STM32用flash保存参数实现平衡擦写的一种方法
#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 |
|
二、源码
#include
#include //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。