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-rw-r--r--fs/ext2/dev.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/fs/ext2/dev.c b/fs/ext2/dev.c
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+++ b/fs/ext2/dev.c
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+/*
+ * (C) Copyright 2004
+ * esd gmbh <www.esd-electronics.com>
+ * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
+ *
+ * based on code of fs/reiserfs/dev.c by
+ *
+ * (C) Copyright 2003 - 2004
+ * Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include <common.h>
+#if (CONFIG_COMMANDS & CFG_CMD_EXT2)
+
+#include <config.h>
+#include <ext2fs.h>
+
+static block_dev_desc_t *ext2fs_block_dev_desc;
+static disk_partition_t part_info;
+
+#undef DEBUG
+int ext2fs_set_blk_dev
+ (
+ block_dev_desc_t *rbdd,
+ int part
+ )
+ {
+ ext2fs_block_dev_desc = rbdd;
+
+ if (part == 0)
+ {
+ /* disk doesn't use partition table */
+ part_info.start = 0;
+ part_info.size = rbdd->lba;
+ part_info.blksz = rbdd->blksz;
+ }
+ else
+ {
+ if (get_partition_info (ext2fs_block_dev_desc, part, &part_info))
+ {
+ return 0;
+ }
+ }
+ return (part_info.size);
+ }
+
+
+int ext2fs_devread
+ (
+ int sector,
+ int byte_offset,
+ int byte_len,
+ char *buf
+ )
+ {
+ char sec_buf[SECTOR_SIZE];
+ unsigned block_len;
+/*
+ * Check partition boundaries
+ */
+ if ((sector < 0) || ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) >= part_info.size))
+ {
+/* errnum = ERR_OUTSIDE_PART; */
+ printf (" ** ext2fs_devread() read outside partition sector %d\n", sector);
+ return(0);
+ }
+
+/*
+ * Get the read to the beginning of a partition.
+ */
+ sector += byte_offset >> SECTOR_BITS;
+ byte_offset &= SECTOR_SIZE - 1;
+
+#if defined(DEBUG)
+ printf (" <%d, %d, %d>\n", sector, byte_offset, byte_len);
+#endif
+
+ if (ext2fs_block_dev_desc == NULL)
+ {
+ printf("** Invalid Block Device Descriptor (NULL)\n");
+ return(0);
+ }
+
+ if (byte_offset != 0)
+ {
+/* read first part which isn't aligned with start of sector */
+ if (ext2fs_block_dev_desc->block_read(ext2fs_block_dev_desc->dev, part_info.start+sector, 1, (unsigned long *)sec_buf) != 1)
+ {
+ printf (" ** ext2fs_devread() read error **\n");
+ return(0);
+ }
+ memcpy(buf, sec_buf+byte_offset, min(SECTOR_SIZE-byte_offset, byte_len));
+ buf+=min(SECTOR_SIZE-byte_offset, byte_len);
+ byte_len-=min(SECTOR_SIZE-byte_offset, byte_len);
+ sector++;
+ }
+
+/* read sector aligned part */
+ block_len = byte_len & ~(SECTOR_SIZE-1);
+ if (ext2fs_block_dev_desc->block_read(ext2fs_block_dev_desc->dev,
+ part_info.start+sector,
+ block_len/SECTOR_SIZE,
+ (unsigned long *)buf) != block_len/SECTOR_SIZE)
+ {
+ printf (" ** ext2fs_devread() read error - block\n");
+ return(0);
+ }
+ buf+=block_len;
+ byte_len-=block_len;
+ sector+= block_len/SECTOR_SIZE;
+
+ if (byte_len != 0)
+ {
+/* read rest of data which are not in whole sector */
+ if (ext2fs_block_dev_desc->block_read(ext2fs_block_dev_desc->dev,
+ part_info.start+sector,
+ 1,
+ (unsigned long *)sec_buf) != 1)
+ {
+ printf (" ** ext2fs_devread() read error - last part\n");
+ return(0);
+ }
+ memcpy(buf, sec_buf, byte_len);
+ }
+ return(1);
+ }
+#endif /* CFG_CMD_EXT2FS */