nand-part: rename `mbr` to a more meaningful name

1 files changed, 321 insertions, 0 deletions

diff --git a/nand-part.c b/nand-part.c
new file mode 100644
index 0000000..2e11bfb
--- /dev/null
+++ b/nand-part.c
@@ -0,0 +1,321 @@
+/*
+ * mbr.c
+ * (C) Copyright 2012
+ * Patrick H Wood, All rights reserved.
+ * Heavily modified from the Allwinner file drivers/block/sun4i_nand/nfd/mbr.c.
+ * (Allwinner copyright block retained below.)
+ *
+ * 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
+ *
+ */
+
+/*
+ * drivers/block/sun4i_nand/nfd/mbr.c
+ * (C) Copyright 2007-2012
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ *
+ * 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 <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include "nand-part.h"
+
+#define MAX_NAME 16
+
+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;
+}
+
+MBR *_get_mbr(int fd, int mbr_num)
+{
+	MBR *mbr;
+
+	/*request mbr space*/
+	mbr = malloc(sizeof(MBR));
+	if(mbr == NULL)
+	{
+		printf("%s : request memory fail\n",__FUNCTION__);
+		return NULL;
+	}
+
+	/*get mbr from nand device*/
+	lseek(fd,MBR_START_ADDRESS + MBR_SIZE*mbr_num,SEEK_SET);
+	if(read(fd,mbr,MBR_SIZE) == MBR_SIZE)
+	{
+		/*checksum*/
+		printf("check partition table copy %d: ", mbr_num);
+		if(*(__u32 *)mbr == calc_crc32((__u32 *)mbr + 1,MBR_SIZE - 4))
+		{
+			printf("OK\n");
+			return mbr;
+		}
+		printf("BAD!\n");
+	}
+	return NULL;
+}
+
+__s32 _free_mbr(MBR *mbr)
+{
+	if(mbr)
+	{
+		free(mbr);
+		mbr = 0;
+	}
+
+	return 0;
+}
+
+void checkmbrs(int fd)
+{
+	int part_cnt = 0;
+	int i;
+	MBR *mbrs[MBR_COPY_NUM];
+	MBR *mbr = NULL;
+
+	memset((void *) mbrs, 0, sizeof(mbrs));
+	for (i = 0; i < MBR_COPY_NUM; i++) {
+		mbrs[i] = _get_mbr(fd, i);
+		if (mbrs[i])
+			mbr = mbrs[i];
+	}
+	if (!mbr) {
+		printf("all partition tables are bad!\n");
+		for (i = 0; i < MBR_COPY_NUM; i++) {
+			if (mbrs[i])
+				_free_mbr(mbrs[i]);
+		}
+		return;
+	}
+
+	for(part_cnt = 0; part_cnt < mbr->PartCount && part_cnt < MAX_PART_COUNT; part_cnt++)
+	{
+		if((mbr->array[part_cnt].user_type == 2) || (mbr->array[part_cnt].user_type == 0))
+		{
+			printf("partition %2d: name = %12s, partition start = %8d, partition size = %8d\n",
+						part_cnt,
+						mbr->array[part_cnt].name,
+						mbr->array[part_cnt].addrlo,
+						mbr->array[part_cnt].lenlo);
+		}
+	}
+	for (i = 0; i < MBR_COPY_NUM; i++) {
+		if (mbrs[i])
+			_free_mbr(mbrs[i]);
+	}
+	printf("%d partitions\n", part_cnt);
+}
+
+int writembrs(int fd, char names[][MAX_NAME], __u32 *lens, int nparts)
+{
+	int part_cnt = 0;
+	int i;
+	__u32 start;
+	char yn = 'n';
+	MBR *mbrs[MBR_COPY_NUM];
+	MBR *mbr = NULL;
+	FILE *backup;
+
+	memset((void *) mbrs, 0, sizeof(mbrs));
+	for (i = 0; i < MBR_COPY_NUM; i++) {
+		mbrs[i] = _get_mbr(fd, i);
+		if (mbrs[i])
+			mbr = mbrs[i];
+	}
+	if (!mbr) {
+		printf("all partition tables are bad!\n");
+		for (i = 0; i < MBR_COPY_NUM; i++) {
+			if (mbrs[i])
+				_free_mbr(mbrs[i]);
+		}
+		return 0;
+	}
+	// back up mbr data
+	backup = fopen("nand_mbr.backup", "w");
+	if (!backup) {
+		printf("can't open nand_mbr.backup to back up mbr data\n");
+		for (i = 0; i < MBR_COPY_NUM; i++) {
+			if (mbrs[i])
+				_free_mbr(mbrs[i]);
+		}
+		return 0;
+	}
+
+	for(part_cnt = 1; part_cnt < mbr->PartCount && part_cnt < MAX_PART_COUNT; part_cnt++)
+	{
+		if((mbr->array[part_cnt].user_type == 2) || (mbr->array[part_cnt].user_type == 0))
+		{
+			fprintf(backup, "'%s %d' ", mbr->array[part_cnt].name,
+			                  mbr->array[part_cnt].lenlo);
+		}
+	}
+	fprintf(backup, "\n");
+	fclose(backup);
+
+	// don't muck with first partition
+	mbr->PartCount = nparts + 1;
+	start = mbr->array[0].addrlo + mbr->array[0].lenlo;
+	for(i = 0; i < nparts; i++) {
+		strcpy((char *)mbr->array[i+1].name, names[i]);
+		strcpy((char *)mbr->array[i+1].classname, "DISK");
+		memset(mbr->array[i+1].res, 0, sizeof(mbr->array[i+1].res));
+		mbr->array[i+1].user_type = 0;
+		mbr->array[i+1].ro = 0;
+		mbr->array[i+1].addrhi = 0;
+		mbr->array[i+1].lenhi = 0;
+		mbr->array[i+1].addrlo = start;
+		mbr->array[i+1].lenlo = lens[i];
+		start += lens[i];
+	}
+
+	printf("\nready to write new partition tables:\n");
+	for(part_cnt = 0; part_cnt < mbr->PartCount && part_cnt < MAX_PART_COUNT; part_cnt++)
+	{
+		if((mbr->array[part_cnt].user_type == 2) || (mbr->array[part_cnt].user_type == 0))
+		{
+			printf("partition %2d: name = %12s, partition start = %8d, partition size = %8d\n",
+						part_cnt,
+						mbr->array[part_cnt].name,
+						mbr->array[part_cnt].addrlo,
+						mbr->array[part_cnt].lenlo);
+		}
+	}
+	for (i = 0; i < MBR_COPY_NUM; i++) {
+		if (mbrs[i])
+			_free_mbr(mbrs[i]);
+	}
+	printf("%d partitions\n", part_cnt);
+	printf("\nwrite new partition tables? (Y/N)\n");
+	read(0, &yn, 1);
+	if (yn != 'Y' && yn != 'y') {
+		printf("aborting\n");
+		return 0;
+	}
+
+	for (i = 0; i < MBR_COPY_NUM; i++) {
+		mbr->index = i;
+		// calculate new checksum
+		*(__u32 *)mbr = calc_crc32((__u32 *)mbr + 1,MBR_SIZE - 4);
+		lseek(fd,MBR_START_ADDRESS + MBR_SIZE*i,SEEK_SET);
+		write(fd,mbr,MBR_SIZE);
+	}
+	return 1;
+}
+
+int main (int argc, char **argv)
+{
+	int fd;
+	int i;
+	char *nand = "/dev/nand";
+	char *cmd = argv[0];
+	char names[MAX_PART_COUNT][MAX_NAME];
+	__u32 lens[MAX_PART_COUNT];
+
+	argc--;
+	argv++;
+
+	if (argc > 0) {
+		nand = argv[0];
+		argc--;
+		argv++;
+	}
+	fd = open(nand, O_RDWR);
+	if (fd < 0) {
+		printf("usage: %s nand-device \'name2 len2\' [\'name3 len3\'] ...\n", cmd);
+		return -1;
+	}
+
+	// parse name/len arguments
+	if (argc > 0) {
+		for (i = 0; i < argc; i++) {
+			if (sscanf(argv[i], "%s %d", names[i], &lens[i]) != 2) {
+				printf("bad 'name len' argument\n");
+				printf("usage: %s nand-device \'name2 len2\' [\'name3 len3\'] ...\n", cmd);
+				close(fd);
+				return -3;
+			}
+		}
+	}
+
+	checkmbrs(fd);
+
+	if (argc > MAX_PART_COUNT - 1) {
+		printf("too many partitions specified (MAX 14)\n");
+		printf("usage: %s nand-device \'name2 len2\' [\'name3 len3\'] ...\n", cmd);
+		close(fd);
+		return -2;
+	}
+
+
+	if (argc > 0) {
+		if (writembrs(fd, names, lens, argc)) {
+			printf("\nverifying new partition tables:\n");
+			checkmbrs(fd);
+		}
+	}
+	close(fd);
+
+	return 0;
+}