STM32用flash保存参数实现平衡擦写的一种方法_flash均衡保存算法

作者：weixin_40725706 | 2024-06-05 11:18:26

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flash均衡保存算法

#FLASH平衡擦写#

一、概述

简易示意图如下：

写参数前要擦除对应的扇区全为0XFFFFFFFF操作的最小单位为32位 uint32_t; 当一块扇区写完时，将所有有用参数复制到第二块扇区，开始写新的参数，如果所有参数写完，又重第一块参数开始写，这样就能实现平衡写的目的，所以要实现这个功能，至少需要分配2个扇区实现均衡擦写。


/* 储存扇区信息的结构体 */
struct SSCT_HDR
{
 
    uint32_t st;   // 状态
    uint32_t cnt;      // 标号
    uint32_t version;  // 版本
};  // 扇区HEAD结构
 
 
typedef struct 
{
    uint16_t len:16;    
    uint16_t alen:16;    
    /* data */
}VARLEN;
struct VAR_ST  //Flash数据存储结构
{
    uint32_t  status;  //数据当前状态
    uint32_t key;     //数据key
    union 
    {
    uint32_t len;     //数据长度  len +alen   数据实际长度+所在内存长度   内存长度必须是4的整数倍
    VARLEN   len_b;
        /* data */
    };
     
};

扇区1

扇区使用状态

扇区

标号

扇区版本号

数据状态ad1

数据key

长度

len

alen1

数据状态ad1+

alen1/4

数据key

长度

Len2

Alen2

数据状态ad2+

Alen2/4

数据key

长度

Len3

Alen3

...

二、源码


 
#include <stdbool.h>
#include <stdint.h>  //引用框架配置文件
 
#define MAX_CVAR_NUM (200)        //数据存储最大个数
 
 
 
typedef struct 
{
    uint16_t len:16;    
    uint16_t alen:16;    
    /* data */
}VARLEN;
struct VAR_ST  //Flash数据存储结构
{
    uint32_t  status;  //数据当前状态
    uint32_t key;     //数据key
    union 
    {
    uint32_t len;     //数据长度  len +alen   数据实际长度+所在内存长度   内存长度必须是4的整数倍
    VARLEN   len_b;
        /* data */
    };
     
};
 
 
 
struct SFVAR_POINT
{
    uint32_t key;         //数据key
    uint8_t* flashAddr;   //数据地址
};
 
typedef struct
{
    uint8_t* sectorBaseAdr;
    uint32_t sectorSize;
    uint8_t  sectorNum;
 
    void (*FlashInit_Cbk)(void);                                             // Flash初始化函数
    bool (*FlashErase_Cbk)(uint8_t* addr, uint32_t size);                    // Flash擦除函数
    uint32_t (*FlashWrite_Cbk)(void* addr, const void* buf, uint32_t size);  // Flash写入函数
    uint32_t (*FlashRead_Cbk)(void* addr, void* buf, uint32_t size);         /// flash读函数
 
 
    // private
    struct
    {
        uint32_t makeTime;
        uint8_t* sectorUseBaseAdr;  // flash  参数存储区基地址
        uint8_t  sectorUseCnt;   // Flash 所有的序号
        uint32_t varNum;    // Flash存储数据个数
        uint32_t tail;           // Flash当前地址
        uint32_t head;           // 有效头部位置
        uint8_t  swSctFlag;      //扇区切换flag
        uint8_t* rmAdr;         //需要删除的 地址
 
        struct VAR_ST  pCVar;              //单个参数的头部结构
 
        struct SFVAR_POINT varList[MAX_CVAR_NUM];  //数据Z指针数组
 
    } pri;
 
 
}FlashPar_Prop;
 
typedef struct
{
    void (* const Create)(FlashPar_Prop* self);  // FlashVar
 
    void (*Init)(FlashPar_Prop* self,
            uint32_t makeTime,
            uint8_t* sectorBaseAdr,                                                          // FLASH基地址
            uint32_t sectorSize,                                                          // flash大小
            uint32_t sectorNum,                                                           // flash块的个数
            void (*FlashInit_Cbk)(void),                                             // flash初始化函数
            bool (*FlashErase_Cbk)(uint8_t* addr, uint32_t size),                    // flash擦除函数
            uint32_t (*FlashWrite_Cbk)(void* addr, const void* buf, uint32_t size),  // flash写入函数
            uint32_t (*FlashRead_Cbk)(void* addr, void* buf, uint32_t size)          // flash读函数
    );
 
    // API
    uint32_t (*RdPar)(FlashPar_Prop* self, uint32_t key, uint8_t* pRdBuf, uint32_t bufLen);  ///数据读取函数
    MOBJ_BOOL (*WtPar)(FlashPar_Prop* self, uint32_t key, uint8_t* pWtDat, uint32_t datLen);  //数据写入函数
    MOBJ_BOOL (*DelPar)(FlashPar_Prop* self, uint32_t key);                                   //数据删除函数
 
 
}FlashPar_Func;
 
extern const FlashPar_Func FlashPar;


#include "MFlashVar.h"
#include "string.h"
#include "MTime.h"
/* 扇区使用情况  表示各个扇区状态*/
 
#define SSCT_UNUSE  (0xFFFFFFFF)  // 未使用
#define SSCT_USE    (0xBBBBBBBB)  // 使用中
#define SSCT_DEL    (0x00000000)  // 删除状状态
 
   
/* 某区域保存参数的状态 */
 
   #define SCVAR_UNUSE   (0xFFFFFFFF)  // 未使用
   #define SCVAR_USE     (0xAAAAAAAA)  // 使用中
   #define SCVAR_DEL     (0x00000000)  // 删除状状态
                          // 表示各个数据状态
 
/* 储存扇区信息的结构体 */
struct SSCT_HDR
{
 
    uint32_t st;   // 状态
    uint32_t cnt;      // 标号
    uint32_t version;  // 版本
 
};  // 扇区HEAD结构
 
static int32_t FindVarAddr(FlashPar_Prop *self, uint32_t key);
static uint32_t AllocVar(FlashPar_Prop *self, uint32_t len, uint32_t key);
static void DelVar(FlashPar_Prop *self, uint8_t *addr);
static void PrgVar(FlashPar_Prop *self, void *flashAddr, uint32_t key, uint8_t *pWtDat, uint32_t dataLen);
static void LoadSector(FlashPar_Prop *self);
static void LoadFVar(FlashPar_Prop *self);
static void SwitchSct(FlashPar_Prop *self);
 
/**
 * @brief FlashPar
 *
 */
static void FlashPar_Init(FlashPar_Prop *self,
                           uint32_t makeTime,
                           uint8_t *sectorBaseAdr,
                           uint32_t sectorSize,
                           uint32_t sectorNum,
                           void (*FlashInit_Cbk)(void),
                           bool (*FlashErase_Cbk)(uint8_t *addr, uint32_t size),
                           uint32_t (*FlashWrite_Cbk)(void *addr, const void *buf, uint32_t size),
                           uint32_t (*FlashRead_Cbk)(void *addr, void *buf, uint32_t size)  // flash读函数
)
{
    self->pri.varNum            = 0;
    self->sectorBaseAdr          = sectorBaseAdr;
    self->sectorSize          = sectorSize;
    self->sectorNum           = sectorNum;
    self->pri.makeTime               = makeTime;
    self->FlashInit_Cbk  = FlashInit_Cbk;
    self->FlashErase_Cbk = FlashErase_Cbk;
    self->FlashWrite_Cbk = FlashWrite_Cbk;
    self->FlashRead_Cbk  = FlashRead_Cbk;
 
    // step1: load useing sector
    LoadSector(self);
 
    // step2 : load flash variable
    LoadFVar(self);
 
}
 
/**
 * @brief 申请地址并检查剩余地址是否足够
 *
 */
static uint32_t AllocVar(FlashPar_Prop *self, uint32_t len, uint32_t key)
{
    uint32_t pFVarAddress;
    uint8_t tmp, actLen;
    uint16_t index;
 
    /******step1 :Caculate the actual space***/
    tmp = len % 4;
    if (tmp != 0)
        actLen = sizeof(struct VAR_ST) + len + (4 - tmp);
    else
        actLen = sizeof(struct VAR_ST) + len;
 
    /*step2: check current sector has enough sapace*/
    if (self->pri.tail + actLen >= self->sectorSize)
    {
        SwitchSct(self);
        index            = FindVarAddr(self, key);
        self->pri.rmAdr = self->pri.varList[index].flashAddr;
    }
    else {}
 
    /*step3: current sector has enough sapace*/
    if (self->pri.tail + actLen < self->sectorSize)
    {
        pFVarAddress = (uint32_t)(self->pri.sectorUseBaseAdr + self->pri.tail);
        self->pri.tail += actLen;
    }
    else
    {
        pFVarAddress = 0;
    }
 
    return pFVarAddress;
}
/**
 * @brief 删除原有变量函数
 *
 */
static void DelVar(FlashPar_Prop *self, uint8_t *addr)
{
    uint32_t st;
    st = SCVAR_DEL;
    self->FlashWrite_Cbk(addr, &st, sizeof(st));
}
/**
 * @brief 写入参数
 *
 */
static void PrgVar(FlashPar_Prop *self, void *flashAddr, uint32_t key, uint8_t *pWtDat, uint32_t dataLen)
{
    struct VAR_ST tmpVar;
    uint32_t tmp;
    uint32_t dtActLen;
 
    uint8_t *pHead = (uint8_t *)flashAddr;
    uint8_t *pData = (uint8_t *)flashAddr + sizeof(struct VAR_ST);
    tmp            = dataLen % 4;
 
    if (tmp != 0)
        dtActLen = dataLen + (4 - tmp);
    else
        dtActLen = dataLen;
 
    tmpVar.status = SCVAR_USE;
    tmpVar.key    = key;
    tmpVar.len_b.len    = dataLen;
    tmpVar.len_b.alen   = dtActLen;
 
    self->FlashWrite_Cbk(pHead, (uint8_t *)&tmpVar, sizeof(struct VAR_ST));
    self->FlashWrite_Cbk(pData, pWtDat, dtActLen);
 
}
 
 
/**
 * @brief 根据关键字查询变量
 *
 */
static uint32_t FlashPar_RdPar(FlashPar_Prop *self, uint32_t key, uint8_t *pRdBuf, uint32_t bufLen)
{
    struct VAR_ST pFVar;
    uint32_t ret = 0;
    uint8_t *pData;
    uint32_t len;
    int32_t index;
    // find var in ram
    index = FindVarAddr(self, key);
    if (index < 0)
    {
        return ret;
    }
    self->FlashRead_Cbk(self->pri.varList[index].flashAddr, &pFVar, sizeof(struct VAR_ST));
 
    len = pFVar.len_b.len;
    if (bufLen < len)
    {
        len = bufLen;
    }
 
    pData = self->pri.varList[index].flashAddr + sizeof(struct VAR_ST);
    self->FlashRead_Cbk(pData, pRdBuf, len);
    ret = len;
    return ret;
}
/* 根据KEY 删除一个参数 */
static MOBJ_BOOL FlashPar_DelPar(FlashPar_Prop *self, uint32_t key)
{
    uint8_t *pFVar;
    int32_t index;
    uint32_t MvDataNum;
 
    // find var in ram
    index = FindVarAddr(self, key);
 
    if (index < 0)
    {
        return NOT;
    }
 
    pFVar = self->pri.varList[index].flashAddr;
 
    MvDataNum = self->pri.varNum - (index + 1);
    while (MvDataNum--)
    {
        self->pri.varList[index].flashAddr = self->pri.varList[index + 1].flashAddr;
        self->pri.varList[index].key       = self->pri.varList[index + 1].key;
        index++;
    }
    self->pri.varList[index].flashAddr = 0;
    self->pri.varList[index].key       = 0;
    self->pri.varNum--;
    DelVar(self, pFVar);
 
    return YES;
}
 
/**
 * @brief 根据key保存一个参数
 *
 */
static MOBJ_BOOL FlashPar_WtPar(FlashPar_Prop *self, uint32_t key, uint8_t *pWtDat, uint32_t datLen)
{
    uint8_t *pNewVar;
 
    uint8_t tempdata[258] = {0};
    struct VAR_ST pOldVar;
    int32_t index;
 
    MOBJ_BOOL ret;
    if (datLen > 256)
    {
    }
    /******step1 :find old var ***/
    index = FindVarAddr(self, key);
 
    /******step2 :wite new var*/
    if (index < 0)  // step2.1 old var not exist
    {
        if (self->pri.varNum >= MAX_CVAR_NUM)  // check number
        {
            ret = NOT;
        }
        else if (0 == (pNewVar = (uint8_t *)AllocVar(self, datLen, key)))  // alloc space
        {
            ret = NOT;
        }
        else
        {
            PrgVar(self, pNewVar, key, pWtDat, datLen);
 
            self->pri.varList[self->pri.varNum].key = key;
 
            self->pri.varList[self->pri.varNum].flashAddr = pNewVar;
 
            self->pri.varNum++;
 
            ret = YES;
        }
    }
    else  // step2.2 old var exist
    {
        self->pri.rmAdr = self->pri.varList[index].flashAddr;
        self->FlashRead_Cbk(self->pri.rmAdr, &pOldVar, sizeof(struct VAR_ST));
        if (pOldVar.key == key)
        {
            self->FlashRead_Cbk(self->pri.rmAdr + sizeof(struct VAR_ST), tempdata, pOldVar.len_b.len);
            if ((pOldVar.len_b.len== datLen) && (0 == memcmp(tempdata, pWtDat, datLen)))
            {
                ret = YES;
            }
            else
            {
                pNewVar = (uint8_t *)AllocVar(self, datLen, key);
                if (0 == pNewVar)  // alloc space
                {
                    // EINT;
                    ret = NOT;
                }
                else
                {
                    PrgVar(self, pNewVar, key, pWtDat, datLen);  // write new var
                    DelVar(self, self->pri.rmAdr);              // 完全删除
 
                    ret = YES;
                }
                self->pri.varList[index].flashAddr = pNewVar;
            }
        }
    }
 
    return ret;
}
static int32_t FindVarAddr(FlashPar_Prop *self, uint32_t key)
{
    int32_t i;
    for (i = 0; i < self->pri.varNum; i++)
    {
        if (self->pri.varList[i].key == key)
            return i;
    }
 
    return -1;
}
 
/**
 * @brief 加载各个扇区的状态信息
 *
 */
static void LoadSector(FlashPar_Prop *self)
{
    int32_t i;
    int32_t maxSctCnt = 0;
    uint8_t *useadd   = 0;
    struct SSCT_HDR pSctHdr, newSctHdr;
 
    // step1 : find using sector
    for (i = 0; i < self->sectorNum; i++)
    {
        useadd = self->sectorBaseAdr + i * self->sectorSize;
        self->FlashRead_Cbk(useadd, &pSctHdr, sizeof(struct SSCT_HDR));
 
        // check the version,
        if ((pSctHdr.version != 0xFFFFFFFF) && (pSctHdr.version != self->pri.makeTime))
        {
            self->FlashErase_Cbk(useadd, self->sectorSize);
        }
        else
        {
            switch (pSctHdr.st)
            {
                case SSCT_UNUSE: {
                    break;
                }
                case SSCT_USE: {
                    if (pSctHdr.cnt >= maxSctCnt)
                    {
                        self->pri.sectorUseBaseAdr = useadd;
                        self->pri.sectorUseCnt  = i;
                        maxSctCnt               = pSctHdr.cnt;
                    }
                    break;
                }
                case SSCT_DEL: {
                    break;
                }
            }
        }
    }
 
    // step2 : if don't find using sector them set sector0 is used
    if (maxSctCnt == 0)
    {
        self->pri.sectorUseBaseAdr = self->sectorBaseAdr;
        self->pri.sectorUseCnt  = 0;
        self->FlashErase_Cbk(self->pri.sectorUseBaseAdr, self->sectorSize);  // 擦除 实际地址需
        newSctHdr.st      = SSCT_USE;
        newSctHdr.cnt     = 1;
        newSctHdr.version = self->pri.makeTime;
        self->FlashWrite_Cbk(self->pri.sectorUseBaseAdr, (uint8_t *)&newSctHdr, sizeof(struct SSCT_HDR));
    }
    self->pri.tail = sizeof(struct SSCT_HDR);
}
/**
 * @brief 加载flash 区的参数信息
 *
 */
static void LoadFVar(FlashPar_Prop *self)
{
    uint8_t rFlag            = 1;
    struct VAR_ST *pErrVar = 0;
    struct VAR_ST nowVar;
    uint32_t errNo        = 0;
    uint8_t *pFVarAddress = 0;
    // uint8_t*        pFVarAddress = 0;
    while ((self->pri.tail < self->sectorSize) && rFlag)
    {
        pFVarAddress = self->pri.sectorUseBaseAdr + self->pri.tail;
        self->FlashRead_Cbk(pFVarAddress, &nowVar, sizeof(struct VAR_ST));
        switch (nowVar.status)
        {
            // if the data was unused than over build process
            case SCVAR_UNUSE: {
                rFlag = 0;  // stop research
                break;
            }
            case SCVAR_USE: {
                if ((pErrVar != 0) && (nowVar.key == pErrVar->key))
                {
                    self->pri.tail += sizeof(struct VAR_ST) + nowVar.len_b.alen;
                    DelVar(self, self->pri.varList[errNo].flashAddr);  // 删除原有错误数据
                    self->pri.varList[errNo].flashAddr = pFVarAddress;
                }
                else  // nomal
                {
                    self->pri.tail += sizeof(struct VAR_ST) + nowVar.len_b.alen;
                    self->pri.varList[self->pri.varNum].key       = nowVar.key;
                    self->pri.varList[self->pri.varNum].flashAddr = pFVarAddress;
                    self->pri.varNum++;
                }
                break;
            }
            // if deleted than jump
            case SCVAR_DEL: {
                self->pri.tail += sizeof(struct VAR_ST) + nowVar.len_b.alen;
            }
            default:  // 参数报错
            {
                // self->pri.tail += sizeof(struct VAR_ST) + dtActLen;
            }
        }
    }  // end while
}
/**
 * @brief Flash扇区切换 (暂时未确认是否ok)
 *
 */
static void SwitchSct(FlashPar_Prop *self)
{
    uint8_t data[256];
    struct VAR_ST pOldVar;
    struct SSCT_HDR pOldSctHD;
    uint8_t *oldSct = self->pri.sectorUseBaseAdr;
    self->FlashRead_Cbk(oldSct, &pOldSctHD, sizeof(struct SSCT_HDR));
    /********step1: find next sector******/
    self->pri.sectorUseCnt++;
    if (self->pri.sectorUseCnt >= self->sectorNum)
    {
        self->pri.sectorUseCnt = 0;
    }
    uint8_t *newSct = self->sectorBaseAdr + self->pri.sectorUseCnt * self->sectorSize;
    self->FlashErase_Cbk(newSct, self->sectorSize);  // 擦除即将切换到的扇区  擦除地址开始后的1个扇区
    /********step2 : produce sector header*******/
    struct SSCT_HDR newSctHD = {
        .st      = SSCT_USE,
        .cnt     = pOldSctHD.cnt + 1,
        .version = self->pri.makeTime,
    };
    self->pri.sectorUseBaseAdr = (uint8_t *)newSct;
    self->pri.tail          = sizeof(struct SSCT_HDR);
    // sector write pre
    self->FlashWrite_Cbk(newSct, (uint8_t *)&newSctHD, sizeof(struct SSCT_HDR));
    /********step3 :将原有参数移动到新区*************/
    int32_t i;
    uint8_t *newvaraddr;
    for (i = 0; i < self->pri.varNum; i++)
    {
        self->FlashRead_Cbk(self->pri.varList[i].flashAddr, &pOldVar, sizeof(struct VAR_ST));
        newvaraddr = (uint8_t *)((uint32_t)self->pri.sectorUseBaseAdr + self->pri.tail);
        self->FlashRead_Cbk(self->pri.varList[i].flashAddr + sizeof(struct VAR_ST), data, pOldVar.len_b.len);  // 读数据
        PrgVar(self, newvaraddr, pOldVar.key, data, pOldVar.len_b.len);  // 保存数据
        self->pri.varList[i].flashAddr = newvaraddr;
        self->pri.tail += sizeof(struct VAR_ST) + pOldVar.len_b.alen;
        if (self->pri.tail > self->sectorSize)
        {
            //扇区溢出
            return;
        }
    }
    pOldSctHD.st = SSCT_DEL;
    // sector write pre
    self->FlashWrite_Cbk(oldSct, (uint8_t *)&pOldSctHD, sizeof(struct SSCT_HDR));
}
/**
 * @brief FlashPar
 *
 */
void FlashPar_Create(FlashPar_Prop *self) { memset(self, 0, sizeof(FlashPar_Prop)); }
const FlashPar_Func FlashPar = {.Create = FlashPar_Create,
                                  .Init   = FlashPar_Init,
                                  .RdPar  = FlashPar_RdPar,
                                  .WtPar  = FlashPar_WtPar,
                                  .DelPar = FlashPar_DelPar};

平衡擦写的流程主要涉及到扇区的选择和切换，以及变量的写入和删除。

1. 首先，在`FlashPar_Init`函数中，通过调用`LoadSector`函数加载扇区的状态信息。该函数会遍历所有扇区，检查状态并选择使用中的扇区作为当前扇区。

2. 接下来，在`LoadFVar`函数中，会加载当前扇区中的flash变量。函数会遍历当前扇区中的每个flash变量，将其存储到`pri.varList`数组中。同时，将当前扇区中的`tail`指针指向下一个可用的地址。

3. 当需要写入一个新的flash变量时，首先通过`AllocVar`函数申请一个地址，并检查当前扇区是否有足够的空间。如果空间不足，则需要切换到下一个扇区，并重新分配地址。然后，通过`PrgVar`函数将变量写入到flash中，并更新`pri.varList`数组和`pri.varNum`变量。如果找到了相同关键字的旧变量，则会先删除旧变量。

4. 当需要删除一个flash变量时，通过`FlashPar_DelPar`函数根据关键字找到变量的地址，并调用`DelVar`函数删除变量。

5. 当需要读取一个flash变量时，通过`FlashPar_RdPar`函数根据关键字找到变量的地址，并将变量的数据读取出来。

在上述流程中，如果当前扇区的空间不足以容纳新的flash变量，就会触发扇区切换。在`SwitchSct`函数中，先找到下一个可用的扇区，并将其标记为使用状态。然后，将当前扇区中的变量逐个移动到新的扇区，并更新变量的地址。同时，将当前扇区的状态设置为删除状态，并将新的扇区的状态设置为使用状态。

通过这样的流程，可以实现对flash的平衡擦写，避免频繁的擦写操作，延长flash的使用寿命。同时，可以方便地存储和读取变量，提供了一种简单有效的持久化存储解决方案。

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