[people/ms/u-boot.git] / doc / README.ext4

This patch series adds support for ext4 ls,load and write features in uboot
Journaling is supported for write feature.

To enable support for the ext4 (and ext2) filesystem implementation,
#define CONFIG_FS_EXT4

If you want write support,
#define CONFIG_EXT4_WRITE

To Enable ext2 ls and load commands, modify the board specific config file with
#define CONFIG_CMD_EXT2
This automatically defines CONFIG_FS_EXT4 for you.

To Enable ext4 ls and load commands, modify the board specific config file with
#define CONFIG_CMD_EXT4
This automatically defines CONFIG_FS_EXT4 for you.

To enable ext4 write command, modify the board specific config file with
#define CONFIG_CMD_EXT4
#define CONFIG_CMD_EXT4_WRITE
These automatically define CONFIG_FS_EXT4 and CONFIG_EXT4_WRITE for you.

Also relevant are the generic filesystem commands,
#define CONFIG_CMD_FS_GENERIC
This does not automatically enable EXT4 support for you.

Steps to test:

1. After applying the patch, ext4 specific commands can be seen
   in the boot loader prompt using
	UBOOT #help

	ext4load- load binary file from a Ext4 file system
	ext4ls  - list files in a directory (default /)
	ext4write- create a file in ext4 formatted partition

2. To list the files in ext4 formatted partition, execute
	ext4ls <interface> <dev[:part]> [directory]
	For example:
	UBOOT #ext4ls mmc 0:5 /usr/lib

3. To read and load a file from an ext4 formatted partition to RAM, execute
	ext4load <interface> <dev[:part]> [addr] [filename] [bytes]
	For example:
	UBOOT #ext4load mmc 2:2 0x30007fc0 uImage

4. To write a file to a ext4 formatted partition.
	a) First load a file to RAM at a particular address for example 0x30007fc0.
	Now execute ext4write command
	ext4write <interface> <dev[:part]> [filename] [Address] [sizebytes]
	For example:
	UBOOT #ext4write mmc 2:2 /boot/uImage 0x30007fc0 6183120
	(here 6183120 is the size of the file to be written)
	Note: Absolute path is required for the file to be written

References :
	-- ext4 implementation in Linux Kernel
	-- Uboot existing ext2 load and ls implementation
	-- Journaling block device JBD2 implementation in linux Kernel
Commit	Line	Data
ed34f34d US	1	This patch series adds support for ext4 ls,load and write features in uboot
	2	Journaling is supported for write feature.
	3
03e2ecf6 SW	4	To enable support for the ext4 (and ext2) filesystem implementation,
	5	#define CONFIG_FS_EXT4
	6
	7	If you want write support,
	8	#define CONFIG_EXT4_WRITE
	9
ed34f34d US	10	To Enable ext2 ls and load commands, modify the board specific config file with
ed34f34d US	11	#define CONFIG_CMD_EXT2
03e2ecf6	12	This automatically defines CONFIG_FS_EXT4 for you.
ed34f34d US	13
	14	To Enable ext4 ls and load commands, modify the board specific config file with
	15	#define CONFIG_CMD_EXT4
03e2ecf6	16	This automatically defines CONFIG_FS_EXT4 for you.
ed34f34d US	17
	18	To enable ext4 write command, modify the board specific config file with
	19	#define CONFIG_CMD_EXT4
	20	#define CONFIG_CMD_EXT4_WRITE
03e2ecf6 SW	21	These automatically define CONFIG_FS_EXT4 and CONFIG_EXT4_WRITE for you.
	22
	23	Also relevant are the generic filesystem commands,
	24	#define CONFIG_CMD_FS_GENERIC
	25	This does not automatically enable EXT4 support for you.
ed34f34d US	26
	27	Steps to test:
	28
	29	1. After applying the patch, ext4 specific commands can be seen
	30	in the boot loader prompt using
93e14596	31	UBOOT #help
ed34f34d	32
93e14596 WD	33	ext4load- load binary file from a Ext4 file system
	34	ext4ls - list files in a directory (default /)
	35	ext4write- create a file in ext4 formatted partition
ed34f34d US	36
ed34f34d US	37	2. To list the files in ext4 formatted partition, execute
93e14596 WD	38	ext4ls <interface> <dev[:part]> [directory]
	39	For example:
	40	UBOOT #ext4ls mmc 0:5 /usr/lib
ed34f34d US	41
ed34f34d US	42	3. To read and load a file from an ext4 formatted partition to RAM, execute
93e14596 WD	43	ext4load <interface> <dev[:part]> [addr] [filename] [bytes]
	44	For example:
	45	UBOOT #ext4load mmc 2:2 0x30007fc0 uImage
ed34f34d US	46
ed34f34d US	47	4. To write a file to a ext4 formatted partition.
93e14596 WD	48	a) First load a file to RAM at a particular address for example 0x30007fc0.
	49	Now execute ext4write command
	50	ext4write <interface> <dev[:part]> [filename] [Address] [sizebytes]
	51	For example:
	52	UBOOT #ext4write mmc 2:2 /boot/uImage 0x30007fc0 6183120
	53	(here 6183120 is the size of the file to be written)
	54	Note: Absolute path is required for the file to be written
ed34f34d US	55
	56	References :
	57	-- ext4 implementation in Linux Kernel
	58	-- Uboot existing ext2 load and ls implementation
	59	-- Journaling block device JBD2 implementation in linux Kernel