The Exynos series boot loader is placed on the Boot Partition(Hidden Partition) in the eMMC memory. (C1/C2/N2/C4 models don't use the Hidden partition).
When it is corrupted or you want to use the eMMC with other different board, you must install the proper boot loader in the eMMC.
Note that you must have a micro-SD card to run the recovery process.

  1. Download Recovery Image file.
  2. Prepare a microSD card and flash the downloaded image. flashing → refer this link
  3. Connect both the eMMC and MicroSD to XU3/XU4
  4. Set the dip-switches or slide-switch on XU3/XU4 to “SD boot mode”. If you have XU3, refer this link
  5. Connect Power and watch the LED status
  6. The blue and red LEDs are solid on. This may take 40seconds ~ 3minutes. After recovery process, blue LED will be flashing like a heartbeat. And remove the power supply.
  7. Set the dip-switchs or slide-switch back to eMMC boot mode.
  8. Remove the MicroSD card.
  9. Proceed with normal power up with your peripherals attached.
  10. After checking the Android on eMMC, you can install other Linux OS images on the eMMC later.
  • If you did this 10 steps of Recoverying with Recovery image, your u-boot version is U-Boot 2017.05-00002-gd0752a9-dirty (Sep 08 2017 - 11:33:04 +0900) for ODROID-XU4. That version does not support Device Tree Overlay.
Exynos5422 # version
U-Boot 2017.05-00002-gd0752a9-dirty (Sep 08 2017 - 11:33:04 +0900) for ODROID-XU4
arm-linux-gnueabihf-gcc (crosstool-NG linaro-1.13.1-4.9-2014.09 - Linaro GCC 4.9-2014.09) 4.9.2 20140904 (prerelease)
GNU ld (crosstool-NG linaro-1.13.1-4.9-2014.09 - Linaro GCC 4.9-2014.09) Linaro 2014.09
  • If you want to use our Ubuntu image version above 20.04 with it, you have to update boot blobs in the hidden sector to support Device Tree Overlay.
root@odroid:~# apt update
root@odroid:~# apt install --reinstall uboot bootini
root@odroid:~# reboot
  • After updating uboot blobs, you can see the version below in the uboot prompt mode using a serial console.
Exynos5422 # version
U-Boot 2017.05-00008-g6a9ddb8303-dirty (May 19 2020 - 19:48:01 +0900) for ODROID-XU4
arm-linux-gnueabihf-gcc (Linaro GCC 7.4-2019.02) 7.4.1 20181213 [linaro-7.4-2019.02 revision 56ec6f6b99cc167ff0c2f8e1a2eed33b1edc85d4]
GNU ld (Linaro_Binutils-2019.02)

This instruction requires USB-UART and terminal application on your desktop.

  1. Set the switch (SW1) to boot with MicroSD on the board
  2. Insert the Micro SD flashed with booting image into its slot and power on. You must stop at U-boot once the board is started.
  3. Invoke the commands below to copy the boot loader image from Micro SD to eMMC. Once copying is done, set the switch (SW) to see if the board can boot with eMMC.
Exynos5422 # run copy_uboot_sd2emmc
  • accessory/emmc/recovery_xu4.txt
  • Last modified: 2023/08/28 12:49
  • by justin