Android 9 Pie device configuration for Raspbery Pi 3 Model B & B+

Setup build environment

The build host is x86_64 platform run ubuntu-16.04 (refer: https://source.android.com/setup/build/initializing)

1. Install JDK

$ sudo apt-get update
$ sudo apt-get install openjdk-8-jdk

2. Install other tools

$ sudo apt-get install git-core gnupg flex bison gperf build-essential zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev x11proto-core-dev libx11-dev lib32z-dev libgl1-mesa-dev libxml2-utils xsltproc unzip

3. Install repo command to download Android 9 Pie project source code

$ mkdir ~/bin
$ PATH=~/bin:$PATH
$ curl -sSL 'https://gerrit-googlesource.proxy.ustclug.org/git-repo/+/master/repo?format=TEXT' | base64 -d > ~/bin/repo
$ chmod a+x ~/bin/repo

Download source code

1. Download The Android 9 Pie official source code The source code can download either from https://android.googlesource.com or https://lug.ustc.edu.cn/wiki/mirrors/help/aosp Run following command to download from ustc.edu.cn

$ repo init -u git://mirrors.ustc.edu.cn/aosp/platform/manifest -b android-9.0.0_r8 --repo-url=git://mirrors.ustc.edu.cn/aosp/tools/repo

2. Download Raspbery Pi 3 device configuration files

$ mkdir -pv device/brobwind
$ git clone git://github.com/yang-neu/pie-device-rpi3 device/brobwind/rpi3

3. Add local manifest file

$ mkdir -p .repo/local_manifests
$ ln -sv ../../device/brobwind/rpi3/local_manifest.xml .repo/local_manifests/

4. Downloading

$ repo sync

Apply patch to Android framework

The following patch must be applyed:

diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index cd8fdbf..6918bc3 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -769,7 +769,7 @@ class DisplayContent extends WindowContainer<DisplayContent.DisplayChildWindowCo
         // appropriately arbitrary number. Eventually we would like to give SurfaceFlinger
         // layers the ability to match their parent sizes and be able to skip
         // such arbitrary size settings.
-        mSurfaceSize = Math.max(mBaseDisplayHeight, mBaseDisplayWidth) * 2;
+        mSurfaceSize = (int)(Math.max(mBaseDisplayHeight, mBaseDisplayWidth) * 1.4);
 
         final SurfaceControl.Builder b = mService.makeSurfaceBuilder(mSession)
                 .setSize(mSurfaceSize, mSurfaceSize)

Configure build environment

$ . build/envsetup.sh
$ lunch rpi3-eng

Build target

$ m -j

It will take about 1 hour 32 minutes for CPU: intel I5 8500T; RAM: 8G DDR42666; HDD: 1TB

Then you will get following images in the out/target/product/rpi3 folder:

1. rpiboot.img
2. boot.img
3. system.img
4. vendor.img
5. userdata.img

Flash images

1. Flash images to sdcard directly

It requires sgdisk and gdisk to create GPT partition table.

$ sudo OUT=${OUT} device/brobwind/rpi3/boot/create_partition_table.sh /path/to/sdcard

After executing the command, it will also install following images to sdcard:

• out/target/product/rpi3/rpiboot.img
• out/target/product/rpi3/boot.img
• out/target/product/rpi3/system.img
• out/target/product/rpi3/vendor.img
• device/brobwind/rpi3/boot/images/oem_bootloader_a.img
• device/brobwind/rpi3/boot/images/zero_4k.bin

2. Using fastboot command

Please refer to https://github.com/brobwind/pie-device-brobwind-rpi3-u-boot/blob/pie-device-brobwind-rpi3/README.md

For detail info, please refer:

1. https://www.brobwind.com/archives/1575
2. https://www.brobwind.com/archives/1541