始读取指定长度的数据
//pBuffer:数据存储区
//ReadAddr:开始读取的地址(24bit)
//NumByteToRead:要读取的字节数(最大65535)
void W25QXX_Read(uint8_t* pBuffer,uint32_t ReadAddr,uint16_t NumByteToRead)
{ uint16_t i;                                               W25QXX_CS_L();                            //使能器件   SPI1_ReadWriteByte(W25X_ReadData);      //发送读取命令  if(W25QXX_TYPE==W25Q256)                //如果是W25Q256的话地址为4字节的，要发送最高8位{SPI1_ReadWriteByte((uint8_t)((ReadAddr)>>24));    }SPI1_ReadWriteByte((uint8_t)((ReadAddr)>>16));   //发送24bit地址    SPI1_ReadWriteByte((uint8_t)((ReadAddr)>>8));   SPI1_ReadWriteByte((uint8_t)ReadAddr);   for(i=0;i<NumByteToRead;i++){ pBuffer[i]=SPI1_ReadWriteByte(0XFF);    //循环读数  }W25QXX_CS_H();
}
//SPI在一页(0~65535)内写入少于256个字节的数据
//在指定地址开始写入最大256字节的数据
//pBuffer:数据存储区
//WriteAddr:开始写入的地址(24bit)
//NumByteToWrite:要写入的字节数(最大256),该数不应该超过该页的剩余字节数!!!
void W25QXX_Write_Page(uint8_t* pBuffer,uint32_t WriteAddr,uint16_t NumByteToWrite)
{uint16_t i;  W25QXX_Write_Enable();                  //SET WEL W25QXX_CS_L();                            //使能器件   SPI1_ReadWriteByte(W25X_PageProgram);   //发送写页命令   if(W25QXX_TYPE==W25Q256)                //如果是W25Q256的话地址为4字节的，要发送最高8位{SPI1_ReadWriteByte((uint8_t)((WriteAddr)>>24)); }SPI1_ReadWriteByte((uint8_t)((WriteAddr)>>16)); //发送24bit地址    SPI1_ReadWriteByte((uint8_t)((WriteAddr)>>8));   SPI1_ReadWriteByte((uint8_t)WriteAddr);   for(i=0;i<NumByteToWrite;i++)SPI1_ReadWriteByte(pBuffer[i]);//循环写数  W25QXX_CS_H();                            //取消片选 W25QXX_Wait_Busy();                       //等待写入结束
}
//无检验写SPI FLASH
//必须确保所写的地址范围内的数据全部为0XFF,否则在非0XFF处写入的数据将失败!
//具有自动换页功能
//在指定地址开始写入指定长度的数据,但是要确保地址不越界!
//pBuffer:数据存储区
//WriteAddr:开始写入的地址(24bit)
//NumByteToWrite:要写入的字节数(最大65535)
//CHECK OK
void W25QXX_Write_NoCheck(uint8_t* pBuffer,uint32_t WriteAddr,uint16_t NumByteToWrite)
{                    uint16_t pageremain;      pageremain=256-WriteAddr%256; //单页剩余的字节数                if(NumByteToWrite<=pageremain)pageremain=NumByteToWrite;//不大于256个字节while(1){      W25QXX_Write_Page(pBuffer,WriteAddr,pageremain);if(NumByteToWrite==pageremain)break;//写入结束了else //NumByteToWrite>pageremain{pBuffer+=pageremain;WriteAddr+=pageremain;  NumByteToWrite-=pageremain;              //减去已经写入了的字节数if(NumByteToWrite>256)pageremain=256; //一次可以写入256个字节else pageremain=NumByteToWrite;       //不够256个字节了}};
}
//写SPI FLASH
//在指定地址开始写入指定长度的数据
//该函数带擦除操作!
//pBuffer:数据存储区
//WriteAddr:开始写入的地址(24bit)
//NumByteToWrite:要写入的字节数(最大65535)
uint8_t W25QXX_BUFFER[4096];
void W25QXX_Write(uint8_t* pBuffer,uint32_t WriteAddr,uint16_t NumByteToWrite)
{ uint32_t secpos;uint16_t secoff;uint16_t secremain;      uint16_t i;    uint8_t * W25QXX_BUF;   W25QXX_BUF=W25QXX_BUFFER;         secpos=WriteAddr/4096;//扇区地址  secoff=WriteAddr%4096;//在扇区内的偏移secremain=4096-secoff;//扇区剩余空间大小
//  printf("ad:%X,nb:%X\r\n",WriteAddr,NumByteToWrite);//测试用if(NumByteToWrite<=secremain)secremain=NumByteToWrite;//不大于4096个字节while(1) { W25QXX_Read(W25QXX_BUF,secpos*4096,4096);//读出整个扇区的内容for(i=0;i<secremain;i++)//校验数据{if(W25QXX_BUF[secoff+i]!=0XFF)break;//需要擦除     }if(i<secremain)//需要擦除{W25QXX_Erase_Sector(secpos);//擦除这个扇区for(i=0;i<secremain;i++)     //复制{W25QXX_BUF[i+secoff]=pBuffer[i];    }W25QXX_Write_NoCheck(W25QXX_BUF,secpos*4096,4096);//写入整个扇区  }else W25QXX_Write_NoCheck(pBuffer,WriteAddr,secremain);//写已经擦除了的,直接写入扇区剩余区间.                   if(NumByteToWrite==secremain)break;//写入结束了else//写入未结束{secpos++;//扇区地址增1secoff=0;//偏移位置为0     pBuffer+=secremain;  //指针偏移WriteAddr+=secremain;//写地址偏移       NumByteToWrite-=secremain;              //字节数递减if(NumByteToWrite>4096)secremain=4096;   //下一个扇区还是写不完else secremain=NumByteToWrite;         //下一个扇区可以写完了}    };
}
//擦除整个芯片
//等待时间超长...
void W25QXX_Erase_Chip(void)
{                                   W25QXX_Write_Enable();                  //SET WEL W25QXX_Wait_Busy();   W25QXX_CS_L();                            //使能器件   SPI1_ReadWriteByte(W25X_ChipErase);        //发送片擦除命令  W25QXX_CS_H();                            //取消片选             W25QXX_Wait_Busy();                      //等待芯片擦除结束
}
//擦除一个扇区
//Dst_Addr:扇区地址 根据实际容量设置
//擦除一个扇区的最少时间:150ms
void W25QXX_Erase_Sector(uint32_t Dst_Addr)
{  //监视falsh擦除情况,测试用   //printf("fe:%x\r\n",Dst_Addr);      Dst_Addr*=4096;W25QXX_Write_Enable();                  //SET WEL      W25QXX_Wait_Busy();   W25QXX_CS_L();                            //使能器件   SPI1_ReadWriteByte(W25X_SectorErase);   //发送扇区擦除指令 if(W25QXX_TYPE==W25Q256)                //如果是W25Q256的话地址为4字节的，要发送最高8位{SPI1_ReadWriteByte((uint8_t)((Dst_Addr)>>24)); }SPI1_ReadWriteByte((uint8_t)((Dst_Addr)>>16));  //发送24bit地址    SPI1_ReadWriteByte((uint8_t)((Dst_Addr)>>8));   SPI1_ReadWriteByte((uint8_t)Dst_Addr);  W25QXX_CS_H();                            //取消片选             W25QXX_Wait_Busy();                       //等待擦除完成
}
//等待空闲
void W25QXX_Wait_Busy(void)
{   while((W25QXX_ReadSR(1)&0x01)==0x01);   // 等待BUSY位清空
}
//进入掉电模式
void W25QXX_PowerDown(void)
{ W25QXX_CS_L();                            //使能器件   SPI1_ReadWriteByte(W25X_PowerDown);     //发送掉电命令  W25QXX_CS_H();                            //取消片选               HAL_Delay(3);                            //等待TPD
}
//唤醒
void W25QXX_WAKEUP(void)
{  W25QXX_CS_L();                                //使能器件   SPI1_ReadWriteByte(W25X_ReleasePowerDown);  //  send W25X_PowerDown command 0xAB    W25QXX_CS_H();                                //取消片选            HAL_Delay(3);                                //等待TRES1
} //SPI1 读写一个字节
//TxData:要写入的字节
//返回值:读取到的字节
uint8_t SPI1_ReadWriteByte(uint8_t TxData)
{uint8_t Rxdata;HAL_SPI_TransmitReceive(&hspi1,&TxData,&Rxdata,1, 1000);       return Rxdata;                   //返回收到的数据
}

w25qxx.h

#ifndef __W25QXX_H
#define __W25QXX_H
#include"stdint.h"
#include "stm32f4xx_hal.h"
//W25X系列/Q系列芯片列表
//W25Q80  ID  0XEF13
//W25Q16  ID  0XEF14
//W25Q32  ID  0XEF15
//W25Q64  ID  0XEF16
//W25Q128 ID  0XEF17
//W25Q256 ID  0XEF18
#define W25Q80  0XEF13
#define W25Q16  0XEF14
#define W25Q32  0XEF15
#define W25Q64  0XEF16
#define W25Q128 0XEF17
#define W25Q256 0XEF18#define NM25Q80   0X5213
#define NM25Q16     0X5214
#define NM25Q32     0X5215
#define NM25Q64     0X5216
#define NM25Q128    0X5217
#define NM25Q256    0X5218extern uint16_t W25QXX_TYPE;                  //定义W25QXX芯片型号         #define W25QXX_CS_L()  HAL_GPIO_WritePin(SPIFLASH_CS_GPIO_Port, SPIFLASH_CS_Pin, GPIO_PIN_RESET)
#define W25QXX_CS_H()  HAL_GPIO_WritePin(SPIFLASH_CS_GPIO_Port, SPIFLASH_CS_Pin, GPIO_PIN_SET)//
//指令表
#define W25X_WriteEnable            0x06
#define W25X_WriteDisable           0x04
#define W25X_ReadStatusReg1     0x05
#define W25X_ReadStatusReg2     0x35
#define W25X_ReadStatusReg3       0x15
#define W25X_WriteStatusReg1    0x01
#define W25X_WriteStatusReg2    0x31
#define W25X_WriteStatusReg3    0x11
#define W25X_ReadData               0x03
#define W25X_FastReadData           0x0B
#define W25X_FastReadDual           0x3B
#define W25X_PageProgram            0x02
#define W25X_BlockErase             0xD8
#define W25X_SectorErase            0x20
#define W25X_ChipErase              0xC7
#define W25X_PowerDown              0xB9
#define W25X_ReleasePowerDown     0xAB
#define W25X_DeviceID                 0xAB
#define W25X_ManufactDeviceID     0x90
#define W25X_JedecDeviceID        0x9F
#define W25X_Enable4ByteAddr    0xB7
#define W25X_Exit4ByteAddr      0xE9HAL_StatusTypeDef W25QXX_Init(void);
uint16_t  W25QXX_ReadID(void);                  //读取FLASH ID
uint8_t W25QXX_ReadSR(uint8_t regno);             //读取状态寄存器
void W25QXX_4ByteAddr_Enable(void);     //使能4字节地址模式
void W25QXX_Write_SR(uint8_t regno,uint8_t sr);   //写状态寄存器
void W25QXX_Write_Enable(void);         //写使能
void W25QXX_Write_Disable(void);        //写保护
void W25QXX_Write_NoCheck(uint8_t* pBuffer,uint32_t WriteAddr,uint16_t NumByteToWrite);
void W25QXX_Read(uint8_t* pBuffer,uint32_t ReadAddr,uint16_t NumByteToRead);    //读取flash
void W25QXX_Write(uint8_t* pBuffer,uint32_t WriteAddr,uint16_t NumByteToWrite); //写入flash
void W25QXX_Erase_Chip(void);           //整片擦除
void W25QXX_Erase_Sector(uint32_t Dst_Addr);    //扇区擦除
void W25QXX_Wait_Busy(void);            //等待空闲
void W25QXX_PowerDown(void);            //进入掉电模式
void W25QXX_WAKEUP(void);               //唤醒void FatfsTest(void);  //FLASH 虚拟U盘测试函数，进行初始化及文件读写操作，在user.diskio.c中定义#endif

其中重要的为读SPI FLASH函数和写SPI FLASH函数

2.修改user_diskio.c

/* USER CODE BEGIN Header */
/********************************************************************************* @file    user_diskio.c* @brief   This file includes a diskio driver skeleton to be completed by the user.******************************************************************************* @attention** <h2><center>&copy; Copyright (c) 2021 STMicroelectronics.* All rights reserved.</center></h2>** This software component is licensed by ST under Ultimate Liberty license* SLA0044, the "License"; You may not use this file except in compliance with* the License. You may obtain a copy of the License at:*                             www.st.com/SLA0044********************************************************************************//* USER CODE END Header */#ifdef USE_OBSOLETE_USER_CODE_SECTION_0
/** Warning: the user section 0 is no more in use (starting from CubeMx version 4.16.0)* To be suppressed in the future.* Kept to ensure backward compatibility with previous CubeMx versions when* migrating projects.* User code previously added there should be copied in the new user sections before* the section contents can be deleted.*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
#endif/* USER CODE BEGIN DECL *//* Includes ------------------------------------------------------------------*/
#include <string.h>
#include "ff_gen_drv.h"#include "spi.h"
#include "w25qxx.h"
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*//* Private variables ---------------------------------------------------------*/
/* Disk status */
static volatile DSTATUS Stat = STA_NOINIT;#define PAGE_SIZE       256
#define SECTOR_SIZE     4096
#define SECTOR_COUNT      200
#define BLOCK_SIZE      65536
#define FLASH_PAGES_PER_SECTOR  SECTOR_SIZE/PAGE_SIZEFATFS fs;
FIL file;                                      /* 文件对象 */
FIL *pf = &file;                   //将FIL结构体对象设置为全局变量！
FRESULT f_res;                     /* 文件操作结果 */
UINT fnum;                                 /*  文件成功读写数量*/
BYTE ReadBuffer[1024]={0};         /* 读缓存区 */
BYTE WriteBuffer[]= "PZKKKKK666\n";   /* 文件写入内容 */
BYTE work[4096];char USER_Path[4];
void mount_disk(void)
{f_res = f_mount(&fs, USER_Path, 0);return;}void format_disk(void)
{f_res = f_mkfs(USER_Path, FM_FAT, 4096, work, sizeof(work));
}UINT bw;
void create_file(void)
{f_res = f_open(pf, "test.txt", FA_OPEN_ALWAYS | FA_WRITE);f_res = f_write(&file, WriteBuffer, sizeof(WriteBuffer), &bw);f_res = f_close(pf);
}void read_file(void)
{f_res = f_open(&file, "123.txt", FA_READ);f_res = f_read(&file, ReadBuffer, sizeof(WriteBuffer), &bw);f_res = f_close(&file);
}FRESULT  fileSystemInit()
{FRESULT res = FR_OK;res = f_mount(&fs, USER_Path, 1);if (res != FR_OK){//No Disk file system,format disk !res = f_mkfs(USER_Path, FM_FAT, 4096, work, sizeof work);if (res == FR_OK){res = f_mount(&fs, USER_Path, 1);if (res == 0){return FR_OK;}elsereturn FR_DISK_ERR;}elsereturn FR_DISK_ERR;}elsereturn FR_OK;
}
//第一次运行文件系统，需要先注册文件系统和格式化
void FatfsTest(void)
{//  mount_disk();           //文件系统注册，
//  format_disk();          //格式化文件系统fileSystemInit();create_file();            //创建TXT文件并写"PZKKKKK666\n"  read_file();             //读取文件内容并放到ReadBuffer中
}/* USER CODE END DECL *//* Private function prototypes -----------------------------------------------*/
DSTATUS SpiDisk_initialize (BYTE pdrv);
DSTATUS SpiDisk_status (BYTE pdrv);
DRESULT SpiDisk_read (BYTE pdrv, BYTE *buff, DWORD sector, UINT count);
//#if _USE_WRITE == 1DRESULT SpiDisk_write (BYTE pdrv, const BYTE *buff, DWORD sector, UINT count);
//#endif /* _USE_WRITE == 1 */
//#if _USE_IOCTL == 1DRESULT SpiDisk_ioctl (BYTE pdrv, BYTE cmd, void *buff);
//#endif /* _USE_IOCTL == 1 */Diskio_drvTypeDef  SPI_Driver =
{SpiDisk_initialize,SpiDisk_status,SpiDisk_read,
#if  _USE_WRITE == 1SpiDisk_write,
#endif  /* _USE_WRITE == 1 */
#if  _USE_IOCTL == 1SpiDisk_ioctl,
#endif /* _USE_IOCTL == 1 */
};/* Private functions ---------------------------------------------------------*//*** @brief  Initializes a Drive* @param  pdrv: Physical drive number (0..)* @retval DSTATUS: Operation status*/
DSTATUS SpiDisk_initialize (BYTE pdrv           /* Physical drive nmuber to identify the drive */
)
{/* USER CODE BEGIN INIT */Stat = STA_NOINIT;if(W25QXX_ReadID() != 0){Stat &= ~STA_NOINIT;}  return Stat;/* USER CODE END INIT */
}/*** @brief  Gets Disk Status* @param  pdrv: Physical drive number (0..)* @retval DSTATUS: Operation status*/
DSTATUS SpiDisk_status (BYTE pdrv       /* Physical drive number to identify the drive */
)
{/* USER CODE BEGIN STATUS */Stat &= ~STA_NOINIT;return Stat;/* USER CODE END STATUS */
}/*** @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 SpiDisk_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 BEGIN READ */DRESULT res = RES_ERROR;UINT i;for(i = 0;i < count;i++){W25QXX_Read(buff + i * 4096,sector * 4096 + i * 4096,4096 );}return RES_OK;/* USER CODE END READ */
}/*** @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 SpiDisk_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 BEGIN WRITE */DRESULT res = RES_ERROR;UINT i;for(i = 0;i < count;i++){W25QXX_Write((void *)(buff + i * 4096),sector * 4096 + i * 4096,4096 );}res = RES_OK;/* USER CODE HERE */return res;/* USER CODE END WRITE */
}
#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 SpiDisk_ioctl (BYTE pdrv,      /* Physical drive nmuber (0..) */BYTE cmd,       /* Control code */void *buff      /* Buffer to send/receive control data */
)
{/* USER CODE BEGIN IOCTL */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;/* USER CODE END IOCTL */
}
#endif /* _USE_IOCTL == 1 *//************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

3.修改usbd_storage_if.c

/* USER CODE BEGIN Header */
/********************************************************************************* @file           : usbd_storage_if.c* @version        : v1.0_Cube* @brief          : Memory management layer.******************************************************************************* @attention** <h2><center>&copy; Copyright (c) 2021 STMicroelectronics.* All rights reserved.</center></h2>** This software component is licensed by ST under Ultimate Liberty license* SLA0044, the "License"; You may not use this file except in compliance with* the License. You may obtain a copy of the License at:*                             www.st.com/SLA0044********************************************************************************/
/* USER CODE END Header *//* Includes ------------------------------------------------------------------*/
#include "usbd_storage_if.h"/* USER CODE BEGIN INCLUDE */
#include "w25qxx.h"
/* USER CODE END INCLUDE *//* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*//* USER CODE BEGIN PV */
/* Private variables ---------------------------------------------------------*//* USER CODE END PV *//** @addtogroup STM32_USB_OTG_DEVICE_LIBRARY* @brief Usb device.* @{*//** @defgroup USBD_STORAGE* @brief Usb mass storage device module* @{*//** @defgroup USBD_STORAGE_Private_TypesDefinitions* @brief Private types.* @{*//* USER CODE BEGIN PRIVATE_TYPES *//* USER CODE END PRIVATE_TYPES *//*** @}*//** @defgroup USBD_STORAGE_Private_Defines* @brief Private defines.* @{*///#define STORAGE_LUN_NBR                  1
//#define STORAGE_BLK_NBR                  0x10000
//#define STORAGE_BLK_SIZ                  0x200/* USER CODE BEGIN PRIVATE_DEFINES */
//虚拟U盘的大小不知与此宏有关，懂得老哥麻烦说一声！！！
#define STORAGE_LUN_NBR                  1
#define STORAGE_BLK_NBR                  2048
#define STORAGE_BLK_SIZ                  4096/* USER CODE END PRIVATE_DEFINES *//*** @}*//** @defgroup USBD_STORAGE_Private_Macros* @brief Private macros.* @{*//* USER CODE BEGIN PRIVATE_MACRO *//* USER CODE END PRIVATE_MACRO *//*** @}*//** @defgroup USBD_STORAGE_Private_Variables* @brief Private variables.* @{*//* USER CODE BEGIN INQUIRY_DATA_FS */
/** USB Mass storage Standard Inquiry Data. */
const int8_t STORAGE_Inquirydata_FS[] = {/* 36 *//* LUN 0 */0x00,0x80,0x02,0x02,(STANDARD_INQUIRY_DATA_LEN - 5),0x00,0x00,0x00,'S', 'T', 'M', ' ', ' ', ' ', ' ', ' ', /* Manufacturer : 8 bytes */'P', 'r', 'o', 'd', 'u', 'c', 't', ' ', /* Product      : 16 Bytes */' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ','0', '.', '0' ,'1'                      /* Version      : 4 Bytes */
};
/* USER CODE END INQUIRY_DATA_FS *//* USER CODE BEGIN PRIVATE_VARIABLES *//* USER CODE END PRIVATE_VARIABLES *//*** @}*//** @defgroup USBD_STORAGE_Exported_Variables* @brief Public variables.* @{*/extern USBD_HandleTypeDef hUsbDeviceFS;/* USER CODE BEGIN EXPORTED_VARIABLES *//* USER CODE END EXPORTED_VARIABLES *//*** @}*//** @defgroup USBD_STORAGE_Private_FunctionPrototypes* @brief Private functions declaration.* @{*/static int8_t STORAGE_Init_FS(uint8_t lun);
static int8_t STORAGE_GetCapacity_FS(uint8_t lun, uint32_t *block_num, uint16_t *block_size);
static int8_t STORAGE_IsReady_FS(uint8_t lun);
static int8_t STORAGE_IsWriteProtected_FS(uint8_t lun);
static int8_t STORAGE_Read_FS(uint8_t lun, uint8_t *buf, uint32_t blk_addr, uint16_t blk_len);
static int8_t STORAGE_Write_FS(uint8_t lun, uint8_t *buf, uint32_t blk_addr, uint16_t blk_len);
static int8_t STORAGE_GetMaxLun_FS(void);/* USER CODE BEGIN PRIVATE_FUNCTIONS_DECLARATION *//* USER CODE END PRIVATE_FUNCTIONS_DECLARATION *//*** @}*/USBD_StorageTypeDef USBD_Storage_Interface_fops_FS =
{STORAGE_Init_FS,STORAGE_GetCapacity_FS,STORAGE_IsReady_FS,STORAGE_IsWriteProtected_FS,STORAGE_Read_FS,STORAGE_Write_FS,STORAGE_GetMaxLun_FS,(int8_t *)STORAGE_Inquirydata_FS
};/* Private functions ---------------------------------------------------------*/
/*** @brief  Initializes over USB FS IP* @param  lun:* @retval USBD_OK if all operations are OK else USBD_FAIL*/
int8_t STORAGE_Init_FS(uint8_t lun)
{/* USER CODE BEGIN 2 */return (USBD_OK);/* USER CODE END 2 */
}/*** @brief  .* @param  lun: .* @param  block_num: .* @param  block_size: .* @retval USBD_OK if all operations are OK else USBD_FAIL*/
int8_t STORAGE_GetCapacity_FS(uint8_t lun, uint32_t *block_num, uint16_t *block_size)
{/* USER CODE BEGIN 3 */*block_num  = STORAGE_BLK_NBR;*block_size = STORAGE_BLK_SIZ;return (USBD_OK);/* USER CODE END 3 */
}/*** @brief  .* @param  lun: .* @retval USBD_OK if all operations are OK else USBD_FAIL*/
int8_t STORAGE_IsReady_FS(uint8_t lun)
{/* USER CODE BEGIN 4 */if(W25QXX_ReadID() != 0)return (USBD_OK);elsereturn -1;
//  return (USBD_OK);/* USER CODE END 4 */
}/*** @brief  .* @param  lun: .* @retval USBD_OK if all operations are OK else USBD_FAIL*/
int8_t STORAGE_IsWriteProtected_FS(uint8_t lun)
{/* USER CODE BEGIN 5 */return (USBD_OK);/* USER CODE END 5 */
}/*** @brief  .* @param  lun: .* @retval USBD_OK if all operations are OK else USBD_FAIL*/
int8_t STORAGE_Read_FS(uint8_t lun, uint8_t *buf, uint32_t blk_addr, uint16_t blk_len)
{/* USER CODE BEGIN 6 */uint16_t i = 0;for(i = 0;i < blk_len;i++){W25QXX_Read(buf + i * STORAGE_BLK_SIZ,blk_addr * STORAGE_BLK_SIZ + i * STORAGE_BLK_SIZ,STORAGE_BLK_SIZ );}return (USBD_OK);/* USER CODE END 6 */
}/*** @brief  .* @param  lun: .* @retval USBD_OK if all operations are OK else USBD_FAIL*/
int8_t STORAGE_Write_FS(uint8_t lun, uint8_t *buf, uint32_t blk_addr, uint16_t blk_len)
{/* USER CODE BEGIN 7 */uint16_t i = 0;for(i = 0;i < blk_len;i++){W25QXX_Write((uint8_t *)(buf + i * STORAGE_BLK_SIZ),blk_addr * STORAGE_BLK_SIZ + i * STORAGE_BLK_SIZ,STORAGE_BLK_SIZ );}return (USBD_OK);/* USER CODE END 7 */
}/*** @brief  .* @param  None* @retval .*/
int8_t STORAGE_GetMaxLun_FS(void)
{/* USER CODE BEGIN 8 */return (STORAGE_LUN_NBR - 1);/* USER CODE END 8 */
}/* USER CODE BEGIN PRIVATE_FUNCTIONS_IMPLEMENTATION *//* USER CODE END PRIVATE_FUNCTIONS_IMPLEMENTATION *//*** @}*//*** @}*//************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

4.main.c主函数修改

  /* USER CODE BEGIN 2 */
//  W25QXX_Init();
//  W25QXX_Write((uint8_t*)TEXT_Buffer,ADDERSS_FLASH,SIZE);
//  W25QXX_Read(datatemp,ADDERSS_FLASH,SIZE);   FatfsTest();/* USER CODE END 2 */

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "w25qxx.h"
/* USER CODE END Includes *//* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
//const uint8_t TEXT_Buffer[]={"PZK"};
//#define SIZE sizeof(TEXT_Buffer)
//#define ADDERSS_FLASH   0x000000
//uint8_t datatemp[SIZE];
/* USER CODE END PTD */

五、程序测试

编译无错误，下载程序到板子，调试。
1.PC端成功读取U盘，显示利用文件系统创建的TXT文件，文件内容即为
WriteBuffer[]= "PZKKKKK666\n";

2.在pc端对U盘中TEST.TXT内容修改，同时可以注释掉void FatfsTest(void)中的create_file();因为文件已经在虚拟U盘中创建，我们此时需要读出文件内容，应用read_file();修改如下

同时修改

//第二次使用文件系统即可不用格式化文件系统，否则虚拟U盘中创建好的文件会消失
void FatfsTest(void)
{//  mount_disk();
//  format_disk();       fileSystemInit();
//  create_file();        read_file();            //读取创建好的文件中的内容并放到ReadBuffer中
}

3.成功读取TXT文件内容

测试完毕。

对于虚拟U盘大小，w25q128，容量为128Mbit，16MB，共有256个块，每个块16个扇区，每个扇区4K字节，一共有256*16个扇区。
修改user.diskio.c文件

/* Private variables ---------------------------------------------------------*/
/* Disk status */
static volatile DSTATUS Stat = STA_NOINIT;#define PAGE_SIZE 256
#define SECTOR_SIZE 4096
#define SECTOR_COUNT 256 * 16
#define BLOCK_SIZE 65536
#define FLASH_PAGES_PER_SECTOR SECTOR_SIZE / PAGE_SIZE

修改之后，PC端显示U盘大小即为16MB