编译SDK
编译SDK可以得到与源码同步的SDK，还会生成一些tools，在源码根目录下：
- $ sudo make PRODUCT-sdk-sdk
编译生成的SDK在out/host/linux-x86/SDK下。之后如果在ubuntu下使用eclipse进行开发，可以使用你编译的SDK。
下面就在模拟器中运行镜像，建议切到root用户下，首先配置几个环境变量，将自己编译的SDK设为优先级最高，在源码根目录下执行：
- $ update-alternatives --install /usr/bin/AndroidSDK AndroidSDK ./out/host/linux-x86/sdk/android-sdk_eng.root_linux-x86 255
这样会在/etc/alternatives下生成一个指向该SDK目录的软连接AndroidSDK，这个目录主要存放一些系统默认打开的程序的信息和配置。那么/usr/bin/AndroidSDK就指向这个软连接。接着执行:
- $ gedit ~/.bashrc
在文件末尾添加：
- export ANDROID_SDK_HOME=/usr/bin/AndroidSDK
- export PATH=$ANDROID_SDK_HOME/tools:$PATH
首先你需要设置一下emulator工具的目录之类的，这个不细说了，
要在.bashrc中新增环境变量，如下
ANDROID_PRODUCT_OUT=~/android/out/target/product/generic
ANDROID_PRODUCT_OUT_BIN=~/android/out/host/linux-x86/bin
这里是设置你的输出文件的位置和bin工具目录，不用多解释吧？
然后在命令行输入：
export PATH=${PATH}:${ANDROID_PRODUCT_OUT_BIN}:${ANDROID_PRODUCT_OUT};
上面是导入了相关的配置，然后使之生效。
source ~/.bashrc
接着切换到输出的system文件夹
cd ~/android/out/target/product/generic
然后来创建模拟器
emulator -system system.img -data userdata.img -ramdisk ramdisk.img
如果你运气够好的话，也许现在已经在运行了，不过我运气明显不够好。
提示一：
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
既然人家提示了，那就按照步骤走吧，输入命令：
emulator -help-avd
接着提示如下：
use ‘-avd <name>’ to start the emulator program with a given Android
Virtual Device (a.k.a. AVD), where <name> must correspond to the name
of one of the existing AVDs available on your host machine.See -help-virtual-device to learn how to create/list/manage AVDs.
As a special convenience, using ‘@<name>’ is equivalent to using
‘-avd <name>’.
跟着提示继续走，输入命令：
emulator -help-virtual-device
又是提示了：
An Android Virtual Device (AVD) models a single virtual
device running the Android platform that has, at least, its own
kernel, system image and data partition.Only one emulator process can run a given AVD at a time, but
you can create several AVDs and run them concurrently.You can invoke a given AVD at startup using either ‘-avd <name>’
or ‘@<name>’, both forms being equivalent. For example, to launch
the AVD named ‘foo’, type:emulator @foo
The ‘android’ helper tool can be used to manage virtual devices.
For example:android create avd -n <name> -t 1 # creates a new virtual device.
android list avd # list all virtual devices available.Try ‘android –help’ for more commands.
Each AVD really corresponds to a content directory which stores
persistent and writable disk images as well as configuration files.
Each AVD must be created against an existing SDK platform or add-on.
For more information on this topic, see -help-sdk-images.SPECIAL NOTE: in the case where you are *not* using the emulator
with the Android SDK, but with the Android build system, you will
need to define the ANDROID_PRODUCT_OUT variable in your environment.
See -help-build-images for the details.
说实在的，这提示看着很郁闷，让你跳来跳去，就是不能解决问题。
直接创建avd吧，先看下说明：
Usage:
android [global options] create avd [action options]
Global options:
-h –help : Help on a specific command.
-v –verbose : Verbose mode, shows errors, warnings and all messages.
-s –silent : Silent mode, shows errors only.Action “create avd”:
Creates a new Android Virtual Device.
Options:
-c –sdcard : Path to a shared SD card image, or size of a new sdcard for
the new AVD.
-n –name : Name of the new AVD. [required]
-a –snapshot: Place a snapshots file in the AVD, to enable persistence.
-p –path : Directory where the new AVD will be created.
-f –force : Forces creation (overwrites an existing AVD)
-s –skin : Skin for the new AVD.
-t –target : Target ID of the new AVD. [required]
-b –abi : The ABI to use for the AVD. The default is to auto-select the
ABI if the platform has only one ABI for its system images.
看明白了吧？
android create avd -n test2 -f -p /home/thonatos/test -t 1
然后会有提示：
Auto-selecting single ABI armeabi-v7a
Android 4.0.3 is a basic Android platform.
Do you wish to create a custom hardware profile [no]no
Created AVD ‘test2′ based on Android 4.0.3, ARM (armeabi-v7a) processor,
with the following hardware config:
hw.lcd.density=240
vm.heapSize=48
hw.ramSize=512
创建好了，不过你的模拟器估计一运行就出错吧。（我故意滴。。。别怪我。。）
切换到刚才创建模拟器的目录，然后看看有什么东东，打开config.ini
hw.lcd.density=240
skin.name=WVGA800
skin.path=platforms/android-15/skins/WVGA800
hw.cpu.arch=arm
abi.type=armeabi-v7a
hw.cpu.model=cortex-a8
vm.heapSize=48
hw.ramSize=512
image.sysdir.1=system-images/android-15/armeabi-v7a/
知道该做什么了吧？改吧，把相关的目录改成你自己的，然后再执行一下
emulator @test2
怎么样！是不是已经运行啦？呵呵，恭喜哈!
可能大家都知道，内核源码编译和android源码编译的区别在于，内核是linux的内核
最后把编译后结合起来的命令是
emulator -kernel kernel-qemu -system system.img -data userdata.img -ramdisk ramdisk.img
这个不需要安装avd，上面安装的avd，没有使用自己编译的内核
从现在开始，一个自己编译的android系统就这么运行了
回顾一下：
1、编译android源代码
得到文件：-system system.img -data userdata.img -ramdisk ramdisk.img
2、编译内核
具体怎么编译内核，查看
android内核编译
http://blog.csdn.net/flydream0/article/details/7070392
得到文件：kernel/goldfish/arch/arm/boot/zImage,把它重命名为kernel-qemu,并且把它和源代码编译后的文件放入同一个文件夹下面
3、启动android虚拟机
emulator -kernel kernel-qemu -system system.img -data userdata.img -ramdisk ramdisk.img