嵌入式系统配置参数存储方案

2025-04-10 14:12:30 322 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

DS28EC20与PIC18LF25K42实现可靠用户配置存储方案在嵌入式系统开发中，数据存储的可靠性和寿命是关键挑战。EEPROM作为非易失性存储器，通过电荷存储原理实现数据持久化，其擦写次数可达10万次，远高于Flash模拟方案。1-Wire协议以其单线通信的优势，在IO资源受限的场景下特别适用。DS28EC20作为1-Wire接口EEPROM，与PIC18LF25K42微控制器组合，可构建高可靠配置存储系统。该方案在工业控制等严苛环境下表现优异，支持-40℃到85℃工作温度范围。通过双页存储、CRC校验等软件防护机制，能有效预防数据篡改和意外断电风险，是替代内部Fl 阅读详情

#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#define DBG_TAG "config"
#define DBG_LVL DBG_LOG
#include <rtdbg.h>
#include <config/config_file.h>

void backup_config(const char* fpath, const char* bak_fpath)
{
rt_err_t result = -RT_ERROR;

result = access(bak_fpath, F_OK|R_OK|W_OK);

if(result == 0)//文件存在
{
LOG_E("backup file [%s] existed.", bak_fpath);
if (dfs_file_unlink(bak_fpath) < 0)
{
LOG_E("Delete %s failed\n", bak_fpath);
return;
}
}
copy(fpath, bak_fpath);
}

void restore_config(const char* fpath, const char* bak_fpath)
{
rt_err_t result = -RT_ERROR;

result = access(fpath, F_OK|R_OK|W_OK);

if(result == 0)//文件存在
{
rm(bak_fpath);
}
copy(bak_fpath, fpath);
}

rt_bool_t check_file_exist(const char* path)
{
rt_err_t result = -RT_ERROR;

result = access(path, F_OK/*|R_OK|W_OK*/);

if(result == 0)//文件存在
{
return RT_TRUE;
}
return RT_FALSE;
}

struct tm * get_date_time(uint16_t year, uint8_t mon, uint8_t day, uint8_t hour, uint8_t min, uint8_t sec)
{
struct tm * time = rt_malloc(sizeof(struct tm));
time->tm_year = year;
time->tm_mon = mon;
time->tm_mday = day;
time->tm_hour = hour;
time->tm_min = min;
time->tm_sec = sec;
return time;
}

char* read_config_file(const char* file_path)
{
int fd = -1;
int ret = -1;
if (strstr(file_path, ".json") != RT_NULL)
{
/* try to open program */
fd = open(file_path, O_RDWR, 0);
/* search in /bin path */
if (fd < 0)
{
LOG_E("settings file open error.");
return RT_NULL;
}
}
/* found script */
char *line_buf = RT_NULL;
int length = lseek(fd, 0L, SEEK_END);
if(length < 0)
{
return RT_NULL;
}
line_buf = (char *) rt_malloc(length + 1);
if(line_buf==RT_NULL)
{
return RT_NULL;
}
lseek(fd, 0L, SEEK_SET);
ret = read(fd, line_buf, length);
if(ret!=length)
{
return RT_NULL;
}
close(fd);
return line_buf;
}

rt_bool_t save_config_file(const char* path, cJSON* json_root)
{
char* json_buf = RT_NULL;
int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 777);//重新创建文件

if (fd < 0)
{
LOG_E("open file %s failed\n", path);
return RT_FALSE;
}

if(json_root==RT_NULL)
{
close(fd);
return RT_FALSE;
}

json_buf = cJSON_Print(json_root);
if(json_buf==RT_NULL)
{
close(fd);
LOG_E("%s file cJSON_Print error.", path);
return RT_FALSE;;
}

int len = strlen(json_buf);

if (flock(fd, LOCK_EX) == -1) {
LOG_E("%s file add lock error.", path);
cJSON_free(json_buf);
close(fd);
return RT_FALSE;
}

if(len != write(fd, json_buf, len))
{
LOG_E("%s file write size error.", path);
cJSON_free(json_buf);
close(fd);
return RT_FALSE;
}

if (flock(fd, LOCK_UN) == -1)
{ // 解锁
LOG_E("%s file unlock error.", path);
return RT_FALSE;
}
cJSON_free(json_buf);
close(fd);
return RT_TRUE;
}

rt_bool_t parse_general_config(cJSON* json_root, general_config_t *p_config)
{
cJSON *general_json = NULL;
//获取general配置项
general_json = cJSON_GetObjectItem(json_root, "general");
if(general_json==NULL)
{
return RT_FALSE;
}
cJSON *lang = cJSON_GetObjectItem(general_json, "lang");
if(lang!=NULL&&cJSON_IsNumber(lang))
{
p_config->lang = lang->valueint;
}

cJSON *model = cJSON_GetObjectItem(general_json, "model");
if(model!=NULL&&cJSON_IsString(model))
{
sprintf(p_config->model, "%s", model->valuestring);
}

cJSON *version = cJSON_GetObjectItem(general_json, "version");
if(version!=NULL&&cJSON_IsString(version))
{
sscanf(version->valuestring, "%d.%d.%d",&p_config->version.major,
&p_config->version.minor, &p_config->version.build);
}

cJSON *keytone = cJSON_GetObjectItem(general_json, "keytone");
if(keytone!=NULL&&cJSON_IsNumber(keytone))
{
p_config->keytone = keytone->valueint;
}
return RT_TRUE;
}

//当前参数转换到json格式（仅配置参数）
cJSON* general_config_to_json(general_config_t *p_control)
{
assert(p_control);

cJSON *root = cJSON_CreateObject();
if(root==NULL)
{
return NULL;
}
cJSON *general = cJSON_CreateObject();
if(general!=NULL)
{
cJSON_AddItemToObject(root, "general", general);
}
cJSON_AddNumberToObject(general, "lang", p_control->lang);
cJSON_AddStringToObject(general, "model", p_control->model);
char temp[32];
sprintf(temp, "%d.%d.%d", p_control->version.major,p_control->version.minor,p_control->version.build);
cJSON_AddStringToObject(general, "version", temp);
cJSON_AddNumberToObject(general, "keytone", p_control->keytone);

return root;
}

//从json文件中读取电流配置
void read_general_config(const char* path, general_config_t *p_control)
{
cJSON* json_root = RT_NULL;
char* json_buf = RT_NULL;
if(!check_file_exist(path))
{
if(check_file_exist(GENERAL_CONFIG_FILE_BAK))
{
restore_config(path, GENERAL_CONFIG_FILE_BAK);
}
else {
reset_general_config(p_control);
save_general_config(p_control, path);
}
}

json_buf = read_config_file(path);

if(json_buf==RT_NULL)
{
reset_general_config(p_control);
save_general_config(p_control, path);
json_buf = read_config_file(path);
}

json_root = cJSON_Parse(json_buf);

if(json_root==RT_NULL)
{
free(json_buf);
return ;
}
parse_general_config(json_root, p_control);
if(!check_file_exist(GENERAL_CONFIG_FILE_BAK))
{
backup_config(path, GENERAL_CONFIG_FILE_BAK);
}
cJSON_free(json_root);
free(json_buf);
}

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