单独编译Android源代码中的模块
单独编译Android源代码中的模块
第一次下载好Android源代码后，通过在Android源代码工程下执行make命令，然后得到Android的系统镜像system.img.
那么当我们修改了android源代码中某个模块或者android源代码工程中新增了一个自己的模块。此时可以用make命令进行重新编译，不过重新编译比较浪费时间。google提供了另外的命令来进行单独模块的编译，以及重新打包到system.img镜像中的命令。
以下介绍单独编译android中模块的命令，以及打包system.img的命令。
一、首先，执行脚本文件 envsetup.sh
该文件在Android源代码目录下的build目录中，在这个shell 脚本中定义了 hmm, croot, m, mm, mmm 等 function执行命令如下：
fantasy@ubuntu:~/my_android$ . ./build/envsetup.sh
或者
fantasy@ubuntu:~/my_android$ source build/envsetup.sh
在当前目录下输入命令hmm(android 4.2版本使用hmm，其他版本貌似使用的是help命令)，显示envsetup.sh提供命令
fantasy@ubuntu:~/my_android$ hmm
输出为：
Invoke ". build/envsetup.sh" from your shell to add the following functions to your environment: - lunch: lunch <product_name>-<build_variant> - tapas: tapas [<App1> <App2> ...] [arm|x86|mips] [eng|userdebug|user] - 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. Look at the source to view more functions. The complete list is: addcompletions add_lunch_combo cgrep check_product check_variant choosecombo chooseproduct choosetype choosevariant cproj croot findmakefile gdbclient gdbwrapper get_abs_build_var getbugreports get_build_var getlastscreenshot getprebuilt getscreenshotpath getsdcardpath gettargetarch gettop godir hmm isviewserverstarted jgrep key_back key_home key_menu lunch _lunch m mangrep mm mmm pid printconfig print_lunch_menu resgrep runhat runtest set_java_home setpaths set_sequence_number set_stuff_for_environment settitle smoketest stacks startviewserver stopviewserver systemstack tapas tracedmdump
注：
关于source
source 命令会把对应脚本中的内容读取到当前的bash 解释器中，在当前的执行环境中执行；其中定义的 function 以及通过 export 声明的变量等在 source 执行结束之后依然存在于当前的bash 环境中。比如我们常用的 source .bashrc 或者 source /etc/profile 等目的是为了引用刚刚改动过的环境变量。
二、使用mmm编译指定模块
以下是通过mmm编译android中自带的一个试验性的应用，命令如下：
fantasy@ubuntu:~/my_android$ mmm packages/experimental/CameraPreviewTest/
============================================ PLATFORM_VERSION_CODENAME=AOSP PLATFORM_VERSION=4.2.2.2.2.2.2.2.2.2 TARGET_PRODUCT=full TARGET_BUILD_VARIANT=eng TARGET_BUILD_TYPE=release TARGET_BUILD_APPS= TARGET_ARCH=arm TARGET_ARCH_VARIANT=armv7-a TARGET_CPU_VARIANT=generic HOST_ARCH=x86 HOST_OS=linux HOST_OS_EXTRA=Linux-3.8.9-x86_64-with-Ubuntu-10.04-lucid HOST_BUILD_TYPE=release BUILD_ID=OPENMASTER OUT_DIR=out ============================================ make: Entering directory `/home/fantasy/my_android' target R.java/Manifest.java: VideoChatCameraTestApp (out/target/common/obj/APPS/VideoChatCameraTestApp_intermediates/src/R.stamp) Warning: AndroidManifest.xml already defines minSdkVersion (in http://schemas.android.com/apk/res/android); using existing value in manifest. Warning: AndroidManifest.xml already defines targetSdkVersion (in http://schemas.android.com/apk/res/android); using existing value in manifest. target Java: VideoChatCameraTestApp (out/target/common/obj/APPS/VideoChatCameraTestApp_intermediates/classes) Note: Some input files use or override a deprecated API. Note: Recompile with -Xlint:deprecation for details. Copying: out/target/common/obj/APPS/VideoChatCameraTestApp_intermediates/classes-jarjar.jar Copying: out/target/common/obj/APPS/VideoChatCameraTestApp_intermediates/emma_out b/classes-jarjar.jar Copying: out/target/common/obj/APPS/VideoChatCameraTestApp_intermediates/classes.jar Copying: out/target/common/obj/APPS/VideoChatCameraTestApp_intermediates proguard.classes.jar target Dex: VideoChatCameraTestApp Copying: out/target/common/obj/APPS/VideoChatCameraTestApp_intermediates proguard.classes.dex target Package: VideoChatCameraTestApp (out/target/product/generic/obj/APPS/VideoChatCameraTestApp_intermediates/package.apk) Warning: AndroidManifest.xml already defines minSdkVersion (in http://schemas.android.com/apk/res/android); using existing value in manifest. Warning: AndroidManifest.xml already defines targetSdkVersion (in http://schemas.android.com/apk/res/android); using existing value in manifest. 'out/target/common/obj/APPS/VideoChatCameraTestApp_intermediates/classes.dex' as 'classes.dex'... Processing target/product/generic/obj/APPS/VideoChatCameraTestApp_intermediates/package.apk Done! Install: out/target/product/generic/data/app/VideoChatCameraTestApp.odex Install: out/target/product/generic/data/app/VideoChatCameraTestApp.apk
编译完成之后，就可以在out/target/product/generic/data/app/VideoChatCameraTestApp.apk目录下看到VideoChatCameraTestApp.apk文件了。
注：
Android系统自带的App是放在目录~/my_android/out/target/product/generic/system/app下。
另外，Android系统的一些可执行文件，例如：
C编译的可执行文件，放在out/target/product/generic/system/bin目录下，
动态链接库文件放在out/target/product/generic/system/lib目录下，
硬件抽象层（HAL）接口文件放在out/target/product/generic/system/lib/hw目录下。
三、打包编译后的模块到system.img中
四、运行模拟器查看结果
参考：
1、http://blog.csdn.net/luoshengyang/article/details/6566662
2、http://blog.csdn.net/luoxianxion/article/details/7683581
3、http://blog.csdn.net/yajun0601/article/details/7309010