export PATH=~/bin:$PATH
export JAVA_HOME=~/bin/jdk1.6.0_45/
export JRE_HOME=$JAVA_HOME/jre
export CLASSPATH=$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH
运行source ~/.bashrc 使之生效
3.按照官网指导
Installing required packages (Ubuntu 12.04)
--------------------------------------------------------------------------------
Building on Ubuntu 12.04 is currently only experimentally supported and is not guaranteed to work on branches other than master.
$ sudo apt-get install git gnupg flex bison gperf build-essential \
zip curl libc6-dev libncurses5-dev:i386 x11proto-core-dev \
libx11-dev:i386 libreadline6-dev:i386 libgl1-mesa-glx:i386 \
libgl1-mesa-dev g++-multilib mingw32 tofrodos \
python-markdown libxml2-utils xsltproc zlib1g-dev:i386
$ sudo ln -s /usr/lib/i386-linux-gnu/mesa/libGL.so.1 /usr/lib/i386-linux-gnu/libGL.so
4.编译代码
进入源码根目录
编译初始化：
在终端中执行：
source build/envsetup.sh
执行后输出：
source build/envsetup.sh
including device/asus/grouper/vendorsetup.sh
including device/asus/tilapia/vendorsetup.sh
including device/generic/armv7-a-neon/vendorsetup.sh
including device/generic/armv7-a/vendorsetup.sh
including device/generic/mips/vendorsetup.sh
including device/generic/x86/vendorsetup.sh
including device/samsung/maguro/vendorsetup.sh
including device/samsung/manta/vendorsetup.sh
including device/samsung/toroplus/vendorsetup.sh
including device/samsung/toro/vendorsetup.sh
including device/ti/panda/vendorsetup.sh
including sdk/bash_completion/adb.bash
选择编译目标：
lunch full-eng
执行后会又以下信息提示：
============================================
PLATFORM_VERSION_CODENAME=REL
PLATFORM_VERSION=4.2
TARGET_PRODUCT=full
TARGET_BUILD_VARIANT=eng
TARGET_BUILD_TYPE=release
TARGET_BUILD_APPS=
TARGET_ARCH=arm
TARGET_ARCH_VARIANT=armv7-a
HOST_ARCH=x86
HOST_OS=linux
HOST_OS_EXTRA=Linux-2.6.32-45-generic-x86_64-with-Ubuntu-10.04-lucid
HOST_BUILD_TYPE=release
BUILD_ID=JOP40C
OUT_DIR=out
============================================
编译代码：
在终端中执行：make -j4
-j4：表示用四个线程来编译：
我用虚拟机，配置为4g，交换空间为2g，编译了大约6个小时。
运行模拟器
在终端中执行：emulator
在 ~/.bashrc
添加环境变量：
export ANDROID_PRODUCT_OUT=~/code/android-4.2/out/target/product/generic
export ANDROID_SWT=~/code/android-4.2/out/host/linux-x86/framework/
备注：
重启系统后：
执行emulator，出现如下错误：
emulator: ERROR: You did not specify a virtual device name, and the system
directory could not be found.
If you are an Android SDK user, please use '@<name>' or '-avd <name>'
to start a given virtual device (see -help-avd for details).
Otherwise, follow the instructions in -help-disk-images to start the emulator
解决：
source build/envsetup.sh
lunch sdk-eng
然后再执行
emulator
可以启动模拟器