U-Boot bootloader allows you to update the firmware of your device over Ethernet. U-Boot uses the TFTP protocol to get the firmware images from a TFTP server running in your computer and program them into the eMMC of the device.

This update process requires a TFTP server running in your computer with a configured exposed folder. The devices look for the firmware files in this folder when performing the update.

These instructions do not include setting up a TFTP server in your computer. We assume you have already installed and configured a TFTP server.

Once you have the TFTP server running in your computer, you can start the update process:

  1. Copy the Android firmware files (previously downloaded or compiled) in your TFTP server’s exposed folder (typically /tftpboot):

  2. Connect the serial adapter cable to the console port [CONS] and a serial cable from the adapter to the development computer.

  3. Open a serial connection to the serial port to which the device is connected. Use the following settings:

    • Port: Serial port to which your device is attached

    • Baud rate: 115200

    • Data Bits: 8

    • Parity: None

    • Stop Bits: 1

    • Flow control: None

  4. Reset the device (press the Reset button on the board) and immediately press a key in the serial terminal to stop the auto-boot process. You will be stopped at the U-Boot bootloader prompt:

    U-Boot dub-2017.03-r2.3 (Jan 15 2019 - 23:01:29 +0100)
    CPU:   Freescale i.MX6Q rev1.5 1200 MHz (running at 792 MHz)
    CPU:   Extended Commercial temperature grade (-20C to 105C) at 48C
    Reset cause: POR
    I2C:   ready
    DRAM:  1 GiB
    MMC:   FSL_SDHC: 0 (eMMC), FSL_SDHC: 1
    In:    serial
    Out:   serial
    Err:   serial
    ConnectCore 6 SOM variant 0x02: Consumer quad-core 1.2GHz, 4GB eMMC, 1GB DDR3, -20/+70C, Wireless, Bluetooth, Kinetis
    Board: ConnectCore 6 SBC, version 3, ID 129
    Boot device: MMC4
    PMIC:  DA9063, Device: 0x61, Variant: 0x60, Customer: 0x00, Config: 0x56
    Net:   FEC [PRIME]
    Normal Boot
    Hit any key to stop autoboot:  0
  5. Configure the network settings of the device by doing one of the following:

    • Use a DHCP server executing the dhcp command:

      => dhcp
    • Configure a static IP address, where a.b.c.d is the IP address of your device:

      => setenv ipaddr a.b.c.d
  6. Configure the IP address of the machine where the TFTP server is running and save the configuration. In this example, w.x.y.z is your machine IP address where the TFTP server is running:

    => setenv serverip w.x.y.z
    => saveenv
  7. Optional. Update the U-Boot image:

    1. Execute the following command to update the U-Boot image:

      => update uboot tftp <u-boot-file>.imx
    2. Reset the board to boot into the recently updated U-Boot, and press any key to stop the auto-boot process.

    3. Reset the U-Boot environment to default values (this will not reset protected variables like the MAC address). To do so, issue this command:

      => env default -a
    4. Configure the network and TFTP settings on your device again and save the configuration. Follow the instructions to configure network settings and IP address.

  8. Configure the partition of the eMMC to hold Android images by running these commands:

    => setenv mmcdev 0
    => run partition_mmc_android
  9. Update the kernel image by executing this command:

    => update boot tftp boot.img
  10. Update the Android vendor image by issuing this command:

    => update vendor tftp vendor.img
  11. Update the Android file system image by issuing this command:

    => update system tftp system.img
  12. Update the recovery image by executing this command:

    => update recovery tftp recovery.img
  13. To clean the data and cache partitions, enter these commands in U-Boot:

    => setenv boot_recovery yes
    => setenv recovery_command recovery --wipe_data
    => saveenv
    => reset
    If the cache and data partitions are already formatted or you wish to preserve their contents, you can skip these commands.
    The above process will boot your device into recovery mode, will format the cache and data partitions and will reboot your device.
    The first Android boot takes several minutes due to system deployment.