Compiling Android 8.1

Prerequisite

Hardware requiremnts

Recommended hardware requirement of development workstation compiling
Android 8.1:

64 bit CPU

16GB  Physical memory + Swap memory

30GB  Free disk space is used for building, and the source tree takes
about 8GB

See also the hardware and software configuration stated in Google
official document:

https://source.android.com/setup/build/requirements

https://source.android.com/setup/initializing

Software requiements

Installing JDK 8

   sudo add-apt-repository ppa:openjdk-r/ppa
   sudo apt-get update
   sudo apt-get install openjdk-8-jdk

Installing required packages

   sudo apt-get install git-core gnupg flex bison gperf libsdl1.2-dev \
     libesd0-dev libwxgtk2.8-dev squashfs-tools build-essential zip curl \
     libncurses5-dev zlib1g-dev pngcrush schedtool libxml2 libxml2-utils \
     xsltproc lzop libc6-dev schedtool g++-multilib lib32z1-dev lib32ncurses5-dev \
     lib32readline-gplv2-dev gcc-multilib libswitch-perl

   sudo apt-get install gcc-arm-linux-gnueabihf \
     libssl1.0.0 libssl-dev \
     p7zip-full

Downloading Android SDK

Due to the huge size of the Android SDK, it is not possible to
directly host it in Gitlab. Therefore the ".git" directory is
compressed as a "7z" archive file, uploaded to cloud storage server.
The increment update of the SDK is saved in "git bundle" and hosted in
Gitlab.

Please download "firefly_rk3328_android8.1_git_20211221" first:

Download

After the download completes, verify the MD5 checksum before
extraction:

   $md5sum ~/firefly_rk3328_android8.1_git_20211221.7z.001
   $md5sum ~/firefly_rk3328_android8.1_git_20211221.7z.001
   $md5sum ~/firefly_rk3328_android8.1_git_20211221.7z.001

   fda8c753df5ba4f20cdc9006f316d028  firefly_rk3328_android8.1_git_20211221.7z.001
   e78f2bb73fcb2afdcbeece2cf6bc581b  firefly_rk3328_android8.1_git_20211221.7z.002
   79b889bb5df551c2f69337b8a8cf3bbb  firefly_rk3328_android8.1_git_20211221.7z.003

Then extract it:

   mkdir -p  ~/proj/firefly_rk3328_android8.1
   cd ~/proj/firefly_rk3328_android8.1
   7z x ~/firefly_rk3328_android8.1_git_20211221.7z.001 -r -o.
   git reset --hard

For first and subsequent SDK update, run the following commands:

   # Update and apply the git bundle
   test -d .bundle || \
     git clone \
       https://gitlab.com/TeeFirefly/rk3328-android8.1-oreo-bundle.git \
       .bundle

   .bundle/update

   # If the command above prompts "[Info]Already up to date!", it indicates that
   # no SDK update is available and nothing need to do here.

   # Otherwise, the latest commit of the SDK update is saved to the symbolic-ref
   # FETCH_HEAD. Show the relation between the local branch and SDK update first.
   git show-branch HEAD FETCH_HEAD
   # If there're local commits, choose either rebase or merge to incorporate
   # the SDK change:
   # To rebase
   git rebase FETCH_HEAD
   # To merge
   git merge FETCH_HEAD

Compiling with Firefly Scripts

Automatic compilation

   ./build.sh rk3328-roc-cc

After executing the above command, it will compile the U-Boot, kernel,
and upper layer of Android, sort out the partition Image and generate
unified firmware "update.img", and put it in the directory of "rockdev
/image-rk3328_box/"

Modular compilation

Compiling configuration file

Note:"Compiling configuration file" is a prerequisite. You must
complete this step before proceeding:

   ./FFTools/make.sh rk3328-roc-cc 

Compiling Kernel

   ./FFTools/make.sh -k -j8

Compiling U-Boot

   ./FFTools/make.sh -u -j8

Compiling Android

   ./FFTools/make.sh -a -j8

Compiling all Image

This will compile kernel, U-Boot and Android with a single command:

   ./FFTools/make.sh -j8

Compiling Without Script

Before compilation, execute the following commands to configure
environment variables:

   export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
   export PATH=$JAVA_HOME/bin:$PATH
   export CLASSPATH=.:$JAVA_HOME/lib:$JAVA_HOME/lib/tools.jar

Compiling Kernel

   make ARCH=arm64 rockchip_defconfig
   make -j8 ARCH=arm64 roc-rk3328-cc.img

Compiling U-Boot

   make rk3328_box_defconfig
   make ARCHV=aarch64 -j8

Compiling Android

   source build/envsetup.sh
   lunch rk3328_box-userdebug
   make installclean
   make -j8
   ./mkimage.sh

Packing Rockchp Firmware

Packing Fimware in Linux

After compiling you can use Firefly official script to pack all
partition image files into the one true Rockchip firmware, by
executing the following command:

   ./FFTools/mkupdate/mkupdate.sh update

The resulting file is "rockdev/Image-rk3328_box/update.img".

The RK firmware needs to use the "SD_Firmware_Tool" tool and the
function mode to select "SD Startup" to create the boot card

Packing Fimware in Windows

It is also very simple in packaging Rockchip firmware "update.img"
under Windows:

Copy all the compiled files in rockdev/Image-rk3328_box/ to the
rockdev\Image directory of AndroidTool

Run the mkupdate.bat batch file in the rockdev directory of
AndroidTool.

update.img will be created in rockdev\Image directory.

Flash Image

Reference:

《Flashing to the eMMC》