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来源 | 我姓梁

很多场景都需要记录日志，在嵌入式系统中，特别是单片机这种存储资源有限的环境下，就需要一种轻量级的存储方法。

系统日志

在嵌入式设备应用场景中，系统日志时常可以监控设备软件的运行状态，及时记录问题点以及关键信息，方便开发人员后期定位以及解决问题。

本文将讲述一种简易的系统日志记录方法，用于保存设备的系统日志，视具体嵌入式设备情况而定，可存储在MCU内部Flash、外部Flash、EEPROM等，本文采用外部Flash作为示例展开介绍。

思路分析

对于系统日志可以当成文件系统，可以划分为三个重要部分：目录区、参数区、日志区。

• 目录区：根据日期进行归类，记录当天的日志的存储地址、日志索引、日志大小，通过目录可以获取整个日志文件的概况；

• 参数区：存储记录日志写位置、目录项个数、写状态等参数；

• 日志区：这是我们主要的存储区，记录系统的日志，支持环写。这三个区域都需要占用部分内存，可以自行分配大小。

实现的效果如下图所示，设置通过指令可查询到整个日志目录区的概况。

查询系统日志目录：AT+CATALOG?

LOG_ID:存储日志按日期分类，该ID用于查询对应日期日志,从1开始计数；

LOG_DATE:系统日志存储日期；

LOG_ADDR:系统日志存储外部FLASH地址；

LOG_OFFSET:系统日志存储偏移量（各日期日志大小，单位：字节）。

查询指定日期系统日志：AT+CATALOG=<LOG_ID>

LOG_ID:在查询系统日志目录时获取，当LOG_ID为0时，为查询整个系统日志。

另外提供移除系统日志（清除日志目录）指令：AT+RMLOG，后面将讲述具体实现。

FLASH内存划分

FLASH内存需要看具体设备进行合理划分，目录区、参数区与日志区实现环形存储，延长擦写寿命。

#define FLASH_SECTOR_SIZE      ((uint32_t)0x001000)
#define FLASH_BLOCK_32K_SIZE    ((uint32_t)0x008000)
#define FLASH_BLOCK_64K_SIZE    ((uint32_t)0x010000)
#define SECTOR_MASK               (FLASH_SECTOR_SIZE - 1)         /*扇区掩码 ------*/
#define SECTOR_BASE(addr)         (addr & (~SECTOR_MASK))        /*扇区的基地址 --*/
#define SECTOR_OFFSET(addr)       (addr & SECTOR_MASK)           /*扇区内的偏移 --*/#define BLOCK_32K_BASE(addr)    (addr & (~(FLASH_BLOCK_32K_SIZE)))
#define BLOCK_64K_BASE(addr)    (addr & (~(FLASH_BLOCK_64K_SIZE)))typedef enum {FLASH_BLOCK_4K  = 0,          /**< flash erase block size 4k */FLASH_BLOCK_32K = 1,          /**< flash erase block size 32k */FLASH_BLOCK_64K = 2           /**< flash erase block size 64k */
}flash_block_t;/* flash 空间索引 */
typedef enum{FLASH_CATALOG_ZONE = 0,FLASH_SYSLOG_PARA_ZONE,FLASH_SYSLOG_ZONE,FLASH_ZONEX,
}flash_zone_e;typedef struct{flash_zone_e zone;uint32_t start_address;uint32_t end_address;
}flash_table_t;/* 地址划分 */
static const flash_table_t flash_table[] = {{ .zone = FLASH_CATALOG_ZONE,       .start_address = 0x03200000, .end_address = 0x032FFFFF},  { .zone = FLASH_SYSLOG_PARA_ZONE,   .start_address = 0x03300000, .end_address = 0x033FFFFF},  { .zone = FLASH_SYSLOG_ZONE,        .start_address = 0x03400000, .end_address = 0x03FFFFFF},
};

Flash底层实现擦除、读写操作接口，由读者自行实现。

flash_table_t *get_flash_table(flash_zone_e zone)
{int i = 0;for (i = 0; i < flash_zone_count; i++) {if (zone == flash_table[i].zone) return (flash_table_t *)&flash_table[i];}return NULL;
}int flash_erase(flash_zone_e zone, uint32_t address, flash_block_t block_type)
{flash_table_t *flash_table_tmp = get_flash_table(zone);if (flash_table_tmp == NULL)return -1;if (address < flash_table_tmp->start_address ||address > flash_table_tmp->end_address) return -1;return bsp_spi_flash_erase(address, block_type);
}int flash_write(flash_zone_e zone, uint32_t address, const uint8_t*data, uint32_t length)
{flash_table_t *flash_table_tmp = get_flash_table(zone);if (flash_table_tmp == NULL)return -1;if ((address < flash_table_tmp->start_address) ||((address + length) > flash_table_tmp->end_address))return -1;return bsp_spi_flash_buffer_write(address, (uint8_t *)data, length);
}int flash_read(flash_zone_e zone, uint32_t address, uint8_t*buffer, uint32_t length)
{flash_table_t *flash_table_tmp = get_flash_table(zone);if (flash_table_tmp == NULL)return -1;if ((address < flash_table_tmp->start_address) ||((address + length) > flash_table_tmp->end_address))return -1;bsp_spi_flash_buffer_read(buffer, address, length);return 0;
}

参数与结构体定义

日志数据存储时间戳，便于问题定位，需要实现RTC接口调用。

typedef struct {uint16_t   Year;    /* 年份:YYYY */uint8_t    Month;    /* 月份:MM */uint8_t    Day;    /* 日:DD */uint8_t     Hour;    /* 小时:HH */uint8_t     Minute;    /* 分钟:MM */uint8_t   Second;    /* 秒:SS */
}time_t;   int bsp_rtc_get_time(time_t *date);

参数区应当保证数据的正确性，应加入参数校验存储，定义校验结构体。

#define SYSTEM_LOG_MAGIC_PARAM    0x87654321  /* 日志参数标识符 */
typedef struct {uint32_t magic;    /* 参数标识符 */uint16_t crc;    /* 校验值 */uint16_t len;    /* 参数长度 */
} single_sav_t;

参数区需记录当前日志记录的写位置，以及目录项个数，还有日志区和目录区环写状态，并且存储最新时间等等。

/* 日志区参数 */
typedef struct {uint32_t   write_pos;             /* 写位置 */uint32_t   catalog_num;            /* 目录项个数 */uint8_t    log_cyclic_status;    /* 系统日志环形写状态 */   uint8_t    catalog_cyclic_status; /* 日志目录环形写状态 */time_t     log_latest_time;     /* 存储最新时间 */
}system_log_t;/* 目录区参数 */
typedef struct {uint32_t log_id;     /* 日志索引 */  uint32_t log_addr;    /* 日志地址 */uint32_t log_offset;  /* 日志偏移大小，单位：字节 */time_t   log_time;    /* 日志存储时间 */
}system_catalog_t;/* 系统日志参数 */
typedef struct {single_sav_t crc_val;system_log_t system_log;system_catalog_t system_catalog;
}sys_log_param_t;typedef struct {uint8_t system_log_print_enable; /* 系统日志打印使能 */uint16_t system_log_print_id;    /* 打印指定id系统日志 */uint32_t system_log_param_addr;  /* 当前日志写地址 */
} sys_ram_t;sys_ram_t  SysRam;
sys_log_param_t SysLogParam;sys_ram_t  *gp_sys_ram = &SysRam;
sys_log_param_t *gp_sys_log = &SysLogParam;

实现接口说明

CRC校验接口，可以自定义实现。

/* 16位CRC校验高位表 */
static const uint8_t auchCRCHi[]={
0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,
0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,
0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,
0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,
0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,
0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,
0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,
0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40
};/* 16位CRC校验低位表 */
static const uint8_t auchCRCLo[]={
0x00,0xc0,0xc1,0x01,0xc3,0x03,0x02,0xc2,0xc6,0x06,0x07,0xc7,0x05,0xc5,0xc4,0x04,
0xcc,0x0c,0x0d,0xcd,0x0f,0xcf,0xce,0x0e,0x0a,0xca,0xcb,0x0b,0xc9,0x09,0x08,0xc8,
0xd8,0x18,0x19,0xd9,0x1b,0xdb,0xda,0x1a,0x1e,0xde,0xdf,0x1f,0xdd,0x1d,0x1c,0xdc,
0x14,0xd4,0xd5,0x15,0xd7,0x17,0x16,0xd6,0xd2,0x12,0x13,0xd3,0x11,0xd1,0xd0,0x10,
0xf0,0x30,0x31,0xf1,0x33,0xf3,0xf2,0x32,0x36,0xf6,0xf7,0x37,0xf5,0x35,0x34,0xf4,
0x3c,0xfc,0xfd,0x3d,0xff,0x3f,0x3e,0xfe,0xfa,0x3a,0x3b,0xfb,0x39,0xf9,0xf8,0x38,
0x28,0xe8,0xe9,0x29,0xeb,0x2b,0x2a,0xea,0xee,0x2e,0x2f,0xef,0x2d,0xed,0xec,0x2c,
0xe4,0x24,0x25,0xe5,0x27,0xe7,0xe6,0x26,0x22,0xe2,0xe3,0x23,0xe1,0x21,0x20,0xe0,0xa0,0x60,0x61,0xa1,0x63,0xa3,0xa2,0x62,0x66,0xa6,0xa7,0x67,0xa5,0x65,0x64,0xa4,
0x6c,0xac,0xad,0x6d,0xaf,0x6f,0x6e,0xae,0xaa,0x6a,0x6b,0xab,0x69,0xa9,0xa8,0x68,
0x78,0xb8,0xb9,0x79,0xbb,0x7b,0x7a,0xba,0xbe,0x7e,0x7f,0xbf,0x7d,0xbd,0xbc,0x7c,
0xb4,0x74,0x75,0xb5,0x77,0xb7,0xb6,0x76,0x72,0xb2,0xb3,0x73,0xb1,0x71,0x70,0xb0,
0x50,0x90,0x91,0x51,0x93,0x53,0x52,0x92,0x96,0x56,0x57,0x97,0x55,0x95,0x94,0x54,
0x9c,0x5c,0x5d,0x9d,0x5f,0x9f,0x9e,0x5e,0x5a,0x9a,0x9b,0x5b,0x99,0x59,0x58,0x98,
0x88,0x48,0x49,0x89,0x4b,0x8b,0x8a,0x4a,0x4e,0x8e,0x8f,0x4f,0x8d,0x4d,0x4c,0x8c,
0x44,0x84,0x85,0x45,0x87,0x47,0x46,0x86,0x82,0x42,0x43,0x83,0x41,0x81,0x80,0x40
};/* 实现crc功能函数 */
static uint16_t CRC16(uint8_t* puchMsg, uint16_t usDataLen)
{uint8_t uchCRCHi=0xff;uint8_t uchCRCLo=0xff;uint16_t uIndex;while(usDataLen--) {uIndex=uchCRCHi^*(puchMsg++);uchCRCHi=uchCRCLo^auchCRCHi[uIndex];uchCRCLo=auchCRCLo[uIndex];}return uchCRCHi<<8|uchCRCLo;
}

保存系统日志参数，每实现写日志操作后都需要保存当前的参数值，防止意外丢失。

void save_system_log_param(void)
{uint32_t i = 0;uint32_t addr = 0;uint32_t remainbyte = 0;uint32_t start_addr;int len = sizeof(sys_log_param_t);uint8_t *pdata = (uint8_t *)&SysLogParam;flash_table_t *flash_tmp = get_flash_table(FLASH_SYSLOG_PARA_ZONE);/* 校验参数 */gp_sys_log->crc_val.magic = SYSTEM_LOG_MAGIC_PARAM;gp_sys_log->crc_val.len = sizeof(sys_log_param_t) - sizeof(single_sav_t);gp_sys_log->crc_val.crc = CRC16(&pdata[sizeof(single_sav_t)], gp_sys_log->crc_val.len);start_addr = gp_sys_ram->system_log_param_addr;/* 剩余内存不够写，则重新从起始地址开始写，实现环形存储功能  */if ((start_addr + len) > flash_tmp->end_address) { start_addr = flash_tmp->start_address;}gp_sys_ram->system_log_param_addr = start_addr + len;/* 首地址存储，擦除整个系统日志参数存储区，如果划分的内存较大，可能出现第一次擦写等待时间较长，但实际应用嵌入式设备应该不会占用太多的内存存储系统日志，只当为辅助使用，有额外应用可自行实现 */if (flash_tmp->start_address == start_addr) {/*for (i = flash_tmp->start_address; i < flash_tmp->end_address; i+= FLASH_SECTOR_SIZE) flash_erase(FLASH_SYSLOG_PARA_ZONE, SECTOR_BASE(i), FLASH_BLOCK_4K);*/addr = flash_tmp->start_address;do {if ((addr + FLASH_BLOCK_64K_SIZE) <= flash_tmp->end_address) {flash_erase(FLASH_SYSLOG_PARA_ZONE, BLOCK_64K_BASE(i), FLASH_BLOCK_64K);addr += FLASH_BLOCK_64K_SIZE;} else if ((addr + FLASH_BLOCK_32K_SIZE) <= flash_tmp->end_address) {flash_erase(FLASH_SYSLOG_PARA_ZONE, BLOCK_32K_BASE(i), FLASH_BLOCK_32K);addr += FLASH_BLOCK_32K_SIZE;} else if ((addr + FLASH_SECTOR_SIZE) <= flash_tmp->end_address) {flash_erase(FLASH_SYSLOG_PARA_ZONE, SECTOR_BASE(i), FLASH_BLOCK_4K);addr += FLASH_SECTOR_SIZE;} else {break;}} while (addr < flash_tmp->end_address);  }remainbyte = FLASH_SECTOR_SIZE - (start_addr % FLASH_SECTOR_SIZE);if (remainbyte > len) {remainbyte = len;}while (1) {flash_write(FLASH_SYSLOG_PARA_ZONE, start_addr, pdata, remainbyte);if (remainbyte == len) {break;} else {pdata += remainbyte;start_addr += remainbyte;len -= remainbyte;remainbyte = (len > FLASH_SECTOR_SIZE) ? FLASH_SECTOR_SIZE : len;}}
}

导入系统日志默认参数接口，初始化默认参数或者移除日志。

void load_system_log_default_param(void)
{/* 系统日志默认参数 *//* 目录环写状态标志 */gp_sys_log->system_log.catalog_cyclic_status = 0x00;/* 目录项个数 */gp_sys_log->system_log.catalog_num = 0;/* 日志环写标志 , 1:环写状态 */gp_sys_log->system_log.log_cyclic_status = 0;/* 设置默认值，实际会重新从RTC获取最新时间 */gp_sys_log->system_log.log_latest_time.Year = 2019;gp_sys_log->system_log.log_latest_time.Month = 5;gp_sys_log->system_log.log_latest_time.Day = 8;gp_sys_log->system_log.log_latest_time.Hour = 13;gp_sys_log->system_log.log_latest_time.Minute = 14;gp_sys_log->system_log.log_latest_time.Second = 10;/* 日志写位置从0开始 */gp_sys_log->system_log.write_pos = 0;gp_sys_log->system_catalog.log_addr = 0;gp_sys_log->system_catalog.log_id = 0;gp_sys_log->system_catalog.log_offset = 0;gp_sys_log->system_catalog.log_time.Year = 2019;gp_sys_log->system_catalog.log_time.Month = 5;gp_sys_log->system_catalog.log_time.Day = 8;gp_sys_log->system_catalog.log_time.Hour = 12;gp_sys_log->system_catalog.log_time.Minute = 12;gp_sys_log->system_catalog.log_time.Second = 14;gp_sys_log->crc_val.magic = SYSTEM_LOG_MAGIC_PARAM;/* 导入默认参数后进行保存 */save_system_log_param();
}

设备开机或者复位都会进行导入系统日志参数操作，恢复日志读写参数，参数区为频繁读写操作区域，每一次写操作都会进行一次偏移，有效的导入参数方法是从参数区结束地址到起始地址进行扫描，扫描不到合法的参数则会导入默认日志参数。

/* 参数初始化，在终端启动时调用 */
int load_system_log_param(void)
{uint32_t i = 0;single_sav_t psav;uint32_t end_addr;uint32_t interal = sizeof(sys_log_param_t);int data_len = sizeof(sys_log_param_t) - sizeof(single_sav_t);uint8_t *pram = (uint8_t *)&SysLogParam;flash_table_t *flash_tmp = get_flash_table(FLASH_SYSLOG_PARA_ZONE);end_addr =flash_tmp->end_address - (flash_tmp->end_address - flash_tmp->start_address) % interal;for (i = end_addr - interal; i > flash_tmp->start_address; i -= interal) {flash_read(FLASH_SYSLOG_PARA_ZONE, i, (uint8_t *)&psav, sizeof(single_sav_t));if ((psav.magic == SYSTEM_LOG_MAGIC_PARAM) && (psav.len ==data_len)) {      flash_read(FLASH_SYSLOG_PARA_ZONE, i + sizeof(single_sav_t), &pram[sizeof(single_sav_t)], data_len);if (psav.crc != CRC16(&pram[sizeof(single_sav_t)], data_len)) continue;gp_sys_ram->system_log_param_addr = i;log_info("Load System Log Param Addr[0x%08x]!", gp_sys_ram->system_log_param_addr);return 0;}}/* 扫描不到合法的参数，导入默认系统日志参数 */load_system_log_default_param();/* 获取日志写地址 */gp_sys_ram->system_log_param_addr = flash_tmp->start_address;log_info("Load System Log Param Addr(Default)[0x%08x]!", gp_sys_ram->system_log_param_addr);return 1;
}

读写系统日志目录接口，读写指定日志索引目录信息。实际实现会定义最新的目录信息存储在日志参数区，当日期发生改变，则表示当前目录信息已经完结，将最新的目录信息录入日志目录区保存，最多每天写入一次目录区。

/* 读取日志目录区指定日志索引目录信息 */
int system_catalog_read(system_catalog_t *catalog, uint32_t id)
{uint32_t addr;int rlen = sizeof(system_catalog_t);uint8_t *pbuf = (uint8_t *)catalog;flash_table_t *flash_tmp = get_flash_table(FLASH_CATALOG_ZONE);if (0 == id) return -1;addr = flash_tmp->start_address + (rlen * (id - 1));if (addr > flash_tmp->end_address) return -1;return flash_read(FLASH_CATALOG_ZONE, addr, pbuf, rlen);
}/* 写日志目录区目录信息 */
int system_catalog_write(system_catalog_t *catalog, uint32_t id)
{uint32_t start_offset;uint32_t start_addr;uint32_t start_base;uint32_t remainbyte;int wlen = sizeof(system_catalog_t);uint8_t *pdata = (uint8_t *)catalog;flash_table_t *flash_tmp = get_flash_table(FLASH_CATALOG_ZONE);if (0 == id) return -1;start_addr = flash_tmp->start_address + wlen * (id - 1);if ((start_addr + wlen) > flash_tmp->end_address) {start_addr = flash_tmp->start_address;}/* 本扇区剩余空间大小 */remainbyte = FLASH_SECTOR_SIZE - (start_addr % FLASH_SECTOR_SIZE);/* 写入数据长度小于本扇区剩余长度，直接写入 */if (remainbyte > wlen) {remainbyte = wlen;}/* 写目录次数不会太频繁，视具体情况改写操作实现 */while (1) {start_base = SECTOR_BASE(start_addr);start_offset = SECTOR_OFFSET(start_addr);flash_read(FLASH_CATALOG_ZONE, start_base, sector_buf, FLASH_SECTOR_SIZE);flash_erase(FLASH_CATALOG_ZONE, start_base, FLASH_BLOCK_4K);memcpy((char *)&sector_buf[start_offset], pdata, remainbyte);flash_write(FLASH_CATALOG_ZONE, start_base, sector_buf, FLASH_SECTOR_SIZE);if (remainbyte == wlen) {break;} else {pdata += remainbyte;start_addr += remainbyte;wlen -= remainbyte;remainbyte = (wlen > FLASH_SECTOR_SIZE) ? FLASH_SECTOR_SIZE : wlen;}}return 0;
}

打印系统日志目录区信息，可实现通过指令查询到目录区信息。

int system_catalog_all_print(void)
{int i = 0;system_catalog_t catalog;printf("System Log Command Information:\r\n");printf("Query Specifies Log : AT+CATALOG=<LOG_ID><CR><LF>\r\n");printf("Query All Log : AT+CATALOG=<0><CR><LF>\r\n\r\n");printf("Query All System Catalog:\r\n");printf("LOG_ID    LOG_DATE    LOG_ADDR    LOG_OFFSET  \r\n");for (i = 0; i < gp_sys_log->system_log.catalog_num; i++) {/* 当前最新目录信息 */    if (i == (gp_sys_log->system_catalog.log_id - 1)) {catalog = gp_sys_log->system_catalog; /* 获取当前最新目录信息 */} else {system_catalog_read(&catalog, i + 1);}printf("%d    %04d-%02d-%02d    0x%08X    %d  \r\n", catalog.log_id, catalog.log_time.Year, catalog.log_time.Month, catalog.log_time.Day, catalog.log_addr, catalog.log_offset);memset((char *)&catalog, 0, sizeof(system_catalog_t));}return 0;
}

读取指定日志目录索引信息接口，可指定日志索引或者读取全部日志数据。

int system_log_task(int argc)
{int rlen = 0;uint32_t offset, start_addr, end_addr;system_catalog_t catalog;flash_table_t *flash_tmp =get_flash_table(FLASH_SYSLOG_ZONE);if (0 == gp_sys_ram->system_log_print_enable) return 1;gp_sys_ram->system_log_print_enable = 0x00;if (gp_sys_ram->system_log_print_id == ALL_LOG_PRINT) {/* log回环写标志,打印整个LOG存储区 */if (0x01 == gp_sys_log->system_log.log_cyclic_status) { start_addr = flash_tmp->start_address;end_addr = flash_tmp->end_address;offset = end_addr - start_addr;} else {start_addr = flash_tmp->start_address;end_addr = start_addr + gp_sys_log->system_log.write_pos;offset = gp_sys_log->system_log.write_pos;}} else { /* 读取指定ID日志 */if (gp_sys_ram->system_log_print_id == gp_sys_log->system_catalog.log_id) {catalog = gp_sys_log->system_catalog;} else {system_catalog_read(&catalog, gp_sys_ram->system_log_print_id);}start_addr = catalog.log_addr;offset = catalog.log_offset;}  if (0 == offset)return 1;while (1) {rlen = (offset > 512) ? 512 : offset;system_log_read(sector_buf, start_addr, rlen);HAL_Delay(80);/* 目录信息通过调式串口打印 */bsp_debug_send(sector_buf, rlen);start_addr += rlen;offset -= rlen;if (0 == offset) break;}return 0;
}

存储系统日志接口，实现更新存储日期，当写位置为扇区地址，则擦除一个扇区作为存储日志，这样避免每写一次就擦除一次。

int system_log_write(uint8_t *wbuf, int wlen)
{uint32_t start_addr;uint8_t *pdata = wbuf;uint32_t remainbyte;int system_catalog_max_id;flash_table_t *flash_tmp =get_flash_table(FLASH_SYSLOG_ZONE);/* 计算目录区的最大存储目录项个数 */system_catalog_max_id = ((flash_tmp->end_address - flash_tmp->start_address) / sizeof(system_catalog_t));start_addr = flash_tmp->start_address + gp_sys_log->system_log.write_pos;/* 存储数据地址大于规划内存地址范围处理 */if ((start_addr + wlen) > flash_tmp->end_address) { start_addr = flash_tmp->start_address;/* 写位置偏移量重置 */gp_sys_log->system_log.write_pos = 0;/* LOG回环存储标志置位 */gp_sys_log->system_log.log_cyclic_status = 0x01; }/* 写位置偏移 */gp_sys_log->system_log.write_pos += wlen; if ((gp_sys_log->system_log.log_latest_time.Year != gp_sys_log->system_catalog.log_time.Year) ||(gp_sys_log->system_log.log_latest_time.Month != gp_sys_log->system_catalog.log_time.Month) ||(gp_sys_log->system_log.log_latest_time.Day != gp_sys_log->system_catalog.log_time.Day)) {/* 日期改变，记录目录信息，当log_id为0，则不写入 */system_catalog_write(&gp_sys_log->system_catalog, gp_sys_log->system_catalog.log_id);/* 记录存储日期 */gp_sys_log->system_catalog.log_time = gp_sys_log->system_log.log_latest_time;if ((gp_sys_log->system_catalog.log_id + 1) >= system_catalog_max_id) {gp_sys_log->system_log.catalog_num = system_catalog_max_id; /* 目录循环写，目录数应为最大 */gp_sys_log->system_log.catalog_cyclic_status = 1; /* 目录回环写标志 */} else {if (0 == gp_sys_log->system_log.catalog_cyclic_status) {/* 获取目录数 */gp_sys_log->system_log.catalog_num = gp_sys_log->system_catalog.log_id + 1; }}/* 存储最新目录项信息 */gp_sys_log->system_catalog.log_id = (gp_sys_log->system_catalog.log_id + 1) % system_catalog_max_id;gp_sys_log->system_catalog.log_addr = start_addr;gp_sys_log->system_catalog.log_offset = wlen; } else {gp_sys_log->system_catalog.log_offset += wlen; }/* 写位置为存储起始地址并且不为扇区首地址 */if ((flash_tmp->start_address == start_addr) && (SECTOR_OFFSET(flash_tmp->start_address))){flash_read(FLASH_SYSLOG_ZONE, SECTOR_BASE(start_addr), sector_buf, FLASH_SECTOR_SIZE);flash_erase(FLASH_SYSLOG_ZONE, SECTOR_BASE(start_addr), FLASH_BLOCK_4K);/* 将扇区头部至起始地址区间的数据回写 */flash_write(FLASH_SYSLOG_ZONE, SECTOR_BASE(start_addr), &sector_buf[0], SECTOR_OFFSET(start_addr)); }/* 写位置为扇区首地址，则擦除一个扇区的存储区    */if (0 == SECTOR_OFFSET(start_addr)) {flash_erase(FLASH_SYSLOG_ZONE, SECTOR_BASE(start_addr), FLASH_BLOCK_4K);}/* 本扇区剩余空间大小 */remainbyte = FLASH_SECTOR_SIZE - (start_addr % FLASH_SECTOR_SIZE);/* 写入数据长度小于本扇区剩余长度，直接写入 */if (remainbyte > wlen) {remainbyte = wlen;}while (1) {flash_write(FLASH_SYSLOG_ZONE, start_addr, pdata, remainbyte);if (remainbyte == wlen) {break;} else {pdata += remainbyte;start_addr += remainbyte;wlen -= remainbyte;remainbyte = (wlen > FLASH_SECTOR_SIZE) ? FLASH_SECTOR_SIZE : wlen;/* 扇区首地址则擦除整个扇区，该扇区数据不保存 */if (0 == SECTOR_OFFSET(start_addr)) {flash_erase(FLASH_SYSLOG_ZONE, SECTOR_BASE(start_addr), FLASH_BLOCK_4K);}}}/* 环形存储参数 */save_system_log_param();return 0;
}

系统调试对接

为了更好记录系统日志，将应用调试等级结合一块，实现记录错误调试信息以及需要保存的关键信息。定义的调试等级有：关闭调试等级、错误调试等级、警告调试等级、关键调试等级、debug调试等级，而LOG_RECORD_LEVEL将主动保存日志并输出信息，LOG_ERROR_LEVEL会存储对应的日志信息，但需要根据应用调试等级输出信息。设置与读取应用调试等级由读者自行定义。

#define LOG_CLOSE_LEVEL        0x00 /* 关闭调试信息 */
#define LOG_ERROR_LEVEL        0x01 /* 错误调试信息 */
#define LOG_WARN_LEVEL        0x02 /* 警告调试信息 */
#define LOG_INFO_LEVEL        0x03 /* 关键调试信息 */
#define LOG_DEBUG_LEVEL        0x04 /* debug调试信息 */
#define LOG_RECORD_LEVEL      0x10 /* 保存日志并输出信息 */
#define LOG_PRINT_LEVEL        0xff#define SET_LOG_LEVEL(LEVEL)    (gp_sys_param->system_print_level = LEVEL)
#define GET_LOG_LEVEL()        (gp_sys_param->system_print_level)#define log_debug(fmt, args...)    log_format(LOG_DEBUG_LEVEL, fmt, ##args)
#define log_info(fmt, args...)    log_format(LOG_INFO_LEVEL, fmt, ##args)
#define log_warn(fmt, args...)    log_format(LOG_WARN_LEVEL, fmt, ##args)
#define log_error(fmt, args...)    log_format(LOG_ERROR_LEVEL, fmt, ##args)
#define log_record(fmt, args...)  log_format(LOG_RECORD_LEVEL, fmt, ##args)
#define printf(fmt, args...)    log_format(LOG_PRINT_LEVEL, fmt, ##args)typedef struct {int level;char *fmt_str;
}system_print_fmt_t;system_print_fmt_t system_print_fmt_list[] = {{ .level = LOG_ERROR_LEVEL,   .fmt_str = "<error>:"},{ .level = LOG_WARN_LEVEL,    .fmt_str = "<warn>:"},{ .level = LOG_INFO_LEVEL,    .fmt_str = "<info>:"},{ .level = LOG_DEBUG_LEVEL,   .fmt_str = "<debug>:"},{ .level = LOG_RECORD_LEVEL,  .fmt_str = "<record>:"},
};int log_format(uint8_t level, const char *fmt, ...)
{#define TIME_PREFIX_SIZE  (21)#define PRINT_MAX_SIZE    (1024 + TIME_PREFIX_SIZE)va_list args;int num = 0, i = 0, fmt_index = 0;int fmt_str_len = 0, ret = -1;int file_str_len = 0, line_str_len = 0;char line_buf[20] = {0};static char buf[PRINT_MAX_SIZE];static QueueHandle_t sem = NULL;time_t time = {0};/* 针对os系统 */if (NULL == sem) {sem = xSemaphoreCreateCounting(1, 1); /* always think of success */}xSemaphoreTake(sem, portMAX_DELAY);ret = -1;fmt_str_len = 0;if (level != LOG_PRINT_LEVEL) {if ((GET_LOG_LEVEL() < level) && (level != LOG_RECORD_LEVEL) && (level != LOG_ERROR_LEVEL))goto exit_end;for (i = 0; i < SYSTEM_PRINT_FMT_LIST_MAX; i++) {if (level == system_print_fmt_list[i].level) {fmt_index = i;break;}}if (i > SYSTEM_PRINT_FMT_LIST_MAX) {goto exit_end;}fmt_str_len = strlen(system_print_fmt_list[fmt_index].fmt_str);strncpy((char *)&buf[TIME_PREFIX_SIZE], system_print_fmt_list[fmt_index].fmt_str, fmt_str_len);}va_start(args, fmt);num = vsnprintf((char *)&buf[fmt_str_len + TIME_PREFIX_SIZE], PRINT_MAX_SIZE - fmt_str_len - TIME_PREFIX_SIZE - 2, fmt, args);va_end(args);if (num <= 0) {goto exit_end;}if (level != LOG_PRINT_LEVEL) {num += fmt_str_len;buf[num + TIME_PREFIX_SIZE] = '\r';buf[num + TIME_PREFIX_SIZE + 1] = '\n';num += 2;}if ((GET_LOG_LEVEL() < level) && (level == LOG_ERROR_LEVEL)) {//do nothing} else {ret = bsp_debug_send((uint8_t*)&buf[TIME_PREFIX_SIZE], num);  }if ((LOG_ERROR_LEVEL == level) || (LOG_RECORD_LEVEL == level)) {bsp_rtc_get_time(&time);sprintf(&buf[0], "[%04d-%02d-%02d %02d:%02d:%02d",time.Year, time.Month, time.Day,time.Hour, time.Minute, time.Second);buf[TIME_PREFIX_SIZE - 1] = ']';gp_sys_log->system_log.log_latest_time = time;system_log_write((uint8_t *)buf, num + TIME_PREFIX_SIZE);}  exit_end:xSemaphoreGive(sem);return ret;
}

结语

本文提供的一种简易嵌入式设备系统日志记录方法，代码量不多，实现简单，针对不同的设备需要合理规划内存使用。

根据软件运行状态，合适加入调试信息并保存对应的日志信息，方便开发人员了解系统或软件运行状况，协助开发分析数据资源从而更好完善系统，提高定位以及解决问题的效果。

来源地址：

https://blog.csdn.net/LiaRonBob/article/details/102766871

声明：本文素材来源网络，版权归原作者所有。如涉及作品版权问题，请与我联系删除。

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