android模块编译

1.在源码目录下执行
. build/envsetup.sh
注意：.和build/envsetup.sh中间有空格
然后我们就可以使用以下命令了：
croot:   Changes directory to the top of the tree.
m:       Makes from the top of the tree.
mm:      Builds all of the modules in the current directory.
mmm:     Builds all of the modules in the supplied directories.
cgrep:   Greps on all local C/C++ files.
jgrep:   Greps on all local Java files.
resgrep: Greps on all local res/*.xml files.
godir:   Go to the directory containing a file.

2.接下来我们就使用mmm来编译指定目录的模块，如编译日历：
mmm packages/apps/Calendar
编完之后生成两个文件：
Install: out/target/product/generic/data/app/CalendarTests.apk
Install: out/target/product/generic/system/app/Calendar.apk