xref: /openbmc/u-boot/doc/README.ext4 (revision 25b26ec6) 
1This patch series adds support for ext4 ls,load and write features in uboot
2Journaling is supported for write feature.
3
4To enable support for the ext4 (and ext2) filesystem implementation,
5#define CONFIG_FS_EXT4
6
7If you want write support,
8#define CONFIG_EXT4_WRITE
9
10To Enable ext2 ls and load commands, modify the board specific config file with
11#define CONFIG_CMD_EXT2
12This automatically defines CONFIG_FS_EXT4 for you.
13
14To Enable ext4 ls and load commands, modify the board specific config file with
15#define CONFIG_CMD_EXT4
16This automatically defines CONFIG_FS_EXT4 for you.
17
18To enable ext4 write command, modify the board specific config file with
19#define CONFIG_CMD_EXT4
20#define CONFIG_CMD_EXT4_WRITE
21These automatically define CONFIG_FS_EXT4 and CONFIG_EXT4_WRITE for you.
22
23Also relevant are the generic filesystem commands,
24#define CONFIG_CMD_FS_GENERIC
25This does not automatically enable EXT4 support for you.
26
27Steps to test:
28
291. 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
372. 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
423. 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
474. 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
56References :
57	-- ext4 implementation in Linux Kernel
58	-- Uboot existing ext2 load and ls implementation
59	-- Journaling block device JBD2 implementation in linux Kernel
60