DEV Community

Cover image for Building Android for UDOO-NEO
Ronaldo Nunez
Ronaldo Nunez

Posted on • Edited on

Building Android for UDOO-NEO

#android #aosp #udoo #embedded

Embedded Android is a hot topic in embedded systems circles. Not due to the easiness of building it. In this article, I'll guide you on the building saga of Android Marshmallow, or simply Android M, for UDOO-NEO boards.

UDOO-NEO is a low-cost development board with some nice support for Android. If you already tried to build Android from the scratch then you know that building it can be very tricky, that's especially true for old versions. For that reason, I decided to share with you a technique to build Android on modern Linux distributions.

First of all, you gonna need a Linux distribution. Android's team suggests Ubuntu 14.04 to build Marshmallow version, mainly for the OpenJDK version available on its repositories, which is v7. It's not possible to use any newer version.

You can use any Linux distribution you like or feel comfortable with, but keep in mind that you gonna need to install OpenJDK-7 anyway. Personally, I don't like to keep many versions of JDK in my machine, even update-alternatives being a good tool to maintain many JVM/JDK versions in the host system.

You doubtless don't want to install Ubuntu 14.04 on your machine, since it lacks support since 2019. You may say "ok, I can go with a VM", but, believe me, there is a faster and less disk/memory-hungry alternative: Docker. Docker containers can work over host's filesystem and can consume up to 90% less RAM, once the host shares most of its resources with containers.

Instead of learning how to use Docker, which may be a bit difficult, we'll use a tool called rebuild, or rbld. Rebuild has a simple command interface to create containers for cross-compiling.

Installing rbld

Before installing rbld, you need to install Docker, gem and Ruby. In OpenSUSE, type the command below on the terminal:

# zypper install -y docker ruby ruby-devel
Enter fullscreen mode Exit fullscreen mode

Add your user to docker group (remember to logoff after running the command below):

$ usermod -aG docker <username>
Enter fullscreen mode Exit fullscreen mode

Finally, you're good to install rbld:

# gem install rbld
Enter fullscreen mode Exit fullscreen mode

Building environment setup

Using rbld is very straight forward:

Usage:
  rbld help                Show this help screen
  rbld help COMMAND        Show help for COMMAND
  rbld COMMAND [PARAMS]    Run COMMAND with PARAMS

rebuild: Zero-dependency, reproducible build environments

Commands:

  checkout
  commit
  create
  deploy
  list
  load
  modify
  publish
  rm
  run
  save
  search
  status
  version
Enter fullscreen mode Exit fullscreen mode

We need to create an environment, for that use command create:

$ rbld create --base ubuntu:14.04 android-m
Enter fullscreen mode Exit fullscreen mode

Now, we need to provision the environment:

$ rbld modify android-m -- "sudo apt-get update && sudo apt-get install git-core gnupg flex bison build-essential zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev x11proto-core-dev libx11-dev lib32z1-dev libgl1-mesa-dev libxml2-utils xsltproc unzip fontconfig python lzop bc u-boot-tools liblz4-dev vim uuid uuid-dev zip lzop gperf zlib1g-dev liblz-dev liblzo2-2 liblzo2-dev u-boot-tools lib32z1 flex git-core curl mtd-utils android-tools-fsutils"
Enter fullscreen mode Exit fullscreen mode

Finally, is time to commit changes (yes, environments in rbld are versioned):

$ rbld commit --tag v1 android-m
Enter fullscreen mode Exit fullscreen mode

Cloning source-code

Let's leave the environment setup aside for a moment and focus on collecting the code to build Android.

In order to clone Android repos, you need to install repo tool:

$ cd ~
$ mkdir ~/bin
$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > ~/bin/repo
$ chmod a+x ~/bin/repo
Enter fullscreen mode Exit fullscreen mode

Now, we can clone Android M repositories (be aware that may take several minutes):

$ mkdir ~/bin ~/android-m
$ cd ~/android-m
$ ~/bin/repo init -u https://github.com/UDOOboard/android_udoo_platform_manifest -b android-6.0.1
$ ~/bin/repo sync -jN #N is the number of parallel jobs
Enter fullscreen mode Exit fullscreen mode

Building Android

We have an environment and the code, then we're ready to build an Android image.
Launch the environment we've created some sections before:

$ rbld run android-m:v1
Enter fullscreen mode Exit fullscreen mode

You'll notice that you're now inside our build environment. This environment is isolated from your host system but the host and the environment share the filesystem. You may be now at the root of Android's source code.
Set ARCH environment variable, then source the envsetup.sh:

$ export ARCH=arm
$ source build/envsetup.sh
Enter fullscreen mode Exit fullscreen mode

In the Android build system, you can choose configurations among a list of options, to show up that list, simply type lunch on the terminal.
For UDOO-NEO we have two options:

  • udooneo_6sx-eng
  • udooneo_6sx-user Eng version integrates some debug tools that are not available in user images. Let's build an eng version for now: 
$ lunch udooneo_6sx-eng
Enter fullscreen mode Exit fullscreen mode

OK, to build it type m:

$ m
Enter fullscreen mode Exit fullscreen mode

You can check Android's build system commands with the command hmm:

$ hmm
Enter fullscreen mode Exit fullscreen mode

The build artifacts reside in out/ directory. You can use make_sd.sh script to create an sd-card and boot up your new Android image on the board.

$ cp make_sd.sh out/target/product/udooneo_6sx
$ cd out/target/product/udooneo_6sx
$ sudo -E ./make_sd.sh /dev/sdx
Enter fullscreen mode Exit fullscreen mode

Troubleshooting

arm-eabi-gcc: error: backports/drivers/net/wireless 

arm-eabi-gcc: error: backports/drivers/net/wireless
/ti/wlcore/main.c: No such file or directory
arm-eabi-gcc: fatal error: no input files
compilation terminated.
Enter fullscreen mode Exit fullscreen mode

Solution:

cd kernel_imx/
make mrproper
cd ..
Make
Enter fullscreen mode Exit fullscreen mode

make: *** No rule to make target ... liblz4-static_intermediates 

make: *** No rule to make target `out/target/product/udooneo_6sx/obj/STATIC_LIBRARIES/liblz4-static_intermediates/export_includes', needed by `out/target/product/udooneo_6sx/obj/EXECUTABLES/updater_intermediates/import_includes'.  Stop.
Enter fullscreen mode Exit fullscreen mode

Solution:
Include the lines below to extenal/lz4/lib/android.mk and build again:

include $(CLEAR_VARS)
LOCAL_MODULE := liblz4-static
LOCAL_SRC_FILES := $(liblz4_src_files)
LOCAL_MODULE_TAGS := optional
include $(BUILD_STATIC_LIBRARY)
Enter fullscreen mode Exit fullscreen mode

References

Top comments (0)

Read next

lymah profile image

Integrate Daytonia in a Url Shortener App

Lymah -

oliviarizona88 profile image

Unleashing the Power of Tailwind CSS: A Comprehensive Guide

oliviarizona -

kakacomputer profile image

How to Survive Your First IT Job (Advice for New Grad Techs)

KaKaComputer -

gokayburuc profile image

Cyberdev Obsidian Theme

gokayburuc.dev -