diff options
Diffstat (limited to 'fs/ext2/dev.c')
| -rw-r--r-- | fs/ext2/dev.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/fs/ext2/dev.c b/fs/ext2/dev.c new file mode 100644 index 0000000..117a449 --- /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 */ |