132 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			132 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
/*
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 * (C) Copyright 2004
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 *  esd gmbh <www.esd-electronics.com>
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 *  Reinhard Arlt <reinhard.arlt@esd-electronics.com>
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 *
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 *  based on code of fs/reiserfs/dev.c by
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 *
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 *  (C) Copyright 2003 - 2004
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 *  Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com>
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 *
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 *  This program is free software; you can redistribute it and/or modify
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 *  it under the terms of the GNU General Public License as published by
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 *  the Free Software Foundation; either version 2 of the License, or
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 *  (at your option) any later version.
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 *
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 *  This program is distributed in the hope that it will be useful,
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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 *  GNU General Public License for more details.
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 *
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 *  You should have received a copy of the GNU General Public License
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 *  along with this program; if not, write to the Free Software
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 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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 */
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#include <common.h>
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#include <config.h>
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#include <ext2fs.h>
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static block_dev_desc_t *ext2fs_block_dev_desc;
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static disk_partition_t part_info;
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int ext2fs_set_blk_dev(block_dev_desc_t *rbdd, int part)
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{
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	ext2fs_block_dev_desc = rbdd;
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	if (part == 0) {
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		/* disk doesn't use partition table */
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		part_info.start = 0;
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		part_info.size = rbdd->lba;
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		part_info.blksz = rbdd->blksz;
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	} else {
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		if (get_partition_info
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		    (ext2fs_block_dev_desc, part, &part_info)) {
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			return 0;
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		}
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	}
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	return part_info.size;
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}
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int ext2fs_devread(int sector, int byte_offset, int byte_len, char *buf)
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{
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	ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, SECTOR_SIZE);
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	unsigned sectors;
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	/*
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	 *  Check partition boundaries
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	 */
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	if ((sector < 0) ||
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	    ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) >=
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		part_info.size)) {
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		/* errnum = ERR_OUTSIDE_PART; */
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		printf(" ** %s read outside partition sector %d\n",
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		       __func__,
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		       sector);
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		return 0;
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	}
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	/*
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	 *  Get the read to the beginning of a partition.
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	 */
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	sector += byte_offset >> SECTOR_BITS;
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	byte_offset &= SECTOR_SIZE - 1;
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	debug(" <%d, %d, %d>\n", sector, byte_offset, byte_len);
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	if (ext2fs_block_dev_desc == NULL) {
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		printf(" ** %s Invalid Block Device Descriptor (NULL)\n",
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		       __func__);
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		return 0;
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	}
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	if (byte_offset != 0) {
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		/* read first part which isn't aligned with start of sector */
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		if (ext2fs_block_dev_desc->
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		    block_read(ext2fs_block_dev_desc->dev,
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			       part_info.start + sector, 1,
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			       (unsigned long *) sec_buf) != 1) {
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			printf(" ** %s read error **\n", __func__);
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			return 0;
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		}
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		memcpy(buf, sec_buf + byte_offset,
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		       min(SECTOR_SIZE - byte_offset, byte_len));
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		buf += min(SECTOR_SIZE - byte_offset, byte_len);
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		byte_len -= min(SECTOR_SIZE - byte_offset, byte_len);
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		sector++;
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	}
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	/*  read sector aligned part */
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	sectors = byte_len / SECTOR_SIZE;
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	if (sectors > 0) {
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		if (ext2fs_block_dev_desc->block_read(
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			ext2fs_block_dev_desc->dev,
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			part_info.start + sector,
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			sectors,
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			(unsigned long *) buf) != sectors) {
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			printf(" ** %s read error - block\n", __func__);
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			return 0;
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		}
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		buf += sectors * SECTOR_SIZE;
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		byte_len -= sectors * SECTOR_SIZE;
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		sector += sectors;
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	}
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	if (byte_len != 0) {
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		/* read rest of data which are not in whole sector */
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		if (ext2fs_block_dev_desc->
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		    block_read(ext2fs_block_dev_desc->dev,
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			       part_info.start + sector, 1,
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			       (unsigned long *) sec_buf) != 1) {
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			printf(" ** %s read error - last part\n", __func__);
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			return 0;
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		}
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		memcpy(buf, sec_buf, byte_len);
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	}
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	return 1;
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}
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