什么是擦除?
把flash相关的区域数据bit置为1的过程
#include
#include
struct erase_info_user {
__u32 start; // 起点
__u32 length; //长度 块大小对齐 不然报参数失败
};
struct erase_info_user64 {
__u64 start;
__u64 length;
};
#include
#include
#include
#include
#include
#include
#include
#include
#include
int main()
{
int mtd_fd; // 文件描述符
struct erase_info_user erase; // 擦除信息结构体
unsigned int erase_start, erase_length;
struct mtd_info_user mtd_info;
struct timeval tv1,tv2;
// 打开MTD设备
mtd_fd = open("/dev/mtd1", O_RDWR);
if (mtd_fd < 0) {
perror("Error opening MTD device");
return EXIT_FAILURE;
}
// 获取MTD设备信息
if (ioctl(mtd_fd, MEMGETINFO, &mtd_info))
{
perror("Error getting MTD info");
close(mtd_fd);
return EXIT_FAILURE;
}
printf("MTD Device Info:\n");
printf(" type: %llu\n", mtd_info.type); //识别是nor flash 还是 nand flash
printf(" flags: %llu\n", mtd_info.flags);
printf(" Size: %llu\n", mtd_info.size); // 分区的大小
printf(" Erase Size: %u\n", mtd_info.erasesize); // 擦除块大小
printf(" Write Size: %u\n", mtd_info.writesize);
printf(" oobsize Size: %u\n", mtd_info.oobsize);
printf(" padding Size: %u\n", mtd_info.padding);
// 设置擦除的起始地址和长度
// 这些值应该基于设备的擦除块大小和你要擦除的区域
erase_start = 0; // 擦除起始地址
erase_length = 16*mtd_info.erasesize; // 擦除块数 // 1M空间
// 填充擦除信息结构体
erase.start = erase_start;
erase.length = erase_length;
gettimeofday(&tv1, NULL);
// 执行擦除操作
if (ioctl(mtd_fd, MEMERASE, &erase) < 0) {
perror("Error erasing MTD device");
close(mtd_fd);
return EXIT_FAILURE;
}
gettimeofday(&tv2, NULL);
printf("millisecond: %ld\n",(tv2.tv_sec * 1000 + tv2.tv_usec / 1000) - ( tv1.tv_sec * 1000 + tv1.tv_usec / 1000));
printf("Erase operation successful. erase.length is%d\n",erase.length);
// 关闭MTD设备
close(mtd_fd);
return EXIT_SUCCESS;
}
./mtd_test
MTD Device Info:
type: 3
flags: 3072
Size: 9437184
Erase Size: 65536
Write Size: 1
oobsize Size: 0
padding Size: 0
millisecond: 3797
Erase operation successful. erase.length is1048576
实践验证了 擦除1M nor flash(64K 块大小)花了3.7S 真的好慢
AC Characteristics