From 2b9187127f6c1fe23adcbec3c390b9bf87779100 Mon Sep 17 00:00:00 2001
From: stroese <stroese>
Date: Thu, 16 Dec 2004 17:26:24 +0000
Subject: ext2fs support added

---
 fs/ext2/dev.c | 142 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 142 insertions(+)
 create mode 100644 fs/ext2/dev.c

(limited to 'fs/ext2/dev.c')

diff --git a/fs/ext2/dev.c b/fs/ext2/dev.c
new file mode 100644
index 0000000000..117a44984e
--- /dev/null
+++ b/fs/ext2/dev.c
@@ -0,0 +1,142 @@
+/*
+ * (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 */
-- 
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