安装git，运行：git clone https://android.googlesource.com/kernel/common

如果common目录为空,则运行：

git branch -r

则可以看到：

origin/HEAD -> origin/master

origin/android-2.6.39

origin/android-3.0

origin/android-3.3

origin/android-3.4

origin/android-3.4-compat

origin/coupled-cpuidle

origin/experimental/android-3.10

origin/experimental/android-3.10-rc5

origin/experimental/android-3.8

origin/experimental/android-3.9

origin/experimental/android-3.9-rc2

origin/experimental/android-3.9-rc7

origin/linux-bcm43xx-2.6.39

origin/master

接着运行：

git checkout origin/android-3.4

就可以看到源码了。