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Note Note: UBIFS is now the default rootfs filesystem used on APF27, APF27 & APF51 boards, so this page should only be considered as reference for these boards. Due to the FLASH memory size of the APF9328 board, there is no added value to use UBIFS on this board.

This is a preliminary page dealing with the installation of UBIFS on the APF boards. UBIFS will replace JFFS2 file system on NAND (and NOR as well) based boards because JFFS2 induces a big overhead when parsing, reading and writing large devices, see UBIFS scalability.


UBIFS website

Host Setup

  • add uuid-dev packages (should be already installed as required to build the HEAD of Armadeus repository):
$ sudo apt-get install uuid-dev

APF build config


$ make menuconfig


Target filesystem options  --->
    [*] ubifs root filesystem
    (0x1f800) UBI logical erase block size
    (0x800) UBI minimum I/O size
    (2047) Maximum LEB count
          ubifs runtime compression (lzo)  --->
          Compression method (no compression)  --->
    [*]   UBI image
    (0x20000) UBI physical erase block size
    (512)   UBI sub-page size


Target filesystem options  --->
    [*] ubifs root filesystem
    (0x20000) UBI physical erase block size
    (0x1f800) UBI logical erase block size
    (0x800) UBI minimum I/O size
    (512) UBI sub-page size
    (2047) Maximum LEB count
$ make


$ make linux-menuconfig
File systems  --->
    [*] Miscellaneous filesystems  --->
        <*>   UBIFS file system support   and disable debugging !!

Device Drivers  --->
    <*> Memory Technology Device (MTD) support  --->
        UBI - Unsorted block images  --->
            <*> Enable UBI
            (4096) UBI wear-leveling threshold  and disable debugging !!
$ make linux
  • reflash your kernel

U-Boot envt variables

BIOS> setenv bootcmd run ubifsboot
BIOS> setenv download_rootfs tftpboot \${loadaddr} \${serverpath}\${board_name}-rootfs.arm.ubi

Additional informations

A new file 'ubinize.cfg' defining the ubi volumes is located in buildroot/target/ubifs/. This file contains the different UBI volumes of the UBI image:


This file is processed by the ubinize utility after mkfs.ubifs.

U-Boot access to UBIFS partitions

U-Boot can read files from the rootfs / UBIFS partition using the commands: uni, ubifsmount, ubifsls, ubifsload. Here is an example applicable to the apf27, apf28 and apf51 boards:

BIOS> ubi part rootfs
UBI: attaching mtd1 to ubi0
UBI: physical eraseblock size:   131072 bytes (128 KiB)
UBI: logical eraseblock size:    129024 bytes
UBI: smallest flash I/O unit:    2048
UBI: sub-page size:              512
UBI: VID header offset:          512 (aligned 512)
UBI: data offset:                2048
UBI: attached mtd1 to ubi0
UBI: MTD device name:            "mtd=7"
UBI: MTD device size:            500 MiB
UBI: number of good PEBs:        3988
UBI: number of bad PEBs:         12
UBI: max. allowed volumes:       128
UBI: wear-leveling threshold:    4096
UBI: number of internal volumes: 1
UBI: number of user volumes:     1
UBI: available PEBs:             0
UBI: total number of reserved PEBs: 3988
UBI: number of PEBs reserved for bad PEB handling: 39
UBI: max/mean erase counter: 2/0

BIOS> ubifsmount ubi0:rootfs
UBIFS: mounted UBI device 0, volume 0, name "rootfs"
UBIFS: mounted read-only
UBIFS: file system size:   504483840 bytes (492660 KiB, 481 MiB, 3910 LEBs)
UBIFS: journal size:       9033728 bytes (8822 KiB, 8 MiB, 71 LEBs)
UBIFS: media format:       w4/r0 (latest is w4/r0)
UBIFS: default compressor: LZO
UBIFS: reserved for root:  0 bytes (0 KiB)

BIOS> ubifsls /boot
	  2604048  Thu Oct 03 08:38:56 2013  apf51-linux.bin

BIOS> ubifsload 90000000 /boot/apf51-linux.bin
Loading file '/boot/apf51-linux.bin' to addr 0x90000000 with size 2604048 (0x0027bc10)...

Acces to UBIFS files from U-Boot can used to do an update of your system after deployement on site through some U-Boot scripts..