xref: /openbmc/u-boot/doc/README.ext4 (revision ca831f4933dc68d9ed1b6399cbda90068c520005)
1 This patch series adds support for ext4 ls,load and write features in uboot
2 Journaling is supported for write feature.
3 
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 
10 To Enable ext2 ls and load commands, modify the board specific config file with
11 #define CONFIG_CMD_EXT2
12 This automatically defines CONFIG_FS_EXT4 for you.
13 
14 To Enable ext4 ls and load commands, modify the board specific config file with
15 #define CONFIG_CMD_EXT4
16 This automatically defines CONFIG_FS_EXT4 for you.
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
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.
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
31 	UBOOT #help
32 
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
36 
37 2. To list the files in ext4 formatted partition, execute
38 	ext4ls <interface> <dev[:part]> [directory]
39 	For example:
40 	UBOOT #ext4ls mmc 0:5 /usr/lib
41 
42 3. To read and load a file from an ext4 formatted partition to RAM, execute
43 	ext4load <interface> <dev[:part]> [addr] [filename] [bytes]
44 	For example:
45 	UBOOT #ext4load mmc 2:2 0x30007fc0 uImage
46 
47 4. To write a file to a ext4 formatted partition.
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
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
60