Patchwork [U-Boot,V4,1/2] ext4fs ls load support

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Submitter uma.shankar@samsung.com
Date Jan. 9, 2012, 5:54 p.m.
Message ID <1326131690-25090-1-git-send-email-uma.shankar@samsung.com>
Download mbox | patch
Permalink /patch/135080/
State Superseded
Headers show

Comments

uma.shankar@samsung.com - Jan. 9, 2012, 5:54 p.m.
From: uma.shankar <uma.shankar@samsung.com>

Signed-off-by: Uma Shankar <uma.shankar@samsung.com>
Signed-off-by: Manjunatha C Achar <a.manjunatha@samsung.com>
Signed-off-by: Iqbal Shareef <iqbal.ams@samsung.com>
Signed-off-by: Hakgoo Lee <goodguy.lee@samsung.com>
---
Changes for v3:
        - Copyright has been updated in respective files
        - ext4fs has been made independant of ext2fs.c
        - Fixed API namespace
        - Removed endianness conversion API, used uboot defined API
          for the same
        - Fixed coding style issues
        - Moved README.ext4 file into doc folder

Changes for v2:
        - Code cleanup, changed comment style
        - camel case removed, resolved code alignment issues
        - memory allocation logic changed, removed busybox logic
        - Modified ext4 load to remove grub dependency (GPLv3)
        - Introduced new Config for ext4 write

Changes for v1:
        - Removed checkpatch warnings and errors
        - Moved common API's of ext2 and ext4 to one generic header file

 Makefile              |    2 +-
 common/Makefile       |    1 +
 common/cmd_ext4.c     |  266 +++++++++++++++
 fs/Makefile           |    1 +
 fs/ext2/dev.c         |    1 +
 fs/ext2/ext2fs.c      |  181 ++---------
 fs/ext4/Makefile      |   51 +++
 fs/ext4/dev.c         |  145 ++++++++
 fs/ext4/ext4_common.c |  875 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/ext4/ext4_common.h |   63 ++++
 fs/ext4/ext4fs.c      |  228 +++++++++++++
 include/ext4fs.h      |  132 ++++++++
 include/ext_common.h  |  188 +++++++++++
 13 files changed, 1977 insertions(+), 157 deletions(-)
 create mode 100644 common/cmd_ext4.c
 create mode 100644 fs/ext4/Makefile
 create mode 100644 fs/ext4/dev.c
 create mode 100644 fs/ext4/ext4_common.c
 create mode 100644 fs/ext4/ext4_common.h
 create mode 100644 fs/ext4/ext4fs.c
 create mode 100644 include/ext4fs.h
 create mode 100644 include/ext_common.h
Rob Herring - March 22, 2012, 3:49 p.m.
On 01/09/2012 11:54 AM, uma.shankar@samsung.com wrote:
> From: uma.shankar <uma.shankar@samsung.com>
> 
> Signed-off-by: Uma Shankar <uma.shankar@samsung.com>
> Signed-off-by: Manjunatha C Achar <a.manjunatha@samsung.com>
> Signed-off-by: Iqbal Shareef <iqbal.ams@samsung.com>
> Signed-off-by: Hakgoo Lee <goodguy.lee@samsung.com>
> ---
> Changes for v3:
>         - Copyright has been updated in respective files
>         - ext4fs has been made independant of ext2fs.c
>         - Fixed API namespace
>         - Removed endianness conversion API, used uboot defined API
>           for the same
>         - Fixed coding style issues
>         - Moved README.ext4 file into doc folder
> 
> Changes for v2:
>         - Code cleanup, changed comment style
>         - camel case removed, resolved code alignment issues
>         - memory allocation logic changed, removed busybox logic
>         - Modified ext4 load to remove grub dependency (GPLv3)
>         - Introduced new Config for ext4 write
> 
> Changes for v1:
>         - Removed checkpatch warnings and errors
>         - Moved common API's of ext2 and ext4 to one generic header file
> 
>  Makefile              |    2 +-
>  common/Makefile       |    1 +
>  common/cmd_ext4.c     |  266 +++++++++++++++

I don't think we need yet another version of filesystem commands that
just duplicates the same code.

I tested this patch and can read ext2 partitions with the ext4ls/load
commands. Using ext2 commands on an ext4 partition will hang now. You
should merge your ext4 command changes into the existing ext2 commands
so that commands work on either ext2/3 or ext4 partitions.

Really, I would like to see all the block based device and file commands
collapsed down into just fsls and fsload commands and then detect (or
specify if necessary) the fs type. But that's a bigger problem.

Rob

>  fs/Makefile           |    1 +
>  fs/ext2/dev.c         |    1 +
>  fs/ext2/ext2fs.c      |  181 ++---------
>  fs/ext4/Makefile      |   51 +++
>  fs/ext4/dev.c         |  145 ++++++++
>  fs/ext4/ext4_common.c |  875 +++++++++++++++++++++++++++++++++++++++++++++++++
>  fs/ext4/ext4_common.h |   63 ++++
>  fs/ext4/ext4fs.c      |  228 +++++++++++++
>  include/ext4fs.h      |  132 ++++++++
>  include/ext_common.h  |  188 +++++++++++
>  13 files changed, 1977 insertions(+), 157 deletions(-)
>  create mode 100644 common/cmd_ext4.c
>  create mode 100644 fs/ext4/Makefile
>  create mode 100644 fs/ext4/dev.c
>  create mode 100644 fs/ext4/ext4_common.c
>  create mode 100644 fs/ext4/ext4_common.h
>  create mode 100644 fs/ext4/ext4fs.c
>  create mode 100644 include/ext4fs.h
>  create mode 100644 include/ext_common.h
> 
> diff --git a/Makefile b/Makefile
> index 7e9491d..e77f6be 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -235,7 +235,7 @@ LIBS += dts/libdts.o
>  endif
>  LIBS += arch/$(ARCH)/lib/lib$(ARCH).o
>  LIBS += fs/cramfs/libcramfs.o fs/fat/libfat.o fs/fdos/libfdos.o fs/jffs2/libjffs2.o \
> -	fs/reiserfs/libreiserfs.o fs/ext2/libext2fs.o fs/yaffs2/libyaffs2.o \
> +	fs/reiserfs/libreiserfs.o fs/ext2/libext2fs.o fs/ext4/libext4fs.o fs/yaffs2/libyaffs2.o \
>  	fs/ubifs/libubifs.o
>  LIBS += net/libnet.o
>  LIBS += disk/libdisk.o
> diff --git a/common/Makefile b/common/Makefile
> index 2d9ae8c..f5243f6 100644
> --- a/common/Makefile
> +++ b/common/Makefile
> @@ -86,6 +86,7 @@ COBJS-$(CONFIG_ENV_IS_IN_EEPROM) += cmd_eeprom.o
>  COBJS-$(CONFIG_CMD_EEPROM) += cmd_eeprom.o
>  COBJS-$(CONFIG_CMD_ELF) += cmd_elf.o
>  COBJS-$(CONFIG_SYS_HUSH_PARSER) += cmd_exit.o
> +COBJS-$(CONFIG_CMD_EXT4) += cmd_ext4.o
>  COBJS-$(CONFIG_CMD_EXT2) += cmd_ext2.o
>  COBJS-$(CONFIG_CMD_FAT) += cmd_fat.o
>  COBJS-$(CONFIG_CMD_FDC)$(CONFIG_CMD_FDOS) += cmd_fdc.o
> diff --git a/common/cmd_ext4.c b/common/cmd_ext4.c
> new file mode 100644
> index 0000000..2c53d2c
> --- /dev/null
> +++ b/common/cmd_ext4.c
> @@ -0,0 +1,266 @@
> +/*
> + * (C) Copyright 2011 - 2012 Samsung Electronics
> + * EXT4 filesystem implementation in Uboot by
> + * Uma Shankar <uma.shankar@samsung.com>
> + * Manjunatha C Achar <a.manjunatha@samsung.com>
> + *
> + * Ext4fs support
> + * made from existing cmd_ext2.c file of Uboot
> + *
> + * (C) Copyright 2004
> + * esd gmbh <www.esd-electronics.com>
> + * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
> + *
> + * made from cmd_reiserfs by
> + *
> + * (C) Copyright 2003 - 2004
> + * Sysgo Real-Time Solutions, 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., 59 Temple Place, Suite 330, Boston,
> + * MA 02111-1307 USA
> + *
> + */
> +
> +/*
> + * Changelog:
> + *	0.1 - Newly created file for ext4fs support. Taken from cmd_ext2.c
> + *	        file in uboot. Added ext4fs ls and load support.
> + */
> +
> +#include <common.h>
> +#include <part.h>
> +#include <config.h>
> +#include <command.h>
> +#include <image.h>
> +#include <linux/ctype.h>
> +#include <asm/byteorder.h>
> +#include <ext_common.h>
> +#include <ext4fs.h>
> +#include <linux/stat.h>
> +#include <malloc.h>
> +
> +#if defined(CONFIG_CMD_USB) && defined(CONFIG_USB_STORAGE)
> +#include <usb.h>
> +#endif
> +
> +#if !defined(CONFIG_DOS_PARTITION) && !defined(CONFIG_EFI_PARTITION)
> +#error DOS or EFI partition support must be selected
> +#endif
> +
> +uint64_t total_sector;
> +uint64_t part_offset;
> +
> +#define DOS_PART_MAGIC_OFFSET	0x1fe
> +#define DOS_FS_TYPE_OFFSET	0x36
> +#define DOS_FS32_TYPE_OFFSET	0x52
> +
> +static int do_ext4_load(cmd_tbl_t *cmdtp, int flag, int argc,
> +						char *const argv[])
> +{
> +	char *filename = NULL;
> +	char *ep;
> +	int dev;
> +	unsigned long part = 1;
> +	ulong addr = 0;
> +	ulong part_length;
> +	int filelen;
> +	disk_partition_t info;
> +	struct ext_filesystem *fs;
> +	char buf[12];
> +	unsigned long count;
> +	const char *addr_str;
> +
> +	count = 0;
> +	addr = simple_strtoul(argv[3], NULL, 16);
> +	filename = getenv("bootfile");
> +	switch (argc) {
> +	case 3:
> +		addr_str = getenv("loadaddr");
> +		if (addr_str != NULL)
> +			addr = simple_strtoul(addr_str, NULL, 16);
> +		else
> +			addr = CONFIG_SYS_LOAD_ADDR;
> +
> +		break;
> +	case 4:
> +		break;
> +	case 5:
> +		filename = argv[4];
> +		break;
> +	case 6:
> +		filename = argv[4];
> +		count = simple_strtoul(argv[5], NULL, 16);
> +		break;
> +
> +	default:
> +		return cmd_usage(cmdtp);
> +	}
> +
> +	if (!filename) {
> +		puts("** No boot file defined **\n");
> +		return 1;
> +	}
> +
> +	dev = (int)simple_strtoul(argv[2], &ep, 16);
> +	ext4_dev_desc = get_dev(argv[1], dev);
> +	if (ext4_dev_desc == NULL) {
> +		printf("** Block device %s %d not supported\n", argv[1], dev);
> +		return 1;
> +	}
> +	if (init_fs(ext4_dev_desc))
> +		return 1;
> +
> +	fs = get_fs();
> +	if (*ep) {
> +		if (*ep != ':') {
> +			puts("** Invalid boot device, use `dev[:part]' **\n");
> +			return 1;
> +		}
> +		part = simple_strtoul(++ep, NULL, 16);
> +	}
> +
> +	if (part != 0) {
> +		if (get_partition_info(fs->dev_desc, part, &info)) {
> +			printf("** Bad partition %lu **\n", part);
> +			return 1;
> +		}
> +
> +		if (strncmp((char *)info.type, BOOT_PART_TYPE,
> +			    strlen(BOOT_PART_TYPE)) != 0) {
> +			printf("** Invalid partition type \"%s\""
> +			       " (expect \"" BOOT_PART_TYPE "\")\n", info.type);
> +			return 1;
> +		}
> +		printf("Loading file \"%s\" "
> +		       "from %s device %d:%lu %s\n",
> +		       filename, argv[1], dev, part, info.name);
> +	} else {
> +		printf("Loading file \"%s\" from %s device %d\n",
> +		       filename, argv[1], dev);
> +	}
> +
> +	part_length = ext4fs_set_blk_dev(fs->dev_desc, part);
> +	if (part_length == 0) {
> +		printf("**Bad partition - %s %d:%lu **\n", argv[1], dev, part);
> +		ext4fs_close();
> +		return 1;
> +	}
> +
> +	if (!ext4fs_mount(part_length)) {
> +		printf("** Bad ext2 partition or disk - %s %d:%lu **\n",
> +		       argv[1], dev, part);
> +		ext4fs_close();
> +		return 1;
> +	}
> +
> +	filelen = ext4fs_open(filename);
> +	if (filelen < 0) {
> +		printf("** File not found %s\n", filename);
> +		ext4fs_close();
> +		return 1;
> +	}
> +	if ((count < filelen) && (count != 0))
> +		filelen = count;
> +
> +	if (ext4fs_read((char *)addr, filelen) != filelen) {
> +		printf("** Unable to read \"%s\" from %s %d:%lu **\n",
> +		       filename, argv[1], dev, part);
> +		ext4fs_close();
> +		return 1;
> +	}
> +
> +	ext4fs_close();
> +	deinit_fs(fs->dev_desc);
> +	/* Loading ok, update default load address */
> +	load_addr = addr;
> +
> +	printf("%d bytes read\n", filelen);
> +	sprintf(buf, "%X", filelen);
> +	setenv("filesize", buf);
> +
> +	return 0;
> +}
> +
> +static int do_ext4_ls(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
> +{
> +	const char *filename = "/";
> +	int dev;
> +	unsigned long part = 1;
> +	char *ep;
> +	struct ext_filesystem *fs;
> +	int part_length;
> +
> +	if (argc < 3)
> +		return cmd_usage(cmdtp);
> +
> +	dev = (int)simple_strtoul(argv[2], &ep, 16);
> +	ext4_dev_desc = get_dev(argv[1], dev);
> +
> +	if (ext4_dev_desc == NULL) {
> +		printf("\n** Block device %s %d not supported\n", argv[1], dev);
> +		return 1;
> +	}
> +
> +	if (init_fs(ext4_dev_desc))
> +		return 1;
> +
> +	fs = get_fs();
> +	if (*ep) {
> +		if (*ep != ':') {
> +			puts("\n** Invalid boot device, use `dev[:part]' **\n");
> +			return 1;
> +		}
> +		part = simple_strtoul(++ep, NULL, 16);
> +	}
> +
> +	if (argc == 4)
> +		filename = argv[3];
> +
> +	part_length = ext4fs_set_blk_dev(fs->dev_desc, part);
> +	if (part_length == 0) {
> +		printf("** Bad partition - %s %d:%lu **\n", argv[1], dev, part);
> +		ext4fs_close();
> +		return 1;
> +	}
> +
> +	if (!ext4fs_mount(part_length)) {
> +		printf("** Bad ext2 partition or disk - %s %d:%lu **\n",
> +		       argv[1], dev, part);
> +		ext4fs_close();
> +		return 1;
> +	}
> +	if (ext4fs_ls(filename)) {
> +		printf("** Error ext2fs_ls() **\n");
> +		ext4fs_close();
> +		return 1;
> +	};
> +
> +	ext4fs_close();
> +	deinit_fs(fs->dev_desc);
> +
> +	return 0;
> +}
> +
> +U_BOOT_CMD(ext4ls, 4, 1, do_ext4_ls,
> +	   "list files in a directory (default /)",
> +	   "<interface> <dev[:part]> [directory]\n"
> +	   "	  - list files from 'dev' on 'interface' in a 'directory'");
> +
> +U_BOOT_CMD(ext4load, 6, 0, do_ext4_load,
> +	   "load binary file from a Ext2 filesystem",
> +	   "<interface> <dev[:part]> [addr] [filename] [bytes]\n"
> +	   "	  - load binary file 'filename' from 'dev' on 'interface'\n"
> +	   "		 to address 'addr' from ext2 filesystem");
> diff --git a/fs/Makefile b/fs/Makefile
> index 22aad12..00a8f37 100644
> --- a/fs/Makefile
> +++ b/fs/Makefile
> @@ -23,6 +23,7 @@
>  #
>  
>  subdirs-$(CONFIG_CMD_CRAMFS) := cramfs
> +subdirs-$(CONFIG_CMD_EXT4) += ext4
>  subdirs-$(CONFIG_CMD_EXT2) += ext2
>  subdirs-$(CONFIG_CMD_FAT) += fat
>  subdirs-$(CONFIG_CMD_FDOS) += fdos
> diff --git a/fs/ext2/dev.c b/fs/ext2/dev.c
> index 874e211..315ff53 100644
> --- a/fs/ext2/dev.c
> +++ b/fs/ext2/dev.c
> @@ -27,6 +27,7 @@
>  #include <common.h>
>  #include <config.h>
>  #include <ext2fs.h>
> +#include <ext_common.h>
>  
>  static block_dev_desc_t *ext2fs_block_dev_desc;
>  static disk_partition_t part_info;
> diff --git a/fs/ext2/ext2fs.c b/fs/ext2/ext2fs.c
> index f621741..a4f3094 100644
> --- a/fs/ext2/ext2fs.c
> +++ b/fs/ext2/ext2fs.c
> @@ -25,152 +25,16 @@
>  
>  #include <common.h>
>  #include <ext2fs.h>
> +#include <ext_common.h>
>  #include <malloc.h>
>  #include <asm/byteorder.h>
>  
>  extern int ext2fs_devread (int sector, int byte_offset, int byte_len,
>  			   char *buf);
>  
> -/* Magic value used to identify an ext2 filesystem.  */
> -#define	EXT2_MAGIC		0xEF53
> -/* Amount of indirect blocks in an inode.  */
> -#define INDIRECT_BLOCKS		12
> -/* Maximum lenght of a pathname.  */
> -#define EXT2_PATH_MAX		4096
> -/* Maximum nesting of symlinks, used to prevent a loop.  */
> -#define	EXT2_MAX_SYMLINKCNT	8
> -
> -/* Filetype used in directory entry.  */
> -#define	FILETYPE_UNKNOWN	0
> -#define	FILETYPE_REG		1
> -#define	FILETYPE_DIRECTORY	2
> -#define	FILETYPE_SYMLINK	7
> -
> -/* Filetype information as used in inodes.  */
> -#define FILETYPE_INO_MASK	0170000
> -#define FILETYPE_INO_REG	0100000
> -#define FILETYPE_INO_DIRECTORY	0040000
> -#define FILETYPE_INO_SYMLINK	0120000
> -
> -/* Bits used as offset in sector */
> -#define DISK_SECTOR_BITS        9
> -
> -/* Log2 size of ext2 block in 512 blocks.  */
> -#define LOG2_EXT2_BLOCK_SIZE(data) (__le32_to_cpu (data->sblock.log2_block_size) + 1)
> -
> -/* Log2 size of ext2 block in bytes.  */
> -#define LOG2_BLOCK_SIZE(data)	   (__le32_to_cpu (data->sblock.log2_block_size) + 10)
> -
> -/* The size of an ext2 block in bytes.  */
> -#define EXT2_BLOCK_SIZE(data)	   (1 << LOG2_BLOCK_SIZE(data))
> -
> -/* The ext2 superblock.  */
> -struct ext2_sblock {
> -	uint32_t total_inodes;
> -	uint32_t total_blocks;
> -	uint32_t reserved_blocks;
> -	uint32_t free_blocks;
> -	uint32_t free_inodes;
> -	uint32_t first_data_block;
> -	uint32_t log2_block_size;
> -	uint32_t log2_fragment_size;
> -	uint32_t blocks_per_group;
> -	uint32_t fragments_per_group;
> -	uint32_t inodes_per_group;
> -	uint32_t mtime;
> -	uint32_t utime;
> -	uint16_t mnt_count;
> -	uint16_t max_mnt_count;
> -	uint16_t magic;
> -	uint16_t fs_state;
> -	uint16_t error_handling;
> -	uint16_t minor_revision_level;
> -	uint32_t lastcheck;
> -	uint32_t checkinterval;
> -	uint32_t creator_os;
> -	uint32_t revision_level;
> -	uint16_t uid_reserved;
> -	uint16_t gid_reserved;
> -	uint32_t first_inode;
> -	uint16_t inode_size;
> -	uint16_t block_group_number;
> -	uint32_t feature_compatibility;
> -	uint32_t feature_incompat;
> -	uint32_t feature_ro_compat;
> -	uint32_t unique_id[4];
> -	char volume_name[16];
> -	char last_mounted_on[64];
> -	uint32_t compression_info;
> -};
> -
> -/* The ext2 blockgroup.  */
> -struct ext2_block_group {
> -	uint32_t block_id;
> -	uint32_t inode_id;
> -	uint32_t inode_table_id;
> -	uint16_t free_blocks;
> -	uint16_t free_inodes;
> -	uint16_t used_dir_cnt;
> -	uint32_t reserved[3];
> -};
> -
> -/* The ext2 inode.  */
> -struct ext2_inode {
> -	uint16_t mode;
> -	uint16_t uid;
> -	uint32_t size;
> -	uint32_t atime;
> -	uint32_t ctime;
> -	uint32_t mtime;
> -	uint32_t dtime;
> -	uint16_t gid;
> -	uint16_t nlinks;
> -	uint32_t blockcnt;	/* Blocks of 512 bytes!! */
> -	uint32_t flags;
> -	uint32_t osd1;
> -	union {
> -		struct datablocks {
> -			uint32_t dir_blocks[INDIRECT_BLOCKS];
> -			uint32_t indir_block;
> -			uint32_t double_indir_block;
> -			uint32_t tripple_indir_block;
> -		} blocks;
> -		char symlink[60];
> -	} b;
> -	uint32_t version;
> -	uint32_t acl;
> -	uint32_t dir_acl;
> -	uint32_t fragment_addr;
> -	uint32_t osd2[3];
> -};
> -
> -/* The header of an ext2 directory entry.  */
> -struct ext2_dirent {
> -	uint32_t inode;
> -	uint16_t direntlen;
> -	uint8_t namelen;
> -	uint8_t filetype;
> -};
> -
> -struct ext2fs_node {
> -	struct ext2_data *data;
> -	struct ext2_inode inode;
> -	int ino;
> -	int inode_read;
> -};
> -
> -/* Information about a "mounted" ext2 filesystem.  */
> -struct ext2_data {
> -	struct ext2_sblock sblock;
> -	struct ext2_inode *inode;
> -	struct ext2fs_node diropen;
> -};
> -
> -
> -typedef struct ext2fs_node *ext2fs_node_t;
>  
>  struct ext2_data *ext2fs_root = NULL;
> -ext2fs_node_t ext2fs_file = NULL;
> +struct ext2fs_node *ext2fs_file;
>  int symlinknest = 0;
>  uint32_t *indir1_block = NULL;
>  int indir1_size = 0;
> @@ -243,14 +107,16 @@ static int ext2fs_read_inode
>  }
>  
>  
> -void ext2fs_free_node (ext2fs_node_t node, ext2fs_node_t currroot) {
> +void ext2fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
> +{
>  	if ((node != &ext2fs_root->diropen) && (node != currroot)) {
>  		free (node);
>  	}
>  }
>  
>  
> -static int ext2fs_read_block (ext2fs_node_t node, int fileblock) {
> +static int ext2fs_read_block(struct ext2fs_node *node, int fileblock)
> +{
>  	struct ext2_data *data = node->data;
>  	struct ext2_inode *inode = &node->inode;
>  	int blknr;
> @@ -396,7 +262,8 @@ static int ext2fs_read_block (ext2fs_node_t node, int fileblock) {
>  
>  
>  int ext2fs_read_file
> -	(ext2fs_node_t node, int pos, unsigned int len, char *buf) {
> +	(struct ext2fs_node *node, int pos, unsigned int len, char *buf)
> +{
>  	int i;
>  	int blockcnt;
>  	int log2blocksize = LOG2_EXT2_BLOCK_SIZE (node->data);
> @@ -455,8 +322,8 @@ int ext2fs_read_file
>  	return (len);
>  }
>  
> -
> -static int ext2fs_iterate_dir (ext2fs_node_t dir, char *name, ext2fs_node_t * fnode, int *ftype)
> +int ext2fs_iterate_dir(struct ext2fs_node *dir, char *name,
> +					struct ext2fs_node **fnode, int *ftype)
>  {
>  	unsigned int fpos = 0;
>  	int status;
> @@ -485,7 +352,7 @@ static int ext2fs_iterate_dir (ext2fs_node_t dir, char *name, ext2fs_node_t * fn
>  		}
>  		if (dirent.namelen != 0) {
>  			char filename[dirent.namelen + 1];
> -			ext2fs_node_t fdiro;
> +			struct ext2fs_node *fdiro;
>  			int type = FILETYPE_UNKNOWN;
>  
>  			status = ext2fs_read_file (diro,
> @@ -587,8 +454,8 @@ static int ext2fs_iterate_dir (ext2fs_node_t dir, char *name, ext2fs_node_t * fn
>  	return (0);
>  }
>  
> -
> -static char *ext2fs_read_symlink (ext2fs_node_t node) {
> +static char *ext2fs_read_symlink(struct ext2fs_node *node)
> +{
>  	char *symlink;
>  	struct ext2fs_node *diro = node;
>  	int status;
> @@ -625,15 +492,16 @@ static char *ext2fs_read_symlink (ext2fs_node_t node) {
>  
>  
>  int ext2fs_find_file1
> -	(const char *currpath,
> -	 ext2fs_node_t currroot, ext2fs_node_t * currfound, int *foundtype) {
> +	(const char *currpath, struct ext2fs_node *currroot,
> +		struct ext2fs_node **currfound, int *foundtype)
> +{
>  	char fpath[strlen (currpath) + 1];
>  	char *name = fpath;
>  	char *next;
>  	int status;
>  	int type = FILETYPE_DIRECTORY;
> -	ext2fs_node_t currnode = currroot;
> -	ext2fs_node_t oldnode = currroot;
> +	struct ext2fs_node *currnode = currroot;
> +	struct ext2fs_node *oldnode = currroot;
>  
>  	strncpy (fpath, currpath, strlen (currpath) + 1);
>  
> @@ -729,8 +597,9 @@ int ext2fs_find_file1
>  
>  
>  int ext2fs_find_file
> -	(const char *path,
> -	 ext2fs_node_t rootnode, ext2fs_node_t * foundnode, int expecttype) {
> +	(const char *path, struct ext2fs_node *rootnode,
> +	struct ext2fs_node **foundnode, int expecttype)
> +{
>  	int status;
>  	int foundtype = FILETYPE_DIRECTORY;
>  
> @@ -756,7 +625,7 @@ int ext2fs_find_file
>  
>  
>  int ext2fs_ls (const char *dirname) {
> -	ext2fs_node_t dirnode;
> +	struct ext2fs_node *dirnode;
>  	int status;
>  
>  	if (ext2fs_root == NULL) {
> @@ -776,7 +645,7 @@ int ext2fs_ls (const char *dirname) {
>  
>  
>  int ext2fs_open (const char *filename) {
> -	ext2fs_node_t fdiro = NULL;
> +	struct ext2fs_node *fdiro = NULL;
>  	int status;
>  	int len;
>  
> @@ -806,8 +675,8 @@ fail:
>  }
>  
>  
> -int ext2fs_close (void
> -	) {
> +int ext2fs_close(void)
> +{
>  	if ((ext2fs_file != NULL) && (ext2fs_root != NULL)) {
>  		ext2fs_free_node (ext2fs_file, &ext2fs_root->diropen);
>  		ext2fs_file = NULL;
> diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
> new file mode 100644
> index 0000000..7add4ab
> --- /dev/null
> +++ b/fs/ext4/Makefile
> @@ -0,0 +1,51 @@
> +#
> +# (C) Copyright 2006
> +# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
> +#
> +# (C) Copyright 2003
> +# Pavel Bartusek, Sysgo Real-Time Solutions AG, pba@sysgo.de
> +#
> +#
> +# See file CREDITS for list of people who contributed to this
> +# project.
> +#
> +# 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 $(TOPDIR)/config.mk
> +
> +LIB	= $(obj)libext4fs.o
> +
> +AOBJS	=
> +COBJS-$(CONFIG_CMD_EXT4) := ext4fs.o ext4_common.o dev.o
> +
> +SRCS	:= $(AOBJS:.o=.S) $(COBJS-y:.o=.c)
> +OBJS	:= $(addprefix $(obj),$(AOBJS) $(COBJS-y))
> +
> +
> +all:	$(LIB) $(AOBJS)
> +
> +$(LIB):	$(obj).depend $(OBJS)
> +	$(call cmd_link_o_target, $(OBJS))
> +
> +#########################################################################
> +
> +# defines $(obj).depend target
> +include $(SRCTREE)/rules.mk
> +
> +sinclude $(obj).depend
> +
> +#########################################################################
> diff --git a/fs/ext4/dev.c b/fs/ext4/dev.c
> new file mode 100644
> index 0000000..2054be3
> --- /dev/null
> +++ b/fs/ext4/dev.c
> @@ -0,0 +1,145 @@
> +/*
> + * (C) Copyright 2011 - 2012 Samsung Electronics
> + * EXT4 filesystem implementation in Uboot by
> + * Uma Shankar <uma.shankar@samsung.com>
> + * Manjunatha C Achar <a.manjunatha@samsung.com>
> + *
> + * made from existing ext2/dev.c file of Uboot
> + * (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.
> + *
> + */
> +
> +/*
> + * Changelog:
> + *	0.1 - Newly created file for ext4fs support. Taken from
> + *	        fs/ext2/dev.c file in uboot.
> + */
> +
> +#include <common.h>
> +#include <config.h>
> +#include <ext_common.h>
> +
> +static block_dev_desc_t *ext4fs_block_dev_desc;
> +static disk_partition_t part_info;
> +
> +int ext4fs_set_blk_dev(block_dev_desc_t *rbdd, int part)
> +{
> +	ext4fs_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(ext4fs_block_dev_desc,
> +					part, &part_info))
> +			return 0;
> +	}
> +	return part_info.size;
> +}
> +
> +int ext4fs_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)) {
> +		printf("%s read outside partition %d\n", __func__, sector);
> +		return 0;
> +	}
> +
> +	/* Get the read to the beginning of a partition */
> +	sector += byte_offset >> SECTOR_BITS;
> +	byte_offset &= SECTOR_SIZE - 1;
> +
> +	debug(" <%d, %d, %d>\n", sector, byte_offset, byte_len);
> +
> +	if (ext4fs_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 (ext4fs_block_dev_desc->
> +		    block_read(ext4fs_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++;
> +	}
> +
> +	if (byte_len == 0)
> +		return 1;
> +
> +	/* read sector aligned part */
> +	block_len = byte_len & ~(SECTOR_SIZE - 1);
> +
> +	if (block_len == 0) {
> +		u8 p[SECTOR_SIZE];
> +
> +		block_len = SECTOR_SIZE;
> +		ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
> +						  part_info.start + sector,
> +						  1, (unsigned long *)p);
> +		memcpy(buf, p, byte_len);
> +		return 1;
> +	}
> +
> +	if (ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
> +					part_info.start + sector,
> +					block_len / SECTOR_SIZE,
> +					(unsigned long *) buf) !=
> +					block_len / SECTOR_SIZE) {
> +		printf(" ** %s read error - block\n", __func__);
> +		return 0;
> +	}
> +	block_len = byte_len & ~(SECTOR_SIZE - 1);
> +	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 (ext4fs_block_dev_desc->
> +		    block_read(ext4fs_block_dev_desc->dev,
> +				part_info.start + sector, 1,
> +				(unsigned long *) sec_buf) != 1) {
> +			printf("* %s read error - last part\n", __func__);
> +			return 0;
> +		}
> +		memcpy(buf, sec_buf, byte_len);
> +	}
> +	return 1;
> +}
> diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
> new file mode 100644
> index 0000000..d9deefe
> --- /dev/null
> +++ b/fs/ext4/ext4_common.c
> @@ -0,0 +1,875 @@
> +/*
> + * (C) Copyright 2011 - 2012 Samsung Electronics
> + * EXT4 filesystem implementation in Uboot by
> + * Uma Shankar <uma.shankar@samsung.com>
> + * Manjunatha C Achar <a.manjunatha@samsung.com>
> + *
> + * ext4ls and ext4load : Based on ext2 ls load support in Uboot.
> + *
> + * (C) Copyright 2004
> + * esd gmbh <www.esd-electronics.com>
> + * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
> + *
> + * based on code from grub2 fs/ext2.c and fs/fshelp.c by
> + * GRUB  --  GRand Unified Bootloader
> + * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
> + *
> + * 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>
> +#include <ext_common.h>
> +#include <ext4fs.h>
> +#include <malloc.h>
> +#include <stddef.h>
> +#include <linux/stat.h>
> +#include <linux/time.h>
> +#include <asm/byteorder.h>
> +#include "ext4_common.h"
> +
> +struct ext2_data *ext4fs_root;
> +struct ext2fs_node *ext4fs_file;
> +uint32_t *ext4fs_indir1_block;
> +int ext4fs_indir1_size;
> +int ext4fs_indir1_blkno = -1;
> +uint32_t *ext4fs_indir2_block;
> +int ext4fs_indir2_size;
> +int ext4fs_indir2_blkno = -1;
> +
> +uint32_t *ext4fs_indir3_block;
> +int ext4fs_indir3_size;
> +int ext4fs_indir3_blkno = -1;
> +struct ext2_inode *g_parent_inode;
> +static int symlinknest;
> +
> +static struct ext4_extent_header *ext4fs_get_extent_block
> +	(struct ext2_data *data, char *buf,
> +		struct ext4_extent_header *ext_block,
> +		uint32_t fileblock, int log2_blksz)
> +{
> +	struct ext4_extent_idx *index;
> +	unsigned long long block;
> +	struct ext_filesystem *fs = get_fs();
> +	int i;
> +
> +	while (1) {
> +		index = (struct ext4_extent_idx *)(ext_block + 1);
> +
> +		if (le32_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
> +			return 0;
> +
> +		if (ext_block->eh_depth == 0)
> +			return ext_block;
> +		i = -1;
> +		do {
> +			i++;
> +			if (i >= le32_to_cpu(ext_block->eh_entries))
> +				break;
> +		} while (fileblock > le32_to_cpu(index[i].ei_block));
> +
> +		if (--i < 0)
> +			return 0;
> +
> +		block = le32_to_cpu(index[i].ei_leaf_hi);
> +		block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
> +
> +		if (ext4fs_devread(block << log2_blksz, 0, fs->blksz, buf))
> +			ext_block = (struct ext4_extent_header *)buf;
> +		else
> +			return 0;
> +	}
> +}
> +
> +static int ext4fs_blockgroup
> +	(struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
> +{
> +	long int blkno;
> +	unsigned int blkoff, desc_per_blk;
> +
> +	desc_per_blk = EXT2_BLOCK_SIZE(data) / sizeof(struct ext2_block_group);
> +
> +	blkno = __le32_to_cpu(data->sblock.first_data_block) + 1 +
> +	    group / desc_per_blk;
> +	blkoff = (group % desc_per_blk) * sizeof(struct ext2_block_group);
> +
> +	debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
> +	      group, blkno, blkoff);
> +
> +	return ext4fs_devread(blkno << LOG2_EXT2_BLOCK_SIZE(data),
> +			      blkoff, sizeof(struct ext2_block_group),
> +			      (char *)blkgrp);
> +}
> +
> +int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
> +{
> +	struct ext2_block_group blkgrp;
> +	struct ext2_sblock *sblock = &data->sblock;
> +	struct ext_filesystem *fs = get_fs();
> +	int inodes_per_block, status;
> +	long int blkno;
> +	unsigned int blkoff;
> +
> +	/* It is easier to calculate if the first inode is 0. */
> +	ino--;
> +	status = ext4fs_blockgroup(data, ino / __le32_to_cpu
> +				   (sblock->inodes_per_group), &blkgrp);
> +	if (status == 0)
> +		return 0;
> +
> +	inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
> +	blkno = __le32_to_cpu(blkgrp.inode_table_id) +
> +	    (ino % __le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
> +	blkoff = (ino % inodes_per_block) * fs->inodesz;
> +	/* Read the inode. */
> +	status = ext4fs_devread(blkno << LOG2_EXT2_BLOCK_SIZE(data), blkoff,
> +				sizeof(struct ext2_inode), (char *)inode);
> +	if (status == 0)
> +		return 0;
> +
> +	return 1;
> +}
> +
> +long int read_allocated_block(struct ext2_inode *inode, int fileblock)
> +{
> +	long int blknr;
> +	int blksz;
> +	int log2_blksz;
> +	int status;
> +	long int rblock;
> +	long int perblock_parent;
> +	long int perblock_child;
> +	unsigned long long start;
> +	/* get the blocksize of the filesystem */
> +	blksz = EXT2_BLOCK_SIZE(ext4fs_root);
> +	log2_blksz = LOG2_EXT2_BLOCK_SIZE(ext4fs_root);
> +	if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
> +		char *buf = zalloc(blksz);
> +		if (!buf)
> +			return -ENOMEM;
> +		struct ext4_extent_header *ext_block;
> +		struct ext4_extent *extent;
> +		int i = -1;
> +		ext_block = ext4fs_get_extent_block(ext4fs_root, buf,
> +						    (struct ext4_extent_header
> +						     *)inode->b.
> +						    blocks.dir_blocks,
> +						    fileblock, log2_blksz);
> +		if (!ext_block) {
> +			printf("invalid extent block\n");
> +			free(buf);
> +			return -EINVAL;
> +		}
> +
> +		extent = (struct ext4_extent *)(ext_block + 1);
> +
> +		do {
> +			i++;
> +			if (i >= le32_to_cpu(ext_block->eh_entries))
> +				break;
> +		} while (fileblock >= le32_to_cpu(extent[i].ee_block));
> +		if (--i >= 0) {
> +			fileblock -= le32_to_cpu(extent[i].ee_block);
> +			if (fileblock >= le32_to_cpu(extent[i].ee_len)) {
> +				free(buf);
> +				return 0;
> +			}
> +
> +			start = le32_to_cpu(extent[i].ee_start_hi);
> +			start = (start << 32) +
> +			    le32_to_cpu(extent[i].ee_start_lo);
> +			free(buf);
> +			return fileblock + start;
> +		}
> +
> +		printf("Extent Error\n");
> +		free(buf);
> +		return -1;
> +	}
> +
> +	/* Direct blocks. */
> +	if (fileblock < INDIRECT_BLOCKS)
> +		blknr = __le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
> +
> +	/* Indirect. */
> +	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
> +		if (ext4fs_indir1_block == NULL) {
> +			ext4fs_indir1_block = zalloc(blksz);
> +			if (ext4fs_indir1_block == NULL) {
> +				printf("** SI ext2fs read block (indir 1)"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir1_size = blksz;
> +			ext4fs_indir1_blkno = -1;
> +		}
> +		if (blksz != ext4fs_indir1_size) {
> +			free(ext4fs_indir1_block);
> +			ext4fs_indir1_block = NULL;
> +			ext4fs_indir1_size = 0;
> +			ext4fs_indir1_blkno = -1;
> +			ext4fs_indir1_block = zalloc(blksz);
> +			if (ext4fs_indir1_block == NULL) {
> +				printf("** SI ext2fs read block (indir 1):"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir1_size = blksz;
> +		}
> +		if ((__le32_to_cpu(inode->b.blocks.indir_block) <<
> +		     log2_blksz) != ext4fs_indir1_blkno) {
> +			status =
> +			    ext4fs_devread(__le32_to_cpu
> +					   (inode->b.blocks.
> +					    indir_block) << log2_blksz, 0,
> +					   blksz, (char *)ext4fs_indir1_block);
> +			if (status == 0) {
> +				printf("** SI ext2fs read block (indir 1)"
> +				       "failed. **\n");
> +				return 0;
> +			}
> +			ext4fs_indir1_blkno =
> +			    __le32_to_cpu(inode->b.blocks.
> +					  indir_block) << log2_blksz;
> +		}
> +		blknr = __le32_to_cpu(ext4fs_indir1_block
> +				      [fileblock - INDIRECT_BLOCKS]);
> +	}
> +	/* Double indirect. */
> +	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
> +					(blksz / 4 + 1)))) {
> +
> +		long int perblock = blksz / 4;
> +		long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
> +
> +		if (ext4fs_indir1_block == NULL) {
> +			ext4fs_indir1_block = zalloc(blksz);
> +			if (ext4fs_indir1_block == NULL) {
> +				printf("** DI ext2fs read block (indir 2 1)"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir1_size = blksz;
> +			ext4fs_indir1_blkno = -1;
> +		}
> +		if (blksz != ext4fs_indir1_size) {
> +			free(ext4fs_indir1_block);
> +			ext4fs_indir1_block = NULL;
> +			ext4fs_indir1_size = 0;
> +			ext4fs_indir1_blkno = -1;
> +			ext4fs_indir1_block = zalloc(blksz);
> +			if (ext4fs_indir1_block == NULL) {
> +				printf("** DI ext2fs read block (indir 2 1)"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir1_size = blksz;
> +		}
> +		if ((__le32_to_cpu(inode->b.blocks.double_indir_block) <<
> +		     log2_blksz) != ext4fs_indir1_blkno) {
> +			status =
> +			    ext4fs_devread(__le32_to_cpu
> +					   (inode->b.blocks.
> +					    double_indir_block) << log2_blksz,
> +					   0, blksz,
> +					   (char *)ext4fs_indir1_block);
> +			if (status == 0) {
> +				printf("** DI ext2fs read block (indir 2 1)"
> +				       "failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir1_blkno =
> +			    __le32_to_cpu(inode->b.blocks.double_indir_block) <<
> +			    log2_blksz;
> +		}
> +
> +		if (ext4fs_indir2_block == NULL) {
> +			ext4fs_indir2_block = zalloc(blksz);
> +			if (ext4fs_indir2_block == NULL) {
> +				printf("** DI ext2fs read block (indir 2 2)"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir2_size = blksz;
> +			ext4fs_indir2_blkno = -1;
> +		}
> +		if (blksz != ext4fs_indir2_size) {
> +			free(ext4fs_indir2_block);
> +			ext4fs_indir2_block = NULL;
> +			ext4fs_indir2_size = 0;
> +			ext4fs_indir2_blkno = -1;
> +			ext4fs_indir2_block = zalloc(blksz);
> +			if (ext4fs_indir2_block == NULL) {
> +				printf("** DI ext2fs read block (indir 2 2)"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir2_size = blksz;
> +		}
> +		if ((__le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
> +		     log2_blksz) != ext4fs_indir2_blkno) {
> +			status = ext4fs_devread(__le32_to_cpu
> +						(ext4fs_indir1_block
> +						 [rblock /
> +						  perblock]) << log2_blksz, 0,
> +						blksz,
> +						(char *)ext4fs_indir2_block);
> +			if (status == 0) {
> +				printf("** DI ext2fs read block (indir 2 2)"
> +				       "failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir2_blkno =
> +			    __le32_to_cpu(ext4fs_indir1_block[rblock
> +							      /
> +							      perblock]) <<
> +			    log2_blksz;
> +		}
> +		blknr = __le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
> +	}
> +	/* Tripple indirect. */
> +	else {
> +		rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
> +				      (blksz / 4 * blksz / 4));
> +		perblock_child = blksz / 4;
> +		perblock_parent = ((blksz / 4) * (blksz / 4));
> +
> +		if (ext4fs_indir1_block == NULL) {
> +			ext4fs_indir1_block = zalloc(blksz);
> +			if (ext4fs_indir1_block == NULL) {
> +				printf("** TI ext2fs read block (indir 2 1)"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir1_size = blksz;
> +			ext4fs_indir1_blkno = -1;
> +		}
> +		if (blksz != ext4fs_indir1_size) {
> +			free(ext4fs_indir1_block);
> +			ext4fs_indir1_block = NULL;
> +			ext4fs_indir1_size = 0;
> +			ext4fs_indir1_blkno = -1;
> +			ext4fs_indir1_block = zalloc(blksz);
> +			if (ext4fs_indir1_block == NULL) {
> +				printf("** TI ext2fs read block (indir 2 1)"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir1_size = blksz;
> +		}
> +		if ((__le32_to_cpu(inode->b.blocks.triple_indir_block) <<
> +		     log2_blksz) != ext4fs_indir1_blkno) {
> +			status = ext4fs_devread
> +			    (__le32_to_cpu(inode->b.blocks.triple_indir_block)
> +			     << log2_blksz, 0, blksz,
> +			     (char *)ext4fs_indir1_block);
> +			if (status == 0) {
> +				printf("** TI ext2fs read block (indir 2 1)"
> +				       "failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir1_blkno =
> +			    __le32_to_cpu(inode->b.blocks.triple_indir_block) <<
> +			    log2_blksz;
> +		}
> +
> +		if (ext4fs_indir2_block == NULL) {
> +			ext4fs_indir2_block = zalloc(blksz);
> +			if (ext4fs_indir2_block == NULL) {
> +				printf("** TI ext2fs read block (indir 2 2)"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir2_size = blksz;
> +			ext4fs_indir2_blkno = -1;
> +		}
> +		if (blksz != ext4fs_indir2_size) {
> +			free(ext4fs_indir2_block);
> +			ext4fs_indir2_block = NULL;
> +			ext4fs_indir2_size = 0;
> +			ext4fs_indir2_blkno = -1;
> +			ext4fs_indir2_block = zalloc(blksz);
> +			if (ext4fs_indir2_block == NULL) {
> +				printf("** TI ext2fs read block (indir 2 2)"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir2_size = blksz;
> +		}
> +		if ((__le32_to_cpu(ext4fs_indir1_block[rblock /
> +						       perblock_parent]) <<
> +		     log2_blksz)
> +		    != ext4fs_indir2_blkno) {
> +			status = ext4fs_devread(__le32_to_cpu
> +						(ext4fs_indir1_block
> +						 [rblock /
> +						  perblock_parent]) <<
> +						log2_blksz, 0, blksz,
> +						(char *)ext4fs_indir2_block);
> +			if (status == 0) {
> +				printf("** TI ext2fs read block (indir 2 2)"
> +				       "failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir2_blkno =
> +			    __le32_to_cpu(ext4fs_indir1_block[rblock /
> +							      perblock_parent])
> +			    << log2_blksz;
> +		}
> +
> +		if (ext4fs_indir3_block == NULL) {
> +			ext4fs_indir3_block = zalloc(blksz);
> +			if (ext4fs_indir3_block == NULL) {
> +				printf("** TI ext2fs read block (indir 2 2)"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir3_size = blksz;
> +			ext4fs_indir3_blkno = -1;
> +		}
> +		if (blksz != ext4fs_indir3_size) {
> +			free(ext4fs_indir3_block);
> +			ext4fs_indir3_block = NULL;
> +			ext4fs_indir3_size = 0;
> +			ext4fs_indir3_blkno = -1;
> +			ext4fs_indir3_block = zalloc(blksz);
> +			if (ext4fs_indir3_block == NULL) {
> +				printf("** TI ext2fs read block (indir 2 2)"
> +				       "malloc failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir3_size = blksz;
> +		}
> +		if ((__le32_to_cpu(ext4fs_indir2_block[rblock
> +						       /
> +						       perblock_child]) <<
> +		     log2_blksz) != ext4fs_indir3_blkno) {
> +			status =
> +			    ext4fs_devread(__le32_to_cpu
> +					   (ext4fs_indir2_block
> +					    [(rblock / perblock_child)
> +					     % (blksz / 4)]) << log2_blksz, 0,
> +					   blksz, (char *)ext4fs_indir3_block);
> +			if (status == 0) {
> +				printf("** TI ext2fs read block (indir 2 2)"
> +				       "failed. **\n");
> +				return -1;
> +			}
> +			ext4fs_indir3_blkno =
> +			    __le32_to_cpu(ext4fs_indir2_block[(rblock /
> +							       perblock_child) %
> +							      (blksz /
> +							       4)]) <<
> +			    log2_blksz;
> +		}
> +
> +		blknr = __le32_to_cpu(ext4fs_indir3_block
> +				      [rblock % perblock_child]);
> +	}
> +	debug("ext4fs_read_block %ld\n", blknr);
> +
> +	return blknr;
> +}
> +
> +void ext4fs_close(void)
> +{
> +	if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
> +		ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
> +		ext4fs_file = NULL;
> +	}
> +	if (ext4fs_root != NULL) {
> +		free(ext4fs_root);
> +		ext4fs_root = NULL;
> +	}
> +	if (ext4fs_indir1_block != NULL) {
> +		free(ext4fs_indir1_block);
> +		ext4fs_indir1_block = NULL;
> +		ext4fs_indir1_size = 0;
> +		ext4fs_indir1_blkno = -1;
> +	}
> +	if (ext4fs_indir2_block != NULL) {
> +		free(ext4fs_indir2_block);
> +		ext4fs_indir2_block = NULL;
> +		ext4fs_indir2_size = 0;
> +		ext4fs_indir2_blkno = -1;
> +	}
> +	if (ext4fs_indir3_block != NULL) {
> +		free(ext4fs_indir3_block);
> +		ext4fs_indir3_block = NULL;
> +		ext4fs_indir3_size = 0;
> +		ext4fs_indir3_blkno = -1;
> +	}
> +}
> +
> +int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
> +		       struct ext2fs_node **fnode, int *ftype)
> +{
> +	unsigned int fpos = 0;
> +	int status;
> +	struct ext2fs_node *diro = (struct ext2fs_node *)dir;
> +
> +#ifdef DEBUG
> +	if (name != NULL)
> +		printf("Iterate dir %s\n", name);
> +#endif				/* of DEBUG */
> +	if (!diro->inode_read) {
> +		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
> +		if (status == 0)
> +			return 0;
> +	}
> +	/* Search the file.  */
> +	while (fpos < __le32_to_cpu(diro->inode.size)) {
> +		struct ext2_dirent dirent;
> +
> +		status = ext4fs_read_file(diro, fpos,
> +					  sizeof(struct ext2_dirent),
> +					  (char *)&dirent);
> +		if (status < 1)
> +			return 0;
> +
> +		if (dirent.namelen != 0) {
> +			char filename[dirent.namelen + 1];
> +			struct ext2fs_node *fdiro;
> +			int type = FILETYPE_UNKNOWN;
> +
> +			status = ext4fs_read_file(diro,
> +						  fpos +
> +						  sizeof(struct ext2_dirent),
> +						  dirent.namelen, filename);
> +			if (status < 1)
> +				return 0;
> +
> +			fdiro = zalloc(sizeof(struct ext2fs_node));
> +			if (!fdiro)
> +				return 0;
> +
> +			fdiro->data = diro->data;
> +			fdiro->ino = __le32_to_cpu(dirent.inode);
> +
> +			filename[dirent.namelen] = '\0';
> +
> +			if (dirent.filetype != FILETYPE_UNKNOWN) {
> +				fdiro->inode_read = 0;
> +
> +				if (dirent.filetype == FILETYPE_DIRECTORY)
> +					type = FILETYPE_DIRECTORY;
> +				else if (dirent.filetype == FILETYPE_SYMLINK)
> +					type = FILETYPE_SYMLINK;
> +				else if (dirent.filetype == FILETYPE_REG)
> +					type = FILETYPE_REG;
> +			} else {
> +				status = ext4fs_read_inode(diro->data,
> +							   __le32_to_cpu
> +							   (dirent.inode),
> +							   &fdiro->inode);
> +				if (status == 0) {
> +					free(fdiro);
> +					return 0;
> +				}
> +				fdiro->inode_read = 1;
> +
> +				if ((__le16_to_cpu(fdiro->inode.mode) &
> +				     FILETYPE_INO_MASK) ==
> +				    FILETYPE_INO_DIRECTORY) {
> +					type = FILETYPE_DIRECTORY;
> +				} else if ((__le16_to_cpu(fdiro->inode.mode)
> +					    & FILETYPE_INO_MASK) ==
> +					   FILETYPE_INO_SYMLINK) {
> +					type = FILETYPE_SYMLINK;
> +				} else if ((__le16_to_cpu(fdiro->inode.mode)
> +					    & FILETYPE_INO_MASK) ==
> +					   FILETYPE_INO_REG) {
> +					type = FILETYPE_REG;
> +				}
> +			}
> +#ifdef DEBUG
> +			printf("iterate >%s<\n", filename);
> +#endif				/* of DEBUG */
> +			if ((name != NULL) && (fnode != NULL)
> +			    && (ftype != NULL)) {
> +				if (strcmp(filename, name) == 0) {
> +					*ftype = type;
> +					*fnode = fdiro;
> +					return 1;
> +				}
> +			} else {
> +				if (fdiro->inode_read == 0) {
> +					status = ext4fs_read_inode(diro->data,
> +								 __le32_to_cpu(
> +								 dirent.inode),
> +								 &fdiro->inode);
> +					if (status == 0) {
> +						free(fdiro);
> +						return 0;
> +					}
> +					fdiro->inode_read = 1;
> +				}
> +				switch (type) {
> +				case FILETYPE_DIRECTORY:
> +					printf("<DIR> ");
> +					break;
> +				case FILETYPE_SYMLINK:
> +					printf("<SYM> ");
> +					break;
> +				case FILETYPE_REG:
> +					printf("      ");
> +					break;
> +				default:
> +					printf("< ? > ");
> +					break;
> +				}
> +				printf("%10d %s\n",
> +				       __le32_to_cpu(fdiro->inode.size),
> +				       filename);
> +			}
> +			free(fdiro);
> +		}
> +		fpos += __le16_to_cpu(dirent.direntlen);
> +	}
> +	return 0;
> +}
> +
> +static char *ext4fs_read_symlink(struct ext2fs_node *node)
> +{
> +	char *symlink;
> +	struct ext2fs_node *diro = node;
> +	int status;
> +
> +	if (!diro->inode_read) {
> +		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
> +		if (status == 0)
> +			return 0;
> +	}
> +	symlink = zalloc(__le32_to_cpu(diro->inode.size) + 1);
> +	if (!symlink)
> +		return 0;
> +
> +	if (__le32_to_cpu(diro->inode.size) <= 60) {
> +		strncpy(symlink, diro->inode.b.symlink,
> +			__le32_to_cpu(diro->inode.size));
> +	} else {
> +		status = ext4fs_read_file(diro, 0,
> +					  __le32_to_cpu(diro->inode.size),
> +					  symlink);
> +		if (status == 0) {
> +			free(symlink);
> +			return 0;
> +		}
> +	}
> +	symlink[__le32_to_cpu(diro->inode.size)] = '\0';
> +	return symlink;
> +}
> +
> +static int ext4fs_find_file1(const char *currpath,
> +			     struct ext2fs_node *currroot,
> +			     struct ext2fs_node **currfound, int *foundtype)
> +{
> +	char fpath[strlen(currpath) + 1];
> +	char *name = fpath;
> +	char *next;
> +	int status;
> +	int type = FILETYPE_DIRECTORY;
> +	struct ext2fs_node *currnode = currroot;
> +	struct ext2fs_node *oldnode = currroot;
> +
> +	strncpy(fpath, currpath, strlen(currpath) + 1);
> +
> +	/* Remove all leading slashes. */
> +	while (*name == '/')
> +		name++;
> +
> +	if (!*name) {
> +		*currfound = currnode;
> +		return 1;
> +	}
> +
> +	for (;;) {
> +		int found;
> +
> +		/* Extract the actual part from the pathname. */
> +		next = strchr(name, '/');
> +		if (next) {
> +			/* Remove all leading slashes. */
> +			while (*next == '/')
> +				*(next++) = '\0';
> +		}
> +
> +		if (type != FILETYPE_DIRECTORY) {
> +			ext4fs_free_node(currnode, currroot);
> +			return 0;
> +		}
> +
> +		oldnode = currnode;
> +
> +		/* Iterate over the directory. */
> +		found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
> +		if (found == 0)
> +			return 0;
> +
> +		if (found == -1)
> +			break;
> +
> +		/* Read in the symlink and follow it. */
> +		if (type == FILETYPE_SYMLINK) {
> +			char *symlink;
> +
> +			/* Test if the symlink does not loop. */
> +			if (++symlinknest == 8) {
> +				ext4fs_free_node(currnode, currroot);
> +				ext4fs_free_node(oldnode, currroot);
> +				return 0;
> +			}
> +
> +			symlink = ext4fs_read_symlink(currnode);
> +			ext4fs_free_node(currnode, currroot);
> +
> +			if (!symlink) {
> +				ext4fs_free_node(oldnode, currroot);
> +				return 0;
> +			}
> +
> +			debug("Got symlink >%s<\n", symlink);
> +
> +			if (symlink[0] == '/') {
> +				ext4fs_free_node(oldnode, currroot);
> +				oldnode = &ext4fs_root->diropen;
> +			}
> +
> +			/* Lookup the node the symlink points to. */
> +			status = ext4fs_find_file1(symlink, oldnode,
> +						   &currnode, &type);
> +
> +			free(symlink);
> +
> +			if (status == 0) {
> +				ext4fs_free_node(oldnode, currroot);
> +				return 0;
> +			}
> +		}
> +
> +		ext4fs_free_node(oldnode, currroot);
> +
> +		/* Found the node! */
> +		if (!next || *next == '\0') {
> +			*currfound = currnode;
> +			*foundtype = type;
> +			return 1;
> +		}
> +		name = next;
> +	}
> +	return -1;
> +}
> +
> +int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
> +	struct ext2fs_node **foundnode, int expecttype)
> +{
> +	int status;
> +	int foundtype = FILETYPE_DIRECTORY;
> +
> +	symlinknest = 0;
> +	if (!path)
> +		return 0;
> +
> +	status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
> +	if (status == 0)
> +		return 0;
> +
> +	/* Check if the node that was found was of the expected type. */
> +	if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
> +		return 0;
> +	else if ((expecttype == FILETYPE_DIRECTORY)
> +		   && (foundtype != expecttype))
> +		return 0;
> +
> +	return 1;
> +}
> +
> +int ext4fs_open(const char *filename)
> +{
> +	struct ext2fs_node *fdiro = NULL;
> +	int status;
> +	int len;
> +
> +	if (ext4fs_root == NULL)
> +		return -1;
> +
> +	ext4fs_file = NULL;
> +	status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
> +				  FILETYPE_REG);
> +	if (status == 0)
> +		goto fail;
> +
> +	if (!fdiro->inode_read) {
> +		status = ext4fs_read_inode(fdiro->data, fdiro->ino,
> +					   &fdiro->inode);
> +		if (status == 0)
> +			goto fail;
> +	}
> +	len = __le32_to_cpu(fdiro->inode.size);
> +	ext4fs_file = fdiro;
> +
> +	return len;
> + fail:
> +	ext4fs_free_node(fdiro, &ext4fs_root->diropen);
> +
> +	return -1;
> +}
> +
> +int ext4fs_mount(unsigned part_length)
> +{
> +	struct ext2_data *data;
> +	int status;
> +	struct ext_filesystem *fs = get_fs();
> +	data = zalloc(sizeof(struct ext2_data));
> +	if (!data)
> +		return 0;
> +
> +	/* Read the superblock. */
> +	status = ext4fs_devread(1 * 2, 0, sizeof(struct ext2_sblock),
> +				(char *)&data->sblock);
> +
> +	if (status == 0)
> +		goto fail;
> +
> +	/* Make sure this is an ext2 filesystem. */
> +	if (__le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
> +		goto fail;
> +
> +	if (__le32_to_cpu(data->sblock.revision_level == 0))
> +		fs->inodesz = 128;
> +	else
> +		fs->inodesz = __le16_to_cpu(data->sblock.inode_size);
> +
> +	debug("EXT2 rev %d, inode_size %d\n",
> +	      __le32_to_cpu(data->sblock.revision_level), fs->inodesz);
> +
> +	data->diropen.data = data;
> +	data->diropen.ino = 2;
> +	data->diropen.inode_read = 1;
> +	data->inode = &data->diropen.inode;
> +
> +	status = ext4fs_read_inode(data, 2, data->inode);
> +	if (status == 0)
> +		goto fail;
> +
> +	ext4fs_root = data;
> +
> +	return 1;
> + fail:
> +	printf("Failed to mount ext2 filesystem...\n");
> +	free(data);
> +	ext4fs_root = NULL;
> +
> +	return 0;
> +}
> diff --git a/fs/ext4/ext4_common.h b/fs/ext4/ext4_common.h
> new file mode 100644
> index 0000000..182049d
> --- /dev/null
> +++ b/fs/ext4/ext4_common.h
> @@ -0,0 +1,63 @@
> +/*
> + * (C) Copyright 2011 - 2012 Samsung Electronics
> + * EXT4 filesystem implementation in Uboot by
> + * Uma Shankar <uma.shankar@samsung.com>
> + * Manjunatha C Achar <a.manjunatha@samsung.com>
> + *
> + * ext4ls and ext4load :  based on ext2 ls load support in Uboot.
> + *
> + * (C) Copyright 2004
> + * esd gmbh <www.esd-electronics.com>
> + * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
> + *
> + * based on code from grub2 fs/ext2.c and fs/fshelp.c by
> + * GRUB  --  GRand Unified Bootloader
> + * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
> + *
> + * 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.
> + */
> +
> +#ifndef __EXT4_COMMON__
> +#define __EXT4_COMMON__
> +#include <ext_common.h>
> +#include <ext4fs.h>
> +#include <malloc.h>
> +#include <asm/errno.h>
> +
> +#define YES		1
> +#define NO		0
> +#define TRUE		1
> +#define FALSE		0
> +#define RECOVER	1
> +#define SCAN		0
> +
> +#define S_IFLNK	0120000		/* symbolic link */
> +#define BLOCK_NO_ONE		1
> +#define SUPERBLOCK_SECTOR	2
> +#define SUPERBLOCK_SIZE	1024
> +#define F_FILE			1
> +
> +#define zalloc(size) calloc(1, size)
> +
> +extern unsigned long part_offset;
> +int ext4fs_read_inode(struct ext2_data *data, int ino,
> +		      struct ext2_inode *inode);
> +int ext4fs_read_file(struct ext2fs_node *node, int pos,
> +		unsigned int len, char *buf);
> +int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
> +			struct ext2fs_node **foundnode, int expecttype);
> +int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
> +			struct ext2fs_node **fnode, int *ftype);
> +#endif
> diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c
> new file mode 100644
> index 0000000..7933769
> --- /dev/null
> +++ b/fs/ext4/ext4fs.c
> @@ -0,0 +1,228 @@
> +/*
> + * (C) Copyright 2011 - 2012 Samsung Electronics
> + * EXT4 filesystem implementation in Uboot by
> + * Uma Shankar <uma.shankar@samsung.com>
> + * Manjunatha C Achar <a.manjunatha@samsung.com>
> + *
> + * ext4ls and ext4load : Based on ext2 ls and load support in Uboot.
> + *		       Ext4 read optimization taken from Open-Moko
> + *		       Qi bootloader
> + *
> + * (C) Copyright 2004
> + * esd gmbh <www.esd-electronics.com>
> + * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
> + *
> + * based on code from grub2 fs/ext2.c and fs/fshelp.c by
> + * GRUB  --  GRand Unified Bootloader
> + * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
> + *
> + * 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>
> +#include <malloc.h>
> +#include <ext_common.h>
> +#include <ext4fs.h>
> +#include <linux/stat.h>
> +#include <linux/time.h>
> +#include <asm/byteorder.h>
> +#include "ext4_common.h"
> +
> +int ext4fs_symlinknest;
> +block_dev_desc_t *ext4_dev_desc;
> +
> +struct ext_filesystem *get_fs(void)
> +{
> +	if (ext4_dev_desc == NULL || ext4_dev_desc->priv == NULL)
> +		printf("Invalid Input Arguments %s\n", __func__);
> +
> +	return ext4_dev_desc->priv;
> +}
> +
> +int init_fs(block_dev_desc_t *dev_desc)
> +{
> +	struct ext_filesystem *fs;
> +	if (dev_desc == NULL) {
> +		printf("Invalid Input Arguments %s\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	fs = zalloc(sizeof(struct ext_filesystem));
> +	if (fs == NULL) {
> +		printf("malloc failed: %s\n", __func__);
> +		return -ENOMEM;
> +	}
> +
> +	fs->dev_desc = dev_desc;
> +	dev_desc->priv = fs;
> +
> +	return 0;
> +}
> +
> +void deinit_fs(block_dev_desc_t *dev_desc)
> +{
> +	if (dev_desc == NULL) {
> +		printf("Invalid Input Arguments %s\n", __func__);
> +		return;
> +	}
> +	free(dev_desc->priv);
> +	dev_desc->priv = NULL;
> +}
> +
> +void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
> +{
> +	if ((node != &ext4fs_root->diropen) && (node != currroot))
> +		free(node);
> +}
> +
> +/*
> + * Taken from openmoko-kernel mailing list: By Andy green
> + * Optimized read file API : collects and defers contiguous sector
> + * reads into one potentially more efficient larger sequential read action
> + */
> +int ext4fs_read_file(struct ext2fs_node *node, int pos,
> +		     unsigned int len, char *buf)
> +{
> +	int i;
> +	int blockcnt;
> +	int log2blocksize = LOG2_EXT2_BLOCK_SIZE(node->data);
> +	int blocksize = 1 << (log2blocksize + DISK_SECTOR_BITS);
> +	unsigned int filesize = __le32_to_cpu(node->inode.size);
> +	int previous_block_number = -1;
> +	int delayed_start = 0;
> +	int delayed_extent = 0;
> +	int delayed_skipfirst = 0;
> +	int delayed_next = 0;
> +	char *delayed_buf = NULL;
> +	short status;
> +
> +	/* Adjust len so it we can't read past the end of the file. */
> +	if (len > filesize)
> +		len = filesize;
> +
> +	blockcnt = ((len + pos) + blocksize - 1) / blocksize;
> +
> +	for (i = pos / blocksize; i < blockcnt; i++) {
> +		int blknr;
> +		int blockoff = pos % blocksize;
> +		int blockend = blocksize;
> +		int skipfirst = 0;
> +		blknr = read_allocated_block(&(node->inode), i);
> +		if (blknr < 0)
> +			return -1;
> +
> +		blknr = blknr << log2blocksize;
> +
> +		/* Last block.  */
> +		if (i == blockcnt - 1) {
> +			blockend = (len + pos) % blocksize;
> +
> +			/* The last portion is exactly blocksize. */
> +			if (!blockend)
> +				blockend = blocksize;
> +		}
> +
> +		/* First block. */
> +		if (i == pos / blocksize) {
> +			skipfirst = blockoff;
> +			blockend -= skipfirst;
> +		}
> +		if (blknr) {
> +			int status;
> +
> +			if (previous_block_number != -1) {
> +				if (delayed_next == blknr) {
> +					delayed_extent += blockend;
> +					delayed_next += blockend >> SECTOR_BITS;
> +				} else {	/* spill */
> +					status = ext4fs_devread(delayed_start,
> +							delayed_skipfirst,
> +							delayed_extent,
> +							delayed_buf);
> +					if (status == 0)
> +						return -1;
> +					previous_block_number = blknr;
> +					delayed_start = blknr;
> +					delayed_extent = blockend;
> +					delayed_skipfirst = skipfirst;
> +					delayed_buf = buf;
> +					delayed_next = blknr +
> +					    (blockend >> SECTOR_BITS);
> +				}
> +			} else {
> +				previous_block_number = blknr;
> +				delayed_start = blknr;
> +				delayed_extent = blockend;
> +				delayed_skipfirst = skipfirst;
> +				delayed_buf = buf;
> +				delayed_next = blknr +
> +				    (blockend >> SECTOR_BITS);
> +			}
> +		} else {
> +			if (previous_block_number != -1) {
> +				/* spill */
> +				status = ext4fs_devread(delayed_start,
> +							delayed_skipfirst,
> +							delayed_extent,
> +							delayed_buf);
> +				if (status == 0)
> +					return -1;
> +				previous_block_number = -1;
> +			}
> +			memset(buf, 0, blocksize - skipfirst);
> +		}
> +		buf += blocksize - skipfirst;
> +	}
> +	if (previous_block_number != -1) {
> +		/* spill */
> +		status = ext4fs_devread(delayed_start,
> +					delayed_skipfirst, delayed_extent,
> +					delayed_buf);
> +		if (status == 0)
> +			return -1;
> +		previous_block_number = -1;
> +	}
> +
> +	return len;
> +}
> +
> +int ext4fs_ls(const char *dirname)
> +{
> +	struct ext2fs_node *dirnode;
> +	int status;
> +
> +	if (dirname == NULL)
> +		return 0;
> +
> +	status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
> +				  FILETYPE_DIRECTORY);
> +	if (status != 1) {
> +		printf("** Can not find directory. **\n");
> +		return 1;
> +	}
> +
> +	ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
> +	ext4fs_free_node(dirnode, &ext4fs_root->diropen);
> +
> +	return 0;
> +}
> +
> +int ext4fs_read(char *buf, unsigned len)
> +{
> +	if (ext4fs_root == NULL || ext4fs_file == NULL)
> +		return 0;
> +
> +	return ext4fs_read_file(ext4fs_file, 0, len, buf);
> +}
> diff --git a/include/ext4fs.h b/include/ext4fs.h
> new file mode 100644
> index 0000000..55f9ccc
> --- /dev/null
> +++ b/include/ext4fs.h
> @@ -0,0 +1,132 @@
> +/*
> + * (C) Copyright 2011 - 2012 Samsung Electronics
> + * EXT4 filesystem implementation in Uboot by
> + * Uma Shankar <uma.shankar@samsung.com>
> + * Manjunatha C Achar <a.manjunatha@samsung.com>
> + *
> + * Ext4 Extent data structures are taken from  original ext4 fs code
> + * as found in the linux kernel.
> + *
> + * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
> + * Written by Alex Tomas <alex@clusterfs.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * 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.
> + */
> +
> +#ifndef __EXT4__
> +#define __EXT4__
> +#include <ext_common.h>
> +
> +#define EXT4_EXTENTS_FL		0x00080000 /* Inode uses extents */
> +#define EXT4_EXT_MAGIC			0xf30a
> +#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM	0x0010
> +#define EXT4_FEATURE_INCOMPAT_EXTENTS	0x0040
> +#define EXT4_INDIRECT_BLOCKS		12
> +
> +#define EXT4_BG_INODE_UNINIT		0x0001
> +#define EXT4_BG_BLOCK_UNINIT		0x0002
> +#define EXT4_BG_INODE_ZEROED		0x0004
> +
> +/*
> + * ext4_inode has i_block array (60 bytes total).
> + * The first 12 bytes store ext4_extent_header;
> + * the remainder stores an array of ext4_extent.
> + */
> +
> +/*
> + * This is the extent on-disk structure.
> + * It's used at the bottom of the tree.
> + */
> +struct ext4_extent {
> +	__le32	ee_block;	/* first logical block extent covers */
> +	__le16	ee_len;		/* number of blocks covered by extent */
> +	__le16	ee_start_hi;	/* high 16 bits of physical block */
> +	__le32	ee_start_lo;	/* low 32 bits of physical block */
> +};
> +
> +/*
> + * This is index on-disk structure.
> + * It's used at all the levels except the bottom.
> + */
> +struct ext4_extent_idx {
> +	__le32	ei_block;	/* index covers logical blocks from 'block' */
> +	__le32	ei_leaf_lo;	/* pointer to the physical block of the next *
> +				 * level. leaf or next index could be there */
> +	__le16	ei_leaf_hi;	/* high 16 bits of physical block */
> +	__u16	ei_unused;
> +};
> +
> +/* Each block (leaves and indexes), even inode-stored has header. */
> +struct ext4_extent_header {
> +	__le16	eh_magic;	/* probably will support different formats */
> +	__le16	eh_entries;	/* number of valid entries */
> +	__le16	eh_max;		/* capacity of store in entries */
> +	__le16	eh_depth;	/* has tree real underlying blocks? */
> +	__le32	eh_generation;	/* generation of the tree */
> +};
> +
> +struct ext_filesystem {
> +	/* Total Sector of partition */
> +	uint64_t total_sect;
> +	/* Block size  of partition */
> +	uint32_t blksz;
> +	/* Inode size of partition */
> +	uint32_t inodesz;
> +	/* Sectors per Block */
> +	uint32_t sect_perblk;
> +	/* Group Descriptor Block Number */
> +	uint32_t gdtable_blkno;
> +	/* Total block groups of partition */
> +	uint32_t no_blkgrp;
> +	/* No of blocks required for bgdtable */
> +	uint32_t no_blk_pergdt;
> +	/* Superblock */
> +	struct ext2_sblock *sb;
> +	/* Block group descritpor table */
> +	struct ext2_block_group *gd;
> +	char *gdtable;
> +
> +	/* Block Bitmap Related */
> +	unsigned char **blk_bmaps;
> +	long int curr_blkno;
> +	uint16_t first_pass_bbmap;
> +
> +	/* Inode Bitmap Related */
> +	unsigned char **inode_bmaps;
> +	int curr_inode_no;
> +	uint16_t first_pass_ibmap;
> +
> +	/* Journal Related */
> +
> +	/* Block Device Descriptor */
> +	block_dev_desc_t *dev_desc;
> +};
> +
> +extern block_dev_desc_t *ext4_dev_desc;
> +extern struct ext2_data *ext4fs_root;
> +extern struct ext2fs_node *ext4fs_file;
> +
> +struct ext_filesystem *get_fs(void);
> +int init_fs(block_dev_desc_t *dev_desc);
> +void deinit_fs(block_dev_desc_t *dev_desc);
> +int ext4fs_open(const char *filename);
> +int ext4fs_read(char *buf, unsigned len);
> +int ext4fs_mount(unsigned part_length);
> +void ext4fs_close(void);
> +int ext4fs_ls(const char *dirname);
> +void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot);
> +int ext4fs_devread(int sector, int byte_offset, int byte_len, char *buf);
> +int ext4fs_set_blk_dev(block_dev_desc_t *rbdd, int part);
> +long int read_allocated_block(struct ext2_inode *inode, int fileblock);
> +#endif
> diff --git a/include/ext_common.h b/include/ext_common.h
> new file mode 100644
> index 0000000..e532570
> --- /dev/null
> +++ b/include/ext_common.h
> @@ -0,0 +1,188 @@
> +/*
> + * (C) Copyright 2011 - 2012 Samsung Electronics
> + * EXT4 filesystem implementation in Uboot by
> + * Uma Shankar <uma.shankar@samsung.com>
> + * Manjunatha C Achar <a.manjunatha@samsung.com>
> + *
> + * Data structures and headers for ext4 support have been taken from
> + * ext2 ls load support in Uboot
> + *
> + * (C) Copyright 2004
> + * esd gmbh <www.esd-electronics.com>
> + * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
> + *
> + * based on code from grub2 fs/ext2.c and fs/fshelp.c by
> + * GRUB  --  GRand Unified Bootloader
> + * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
> + *
> + * 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.
> + */
> +
> +#ifndef __EXT_COMMON__
> +#define __EXT_COMMON__
> +
> +#define SECTOR_SIZE		0x200
> +#define SECTOR_BITS		9
> +
> +/* Magic value used to identify an ext2 filesystem.  */
> +#define	EXT2_MAGIC		0xEF53
> +/* Amount of indirect blocks in an inode.  */
> +#define INDIRECT_BLOCKS		12
> +/* Maximum lenght of a pathname.  */
> +#define EXT2_PATH_MAX			4096
> +/* Maximum nesting of symlinks, used to prevent a loop.  */
> +#define	EXT2_MAX_SYMLINKCNT		8
> +
> +/* Filetype used in directory entry.  */
> +#define	FILETYPE_UNKNOWN		0
> +#define	FILETYPE_REG			1
> +#define	FILETYPE_DIRECTORY		2
> +#define	FILETYPE_SYMLINK		7
> +
> +/* Filetype information as used in inodes.  */
> +#define FILETYPE_INO_MASK		0170000
> +#define FILETYPE_INO_REG		0100000
> +#define FILETYPE_INO_DIRECTORY		0040000
> +#define FILETYPE_INO_SYMLINK		0120000
> +#define EXT2_ROOT_INO			2 /* Root inode */
> +
> +/* Bits used as offset in sector */
> +#define DISK_SECTOR_BITS		9
> +/* The size of an ext2 block in bytes.  */
> +#define EXT2_BLOCK_SIZE(data)	   (1 << LOG2_BLOCK_SIZE(data))
> +
> +/* Log2 size of ext2 block in 512 blocks.  */
> +#define LOG2_EXT2_BLOCK_SIZE(data) (__le32_to_cpu \
> +				(data->sblock.log2_block_size) + 1)
> +
> +/* Log2 size of ext2 block in bytes.  */
> +#define LOG2_BLOCK_SIZE(data)	   (__le32_to_cpu \
> +		(data->sblock.log2_block_size) + 10)
> +#define INODE_SIZE_FILESYSTEM(data)	(__le32_to_cpu \
> +			(data->sblock.inode_size))
> +
> +#define EXT2_FT_DIR	2
> +#define SUCCESS	1
> +
> +/* Macro-instructions used to manage several block sizes  */
> +#define EXT2_MIN_BLOCK_LOG_SIZE	10 /* 1024 */
> +#define EXT2_MAX_BLOCK_LOG_SIZE	16 /* 65536 */
> +#define EXT2_MIN_BLOCK_SIZE		(1 << EXT2_MIN_BLOCK_LOG_SIZE)
> +#define EXT2_MAX_BLOCK_SIZE		(1 << EXT2_MAX_BLOCK_LOG_SIZE)
> +
> +/* The ext2 superblock.  */
> +struct ext2_sblock {
> +	uint32_t total_inodes;
> +	uint32_t total_blocks;
> +	uint32_t reserved_blocks;
> +	uint32_t free_blocks;
> +	uint32_t free_inodes;
> +	uint32_t first_data_block;
> +	uint32_t log2_block_size;
> +	uint32_t log2_fragment_size;
> +	uint32_t blocks_per_group;
> +	uint32_t fragments_per_group;
> +	uint32_t inodes_per_group;
> +	uint32_t mtime;
> +	uint32_t utime;
> +	uint16_t mnt_count;
> +	uint16_t max_mnt_count;
> +	uint16_t magic;
> +	uint16_t fs_state;
> +	uint16_t error_handling;
> +	uint16_t minor_revision_level;
> +	uint32_t lastcheck;
> +	uint32_t checkinterval;
> +	uint32_t creator_os;
> +	uint32_t revision_level;
> +	uint16_t uid_reserved;
> +	uint16_t gid_reserved;
> +	uint32_t first_inode;
> +	uint16_t inode_size;
> +	uint16_t block_group_number;
> +	uint32_t feature_compatibility;
> +	uint32_t feature_incompat;
> +	uint32_t feature_ro_compat;
> +	uint32_t unique_id[4];
> +	char volume_name[16];
> +	char last_mounted_on[64];
> +	uint32_t compression_info;
> +};
> +
> +struct ext2_block_group {
> +	__u32 block_id;	/* Blocks bitmap block */
> +	__u32 inode_id;	/* Inodes bitmap block */
> +	__u32 inode_table_id;	/* Inodes table block */
> +	__u16 free_blocks;	/* Free blocks count */
> +	__u16 free_inodes;	/* Free inodes count */
> +	__u16 used_dir_cnt;	/* Directories count */
> +	__u16 bg_flags;
> +	__u32 bg_reserved[2];
> +	__u16 bg_itable_unused; /* Unused inodes count */
> +	__u16 bg_checksum;	/* crc16(s_uuid+grouo_num+group_desc)*/
> +};
> +
> +/* The ext2 inode. */
> +struct ext2_inode {
> +	uint16_t mode;
> +	uint16_t uid;
> +	uint32_t size;
> +	uint32_t atime;
> +	uint32_t ctime;
> +	uint32_t mtime;
> +	uint32_t dtime;
> +	uint16_t gid;
> +	uint16_t nlinks;
> +	uint32_t blockcnt;	/* Blocks of 512 bytes!! */
> +	uint32_t flags;
> +	uint32_t osd1;
> +	union {
> +		struct datablocks {
> +			uint32_t dir_blocks[INDIRECT_BLOCKS];
> +			uint32_t indir_block;
> +			uint32_t double_indir_block;
> +			uint32_t triple_indir_block;
> +		} blocks;
> +		char symlink[60];
> +	} b;
> +	uint32_t version;
> +	uint32_t acl;
> +	uint32_t dir_acl;
> +	uint32_t fragment_addr;
> +	uint32_t osd2[3];
> +};
> +
> +/* The header of an ext2 directory entry. */
> +struct ext2_dirent {
> +	uint32_t inode;
> +	uint16_t direntlen;
> +	uint8_t namelen;
> +	uint8_t filetype;
> +};
> +
> +struct ext2fs_node {
> +	struct ext2_data *data;
> +	struct ext2_inode inode;
> +	int ino;
> +	int inode_read;
> +};
> +
> +/* Information about a "mounted" ext2 filesystem. */
> +struct ext2_data {
> +	struct ext2_sblock sblock;
> +	struct ext2_inode *inode;
> +	struct ext2fs_node diropen;
> +};
> +#endif
Rob Herring - March 27, 2012, 3:10 p.m.
On 01/09/2012 11:54 AM, uma.shankar@samsung.com wrote:
> From: uma.shankar <uma.shankar@samsung.com>
> 
> Signed-off-by: Uma Shankar <uma.shankar@samsung.com>
> Signed-off-by: Manjunatha C Achar <a.manjunatha@samsung.com>
> Signed-off-by: Iqbal Shareef <iqbal.ams@samsung.com>
> Signed-off-by: Hakgoo Lee <goodguy.lee@samsung.com>
> ---
> Changes for v3:
>         - Copyright has been updated in respective files
>         - ext4fs has been made independant of ext2fs.c
>         - Fixed API namespace
>         - Removed endianness conversion API, used uboot defined API
>           for the same
>         - Fixed coding style issues
>         - Moved README.ext4 file into doc folder
> 
> Changes for v2:
>         - Code cleanup, changed comment style
>         - camel case removed, resolved code alignment issues
>         - memory allocation logic changed, removed busybox logic
>         - Modified ext4 load to remove grub dependency (GPLv3)
>         - Introduced new Config for ext4 write
> 
> Changes for v1:
>         - Removed checkpatch warnings and errors
>         - Moved common API's of ext2 and ext4 to one generic header file

snip

> +static int do_ext4_load(cmd_tbl_t *cmdtp, int flag, int argc,
> +						char *const argv[])
> +{
> +	char *filename = NULL;
> +	char *ep;
> +	int dev;
> +	unsigned long part = 1;
> +	ulong addr = 0;
> +	ulong part_length;
> +	int filelen;
> +	disk_partition_t info;
> +	struct ext_filesystem *fs;
> +	char buf[12];
> +	unsigned long count;
> +	const char *addr_str;
> +
> +	count = 0;
> +	addr = simple_strtoul(argv[3], NULL, 16);
> +	filename = getenv("bootfile");
> +	switch (argc) {
> +	case 3:
> +		addr_str = getenv("loadaddr");
> +		if (addr_str != NULL)
> +			addr = simple_strtoul(addr_str, NULL, 16);
> +		else
> +			addr = CONFIG_SYS_LOAD_ADDR;
> +
> +		break;
> +	case 4:
> +		break;
> +	case 5:
> +		filename = argv[4];
> +		break;
> +	case 6:
> +		filename = argv[4];
> +		count = simple_strtoul(argv[5], NULL, 16);
> +		break;
> +
> +	default:
> +		return cmd_usage(cmdtp);
> +	}
> +
> +	if (!filename) {
> +		puts("** No boot file defined **\n");
> +		return 1;
> +	}
> +
> +	dev = (int)simple_strtoul(argv[2], &ep, 16);
> +	ext4_dev_desc = get_dev(argv[1], dev);
> +	if (ext4_dev_desc == NULL) {
> +		printf("** Block device %s %d not supported\n", argv[1], dev);
> +		return 1;
> +	}
> +	if (init_fs(ext4_dev_desc))
> +		return 1;
> +
> +	fs = get_fs();

These functions pollute the name space and could be combined.

Or can't these 2 calls be rolled into...

> +	if (*ep) {
> +		if (*ep != ':') {
> +			puts("** Invalid boot device, use `dev[:part]' **\n");
> +			return 1;
> +		}
> +		part = simple_strtoul(++ep, NULL, 16);
> +	}
> +
> +	if (part != 0) {
> +		if (get_partition_info(fs->dev_desc, part, &info)) {
> +			printf("** Bad partition %lu **\n", part);
> +			return 1;
> +		}
> +
> +		if (strncmp((char *)info.type, BOOT_PART_TYPE,
> +			    strlen(BOOT_PART_TYPE)) != 0) {
> +			printf("** Invalid partition type \"%s\""
> +			       " (expect \"" BOOT_PART_TYPE "\")\n", info.type);
> +			return 1;
> +		}
> +		printf("Loading file \"%s\" "
> +		       "from %s device %d:%lu %s\n",
> +		       filename, argv[1], dev, part, info.name);
> +	} else {
> +		printf("Loading file \"%s\" from %s device %d\n",
> +		       filename, argv[1], dev);
> +	}
> +
> +	part_length = ext4fs_set_blk_dev(fs->dev_desc, part);

...this function?

> +	if (part_length == 0) {
> +		printf("**Bad partition - %s %d:%lu **\n", argv[1], dev, part);
> +		ext4fs_close();

You are leaking memory allocated in init_fs here.

> +		return 1;
> +	}
> +
> +	if (!ext4fs_mount(part_length)) {
> +		printf("** Bad ext2 partition or disk - %s %d:%lu **\n",
> +		       argv[1], dev, part);
> +		ext4fs_close();

and here...

> +		return 1;
> +	}
> +
> +	filelen = ext4fs_open(filename);
> +	if (filelen < 0) {
> +		printf("** File not found %s\n", filename);
> +		ext4fs_close();

and here...

> +		return 1;
> +	}
> +	if ((count < filelen) && (count != 0))
> +		filelen = count;
> +
> +	if (ext4fs_read((char *)addr, filelen) != filelen) {
> +		printf("** Unable to read \"%s\" from %s %d:%lu **\n",
> +		       filename, argv[1], dev, part);
> +		ext4fs_close();

and here...

Same comments apply in do_ext4_ls.

Rob

Patch

diff --git a/Makefile b/Makefile
index 7e9491d..e77f6be 100644
--- a/Makefile
+++ b/Makefile
@@ -235,7 +235,7 @@  LIBS += dts/libdts.o
 endif
 LIBS += arch/$(ARCH)/lib/lib$(ARCH).o
 LIBS += fs/cramfs/libcramfs.o fs/fat/libfat.o fs/fdos/libfdos.o fs/jffs2/libjffs2.o \
-	fs/reiserfs/libreiserfs.o fs/ext2/libext2fs.o fs/yaffs2/libyaffs2.o \
+	fs/reiserfs/libreiserfs.o fs/ext2/libext2fs.o fs/ext4/libext4fs.o fs/yaffs2/libyaffs2.o \
 	fs/ubifs/libubifs.o
 LIBS += net/libnet.o
 LIBS += disk/libdisk.o
diff --git a/common/Makefile b/common/Makefile
index 2d9ae8c..f5243f6 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -86,6 +86,7 @@  COBJS-$(CONFIG_ENV_IS_IN_EEPROM) += cmd_eeprom.o
 COBJS-$(CONFIG_CMD_EEPROM) += cmd_eeprom.o
 COBJS-$(CONFIG_CMD_ELF) += cmd_elf.o
 COBJS-$(CONFIG_SYS_HUSH_PARSER) += cmd_exit.o
+COBJS-$(CONFIG_CMD_EXT4) += cmd_ext4.o
 COBJS-$(CONFIG_CMD_EXT2) += cmd_ext2.o
 COBJS-$(CONFIG_CMD_FAT) += cmd_fat.o
 COBJS-$(CONFIG_CMD_FDC)$(CONFIG_CMD_FDOS) += cmd_fdc.o
diff --git a/common/cmd_ext4.c b/common/cmd_ext4.c
new file mode 100644
index 0000000..2c53d2c
--- /dev/null
+++ b/common/cmd_ext4.c
@@ -0,0 +1,266 @@ 
+/*
+ * (C) Copyright 2011 - 2012 Samsung Electronics
+ * EXT4 filesystem implementation in Uboot by
+ * Uma Shankar <uma.shankar@samsung.com>
+ * Manjunatha C Achar <a.manjunatha@samsung.com>
+ *
+ * Ext4fs support
+ * made from existing cmd_ext2.c file of Uboot
+ *
+ * (C) Copyright 2004
+ * esd gmbh <www.esd-electronics.com>
+ * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
+ *
+ * made from cmd_reiserfs by
+ *
+ * (C) Copyright 2003 - 2004
+ * Sysgo Real-Time Solutions, 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+/*
+ * Changelog:
+ *	0.1 - Newly created file for ext4fs support. Taken from cmd_ext2.c
+ *	        file in uboot. Added ext4fs ls and load support.
+ */
+
+#include <common.h>
+#include <part.h>
+#include <config.h>
+#include <command.h>
+#include <image.h>
+#include <linux/ctype.h>
+#include <asm/byteorder.h>
+#include <ext_common.h>
+#include <ext4fs.h>
+#include <linux/stat.h>
+#include <malloc.h>
+
+#if defined(CONFIG_CMD_USB) && defined(CONFIG_USB_STORAGE)
+#include <usb.h>
+#endif
+
+#if !defined(CONFIG_DOS_PARTITION) && !defined(CONFIG_EFI_PARTITION)
+#error DOS or EFI partition support must be selected
+#endif
+
+uint64_t total_sector;
+uint64_t part_offset;
+
+#define DOS_PART_MAGIC_OFFSET	0x1fe
+#define DOS_FS_TYPE_OFFSET	0x36
+#define DOS_FS32_TYPE_OFFSET	0x52
+
+static int do_ext4_load(cmd_tbl_t *cmdtp, int flag, int argc,
+						char *const argv[])
+{
+	char *filename = NULL;
+	char *ep;
+	int dev;
+	unsigned long part = 1;
+	ulong addr = 0;
+	ulong part_length;
+	int filelen;
+	disk_partition_t info;
+	struct ext_filesystem *fs;
+	char buf[12];
+	unsigned long count;
+	const char *addr_str;
+
+	count = 0;
+	addr = simple_strtoul(argv[3], NULL, 16);
+	filename = getenv("bootfile");
+	switch (argc) {
+	case 3:
+		addr_str = getenv("loadaddr");
+		if (addr_str != NULL)
+			addr = simple_strtoul(addr_str, NULL, 16);
+		else
+			addr = CONFIG_SYS_LOAD_ADDR;
+
+		break;
+	case 4:
+		break;
+	case 5:
+		filename = argv[4];
+		break;
+	case 6:
+		filename = argv[4];
+		count = simple_strtoul(argv[5], NULL, 16);
+		break;
+
+	default:
+		return cmd_usage(cmdtp);
+	}
+
+	if (!filename) {
+		puts("** No boot file defined **\n");
+		return 1;
+	}
+
+	dev = (int)simple_strtoul(argv[2], &ep, 16);
+	ext4_dev_desc = get_dev(argv[1], dev);
+	if (ext4_dev_desc == NULL) {
+		printf("** Block device %s %d not supported\n", argv[1], dev);
+		return 1;
+	}
+	if (init_fs(ext4_dev_desc))
+		return 1;
+
+	fs = get_fs();
+	if (*ep) {
+		if (*ep != ':') {
+			puts("** Invalid boot device, use `dev[:part]' **\n");
+			return 1;
+		}
+		part = simple_strtoul(++ep, NULL, 16);
+	}
+
+	if (part != 0) {
+		if (get_partition_info(fs->dev_desc, part, &info)) {
+			printf("** Bad partition %lu **\n", part);
+			return 1;
+		}
+
+		if (strncmp((char *)info.type, BOOT_PART_TYPE,
+			    strlen(BOOT_PART_TYPE)) != 0) {
+			printf("** Invalid partition type \"%s\""
+			       " (expect \"" BOOT_PART_TYPE "\")\n", info.type);
+			return 1;
+		}
+		printf("Loading file \"%s\" "
+		       "from %s device %d:%lu %s\n",
+		       filename, argv[1], dev, part, info.name);
+	} else {
+		printf("Loading file \"%s\" from %s device %d\n",
+		       filename, argv[1], dev);
+	}
+
+	part_length = ext4fs_set_blk_dev(fs->dev_desc, part);
+	if (part_length == 0) {
+		printf("**Bad partition - %s %d:%lu **\n", argv[1], dev, part);
+		ext4fs_close();
+		return 1;
+	}
+
+	if (!ext4fs_mount(part_length)) {
+		printf("** Bad ext2 partition or disk - %s %d:%lu **\n",
+		       argv[1], dev, part);
+		ext4fs_close();
+		return 1;
+	}
+
+	filelen = ext4fs_open(filename);
+	if (filelen < 0) {
+		printf("** File not found %s\n", filename);
+		ext4fs_close();
+		return 1;
+	}
+	if ((count < filelen) && (count != 0))
+		filelen = count;
+
+	if (ext4fs_read((char *)addr, filelen) != filelen) {
+		printf("** Unable to read \"%s\" from %s %d:%lu **\n",
+		       filename, argv[1], dev, part);
+		ext4fs_close();
+		return 1;
+	}
+
+	ext4fs_close();
+	deinit_fs(fs->dev_desc);
+	/* Loading ok, update default load address */
+	load_addr = addr;
+
+	printf("%d bytes read\n", filelen);
+	sprintf(buf, "%X", filelen);
+	setenv("filesize", buf);
+
+	return 0;
+}
+
+static int do_ext4_ls(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	const char *filename = "/";
+	int dev;
+	unsigned long part = 1;
+	char *ep;
+	struct ext_filesystem *fs;
+	int part_length;
+
+	if (argc < 3)
+		return cmd_usage(cmdtp);
+
+	dev = (int)simple_strtoul(argv[2], &ep, 16);
+	ext4_dev_desc = get_dev(argv[1], dev);
+
+	if (ext4_dev_desc == NULL) {
+		printf("\n** Block device %s %d not supported\n", argv[1], dev);
+		return 1;
+	}
+
+	if (init_fs(ext4_dev_desc))
+		return 1;
+
+	fs = get_fs();
+	if (*ep) {
+		if (*ep != ':') {
+			puts("\n** Invalid boot device, use `dev[:part]' **\n");
+			return 1;
+		}
+		part = simple_strtoul(++ep, NULL, 16);
+	}
+
+	if (argc == 4)
+		filename = argv[3];
+
+	part_length = ext4fs_set_blk_dev(fs->dev_desc, part);
+	if (part_length == 0) {
+		printf("** Bad partition - %s %d:%lu **\n", argv[1], dev, part);
+		ext4fs_close();
+		return 1;
+	}
+
+	if (!ext4fs_mount(part_length)) {
+		printf("** Bad ext2 partition or disk - %s %d:%lu **\n",
+		       argv[1], dev, part);
+		ext4fs_close();
+		return 1;
+	}
+	if (ext4fs_ls(filename)) {
+		printf("** Error ext2fs_ls() **\n");
+		ext4fs_close();
+		return 1;
+	};
+
+	ext4fs_close();
+	deinit_fs(fs->dev_desc);
+
+	return 0;
+}
+
+U_BOOT_CMD(ext4ls, 4, 1, do_ext4_ls,
+	   "list files in a directory (default /)",
+	   "<interface> <dev[:part]> [directory]\n"
+	   "	  - list files from 'dev' on 'interface' in a 'directory'");
+
+U_BOOT_CMD(ext4load, 6, 0, do_ext4_load,
+	   "load binary file from a Ext2 filesystem",
+	   "<interface> <dev[:part]> [addr] [filename] [bytes]\n"
+	   "	  - load binary file 'filename' from 'dev' on 'interface'\n"
+	   "		 to address 'addr' from ext2 filesystem");
diff --git a/fs/Makefile b/fs/Makefile
index 22aad12..00a8f37 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -23,6 +23,7 @@ 
 #
 
 subdirs-$(CONFIG_CMD_CRAMFS) := cramfs
+subdirs-$(CONFIG_CMD_EXT4) += ext4
 subdirs-$(CONFIG_CMD_EXT2) += ext2
 subdirs-$(CONFIG_CMD_FAT) += fat
 subdirs-$(CONFIG_CMD_FDOS) += fdos
diff --git a/fs/ext2/dev.c b/fs/ext2/dev.c
index 874e211..315ff53 100644
--- a/fs/ext2/dev.c
+++ b/fs/ext2/dev.c
@@ -27,6 +27,7 @@ 
 #include <common.h>
 #include <config.h>
 #include <ext2fs.h>
+#include <ext_common.h>
 
 static block_dev_desc_t *ext2fs_block_dev_desc;
 static disk_partition_t part_info;
diff --git a/fs/ext2/ext2fs.c b/fs/ext2/ext2fs.c
index f621741..a4f3094 100644
--- a/fs/ext2/ext2fs.c
+++ b/fs/ext2/ext2fs.c
@@ -25,152 +25,16 @@ 
 
 #include <common.h>
 #include <ext2fs.h>
+#include <ext_common.h>
 #include <malloc.h>
 #include <asm/byteorder.h>
 
 extern int ext2fs_devread (int sector, int byte_offset, int byte_len,
 			   char *buf);
 
-/* Magic value used to identify an ext2 filesystem.  */
-#define	EXT2_MAGIC		0xEF53
-/* Amount of indirect blocks in an inode.  */
-#define INDIRECT_BLOCKS		12
-/* Maximum lenght of a pathname.  */
-#define EXT2_PATH_MAX		4096
-/* Maximum nesting of symlinks, used to prevent a loop.  */
-#define	EXT2_MAX_SYMLINKCNT	8
-
-/* Filetype used in directory entry.  */
-#define	FILETYPE_UNKNOWN	0
-#define	FILETYPE_REG		1
-#define	FILETYPE_DIRECTORY	2
-#define	FILETYPE_SYMLINK	7
-
-/* Filetype information as used in inodes.  */
-#define FILETYPE_INO_MASK	0170000
-#define FILETYPE_INO_REG	0100000
-#define FILETYPE_INO_DIRECTORY	0040000
-#define FILETYPE_INO_SYMLINK	0120000
-
-/* Bits used as offset in sector */
-#define DISK_SECTOR_BITS        9
-
-/* Log2 size of ext2 block in 512 blocks.  */
-#define LOG2_EXT2_BLOCK_SIZE(data) (__le32_to_cpu (data->sblock.log2_block_size) + 1)
-
-/* Log2 size of ext2 block in bytes.  */
-#define LOG2_BLOCK_SIZE(data)	   (__le32_to_cpu (data->sblock.log2_block_size) + 10)
-
-/* The size of an ext2 block in bytes.  */
-#define EXT2_BLOCK_SIZE(data)	   (1 << LOG2_BLOCK_SIZE(data))
-
-/* The ext2 superblock.  */
-struct ext2_sblock {
-	uint32_t total_inodes;
-	uint32_t total_blocks;
-	uint32_t reserved_blocks;
-	uint32_t free_blocks;
-	uint32_t free_inodes;
-	uint32_t first_data_block;
-	uint32_t log2_block_size;
-	uint32_t log2_fragment_size;
-	uint32_t blocks_per_group;
-	uint32_t fragments_per_group;
-	uint32_t inodes_per_group;
-	uint32_t mtime;
-	uint32_t utime;
-	uint16_t mnt_count;
-	uint16_t max_mnt_count;
-	uint16_t magic;
-	uint16_t fs_state;
-	uint16_t error_handling;
-	uint16_t minor_revision_level;
-	uint32_t lastcheck;
-	uint32_t checkinterval;
-	uint32_t creator_os;
-	uint32_t revision_level;
-	uint16_t uid_reserved;
-	uint16_t gid_reserved;
-	uint32_t first_inode;
-	uint16_t inode_size;
-	uint16_t block_group_number;
-	uint32_t feature_compatibility;
-	uint32_t feature_incompat;
-	uint32_t feature_ro_compat;
-	uint32_t unique_id[4];
-	char volume_name[16];
-	char last_mounted_on[64];
-	uint32_t compression_info;
-};
-
-/* The ext2 blockgroup.  */
-struct ext2_block_group {
-	uint32_t block_id;
-	uint32_t inode_id;
-	uint32_t inode_table_id;
-	uint16_t free_blocks;
-	uint16_t free_inodes;
-	uint16_t used_dir_cnt;
-	uint32_t reserved[3];
-};
-
-/* The ext2 inode.  */
-struct ext2_inode {
-	uint16_t mode;
-	uint16_t uid;
-	uint32_t size;
-	uint32_t atime;
-	uint32_t ctime;
-	uint32_t mtime;
-	uint32_t dtime;
-	uint16_t gid;
-	uint16_t nlinks;
-	uint32_t blockcnt;	/* Blocks of 512 bytes!! */
-	uint32_t flags;
-	uint32_t osd1;
-	union {
-		struct datablocks {
-			uint32_t dir_blocks[INDIRECT_BLOCKS];
-			uint32_t indir_block;
-			uint32_t double_indir_block;
-			uint32_t tripple_indir_block;
-		} blocks;
-		char symlink[60];
-	} b;
-	uint32_t version;
-	uint32_t acl;
-	uint32_t dir_acl;
-	uint32_t fragment_addr;
-	uint32_t osd2[3];
-};
-
-/* The header of an ext2 directory entry.  */
-struct ext2_dirent {
-	uint32_t inode;
-	uint16_t direntlen;
-	uint8_t namelen;
-	uint8_t filetype;
-};
-
-struct ext2fs_node {
-	struct ext2_data *data;
-	struct ext2_inode inode;
-	int ino;
-	int inode_read;
-};
-
-/* Information about a "mounted" ext2 filesystem.  */
-struct ext2_data {
-	struct ext2_sblock sblock;
-	struct ext2_inode *inode;
-	struct ext2fs_node diropen;
-};
-
-
-typedef struct ext2fs_node *ext2fs_node_t;
 
 struct ext2_data *ext2fs_root = NULL;
-ext2fs_node_t ext2fs_file = NULL;
+struct ext2fs_node *ext2fs_file;
 int symlinknest = 0;
 uint32_t *indir1_block = NULL;
 int indir1_size = 0;
@@ -243,14 +107,16 @@  static int ext2fs_read_inode
 }
 
 
-void ext2fs_free_node (ext2fs_node_t node, ext2fs_node_t currroot) {
+void ext2fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
+{
 	if ((node != &ext2fs_root->diropen) && (node != currroot)) {
 		free (node);
 	}
 }
 
 
-static int ext2fs_read_block (ext2fs_node_t node, int fileblock) {
+static int ext2fs_read_block(struct ext2fs_node *node, int fileblock)
+{
 	struct ext2_data *data = node->data;
 	struct ext2_inode *inode = &node->inode;
 	int blknr;
@@ -396,7 +262,8 @@  static int ext2fs_read_block (ext2fs_node_t node, int fileblock) {
 
 
 int ext2fs_read_file
-	(ext2fs_node_t node, int pos, unsigned int len, char *buf) {
+	(struct ext2fs_node *node, int pos, unsigned int len, char *buf)
+{
 	int i;
 	int blockcnt;
 	int log2blocksize = LOG2_EXT2_BLOCK_SIZE (node->data);
@@ -455,8 +322,8 @@  int ext2fs_read_file
 	return (len);
 }
 
-
-static int ext2fs_iterate_dir (ext2fs_node_t dir, char *name, ext2fs_node_t * fnode, int *ftype)
+int ext2fs_iterate_dir(struct ext2fs_node *dir, char *name,
+					struct ext2fs_node **fnode, int *ftype)
 {
 	unsigned int fpos = 0;
 	int status;
@@ -485,7 +352,7 @@  static int ext2fs_iterate_dir (ext2fs_node_t dir, char *name, ext2fs_node_t * fn
 		}
 		if (dirent.namelen != 0) {
 			char filename[dirent.namelen + 1];
-			ext2fs_node_t fdiro;
+			struct ext2fs_node *fdiro;
 			int type = FILETYPE_UNKNOWN;
 
 			status = ext2fs_read_file (diro,
@@ -587,8 +454,8 @@  static int ext2fs_iterate_dir (ext2fs_node_t dir, char *name, ext2fs_node_t * fn
 	return (0);
 }
 
-
-static char *ext2fs_read_symlink (ext2fs_node_t node) {
+static char *ext2fs_read_symlink(struct ext2fs_node *node)
+{
 	char *symlink;
 	struct ext2fs_node *diro = node;
 	int status;
@@ -625,15 +492,16 @@  static char *ext2fs_read_symlink (ext2fs_node_t node) {
 
 
 int ext2fs_find_file1
-	(const char *currpath,
-	 ext2fs_node_t currroot, ext2fs_node_t * currfound, int *foundtype) {
+	(const char *currpath, struct ext2fs_node *currroot,
+		struct ext2fs_node **currfound, int *foundtype)
+{
 	char fpath[strlen (currpath) + 1];
 	char *name = fpath;
 	char *next;
 	int status;
 	int type = FILETYPE_DIRECTORY;
-	ext2fs_node_t currnode = currroot;
-	ext2fs_node_t oldnode = currroot;
+	struct ext2fs_node *currnode = currroot;
+	struct ext2fs_node *oldnode = currroot;
 
 	strncpy (fpath, currpath, strlen (currpath) + 1);
 
@@ -729,8 +597,9 @@  int ext2fs_find_file1
 
 
 int ext2fs_find_file
-	(const char *path,
-	 ext2fs_node_t rootnode, ext2fs_node_t * foundnode, int expecttype) {
+	(const char *path, struct ext2fs_node *rootnode,
+	struct ext2fs_node **foundnode, int expecttype)
+{
 	int status;
 	int foundtype = FILETYPE_DIRECTORY;
 
@@ -756,7 +625,7 @@  int ext2fs_find_file
 
 
 int ext2fs_ls (const char *dirname) {
-	ext2fs_node_t dirnode;
+	struct ext2fs_node *dirnode;
 	int status;
 
 	if (ext2fs_root == NULL) {
@@ -776,7 +645,7 @@  int ext2fs_ls (const char *dirname) {
 
 
 int ext2fs_open (const char *filename) {
-	ext2fs_node_t fdiro = NULL;
+	struct ext2fs_node *fdiro = NULL;
 	int status;
 	int len;
 
@@ -806,8 +675,8 @@  fail:
 }
 
 
-int ext2fs_close (void
-	) {
+int ext2fs_close(void)
+{
 	if ((ext2fs_file != NULL) && (ext2fs_root != NULL)) {
 		ext2fs_free_node (ext2fs_file, &ext2fs_root->diropen);
 		ext2fs_file = NULL;
diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
new file mode 100644
index 0000000..7add4ab
--- /dev/null
+++ b/fs/ext4/Makefile
@@ -0,0 +1,51 @@ 
+#
+# (C) Copyright 2006
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# (C) Copyright 2003
+# Pavel Bartusek, Sysgo Real-Time Solutions AG, pba@sysgo.de
+#
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# 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 $(TOPDIR)/config.mk
+
+LIB	= $(obj)libext4fs.o
+
+AOBJS	=
+COBJS-$(CONFIG_CMD_EXT4) := ext4fs.o ext4_common.o dev.o
+
+SRCS	:= $(AOBJS:.o=.S) $(COBJS-y:.o=.c)
+OBJS	:= $(addprefix $(obj),$(AOBJS) $(COBJS-y))
+
+
+all:	$(LIB) $(AOBJS)
+
+$(LIB):	$(obj).depend $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
diff --git a/fs/ext4/dev.c b/fs/ext4/dev.c
new file mode 100644
index 0000000..2054be3
--- /dev/null
+++ b/fs/ext4/dev.c
@@ -0,0 +1,145 @@ 
+/*
+ * (C) Copyright 2011 - 2012 Samsung Electronics
+ * EXT4 filesystem implementation in Uboot by
+ * Uma Shankar <uma.shankar@samsung.com>
+ * Manjunatha C Achar <a.manjunatha@samsung.com>
+ *
+ * made from existing ext2/dev.c file of Uboot
+ * (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.
+ *
+ */
+
+/*
+ * Changelog:
+ *	0.1 - Newly created file for ext4fs support. Taken from
+ *	        fs/ext2/dev.c file in uboot.
+ */
+
+#include <common.h>
+#include <config.h>
+#include <ext_common.h>
+
+static block_dev_desc_t *ext4fs_block_dev_desc;
+static disk_partition_t part_info;
+
+int ext4fs_set_blk_dev(block_dev_desc_t *rbdd, int part)
+{
+	ext4fs_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(ext4fs_block_dev_desc,
+					part, &part_info))
+			return 0;
+	}
+	return part_info.size;
+}
+
+int ext4fs_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)) {
+		printf("%s read outside partition %d\n", __func__, sector);
+		return 0;
+	}
+
+	/* Get the read to the beginning of a partition */
+	sector += byte_offset >> SECTOR_BITS;
+	byte_offset &= SECTOR_SIZE - 1;
+
+	debug(" <%d, %d, %d>\n", sector, byte_offset, byte_len);
+
+	if (ext4fs_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 (ext4fs_block_dev_desc->
+		    block_read(ext4fs_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++;
+	}
+
+	if (byte_len == 0)
+		return 1;
+
+	/* read sector aligned part */
+	block_len = byte_len & ~(SECTOR_SIZE - 1);
+
+	if (block_len == 0) {
+		u8 p[SECTOR_SIZE];
+
+		block_len = SECTOR_SIZE;
+		ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
+						  part_info.start + sector,
+						  1, (unsigned long *)p);
+		memcpy(buf, p, byte_len);
+		return 1;
+	}
+
+	if (ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
+					part_info.start + sector,
+					block_len / SECTOR_SIZE,
+					(unsigned long *) buf) !=
+					block_len / SECTOR_SIZE) {
+		printf(" ** %s read error - block\n", __func__);
+		return 0;
+	}
+	block_len = byte_len & ~(SECTOR_SIZE - 1);
+	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 (ext4fs_block_dev_desc->
+		    block_read(ext4fs_block_dev_desc->dev,
+				part_info.start + sector, 1,
+				(unsigned long *) sec_buf) != 1) {
+			printf("* %s read error - last part\n", __func__);
+			return 0;
+		}
+		memcpy(buf, sec_buf, byte_len);
+	}
+	return 1;
+}
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
new file mode 100644
index 0000000..d9deefe
--- /dev/null
+++ b/fs/ext4/ext4_common.c
@@ -0,0 +1,875 @@ 
+/*
+ * (C) Copyright 2011 - 2012 Samsung Electronics
+ * EXT4 filesystem implementation in Uboot by
+ * Uma Shankar <uma.shankar@samsung.com>
+ * Manjunatha C Achar <a.manjunatha@samsung.com>
+ *
+ * ext4ls and ext4load : Based on ext2 ls load support in Uboot.
+ *
+ * (C) Copyright 2004
+ * esd gmbh <www.esd-electronics.com>
+ * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
+ *
+ * based on code from grub2 fs/ext2.c and fs/fshelp.c by
+ * GRUB  --  GRand Unified Bootloader
+ * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
+ *
+ * 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>
+#include <ext_common.h>
+#include <ext4fs.h>
+#include <malloc.h>
+#include <stddef.h>
+#include <linux/stat.h>
+#include <linux/time.h>
+#include <asm/byteorder.h>
+#include "ext4_common.h"
+
+struct ext2_data *ext4fs_root;
+struct ext2fs_node *ext4fs_file;
+uint32_t *ext4fs_indir1_block;
+int ext4fs_indir1_size;
+int ext4fs_indir1_blkno = -1;
+uint32_t *ext4fs_indir2_block;
+int ext4fs_indir2_size;
+int ext4fs_indir2_blkno = -1;
+
+uint32_t *ext4fs_indir3_block;
+int ext4fs_indir3_size;
+int ext4fs_indir3_blkno = -1;
+struct ext2_inode *g_parent_inode;
+static int symlinknest;
+
+static struct ext4_extent_header *ext4fs_get_extent_block
+	(struct ext2_data *data, char *buf,
+		struct ext4_extent_header *ext_block,
+		uint32_t fileblock, int log2_blksz)
+{
+	struct ext4_extent_idx *index;
+	unsigned long long block;
+	struct ext_filesystem *fs = get_fs();
+	int i;
+
+	while (1) {
+		index = (struct ext4_extent_idx *)(ext_block + 1);
+
+		if (le32_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
+			return 0;
+
+		if (ext_block->eh_depth == 0)
+			return ext_block;
+		i = -1;
+		do {
+			i++;
+			if (i >= le32_to_cpu(ext_block->eh_entries))
+				break;
+		} while (fileblock > le32_to_cpu(index[i].ei_block));
+
+		if (--i < 0)
+			return 0;
+
+		block = le32_to_cpu(index[i].ei_leaf_hi);
+		block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
+
+		if (ext4fs_devread(block << log2_blksz, 0, fs->blksz, buf))
+			ext_block = (struct ext4_extent_header *)buf;
+		else
+			return 0;
+	}
+}
+
+static int ext4fs_blockgroup
+	(struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
+{
+	long int blkno;
+	unsigned int blkoff, desc_per_blk;
+
+	desc_per_blk = EXT2_BLOCK_SIZE(data) / sizeof(struct ext2_block_group);
+
+	blkno = __le32_to_cpu(data->sblock.first_data_block) + 1 +
+	    group / desc_per_blk;
+	blkoff = (group % desc_per_blk) * sizeof(struct ext2_block_group);
+
+	debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
+	      group, blkno, blkoff);
+
+	return ext4fs_devread(blkno << LOG2_EXT2_BLOCK_SIZE(data),
+			      blkoff, sizeof(struct ext2_block_group),
+			      (char *)blkgrp);
+}
+
+int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
+{
+	struct ext2_block_group blkgrp;
+	struct ext2_sblock *sblock = &data->sblock;
+	struct ext_filesystem *fs = get_fs();
+	int inodes_per_block, status;
+	long int blkno;
+	unsigned int blkoff;
+
+	/* It is easier to calculate if the first inode is 0. */
+	ino--;
+	status = ext4fs_blockgroup(data, ino / __le32_to_cpu
+				   (sblock->inodes_per_group), &blkgrp);
+	if (status == 0)
+		return 0;
+
+	inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
+	blkno = __le32_to_cpu(blkgrp.inode_table_id) +
+	    (ino % __le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
+	blkoff = (ino % inodes_per_block) * fs->inodesz;
+	/* Read the inode. */
+	status = ext4fs_devread(blkno << LOG2_EXT2_BLOCK_SIZE(data), blkoff,
+				sizeof(struct ext2_inode), (char *)inode);
+	if (status == 0)
+		return 0;
+
+	return 1;
+}
+
+long int read_allocated_block(struct ext2_inode *inode, int fileblock)
+{
+	long int blknr;
+	int blksz;
+	int log2_blksz;
+	int status;
+	long int rblock;
+	long int perblock_parent;
+	long int perblock_child;
+	unsigned long long start;
+	/* get the blocksize of the filesystem */
+	blksz = EXT2_BLOCK_SIZE(ext4fs_root);
+	log2_blksz = LOG2_EXT2_BLOCK_SIZE(ext4fs_root);
+	if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
+		char *buf = zalloc(blksz);
+		if (!buf)
+			return -ENOMEM;
+		struct ext4_extent_header *ext_block;
+		struct ext4_extent *extent;
+		int i = -1;
+		ext_block = ext4fs_get_extent_block(ext4fs_root, buf,
+						    (struct ext4_extent_header
+						     *)inode->b.
+						    blocks.dir_blocks,
+						    fileblock, log2_blksz);
+		if (!ext_block) {
+			printf("invalid extent block\n");
+			free(buf);
+			return -EINVAL;
+		}
+
+		extent = (struct ext4_extent *)(ext_block + 1);
+
+		do {
+			i++;
+			if (i >= le32_to_cpu(ext_block->eh_entries))
+				break;
+		} while (fileblock >= le32_to_cpu(extent[i].ee_block));
+		if (--i >= 0) {
+			fileblock -= le32_to_cpu(extent[i].ee_block);
+			if (fileblock >= le32_to_cpu(extent[i].ee_len)) {
+				free(buf);
+				return 0;
+			}
+
+			start = le32_to_cpu(extent[i].ee_start_hi);
+			start = (start << 32) +
+			    le32_to_cpu(extent[i].ee_start_lo);
+			free(buf);
+			return fileblock + start;
+		}
+
+		printf("Extent Error\n");
+		free(buf);
+		return -1;
+	}
+
+	/* Direct blocks. */
+	if (fileblock < INDIRECT_BLOCKS)
+		blknr = __le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
+
+	/* Indirect. */
+	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
+		if (ext4fs_indir1_block == NULL) {
+			ext4fs_indir1_block = zalloc(blksz);
+			if (ext4fs_indir1_block == NULL) {
+				printf("** SI ext2fs read block (indir 1)"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir1_size = blksz;
+			ext4fs_indir1_blkno = -1;
+		}
+		if (blksz != ext4fs_indir1_size) {
+			free(ext4fs_indir1_block);
+			ext4fs_indir1_block = NULL;
+			ext4fs_indir1_size = 0;
+			ext4fs_indir1_blkno = -1;
+			ext4fs_indir1_block = zalloc(blksz);
+			if (ext4fs_indir1_block == NULL) {
+				printf("** SI ext2fs read block (indir 1):"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir1_size = blksz;
+		}
+		if ((__le32_to_cpu(inode->b.blocks.indir_block) <<
+		     log2_blksz) != ext4fs_indir1_blkno) {
+			status =
+			    ext4fs_devread(__le32_to_cpu
+					   (inode->b.blocks.
+					    indir_block) << log2_blksz, 0,
+					   blksz, (char *)ext4fs_indir1_block);
+			if (status == 0) {
+				printf("** SI ext2fs read block (indir 1)"
+				       "failed. **\n");
+				return 0;
+			}
+			ext4fs_indir1_blkno =
+			    __le32_to_cpu(inode->b.blocks.
+					  indir_block) << log2_blksz;
+		}
+		blknr = __le32_to_cpu(ext4fs_indir1_block
+				      [fileblock - INDIRECT_BLOCKS]);
+	}
+	/* Double indirect. */
+	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
+					(blksz / 4 + 1)))) {
+
+		long int perblock = blksz / 4;
+		long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
+
+		if (ext4fs_indir1_block == NULL) {
+			ext4fs_indir1_block = zalloc(blksz);
+			if (ext4fs_indir1_block == NULL) {
+				printf("** DI ext2fs read block (indir 2 1)"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir1_size = blksz;
+			ext4fs_indir1_blkno = -1;
+		}
+		if (blksz != ext4fs_indir1_size) {
+			free(ext4fs_indir1_block);
+			ext4fs_indir1_block = NULL;
+			ext4fs_indir1_size = 0;
+			ext4fs_indir1_blkno = -1;
+			ext4fs_indir1_block = zalloc(blksz);
+			if (ext4fs_indir1_block == NULL) {
+				printf("** DI ext2fs read block (indir 2 1)"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir1_size = blksz;
+		}
+		if ((__le32_to_cpu(inode->b.blocks.double_indir_block) <<
+		     log2_blksz) != ext4fs_indir1_blkno) {
+			status =
+			    ext4fs_devread(__le32_to_cpu
+					   (inode->b.blocks.
+					    double_indir_block) << log2_blksz,
+					   0, blksz,
+					   (char *)ext4fs_indir1_block);
+			if (status == 0) {
+				printf("** DI ext2fs read block (indir 2 1)"
+				       "failed. **\n");
+				return -1;
+			}
+			ext4fs_indir1_blkno =
+			    __le32_to_cpu(inode->b.blocks.double_indir_block) <<
+			    log2_blksz;
+		}
+
+		if (ext4fs_indir2_block == NULL) {
+			ext4fs_indir2_block = zalloc(blksz);
+			if (ext4fs_indir2_block == NULL) {
+				printf("** DI ext2fs read block (indir 2 2)"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir2_size = blksz;
+			ext4fs_indir2_blkno = -1;
+		}
+		if (blksz != ext4fs_indir2_size) {
+			free(ext4fs_indir2_block);
+			ext4fs_indir2_block = NULL;
+			ext4fs_indir2_size = 0;
+			ext4fs_indir2_blkno = -1;
+			ext4fs_indir2_block = zalloc(blksz);
+			if (ext4fs_indir2_block == NULL) {
+				printf("** DI ext2fs read block (indir 2 2)"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir2_size = blksz;
+		}
+		if ((__le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
+		     log2_blksz) != ext4fs_indir2_blkno) {
+			status = ext4fs_devread(__le32_to_cpu
+						(ext4fs_indir1_block
+						 [rblock /
+						  perblock]) << log2_blksz, 0,
+						blksz,
+						(char *)ext4fs_indir2_block);
+			if (status == 0) {
+				printf("** DI ext2fs read block (indir 2 2)"
+				       "failed. **\n");
+				return -1;
+			}
+			ext4fs_indir2_blkno =
+			    __le32_to_cpu(ext4fs_indir1_block[rblock
+							      /
+							      perblock]) <<
+			    log2_blksz;
+		}
+		blknr = __le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
+	}
+	/* Tripple indirect. */
+	else {
+		rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
+				      (blksz / 4 * blksz / 4));
+		perblock_child = blksz / 4;
+		perblock_parent = ((blksz / 4) * (blksz / 4));
+
+		if (ext4fs_indir1_block == NULL) {
+			ext4fs_indir1_block = zalloc(blksz);
+			if (ext4fs_indir1_block == NULL) {
+				printf("** TI ext2fs read block (indir 2 1)"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir1_size = blksz;
+			ext4fs_indir1_blkno = -1;
+		}
+		if (blksz != ext4fs_indir1_size) {
+			free(ext4fs_indir1_block);
+			ext4fs_indir1_block = NULL;
+			ext4fs_indir1_size = 0;
+			ext4fs_indir1_blkno = -1;
+			ext4fs_indir1_block = zalloc(blksz);
+			if (ext4fs_indir1_block == NULL) {
+				printf("** TI ext2fs read block (indir 2 1)"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir1_size = blksz;
+		}
+		if ((__le32_to_cpu(inode->b.blocks.triple_indir_block) <<
+		     log2_blksz) != ext4fs_indir1_blkno) {
+			status = ext4fs_devread
+			    (__le32_to_cpu(inode->b.blocks.triple_indir_block)
+			     << log2_blksz, 0, blksz,
+			     (char *)ext4fs_indir1_block);
+			if (status == 0) {
+				printf("** TI ext2fs read block (indir 2 1)"
+				       "failed. **\n");
+				return -1;
+			}
+			ext4fs_indir1_blkno =
+			    __le32_to_cpu(inode->b.blocks.triple_indir_block) <<
+			    log2_blksz;
+		}
+
+		if (ext4fs_indir2_block == NULL) {
+			ext4fs_indir2_block = zalloc(blksz);
+			if (ext4fs_indir2_block == NULL) {
+				printf("** TI ext2fs read block (indir 2 2)"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir2_size = blksz;
+			ext4fs_indir2_blkno = -1;
+		}
+		if (blksz != ext4fs_indir2_size) {
+			free(ext4fs_indir2_block);
+			ext4fs_indir2_block = NULL;
+			ext4fs_indir2_size = 0;
+			ext4fs_indir2_blkno = -1;
+			ext4fs_indir2_block = zalloc(blksz);
+			if (ext4fs_indir2_block == NULL) {
+				printf("** TI ext2fs read block (indir 2 2)"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir2_size = blksz;
+		}
+		if ((__le32_to_cpu(ext4fs_indir1_block[rblock /
+						       perblock_parent]) <<
+		     log2_blksz)
+		    != ext4fs_indir2_blkno) {
+			status = ext4fs_devread(__le32_to_cpu
+						(ext4fs_indir1_block
+						 [rblock /
+						  perblock_parent]) <<
+						log2_blksz, 0, blksz,
+						(char *)ext4fs_indir2_block);
+			if (status == 0) {
+				printf("** TI ext2fs read block (indir 2 2)"
+				       "failed. **\n");
+				return -1;
+			}
+			ext4fs_indir2_blkno =
+			    __le32_to_cpu(ext4fs_indir1_block[rblock /
+							      perblock_parent])
+			    << log2_blksz;
+		}
+
+		if (ext4fs_indir3_block == NULL) {
+			ext4fs_indir3_block = zalloc(blksz);
+			if (ext4fs_indir3_block == NULL) {
+				printf("** TI ext2fs read block (indir 2 2)"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir3_size = blksz;
+			ext4fs_indir3_blkno = -1;
+		}
+		if (blksz != ext4fs_indir3_size) {
+			free(ext4fs_indir3_block);
+			ext4fs_indir3_block = NULL;
+			ext4fs_indir3_size = 0;
+			ext4fs_indir3_blkno = -1;
+			ext4fs_indir3_block = zalloc(blksz);
+			if (ext4fs_indir3_block == NULL) {
+				printf("** TI ext2fs read block (indir 2 2)"
+				       "malloc failed. **\n");
+				return -1;
+			}
+			ext4fs_indir3_size = blksz;
+		}
+		if ((__le32_to_cpu(ext4fs_indir2_block[rblock
+						       /
+						       perblock_child]) <<
+		     log2_blksz) != ext4fs_indir3_blkno) {
+			status =
+			    ext4fs_devread(__le32_to_cpu
+					   (ext4fs_indir2_block
+					    [(rblock / perblock_child)
+					     % (blksz / 4)]) << log2_blksz, 0,
+					   blksz, (char *)ext4fs_indir3_block);
+			if (status == 0) {
+				printf("** TI ext2fs read block (indir 2 2)"
+				       "failed. **\n");
+				return -1;
+			}
+			ext4fs_indir3_blkno =
+			    __le32_to_cpu(ext4fs_indir2_block[(rblock /
+							       perblock_child) %
+							      (blksz /
+							       4)]) <<
+			    log2_blksz;
+		}
+
+		blknr = __le32_to_cpu(ext4fs_indir3_block
+				      [rblock % perblock_child]);
+	}
+	debug("ext4fs_read_block %ld\n", blknr);
+
+	return blknr;
+}
+
+void ext4fs_close(void)
+{
+	if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
+		ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
+		ext4fs_file = NULL;
+	}
+	if (ext4fs_root != NULL) {
+		free(ext4fs_root);
+		ext4fs_root = NULL;
+	}
+	if (ext4fs_indir1_block != NULL) {
+		free(ext4fs_indir1_block);
+		ext4fs_indir1_block = NULL;
+		ext4fs_indir1_size = 0;
+		ext4fs_indir1_blkno = -1;
+	}
+	if (ext4fs_indir2_block != NULL) {
+		free(ext4fs_indir2_block);
+		ext4fs_indir2_block = NULL;
+		ext4fs_indir2_size = 0;
+		ext4fs_indir2_blkno = -1;
+	}
+	if (ext4fs_indir3_block != NULL) {
+		free(ext4fs_indir3_block);
+		ext4fs_indir3_block = NULL;
+		ext4fs_indir3_size = 0;
+		ext4fs_indir3_blkno = -1;
+	}
+}
+
+int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
+		       struct ext2fs_node **fnode, int *ftype)
+{
+	unsigned int fpos = 0;
+	int status;
+	struct ext2fs_node *diro = (struct ext2fs_node *)dir;
+
+#ifdef DEBUG
+	if (name != NULL)
+		printf("Iterate dir %s\n", name);
+#endif				/* of DEBUG */
+	if (!diro->inode_read) {
+		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
+		if (status == 0)
+			return 0;
+	}
+	/* Search the file.  */
+	while (fpos < __le32_to_cpu(diro->inode.size)) {
+		struct ext2_dirent dirent;
+
+		status = ext4fs_read_file(diro, fpos,
+					  sizeof(struct ext2_dirent),
+					  (char *)&dirent);
+		if (status < 1)
+			return 0;
+
+		if (dirent.namelen != 0) {
+			char filename[dirent.namelen + 1];
+			struct ext2fs_node *fdiro;
+			int type = FILETYPE_UNKNOWN;
+
+			status = ext4fs_read_file(diro,
+						  fpos +
+						  sizeof(struct ext2_dirent),
+						  dirent.namelen, filename);
+			if (status < 1)
+				return 0;
+
+			fdiro = zalloc(sizeof(struct ext2fs_node));
+			if (!fdiro)
+				return 0;
+
+			fdiro->data = diro->data;
+			fdiro->ino = __le32_to_cpu(dirent.inode);
+
+			filename[dirent.namelen] = '\0';
+
+			if (dirent.filetype != FILETYPE_UNKNOWN) {
+				fdiro->inode_read = 0;
+
+				if (dirent.filetype == FILETYPE_DIRECTORY)
+					type = FILETYPE_DIRECTORY;
+				else if (dirent.filetype == FILETYPE_SYMLINK)
+					type = FILETYPE_SYMLINK;
+				else if (dirent.filetype == FILETYPE_REG)
+					type = FILETYPE_REG;
+			} else {
+				status = ext4fs_read_inode(diro->data,
+							   __le32_to_cpu
+							   (dirent.inode),
+							   &fdiro->inode);
+				if (status == 0) {
+					free(fdiro);
+					return 0;
+				}
+				fdiro->inode_read = 1;
+
+				if ((__le16_to_cpu(fdiro->inode.mode) &
+				     FILETYPE_INO_MASK) ==
+				    FILETYPE_INO_DIRECTORY) {
+					type = FILETYPE_DIRECTORY;
+				} else if ((__le16_to_cpu(fdiro->inode.mode)
+					    & FILETYPE_INO_MASK) ==
+					   FILETYPE_INO_SYMLINK) {
+					type = FILETYPE_SYMLINK;
+				} else if ((__le16_to_cpu(fdiro->inode.mode)
+					    & FILETYPE_INO_MASK) ==
+					   FILETYPE_INO_REG) {
+					type = FILETYPE_REG;
+				}
+			}
+#ifdef DEBUG
+			printf("iterate >%s<\n", filename);
+#endif				/* of DEBUG */
+			if ((name != NULL) && (fnode != NULL)
+			    && (ftype != NULL)) {
+				if (strcmp(filename, name) == 0) {
+					*ftype = type;
+					*fnode = fdiro;
+					return 1;
+				}
+			} else {
+				if (fdiro->inode_read == 0) {
+					status = ext4fs_read_inode(diro->data,
+								 __le32_to_cpu(
+								 dirent.inode),
+								 &fdiro->inode);
+					if (status == 0) {
+						free(fdiro);
+						return 0;
+					}
+					fdiro->inode_read = 1;
+				}
+				switch (type) {
+				case FILETYPE_DIRECTORY:
+					printf("<DIR> ");
+					break;
+				case FILETYPE_SYMLINK:
+					printf("<SYM> ");
+					break;
+				case FILETYPE_REG:
+					printf("      ");
+					break;
+				default:
+					printf("< ? > ");
+					break;
+				}
+				printf("%10d %s\n",
+				       __le32_to_cpu(fdiro->inode.size),
+				       filename);
+			}
+			free(fdiro);
+		}
+		fpos += __le16_to_cpu(dirent.direntlen);
+	}
+	return 0;
+}
+
+static char *ext4fs_read_symlink(struct ext2fs_node *node)
+{
+	char *symlink;
+	struct ext2fs_node *diro = node;
+	int status;
+
+	if (!diro->inode_read) {
+		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
+		if (status == 0)
+			return 0;
+	}
+	symlink = zalloc(__le32_to_cpu(diro->inode.size) + 1);
+	if (!symlink)
+		return 0;
+
+	if (__le32_to_cpu(diro->inode.size) <= 60) {
+		strncpy(symlink, diro->inode.b.symlink,
+			__le32_to_cpu(diro->inode.size));
+	} else {
+		status = ext4fs_read_file(diro, 0,
+					  __le32_to_cpu(diro->inode.size),
+					  symlink);
+		if (status == 0) {
+			free(symlink);
+			return 0;
+		}
+	}
+	symlink[__le32_to_cpu(diro->inode.size)] = '\0';
+	return symlink;
+}
+
+static int ext4fs_find_file1(const char *currpath,
+			     struct ext2fs_node *currroot,
+			     struct ext2fs_node **currfound, int *foundtype)
+{
+	char fpath[strlen(currpath) + 1];
+	char *name = fpath;
+	char *next;
+	int status;
+	int type = FILETYPE_DIRECTORY;
+	struct ext2fs_node *currnode = currroot;
+	struct ext2fs_node *oldnode = currroot;
+
+	strncpy(fpath, currpath, strlen(currpath) + 1);
+
+	/* Remove all leading slashes. */
+	while (*name == '/')
+		name++;
+
+	if (!*name) {
+		*currfound = currnode;
+		return 1;
+	}
+
+	for (;;) {
+		int found;
+
+		/* Extract the actual part from the pathname. */
+		next = strchr(name, '/');
+		if (next) {
+			/* Remove all leading slashes. */
+			while (*next == '/')
+				*(next++) = '\0';
+		}
+
+		if (type != FILETYPE_DIRECTORY) {
+			ext4fs_free_node(currnode, currroot);
+			return 0;
+		}
+
+		oldnode = currnode;
+
+		/* Iterate over the directory. */
+		found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
+		if (found == 0)
+			return 0;
+
+		if (found == -1)
+			break;
+
+		/* Read in the symlink and follow it. */
+		if (type == FILETYPE_SYMLINK) {
+			char *symlink;
+
+			/* Test if the symlink does not loop. */
+			if (++symlinknest == 8) {
+				ext4fs_free_node(currnode, currroot);
+				ext4fs_free_node(oldnode, currroot);
+				return 0;
+			}
+
+			symlink = ext4fs_read_symlink(currnode);
+			ext4fs_free_node(currnode, currroot);
+
+			if (!symlink) {
+				ext4fs_free_node(oldnode, currroot);
+				return 0;
+			}
+
+			debug("Got symlink >%s<\n", symlink);
+
+			if (symlink[0] == '/') {
+				ext4fs_free_node(oldnode, currroot);
+				oldnode = &ext4fs_root->diropen;
+			}
+
+			/* Lookup the node the symlink points to. */
+			status = ext4fs_find_file1(symlink, oldnode,
+						   &currnode, &type);
+
+			free(symlink);
+
+			if (status == 0) {
+				ext4fs_free_node(oldnode, currroot);
+				return 0;
+			}
+		}
+
+		ext4fs_free_node(oldnode, currroot);
+
+		/* Found the node! */
+		if (!next || *next == '\0') {
+			*currfound = currnode;
+			*foundtype = type;
+			return 1;
+		}
+		name = next;
+	}
+	return -1;
+}
+
+int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
+	struct ext2fs_node **foundnode, int expecttype)
+{
+	int status;
+	int foundtype = FILETYPE_DIRECTORY;
+
+	symlinknest = 0;
+	if (!path)
+		return 0;
+
+	status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
+	if (status == 0)
+		return 0;
+
+	/* Check if the node that was found was of the expected type. */
+	if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
+		return 0;
+	else if ((expecttype == FILETYPE_DIRECTORY)
+		   && (foundtype != expecttype))
+		return 0;
+
+	return 1;
+}
+
+int ext4fs_open(const char *filename)
+{
+	struct ext2fs_node *fdiro = NULL;
+	int status;
+	int len;
+
+	if (ext4fs_root == NULL)
+		return -1;
+
+	ext4fs_file = NULL;
+	status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
+				  FILETYPE_REG);
+	if (status == 0)
+		goto fail;
+
+	if (!fdiro->inode_read) {
+		status = ext4fs_read_inode(fdiro->data, fdiro->ino,
+					   &fdiro->inode);
+		if (status == 0)
+			goto fail;
+	}
+	len = __le32_to_cpu(fdiro->inode.size);
+	ext4fs_file = fdiro;
+
+	return len;
+ fail:
+	ext4fs_free_node(fdiro, &ext4fs_root->diropen);
+
+	return -1;
+}
+
+int ext4fs_mount(unsigned part_length)
+{
+	struct ext2_data *data;
+	int status;
+	struct ext_filesystem *fs = get_fs();
+	data = zalloc(sizeof(struct ext2_data));
+	if (!data)
+		return 0;
+
+	/* Read the superblock. */
+	status = ext4fs_devread(1 * 2, 0, sizeof(struct ext2_sblock),
+				(char *)&data->sblock);
+
+	if (status == 0)
+		goto fail;
+
+	/* Make sure this is an ext2 filesystem. */
+	if (__le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
+		goto fail;
+
+	if (__le32_to_cpu(data->sblock.revision_level == 0))
+		fs->inodesz = 128;
+	else
+		fs->inodesz = __le16_to_cpu(data->sblock.inode_size);
+
+	debug("EXT2 rev %d, inode_size %d\n",
+	      __le32_to_cpu(data->sblock.revision_level), fs->inodesz);
+
+	data->diropen.data = data;
+	data->diropen.ino = 2;
+	data->diropen.inode_read = 1;
+	data->inode = &data->diropen.inode;
+
+	status = ext4fs_read_inode(data, 2, data->inode);
+	if (status == 0)
+		goto fail;
+
+	ext4fs_root = data;
+
+	return 1;
+ fail:
+	printf("Failed to mount ext2 filesystem...\n");
+	free(data);
+	ext4fs_root = NULL;
+
+	return 0;
+}
diff --git a/fs/ext4/ext4_common.h b/fs/ext4/ext4_common.h
new file mode 100644
index 0000000..182049d
--- /dev/null
+++ b/fs/ext4/ext4_common.h
@@ -0,0 +1,63 @@ 
+/*
+ * (C) Copyright 2011 - 2012 Samsung Electronics
+ * EXT4 filesystem implementation in Uboot by
+ * Uma Shankar <uma.shankar@samsung.com>
+ * Manjunatha C Achar <a.manjunatha@samsung.com>
+ *
+ * ext4ls and ext4load :  based on ext2 ls load support in Uboot.
+ *
+ * (C) Copyright 2004
+ * esd gmbh <www.esd-electronics.com>
+ * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
+ *
+ * based on code from grub2 fs/ext2.c and fs/fshelp.c by
+ * GRUB  --  GRand Unified Bootloader
+ * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
+ *
+ * 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.
+ */
+
+#ifndef __EXT4_COMMON__
+#define __EXT4_COMMON__
+#include <ext_common.h>
+#include <ext4fs.h>
+#include <malloc.h>
+#include <asm/errno.h>
+
+#define YES		1
+#define NO		0
+#define TRUE		1
+#define FALSE		0
+#define RECOVER	1
+#define SCAN		0
+
+#define S_IFLNK	0120000		/* symbolic link */
+#define BLOCK_NO_ONE		1
+#define SUPERBLOCK_SECTOR	2
+#define SUPERBLOCK_SIZE	1024
+#define F_FILE			1
+
+#define zalloc(size) calloc(1, size)
+
+extern unsigned long part_offset;
+int ext4fs_read_inode(struct ext2_data *data, int ino,
+		      struct ext2_inode *inode);
+int ext4fs_read_file(struct ext2fs_node *node, int pos,
+		unsigned int len, char *buf);
+int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
+			struct ext2fs_node **foundnode, int expecttype);
+int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
+			struct ext2fs_node **fnode, int *ftype);
+#endif
diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c
new file mode 100644
index 0000000..7933769
--- /dev/null
+++ b/fs/ext4/ext4fs.c
@@ -0,0 +1,228 @@ 
+/*
+ * (C) Copyright 2011 - 2012 Samsung Electronics
+ * EXT4 filesystem implementation in Uboot by
+ * Uma Shankar <uma.shankar@samsung.com>
+ * Manjunatha C Achar <a.manjunatha@samsung.com>
+ *
+ * ext4ls and ext4load : Based on ext2 ls and load support in Uboot.
+ *		       Ext4 read optimization taken from Open-Moko
+ *		       Qi bootloader
+ *
+ * (C) Copyright 2004
+ * esd gmbh <www.esd-electronics.com>
+ * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
+ *
+ * based on code from grub2 fs/ext2.c and fs/fshelp.c by
+ * GRUB  --  GRand Unified Bootloader
+ * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
+ *
+ * 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>
+#include <malloc.h>
+#include <ext_common.h>
+#include <ext4fs.h>
+#include <linux/stat.h>
+#include <linux/time.h>
+#include <asm/byteorder.h>
+#include "ext4_common.h"
+
+int ext4fs_symlinknest;
+block_dev_desc_t *ext4_dev_desc;
+
+struct ext_filesystem *get_fs(void)
+{
+	if (ext4_dev_desc == NULL || ext4_dev_desc->priv == NULL)
+		printf("Invalid Input Arguments %s\n", __func__);
+
+	return ext4_dev_desc->priv;
+}
+
+int init_fs(block_dev_desc_t *dev_desc)
+{
+	struct ext_filesystem *fs;
+	if (dev_desc == NULL) {
+		printf("Invalid Input Arguments %s\n", __func__);
+		return -EINVAL;
+	}
+
+	fs = zalloc(sizeof(struct ext_filesystem));
+	if (fs == NULL) {
+		printf("malloc failed: %s\n", __func__);
+		return -ENOMEM;
+	}
+
+	fs->dev_desc = dev_desc;
+	dev_desc->priv = fs;
+
+	return 0;
+}
+
+void deinit_fs(block_dev_desc_t *dev_desc)
+{
+	if (dev_desc == NULL) {
+		printf("Invalid Input Arguments %s\n", __func__);
+		return;
+	}
+	free(dev_desc->priv);
+	dev_desc->priv = NULL;
+}
+
+void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
+{
+	if ((node != &ext4fs_root->diropen) && (node != currroot))
+		free(node);
+}
+
+/*
+ * Taken from openmoko-kernel mailing list: By Andy green
+ * Optimized read file API : collects and defers contiguous sector
+ * reads into one potentially more efficient larger sequential read action
+ */
+int ext4fs_read_file(struct ext2fs_node *node, int pos,
+		     unsigned int len, char *buf)
+{
+	int i;
+	int blockcnt;
+	int log2blocksize = LOG2_EXT2_BLOCK_SIZE(node->data);
+	int blocksize = 1 << (log2blocksize + DISK_SECTOR_BITS);
+	unsigned int filesize = __le32_to_cpu(node->inode.size);
+	int previous_block_number = -1;
+	int delayed_start = 0;
+	int delayed_extent = 0;
+	int delayed_skipfirst = 0;
+	int delayed_next = 0;
+	char *delayed_buf = NULL;
+	short status;
+
+	/* Adjust len so it we can't read past the end of the file. */
+	if (len > filesize)
+		len = filesize;
+
+	blockcnt = ((len + pos) + blocksize - 1) / blocksize;
+
+	for (i = pos / blocksize; i < blockcnt; i++) {
+		int blknr;
+		int blockoff = pos % blocksize;
+		int blockend = blocksize;
+		int skipfirst = 0;
+		blknr = read_allocated_block(&(node->inode), i);
+		if (blknr < 0)
+			return -1;
+
+		blknr = blknr << log2blocksize;
+
+		/* Last block.  */
+		if (i == blockcnt - 1) {
+			blockend = (len + pos) % blocksize;
+
+			/* The last portion is exactly blocksize. */
+			if (!blockend)
+				blockend = blocksize;
+		}
+
+		/* First block. */
+		if (i == pos / blocksize) {
+			skipfirst = blockoff;
+			blockend -= skipfirst;
+		}
+		if (blknr) {
+			int status;
+
+			if (previous_block_number != -1) {
+				if (delayed_next == blknr) {
+					delayed_extent += blockend;
+					delayed_next += blockend >> SECTOR_BITS;
+				} else {	/* spill */
+					status = ext4fs_devread(delayed_start,
+							delayed_skipfirst,
+							delayed_extent,
+							delayed_buf);
+					if (status == 0)
+						return -1;
+					previous_block_number = blknr;
+					delayed_start = blknr;
+					delayed_extent = blockend;
+					delayed_skipfirst = skipfirst;
+					delayed_buf = buf;
+					delayed_next = blknr +
+					    (blockend >> SECTOR_BITS);
+				}
+			} else {
+				previous_block_number = blknr;
+				delayed_start = blknr;
+				delayed_extent = blockend;
+				delayed_skipfirst = skipfirst;
+				delayed_buf = buf;
+				delayed_next = blknr +
+				    (blockend >> SECTOR_BITS);
+			}
+		} else {
+			if (previous_block_number != -1) {
+				/* spill */
+				status = ext4fs_devread(delayed_start,
+							delayed_skipfirst,
+							delayed_extent,
+							delayed_buf);
+				if (status == 0)
+					return -1;
+				previous_block_number = -1;
+			}
+			memset(buf, 0, blocksize - skipfirst);
+		}
+		buf += blocksize - skipfirst;
+	}
+	if (previous_block_number != -1) {
+		/* spill */
+		status = ext4fs_devread(delayed_start,
+					delayed_skipfirst, delayed_extent,
+					delayed_buf);
+		if (status == 0)
+			return -1;
+		previous_block_number = -1;
+	}
+
+	return len;
+}
+
+int ext4fs_ls(const char *dirname)
+{
+	struct ext2fs_node *dirnode;
+	int status;
+
+	if (dirname == NULL)
+		return 0;
+
+	status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
+				  FILETYPE_DIRECTORY);
+	if (status != 1) {
+		printf("** Can not find directory. **\n");
+		return 1;
+	}
+
+	ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
+	ext4fs_free_node(dirnode, &ext4fs_root->diropen);
+
+	return 0;
+}
+
+int ext4fs_read(char *buf, unsigned len)
+{
+	if (ext4fs_root == NULL || ext4fs_file == NULL)
+		return 0;
+
+	return ext4fs_read_file(ext4fs_file, 0, len, buf);
+}
diff --git a/include/ext4fs.h b/include/ext4fs.h
new file mode 100644
index 0000000..55f9ccc
--- /dev/null
+++ b/include/ext4fs.h
@@ -0,0 +1,132 @@ 
+/*
+ * (C) Copyright 2011 - 2012 Samsung Electronics
+ * EXT4 filesystem implementation in Uboot by
+ * Uma Shankar <uma.shankar@samsung.com>
+ * Manjunatha C Achar <a.manjunatha@samsung.com>
+ *
+ * Ext4 Extent data structures are taken from  original ext4 fs code
+ * as found in the linux kernel.
+ *
+ * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
+ * Written by Alex Tomas <alex@clusterfs.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#ifndef __EXT4__
+#define __EXT4__
+#include <ext_common.h>
+
+#define EXT4_EXTENTS_FL		0x00080000 /* Inode uses extents */
+#define EXT4_EXT_MAGIC			0xf30a
+#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM	0x0010
+#define EXT4_FEATURE_INCOMPAT_EXTENTS	0x0040
+#define EXT4_INDIRECT_BLOCKS		12
+
+#define EXT4_BG_INODE_UNINIT		0x0001
+#define EXT4_BG_BLOCK_UNINIT		0x0002
+#define EXT4_BG_INODE_ZEROED		0x0004
+
+/*
+ * ext4_inode has i_block array (60 bytes total).
+ * The first 12 bytes store ext4_extent_header;
+ * the remainder stores an array of ext4_extent.
+ */
+
+/*
+ * This is the extent on-disk structure.
+ * It's used at the bottom of the tree.
+ */
+struct ext4_extent {
+	__le32	ee_block;	/* first logical block extent covers */
+	__le16	ee_len;		/* number of blocks covered by extent */
+	__le16	ee_start_hi;	/* high 16 bits of physical block */
+	__le32	ee_start_lo;	/* low 32 bits of physical block */
+};
+
+/*
+ * This is index on-disk structure.
+ * It's used at all the levels except the bottom.
+ */
+struct ext4_extent_idx {
+	__le32	ei_block;	/* index covers logical blocks from 'block' */
+	__le32	ei_leaf_lo;	/* pointer to the physical block of the next *
+				 * level. leaf or next index could be there */
+	__le16	ei_leaf_hi;	/* high 16 bits of physical block */
+	__u16	ei_unused;
+};
+
+/* Each block (leaves and indexes), even inode-stored has header. */
+struct ext4_extent_header {
+	__le16	eh_magic;	/* probably will support different formats */
+	__le16	eh_entries;	/* number of valid entries */
+	__le16	eh_max;		/* capacity of store in entries */
+	__le16	eh_depth;	/* has tree real underlying blocks? */
+	__le32	eh_generation;	/* generation of the tree */
+};
+
+struct ext_filesystem {
+	/* Total Sector of partition */
+	uint64_t total_sect;
+	/* Block size  of partition */
+	uint32_t blksz;
+	/* Inode size of partition */
+	uint32_t inodesz;
+	/* Sectors per Block */
+	uint32_t sect_perblk;
+	/* Group Descriptor Block Number */
+	uint32_t gdtable_blkno;
+	/* Total block groups of partition */
+	uint32_t no_blkgrp;
+	/* No of blocks required for bgdtable */
+	uint32_t no_blk_pergdt;
+	/* Superblock */
+	struct ext2_sblock *sb;
+	/* Block group descritpor table */
+	struct ext2_block_group *gd;
+	char *gdtable;
+
+	/* Block Bitmap Related */
+	unsigned char **blk_bmaps;
+	long int curr_blkno;
+	uint16_t first_pass_bbmap;
+
+	/* Inode Bitmap Related */
+	unsigned char **inode_bmaps;
+	int curr_inode_no;
+	uint16_t first_pass_ibmap;
+
+	/* Journal Related */
+
+	/* Block Device Descriptor */
+	block_dev_desc_t *dev_desc;
+};
+
+extern block_dev_desc_t *ext4_dev_desc;
+extern struct ext2_data *ext4fs_root;
+extern struct ext2fs_node *ext4fs_file;
+
+struct ext_filesystem *get_fs(void);
+int init_fs(block_dev_desc_t *dev_desc);
+void deinit_fs(block_dev_desc_t *dev_desc);
+int ext4fs_open(const char *filename);
+int ext4fs_read(char *buf, unsigned len);
+int ext4fs_mount(unsigned part_length);
+void ext4fs_close(void);
+int ext4fs_ls(const char *dirname);
+void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot);
+int ext4fs_devread(int sector, int byte_offset, int byte_len, char *buf);
+int ext4fs_set_blk_dev(block_dev_desc_t *rbdd, int part);
+long int read_allocated_block(struct ext2_inode *inode, int fileblock);
+#endif
diff --git a/include/ext_common.h b/include/ext_common.h
new file mode 100644
index 0000000..e532570
--- /dev/null
+++ b/include/ext_common.h
@@ -0,0 +1,188 @@ 
+/*
+ * (C) Copyright 2011 - 2012 Samsung Electronics
+ * EXT4 filesystem implementation in Uboot by
+ * Uma Shankar <uma.shankar@samsung.com>
+ * Manjunatha C Achar <a.manjunatha@samsung.com>
+ *
+ * Data structures and headers for ext4 support have been taken from
+ * ext2 ls load support in Uboot
+ *
+ * (C) Copyright 2004
+ * esd gmbh <www.esd-electronics.com>
+ * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
+ *
+ * based on code from grub2 fs/ext2.c and fs/fshelp.c by
+ * GRUB  --  GRand Unified Bootloader
+ * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
+ *
+ * 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.
+ */
+
+#ifndef __EXT_COMMON__
+#define __EXT_COMMON__
+
+#define SECTOR_SIZE		0x200
+#define SECTOR_BITS		9
+
+/* Magic value used to identify an ext2 filesystem.  */
+#define	EXT2_MAGIC		0xEF53
+/* Amount of indirect blocks in an inode.  */
+#define INDIRECT_BLOCKS		12
+/* Maximum lenght of a pathname.  */
+#define EXT2_PATH_MAX			4096
+/* Maximum nesting of symlinks, used to prevent a loop.  */
+#define	EXT2_MAX_SYMLINKCNT		8
+
+/* Filetype used in directory entry.  */
+#define	FILETYPE_UNKNOWN		0
+#define	FILETYPE_REG			1
+#define	FILETYPE_DIRECTORY		2
+#define	FILETYPE_SYMLINK		7
+
+/* Filetype information as used in inodes.  */
+#define FILETYPE_INO_MASK		0170000
+#define FILETYPE_INO_REG		0100000
+#define FILETYPE_INO_DIRECTORY		0040000
+#define FILETYPE_INO_SYMLINK		0120000
+#define EXT2_ROOT_INO			2 /* Root inode */
+
+/* Bits used as offset in sector */
+#define DISK_SECTOR_BITS		9
+/* The size of an ext2 block in bytes.  */
+#define EXT2_BLOCK_SIZE(data)	   (1 << LOG2_BLOCK_SIZE(data))
+
+/* Log2 size of ext2 block in 512 blocks.  */
+#define LOG2_EXT2_BLOCK_SIZE(data) (__le32_to_cpu \
+				(data->sblock.log2_block_size) + 1)
+
+/* Log2 size of ext2 block in bytes.  */
+#define LOG2_BLOCK_SIZE(data)	   (__le32_to_cpu \
+		(data->sblock.log2_block_size) + 10)
+#define INODE_SIZE_FILESYSTEM(data)	(__le32_to_cpu \
+			(data->sblock.inode_size))
+
+#define EXT2_FT_DIR	2
+#define SUCCESS	1
+
+/* Macro-instructions used to manage several block sizes  */
+#define EXT2_MIN_BLOCK_LOG_SIZE	10 /* 1024 */
+#define EXT2_MAX_BLOCK_LOG_SIZE	16 /* 65536 */
+#define EXT2_MIN_BLOCK_SIZE		(1 << EXT2_MIN_BLOCK_LOG_SIZE)
+#define EXT2_MAX_BLOCK_SIZE		(1 << EXT2_MAX_BLOCK_LOG_SIZE)
+
+/* The ext2 superblock.  */
+struct ext2_sblock {
+	uint32_t total_inodes;
+	uint32_t total_blocks;
+	uint32_t reserved_blocks;
+	uint32_t free_blocks;
+	uint32_t free_inodes;
+	uint32_t first_data_block;
+	uint32_t log2_block_size;
+	uint32_t log2_fragment_size;
+	uint32_t blocks_per_group;
+	uint32_t fragments_per_group;
+	uint32_t inodes_per_group;
+	uint32_t mtime;
+	uint32_t utime;
+	uint16_t mnt_count;
+	uint16_t max_mnt_count;
+	uint16_t magic;
+	uint16_t fs_state;
+	uint16_t error_handling;
+	uint16_t minor_revision_level;
+	uint32_t lastcheck;
+	uint32_t checkinterval;
+	uint32_t creator_os;
+	uint32_t revision_level;
+	uint16_t uid_reserved;
+	uint16_t gid_reserved;
+	uint32_t first_inode;
+	uint16_t inode_size;
+	uint16_t block_group_number;
+	uint32_t feature_compatibility;
+	uint32_t feature_incompat;
+	uint32_t feature_ro_compat;
+	uint32_t unique_id[4];
+	char volume_name[16];
+	char last_mounted_on[64];
+	uint32_t compression_info;
+};
+
+struct ext2_block_group {
+	__u32 block_id;	/* Blocks bitmap block */
+	__u32 inode_id;	/* Inodes bitmap block */
+	__u32 inode_table_id;	/* Inodes table block */
+	__u16 free_blocks;	/* Free blocks count */
+	__u16 free_inodes;	/* Free inodes count */
+	__u16 used_dir_cnt;	/* Directories count */
+	__u16 bg_flags;
+	__u32 bg_reserved[2];
+	__u16 bg_itable_unused; /* Unused inodes count */
+	__u16 bg_checksum;	/* crc16(s_uuid+grouo_num+group_desc)*/
+};
+
+/* The ext2 inode. */
+struct ext2_inode {
+	uint16_t mode;
+	uint16_t uid;
+	uint32_t size;
+	uint32_t atime;
+	uint32_t ctime;
+	uint32_t mtime;
+	uint32_t dtime;
+	uint16_t gid;
+	uint16_t nlinks;
+	uint32_t blockcnt;	/* Blocks of 512 bytes!! */
+	uint32_t flags;
+	uint32_t osd1;
+	union {
+		struct datablocks {
+			uint32_t dir_blocks[INDIRECT_BLOCKS];
+			uint32_t indir_block;
+			uint32_t double_indir_block;
+			uint32_t triple_indir_block;
+		} blocks;
+		char symlink[60];
+	} b;
+	uint32_t version;
+	uint32_t acl;
+	uint32_t dir_acl;
+	uint32_t fragment_addr;
+	uint32_t osd2[3];
+};
+
+/* The header of an ext2 directory entry. */
+struct ext2_dirent {
+	uint32_t inode;
+	uint16_t direntlen;
+	uint8_t namelen;
+	uint8_t filetype;
+};
+
+struct ext2fs_node {
+	struct ext2_data *data;
+	struct ext2_inode inode;
+	int ino;
+	int inode_read;
+};
+
+/* Information about a "mounted" ext2 filesystem. */
+struct ext2_data {
+	struct ext2_sblock sblock;
+	struct ext2_inode *inode;
+	struct ext2fs_node diropen;
+};
+#endif