Build android source code -- 初始化环境

Initializing a Build Environment

The "Getting Started" section describes how to set up your local work environment, how to use Repo to get the Android files, and how to build the files on your machine. To build the Android source files, you will need to use Linux or Mac OS. Building under Windows is not currently supported.

Note: The source download is approximately 6GB in size. You will need 25GB free to complete a single build, and up to 90GB (or more) for a full set of builds.

For an overview of the entire code-review and code-update process, seeLife of a Patch.

Setting up a Linux build environment

The Android build is routinely tested in house on recent versions of Ubuntu LTS (10.04), but most distributions should have the required build tools available. Reports of successes or failures on other distributions are welcome.

Note: It is also possible to build Android in a virtual machine. If you are running Linux in a virtual machine, you will need at least 16GB of RAM/swap and 30GB or more of disk space in order to build the Android tree.

In general you will need:

• Python 2.5 -- 2.7, which you can download frompython.org.

• GNU Make 3.81 -- 3.82, which you can download fromgnu.org,

• JDK 6 if you wish to build Gingerbread or newer; JDK 5 for Froyo or older. You can download both fromjava.sun.com.

• Git 1.7 or newer. You can find it atgit-scm.com.

Detailed instructions for Ubuntu 10.04+ follow.

Installing the JDK

The Sun JDK is no longer in Ubuntu's main package repository. In order to download it, you need to add the appropriate repository and indicate to the system which JDK should be used.

Java 6: for Gingerbread and newer

$ sudo add-apt-repository "deb http://archive.canonical.com/ lucid partner"
$ sudo apt-get update
$ sudo apt-get install sun-java6-jdk

Java 5: for Froyo and older

$ sudo add-apt-repository "deb http://archive.ubuntu.com/ubuntu hardy main multiverse"
$ sudo add-apt-repository "deb http://archive.ubuntu.com/ubuntu hardy-updates main multiverse"
$ sudo apt-get update
$ sudo apt-get install sun-java5-jdk

Installing required packages

64-bit (recommended)

$ sudo apt-get install git-core gnupg flex bison gperf build-essential \
  zip curl zlib1g-dev libc6-dev lib32ncurses5-dev ia32-libs \
  x11proto-core-dev libx11-dev lib32readline5-dev lib32z-dev \
  libgl1-mesa-dev g++-multilib mingw32 tofrodos python-markdown \
  libxml2-utils xsltproc

On Ubuntu 10.10:

$ sudo ln -s /usr/lib32/mesa/libGL.so.1 /usr/lib32/mesa/libGL.so

On Ubuntu 11.10:

$ sudo apt-get install libx11-dev:i386

32-bit (experimental)

$ sudo apt-get install git-core gnupg flex bison gperf build-essential \
  zip curl zlib1g-dev libc6-dev libncurses5-dev x11proto-core-dev \
  libx11-dev libreadline6-dev libgl1-mesa-dev tofrodos python-markdown \
  libxml2-utils xsltproc

Configuring USB Access

Under GNU/linux systems (and specifically under Ubuntu systems), regular users can't directly access USB devices by default. The system needs to be configured to allow such access.

The recommended approach is to create a file/etc/udev/rules.d/51-android.rules(as the root user) and to copy the following lines in it.must be replaced by the actual username of the user who is authorized to access the phones over USB.

# adb protocol on passion (Nexus One)
SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e12", MODE="0600", OWNER="<username>"
# fastboot protocol on passion (Nexus One)
SUBSYSTEM=="usb", ATTR{idVendor}=="0bb4", ATTR{idProduct}=="0fff", MODE="0600", OWNER="<username>"
# adb protocol on crespo/crespo4g (Nexus S)
SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e22", MODE="0600", OWNER="<username>"
# fastboot protocol on crespo/crespo4g (Nexus S)
SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e20", MODE="0600", OWNER="<username>"
# adb protocol on stingray/wingray (Xoom)
SUBSYSTEM=="usb", ATTR{idVendor}=="22b8", ATTR{idProduct}=="70a9", MODE="0600", OWNER="<username>"
# fastboot protocol on stingray/wingray (Xoom)
SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="708c", MODE="0600", OWNER="<username>"
# adb protocol on maguro/toro (Galaxy Nexus)
SUBSYSTEM=="usb", ATTR{idVendor}=="04e8", ATTR{idProduct}=="6860", MODE="0600", OWNER="<username>"
# fastboot protocol on maguro/toro (Galaxy Nexus)
SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e30", MODE="0600", OWNER="<username>"
# adb protocol on panda (PandaBoard)
SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d101", MODE="0600", OWNER="<username>"
# fastboot protocol on panda (PandaBoard)
SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d022", MODE="0600", OWNER="<username>"

Those new rules take effect the next time a device is plugged in. It might therefore be necessary to unplug the device and plug it back into the computer.

This is known to work on both Ubuntu Hardy Heron (8.04.x LTS) and Lucid Lynx (10.04.x LTS). Other versions of Ubuntu or other variants of GNU/linux might require different configurations.

Setting up ccache

You can optionally tell the build to use the ccache compilation tool. Ccache acts as a compiler cache that can be used to speed-up rebuilds. This works very well if you do "make clean" often, or if you frequently switch between different build products.

Put the following in your .bashrc or equivalent.

export USE_CCACHE=1

By default the cache will be stored in ~/.ccache. If your home directory is on NFS or some other non-local filesystem, you will want to specify the directory in your .bashrc as well.

export CCACHE_DIR=<path-to-your-cache-directory>

The suggested cache size is 50-100GB. You will need to run the following command once you have downloaded the source code.

prebuilt/linux-x86/ccache/ccache -M 50G

This setting is stored in the CCACHE_DIR and is persistent.

Setting up a Mac OS X build environment

To build the Android files in a Mac OS environment, you need an Intel/x86 machine running MacOS 10.6 (Snow Leopard).

Android must be built on a case-sensitive file system because the sources contain files that differ only in case. We recommend that you build Android on a partition that has been formatted with the journaled file system HFS+. HFS+ is required to successfully build Mac OS applications such as the Android Emulator for OS X.

Creating a case sensitive disk image

If you want to avoid partitioning/formatting your hard drive, you can use a case-sensitive disk image instead. To create the image, launch Disk Utility and select "New Image". A size of 25GB is the minimum to complete the build, larger numbers are more future-proof. Using sparse images saves space while allowing to grow later as the need arises. Be sure to select "case sensitive, journaled" as the volume format.

You can also create it from a shell with the following command:

# hdiutil create -type SPARSE -fs 'Case-sensitive Journaled HFS+' -size 40g ~/android.dmg

This will create a .dmg (or possibly a .dmg.sparsefile) file which, once mounted, acts as a drive with the required formatting for Android development. For a disk image named "android.dmg" stored in your home directory, you can add the following to your~/.bash_profileto mount the image when you execute "mountAndroid":

# mount the android file image
function mountAndroid { hdiutil attach ~/android.dmg -mountpoint /Volumes/android; }

Once mounted, you'll do all your work in the "android" volume. You can eject it (unmount it) just like you would with an external drive.

Installing required packages

• Install XCode fromthe Apple developer site. We recommend version 3.1.4 or newer, i.e. gcc 4.2. Version 4.x could cause difficulties. If you are not already registered as an Apple developer, you will have to create an Apple ID in order to download.

• Install MacPorts frommacports.org.

  Note: Make sure that/opt/local/binappears in your path BEFORE/usr/bin. If not, add

  export PATH=/opt/local/bin:$PATH
  

  to your~/.bash_profile.

• Get make, git, and GPG packages from MacPorts:

  $ POSIXLY_CORRECT=1 sudo port install gmake libsdl git-core gnupg
  

  If using Mac OS 10.4, also install bison:

  $ POSIXLY_CORRECT=1 sudo port install bison
  

Reverting from make 3.82

There is a bug in gmake 3.82 that prevents android from building. You can install version 3.81 using MacPorts by taking the following steps:

• Edit/opt/local/etc/macports/sources.confand add a line that says

  file:///Users/Shared/dports
  

  above the rsync line. Then create this directory:

  $ mkdir /Users/Shared/dports
  

• In the newdportsdirectory, run

  $ svn co --revision 50980 http://svn.macports.org/repository/macports/trunk/dports/devel/gmake/ devel/gmake/
  

• Create a port index for your new local repository:

  $ portindex /Users/Shared/dports
  

• Finally, install the old version of gmake with

  $ sudo port install gmake @3.81
  

Setting a file descriptor limit

On MacOS the default limit on the number of simultaneous file descriptors open is too low and a highly parallel build process may exceed this limit.

To increase the cap, add the following lines to your~/.bash_profile:

# set the number of open files to be 1024
ulimit -S -n 1024

Next: Download the source

Your build environment is good to go! Proceed todownloading the source....