android_device_allwinner-full/tulip-common/sunxi-nand-part/nand-part-main.c
2016-09-03 22:14:59 +02:00

117 lines
2.8 KiB
C

/*
* (C) Copyright 2013
* Patrick H Wood, All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
*/
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <errno.h>
#include <fcntl.h>
#include "nand-common.h"
int checkmbrs_a64(int fd);
int nand_part_a64(int argc, char **argv, const char *cmd, int fd, int force);
void usage(const char *cmd)
{
printf("usage: %s [-f a64] nand-device\n", cmd);
printf(" %s nand-device 'name2 len2 [usertype2]' ['name3 len3 [usertype3]'] ...\n", cmd);
printf(" %s [-f a64] nand-device start1 'name1 len1 [usertype1]' ['name2 len2 [usertype2]'] ...\n", cmd);
}
typedef struct tag_CRC32_DATA
{
__u32 CRC; //int的大小是32位
__u32 CRC_32_Tbl[256]; //用来保存码表
}CRC32_DATA_t;
__u32 calc_crc32(void * buffer, __u32 length)
{
__u32 i, j;
CRC32_DATA_t crc32; //
__u32 CRC32 = 0xffffffff; //设置初始值
crc32.CRC = 0;
for( i = 0; i < 256; ++i)//用++i以提高效率
{
crc32.CRC = i;
for( j = 0; j < 8 ; ++j)
{
//这个循环实际上就是用"计算法"来求取CRC的校验码
if(crc32.CRC & 1)
crc32.CRC = (crc32.CRC >> 1) ^ 0xEDB88320;
else //0xEDB88320就是CRC-32多项表达式的值
crc32.CRC >>= 1;
}
crc32.CRC_32_Tbl[i] = crc32.CRC;
}
CRC32 = 0xffffffff; //设置初始值
for( i = 0; i < length; ++i)
{
CRC32 = crc32.CRC_32_Tbl[(CRC32^((unsigned char*)buffer)[i]) & 0xff] ^ (CRC32>>8);
}
//return CRC32;
return CRC32^0xffffffff;
}
int main (int argc, char **argv)
{
char *nand = "/dev/nand";
const char *cmd = argv[0];
int fd;
int force = 0; // force write even if magics and CRCs don't match
argc--;
argv++;
if (argc > 1) {
if (!strcmp(argv[0], "-f")) {
if (!strcasecmp(argv[1], "a64"))
force = 64;
else {
usage(cmd);
return -1;
}
argc -= 2;
argv += 2;
}
}
if (argc > 0) {
nand = argv[0];
argc--;
argv++;
}
fd = open(nand, O_RDWR);
if (fd < 0) {
fprintf(stderr, "failed to open %s: %s\n", nand, strerror(errno));
usage(cmd);
return -2;
}
if (force == 64)
return nand_part_a64 (argc, argv, cmd, fd, force);
if (checkmbrs_a64(fd))
return nand_part_a64 (argc, argv, cmd, fd, force);
return -1;
}