nandflash的mtdblock分区写入数据，重启后数据丢失
参照手册，如图，直接编写应用程序来对nandflash进行数据的存储操作。运行程序后能正常的读取和写入，但是掉电后再次读写，数据丢失了。是怎么回事？是不是块设备的读和写的应用函数写的不正确呢????
#include<sys/types.h>
#include<fcntl.h>
#include<sys/stat.h>
#include<unistd.h>
#include<stdio.h>
#include<string.h>
#include<errno.h>
#include<stdlib.h>
//#define BUF_SIZE 256
#define ROW 28
#define COLUMN 6
/* ./nandflash -w
./nandflash -r*/
int main(int argc, char **argv)
{
int ret = 0;
int i,j;
//char arr = {'0'};
//char buf = {'0'};
float data_base_write = {
1.891052295,1.880637028,1.880662672,1.880770901,1.879450873,1.880700352,
1.879935252,1.881508812,1.869690787,1.87005238, 1.870044239,1.859651899,
1.859074656,1.859008458,1.859362259,1.858735545,1.847817291,1.848525292,
1.848378952,1.880780544,1.88147216, 1.881095431,1.871008965,1.870199515,
1.870671536,1.859612464,1.86003391, 1.859165311,1.848139818,1.849201702,
1.883467744,1.862821112,1.85208504, 1.846950465,1.836828431,1.837161962,
1.831672258,1.821147095,1.816506092,1.81138156, 1.811605633,1.806054896,
1.813204183,1.806264194,1.795831025,1.78588526, 1.78032686, 1.81507569,
1.815702515,1.800243218,1.790447621,1.780343032,1.77532877, 1.770262973,
1.760081062,1.749647594,1.749650075,1.745028739,1.739645746,1.728564228,
1.723900325,1.713978878,1.7139702,1.703652117,1.704013747,1.693571616,
1.687657736,1.683074436,1.677927014,1.673206028,1.667436721,1.662266263,
1.657424307,1.652538685,1.647217463,1.636413681,1.636255431,1.641119179,
1.631570079,1.621213283,1.616427321,1.61582351, 1.61672418, 1.610865586,
1.600660337,1.595917449,1.596217952,1.595806511,1.590650782,1.688821116,
1.625993828,1.615743386,1.605662676,1.594974692,1.590410244,1.585351706,
1.579973715,1.575218547,1.569798485,1.570256538,1.565249874,1.559633934,
1.564982053,1.5749795,1.565281117,1.559755497,1.549897686,1.543877153,
1.545018749,1.544594015,1.534308672,1.528760394,1.528926025,1.52909165,
1.523905932,1.518667542,1.513648227,1.513605019,1.513947061,1.533959919,
1.53913728, 1.523624797,1.513581304,1.507785075,1.503196068,1.49782206,
1.492848535,1.49241439, 1.487482777,1.482535149,1.482787432,1.47697118,
1.481901555,1.49813662, 1.482077521,1.477115531,1.472077278,1.472248014,
1.467010667,1.46176725, 1.456695267,1.451354973,1.451615926,1.446816133,
1.446757061,1.441379748,1.436245625,1.436815415,1.436294515,1.441857532,
1.467206348,1.451864037,1.447137975,1.441790587,1.431630948,1.431808425,
1.426256259,1.426087753,1.421263351,1.416327275,1.416578183,1.410840173,
1.410994963,1.406171429,1.406335848,1.40045524, 1.421786505,1.432455272
};
float data_base_read = {0.0};
int fd = open("/dev/mtdblock7", O_RDWR);
if (fd < 0) {
perror("open nandflash device:");
exit(1);
}
if(argc < 2)
{
printf("please input correct argument\n");
exit(1);
}
if(!strcmp(argv,"-w"))
{
/*if(argc != 3)
{
printf("please input like this : ./nandflash -wforlinx\n");
exit(1);
}
strcpy(arr,argv);
ret = write(fd,arr,strlen(arr));
*/
ret = write(fd, data_base_write, sizeof(data_base_write));
printf("%d data has been writen\n",sizeof(data_base_write)/sizeof(float));
if(ret < 0)
{
fprintf(stderr,"error nandflash_write: %s\n",strerror(errno));
exit(1);
}
// printf("write ret = %d\n",ret);
// ret = lseek(fd,30,SEEK_SET);
// ret = write(fd,arr,strlen(arr) + 1);
// if(ret < 0)
// {
// fprintf(stderr,"error eeprom_write: %s\n",strerror(errno));
// exit(1);
// }
// printf("write ret = %d\n",ret);
}
if(!strcmp(argv,"-r"))
{
if(argc != 2)
{
printf("please input like this : ./nandflash -r\n");
exit(1);
}
//ret =read(fd,buf,BUF_SIZE);
ret = read(fd, data_base_read, sizeof(data_base_write));
if(ret < 0)
{
fprintf(stderr,"error nandflash_read: %s\n",strerror(errno));
exit(1);
}
//printf("the value inbuf is%s\n",buf);
for(i = 0;i < ROW;i++)
for(j = 0;j < COLUMN;j++)
{
printf("%.9f",data_base_read);
if (j==COLUMN-1)
printf("\n");
}
/* ret = lseek(fd,6,SEEK_SET);
ret =read(fd,buf,BUF_SIZE);
if(ret < 0)
{
fprintf(stderr,"error nandflash_read: %s\n",strerror(errno));
exit(1);
}
printf("lseek to the seventh bytes in buf is %s\n",buf);
*/
}
close(fd);
return 0;
您好，您可以直接通过sd卡或者u盘 拷贝一些文件放到开发板的文件系统中，然后sync同步一下，重启看看文件有没有丢失，如果该操作正常的话，那您就检查检查您的应用代码可能是有些地方没有写好。
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