单机搭建安卓开发环境，前三篇主要是磨刀霍霍，这一篇将重点介绍JDK、REPO、GIT及编译工具的安装，下载项目代码并编译。特别说明，以下操作基于64位12.04 Server版Ubuntu。若采用其他版本系统，请参考Google官方操作步骤。访问不了的同学，请找大师(蓝灯)，他能助你一臂之力。
1)安装OpenJDK 7
sudo apt-get install openjdk-7-jdk --force-yes –y
安装OpenJDK8
sudo add-apt-repository ppa:openjdk-r/ppa
sudo apt-get update
sudo apt-get install openjdk-8-jdk --force-yes -y
查看java的版本
java –version
java version "1.7.0_95"
OpenJDK Runtime Environment (IcedTea 2.6.4) (7u95-2.6.4-0ubuntu0.12.04.1)
OpenJDK 64-Bit Server VM (build 24.95-b01, mixed mode)
设置环境变量
vim ~/.profile
在末尾添加如下配置，保存并退出
export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64
export CLASSPATH=.:$JAVA_HOME/lib:$JAVA_HOME/jre/lib:$CLASSPATH
export PATH=$JAVA_HOME/bin:$JAVA_HOME/jre/bin:$PATH
终端输入如下命令使配置生效
source ~/.profile
2)安装google推荐的编译工具
sudo apt-get install gnupg flex bison gperf build-essential --force-yes -y
sudo apt-get install zip curl libc6-dev libncurses5-dev:i386 x11proto-core-dev --force-yes -y
sudo apt-get install libx11-dev:i386 libreadline6-dev:i386 --force-yes -y
sudo apt-get install libgl1-mesa-dev g++-multilib mingw32 tofrodos --force-yes -y
sudo apt-get install python-markdown libxml2-utils xsltproc zlib1g-dev:i386 --force-yes -y
sudo apt-get install libgl1-mesa-dri:i386 dpkg-dev --force-yes –y
3)安装repo
下载repo V1.22国内定制版，已处理原版在国内使用时出现如下错误提示：
fatal: Cannot get https://gerrit.googlesource.com/git-repo/clone.bundle
fatal: error [Errno 101] Network is unreachable
将repo拷贝到/bin目录下，并修改其属性
sudo cp /home/repo /bin/
sudo chmod a+x /bin/repo
4)安装git
sudo apt-get install git --force-yes –y
配置用户邮箱及用户名
git config --global user.email "hjb@mail.com"
git config --global user.name "hjb"
配置完成后可通过git config --list查看配置信息，或通过cat ~/.gitconfig查看git配置文件的详细信息。
5)创建密钥，并添加到服务器端
ssh-keygen -t rsa -C hjb@bonovo.com
拷贝id_rsa.pub并重命名，然后复制到服务器
cp /home/hjb/.ssh/id_rsa.pub /home/hjb/id_rsa.pub.hjb113
在git服务器端登录bnv用户,并执行如下命令，
cat /home/hjbang/id_rsa.pub.hjb113 >> /home/bnv/.ssh/authorized_keys
6)本地创建project目录mt8735，准备下载代码
cd ~
mkdir mt8735
cd mt8735
7)同步代码
repo init -u bnv@192.168.1.12:/home/git/MTK/lp5.1-mt8735m-mirror/bonovo/platform/manifests.git -b default
repo sync
repo forall -c git checkout lp5.1-mt6735m
repo forall -c git checkout mt8735-avn401
repo forall -c git pull
8)安装ccache，并配置ccache
sudo apt-get install -y ccache
配置.bashrc
sudo vim ~/.bashrc
末尾添加
export USE_CCACHE=1
使配置及时生效
source ~/.bashrc
查看设置状态:
echo $USE_CCACHE
9)编译project
cd ~/mt8735
prebuilts/misc/linux-x86/ccache/ccache -M 50G
. build/envsetup.sh
launch 25
make update-api
make update-api，大概需要花18分钟，详细信息如下，
Docs droiddoc: out/target/common/docs/doc-comment-check DroidDoc took sec. to write docs to out/target/common/docs/doc-comment-check Copying current.txt Copying removed.txt Docs droiddoc: out/target/common/docs/system-api-stubs DroidDoc took sec. to write docs to out/target/common/docs/system-api-stubs Copying system-current.txt Copying system-removed.txt #### make completed successfully (: (mm:ss)) ####
编译Android5.1系统
make –j24
编译过程非常漫长，可以通过如下命令查看cahe使用情况，
watch -n1 -d prebuilts/misc/linux-x86/ccache/ccache -s
cache directory /home/hjb/.ccache cache hit (direct) cache hit (preprocessed) cache miss called for link preprocessor error unsupported source language unsupported compiler option files in cache cache size 18.0 Gbytes max cache size 50.0 Gbytes
可以看到cache大概有18GB，故使用ccache,第一次编译的时间会比不用cache更长,但之后编译速度将会有很大提升。
经过4个半小时，第一次编译终于成功了，详细信息如下，
Creating filesystem with parameters: Size: Block size: Blocks per group: Inodes per group: Inode size: Journal blocks: Label: Blocks: Block groups: Reserved block group size: Created filesystem with / inodes and / blocks Install system fs image: out/target/product/mt8735_tb_l1/system.img out/target/product/mt8735_tb_l1/system.img+out/target/product/mt8735_tb_l1/obj/PACKAGING/recovery_patch_intermediates/recovery-from-boot.p maxsize= blocksize= total= reserve= #### make completed successfully (:: (hh:mm:ss)) ####
修改内核模块代码，重新编译系统镜像大概需要13分钟，详细信息如下，
Creating filesystem with parameters: Size: Block size: Blocks per group: Inodes per group: Inode size: Journal blocks: Label: Blocks: Block groups: Reserved block group size: Created filesystem with / inodes and / blocks Install system fs image: out/target/product/mt8735_tb_l1/system.img out/target/product/mt8735_tb_l1/system.img+out/target/product/mt8735_tb_l1/obj/PACKAGING/recovery_patch_intermediates/recovery-from-boot.p maxsize= blocksize= total= reserve= #### make completed successfully (: (mm:ss)) ####
虽然在SSD上编译，这个时间会缩短到5分钟左右，但还是比较长。所以在调试内核驱动模块时，最好使用动态加载模块的方式，以提高工作效率。
至此，Android系统编译的环境基本搭建完成，后一篇将介绍如何搭建Android应用开发的环境。