在应用程序中操作NorFlash

相对于操作NandFlash，操作NorFlash相对简单，因为基本不需要考虑坏块，NorFlash也没有OOB区域，也跟ECC没有一毛钱关系。它的读写擦除相对容易。

int dealwithnor()
{

//    glob_t mtdbuf;
    struct mtd_info_user mtd;
    struct erase_info_user erase;
    int blocks = ;
    int i = ;  //用于控制擦除的块的个数
    int k = ;
    int written = ;  //已写入的字节数，只初始化一次
    unsigned int size = StateOfImage.st_size;  //应该是镜像的实际大小，因为内存中大于镜像的空间的内容不可预知
    unsigned int result = ;
    unsigned int DevNum = ;    //设备的数量
    unsigned int StartDev = ;  //从第startDev开始擦除
    char DevName[] = {};
    unsigned int AllSize = ;
    #define MAXPARTITIONS 40
    struct DeviceInfo
    {
        int fd;
        char dir[];
        uint32_t size;     // Total size of the MTD
        uint32_t erasesize;

    }DevInfo[MAXPARTITIONS];//用来存储设备信息

    bzero(DevInfo, sizeof(struct DeviceInfo));

/* 这是一种方法，但是有一个缺点，当mtd设备大于10个是，通过glob搜索出来的结果
   会出问题，下面采用会采用第二种方法 */
//    if(searchmtd(&mtdbuf) != 0){

//        DEBUG("Sorry! Can not find mtd device\n");
//        return 1;   //返回大于零的数，表示升级失败
//    }
//    else
//    {
//        int fd;
//
//        DEBUG("find %d mtd devices \n",mtdbuf.gl_pathc);
//        DevNum = mtdbuf.gl_pathc;

//        for(i=0; i<DevNum; i++)
//        {
//            fd = safeOpen (mtdbuf.gl_pathv[i],O_SYNC | O_RDWR);
//            if(fd < 0)
//            {
//                printf("failt to open\n");
//                return 1;
//            }
//            bzero(&mtd, sizeof(struct mtd_info_user));
//            if (ioctl(fd, MEMGETINFO,&mtd) < 0)
//            {
//                DEBUG("ioctl(): %m\n");
//                DEBUG("This doesn't seem to be a valid MTD flash device!\n");
//                return 1;
//            }
//
//            strcpy(DevInfo[i].dir, mtdbuf.gl_pathv[i]);
//            DevInfo[i].fd = fd;
//            DevInfo[i].size = mtd.size;
//            DevInfo[i].erasesize = mtd.erasesize;
//        }

//        globfree(&mtdbuf);
//        for(i=0; i<DevNum; i++)
//        {
//            printf("\n\tinfo of %s\n",DevInfo[i].dir);
//            printf("%s.fd:            %d\n",DevInfo[i].dir, DevInfo[i].fd);
//            printf("%s.size:          %d\n",DevInfo[i].dir,DevInfo[i].size);
//            printf("%s.erasesize:     %d\n",DevInfo[i].dir,DevInfo[i].erasesize);
//        }
//    }

/* 下面是第二种方法，这种方法克服了第一种方法的缺陷，不受mtd设备数量的限制 */

    for(i=; i<MAXPARTITIONS; i++)
    {
        int fd;
        sprintf(DevName, "%s%d", "/dev/mtd",i);

        if((fd = open (DevName,O_SYNC | O_RDWR)) > )
        {
            bzero(&mtd, sizeof(struct mtd_info_user));
            if (ioctl(fd, MEMGETINFO,&mtd) < )
            {
                DEBUG("ioctl(): %m\n");
                DEBUG("This doesn't seem to be a valid MTD flash device!\n");
                return ;
            }
            strcpy(DevInfo[i].dir, DevName);
            DevInfo[i].fd = fd;
            DevInfo[i].size = mtd.size;
            DevInfo[i].erasesize = mtd.erasesize;
        }
        else
        {
            DevNum = i;
            break;
        }

    }

    for(i=; i<DevNum; i++)
    {
        printf("\n\tinfo of %s\n",DevInfo[i].dir);
        printf("%s.fd:            %d\n",DevInfo[i].dir, DevInfo[i].fd);
        printf("%s.size:          %d\n",DevInfo[i].dir,DevInfo[i].size);
        printf("%s.erasesize:     %d\n",DevInfo[i].dir,DevInfo[i].erasesize);
        AllSize += DevInfo[i].size;
     }

    if(AllSize < StateOfImage.st_size)
    {
        DEBUG("ERROR!! all device size is less than ImageSize\n");
        return ;
    }

    for(i=StartDev; i<DevNum; i++)
    {

      /**
       * 先进行擦除操作
       */
        int j = ;
        g_AllImgSize = DevInfo[i].size;
        g_AllImgWrite = ;
        erase.start = ;
        blocks = DevInfo[i].size / mtd.erasesize;  //计算要擦除的块的个数
        erase.length = mtd.erasesize;
        printf ("\nbegin to erase block %s\n", DevInfo[i].dir);
        for (j= ; j <= blocks; j++)
        {
            fprintf(stderr, "\rErasing blocks: %d/%d (%d%%)", j, blocks, (int)PERCENTAGE (j, blocks));
            g_percentage =  * ((float)g_AllImgWrite / g_AllImgSize);
              if (ioctl(DevInfo[i].fd, MEMERASE, &erase) < )
              {
                DEBUG("\n");
                DEBUG("While erasing blocks 0x%.8x-0x%.8x on %s\n",\
                (unsigned int) erase.start, (unsigned int) (erase.start + erase.length), DevInfo[i].dir);
                /*return "Error while erasing blocks";*/
                return ;
            }
            g_AllImgWrite += erase.length;
            erase.start += mtd.erasesize;
        }
        printf("\n\rErased blocks: %d/%d (100%%)\n", blocks, blocks); 

        /**
         * 再进行写操作
         */
        printf ("\nbegin to write block %s\n\n", DevInfo[i].dir);
        g_AllImgWrite = ;
        k = BUFSIZE;
        while (size)
        {
            if (size < BUFSIZE)
            {
                k = size;
            }
            printf("\033[1A");
            printf("\r%s usage: %dk/%dk (%d%%)\n",\
            DevInfo[i].dir, KB (g_AllImgWrite + k), KB (DevInfo[i].size), (int)PERCENTAGE (g_AllImgWrite + k, DevInfo[i].size));
            fprintf(stderr, "Writing data: %dk/%ldk (%d%%)", KB (written + k), KB (StateOfImage.st_size), (int)PERCENTAGE (written + k, StateOfImage.st_size));
            result = write(DevInfo[i].fd, &upPack[written], k);
            if (k != result)
            {
                DEBUG ("\n");
                if (result < )
                {
                    DEBUG("While writing data to 0x%.8x-0x%.8x on %s\n", written, written + k, DevInfo[i].dir);
                      return ;
                }
                DEBUG("Short write count returned while writing to x%.8x-0x%.8x on %s: %d/%d bytes written to flash\n", \
                        written,written + k, DevInfo[i].dir, written + result, DevInfo[i].size);
                return ;
            }

            written += k;
            size -= k;

             g_AllImgWrite += k;
            if(g_AllImgWrite >= DevInfo[i].size)
            {
                g_AllImgWrite = ;
                printf("\n");
                break;
            }

        }
        printf("Wrote %d / %ldk bytes\n", written, (unsigned long int)(StateOfImage.st_size));        

    }

    munmap(upPack, UPGRADE_SHM_SIZE);
    for(i=; i<DevNum; i++)
    {
        close (DevInfo[i].fd);
        printf("%s is closed!\n",DevInfo[i].dir);
    }

    return ;
}