Bubblegum-96 Board Recovery

This page outlines steps needed to recover your Bubblegum-96 board from a bricked software state. This instruction set is suggested to those who are experiences boot issues due to a corrution in the file system and/or other software components such as bootloader.

Installing a Bootloader

For most users a board can be “recovered” from a software failure by reloading the operating system. However, if the primary bootloader in the eMMC flash memory has been corrupted then the bootloader will need to be re-installed. This section describes how to reinstall the primary bootloader.

1) Update Host System

The package list and versions on your host machine could be out of date. It is important to run a few commands prior to moving to the next step.

These commands will help us make sure everything on the host machine is current:

  • apt-get update: Downloads package lists from online repositories and “updates” them to get information on the newest versions of packages and their dependencies.
  • apt-get upgrade: Fetches and installs newest package versions which currently exist on the system. APT must know about these new versions by way of ‘apt-get update’
  • apt-get dist-upgrade: In addition to performing the function of upgrade, this option also intelligently handles changing dependencies with new versions of packages

Note: Must be connected to the internet

$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get dist-upgrade

2) Install Host Dependencies

$ sudo apt-get install git cmake
$ sudo apt-get install libusb-1.0-0

3) Download, Build, and Install ADFU tool on Host

This repository consists of the proprietary vendor binaries and ADFU source code. By building and installing this tool, the vendor binaries will be copied to the host and used during recovery process.

$ git clone https://github.com/96boards-bubblegum/linaro-adfu-tool.git
$ cmake .
$ make
$ sudo make install

This will build and install the ADFU tool to /usr/local/share/linaro-adfu-tool.

4) Download recovery image

Apart from the vendor binaries downloaded from the above section, we also need U-Boot image for recovering the board. The following command downloads the pre-built U-Boot image.

$ wget https://releases.linaro.org/96boards/bubblegum/linaro/u-boot/latest/u-boot-dtb.img

5) Enter ADFU Mode

The following instructions are used to recover board from bricked stage with the help of ROM bootloader using ADFU tool.

  • Make sure bubblegum-96 board is in power off mode
  • Plug in the UART debug board and connect serial console to the host PC
    • Set baud rate as 115200
    • Set (8N1) – [8bit data, No-parity, & 1 stop bit]
  • Connect the host PC with Bubblegum-96 USB3.0 port via type USB A-A cable
    • USB3.0 port on Bubblegum96 board is the blue port
    • This cable won’t provide Power, so it will not boot up the board
  • Hold down the ADFU key on the Bubblegum96 board
  • Plug in power to the Bubblegum96 board
  • Continue to hold down ADFU down the ADFU key for 2-4 seconds after the power has been plugged in
  • Release the ADFU key
  • Execute lsusb on host PC
    • You will find a device ID 10d6:10d6 if Bubblegum96 board has entered adfu-mode

6) Access 96board U-boot shell

While Bubblegum96 board is in ADFU mode, execute the following commands in linaro-adfu-tool/ directory to access 96board u-boot shell.

$ sudo linaro-adfu-tool-bg96 u-boot-dtb.img

Note: if you make install the ADFU tool as mentioned above, you should be able to run linaro-adfu-tool from any path, it will search binaries from certain locations, such as

  1. /usr/local/share/linaro-adfu-tool/bg96/firmwares/
  2. /usr/share/linaro-adfu-tool/bg96/firmwares/
  3. ./firmwares/
  4. ../firmwares/

While executing the above steps you can see the log in serial terminal. And once all the images are flashed, Bubblegum96 board will boot using U-Boot. Interrupt during the U-Boot booting stage to access the console and it will show “owl>” prompt.

Note: For now the binaries are only flashed on to RAM, for flashing the binaries on to eMMC, proceed to Fastboot Mode section.