Android系统源代码下载

Downloading the Source Tree Installing Repo Repo is a tool that makes it easier to work with Git in the context of Android. For more information about Repo, see Version Control. To install, initialize, and configure Repo, follow these steps: • Make sure you have a bin/ directory in your home directory, and that it is included in your path: • $ mkdir ~/bin • $ PATH=~/bin:$PATH • Download the Repo script and ensure it is executable: • $ curl https://dl-ssl.google.com/dl/googlesource/git-repo /repo > ~/bin/repo • $ chmod a+x ~/bin/repo • The SHA-1 checksum for repo is 29ba4221d4fccdfa8d87931cd73466fdc24040b5 Initializing a Repo client After installing Repo, set up your client to access the android source repository: • Create an empty directory to hold your working files. If you're using MacOS, this has to be on a case-sensitive filesystem. Give it any name you like: • $ mkdir WORKING_DIRECTORY • $ cd WORKING_DIRECTORY • Run repo init to bring down the latest version of Repo with all its most recent bug fixes. You must specify a URL for the manifest, which specifies where the various repositories included in the Android source will be placed within your working directory. • $ repo init -u https://android.googlesource.com/platform/manifest To check out a branch other than "master", specify it with -b: $ repo init -u https://android.googlesource.com/platform/manifest -b android-4.0.1_r1 • When prompted, please configure Repo with your real name and email address. To use the Gerrit code-review tool, you will need an email address that is connected with a registered Google account. Make sure this is a live address at which you can receive messages. The name that you provide here will show up in attributions for your code submissions. A successful initialization will end with a message stating that Repo is initialized in your working directory. Your client directory should now contain a .repo directory where files such as the manifest will be kept. Getting the files To pull down files to your working directory from the repositories as specified in the default manifest, run $ repo sync The Android source files will be located in your working directory under their project names. The initial sync operation will take an hour or more to complete. For more about repo sync and other Repo commands, see Version Control. Using authentication By default, access to the Android source code is anonymous. To protect the servers against excessive usage, each IP address is associated with a quota. When sharing an IP address with other users (e.g. when accessing the source repositories from beyond a NAT firewall), the quotas can trigger even for regular usage patterns (e.g. if many users sync new clients from the same IP address within a short period). In that case, it is possible to use authenticated access, which then uses a separate quota for each user, regardless of the IP address. The first step is to create a password from the password generator and to save it in ~/.netrc according to the instructions on that page. The second step is to force authenticated access, by using the following manifest URI: https://android.googlesource.com/a/platform/manifest. Notice how the /a/ directory prefix triggers mandatory authentication. You can convert an existing client to use mandatory authentication with the following command: $ repo init -u https://android.googlesource.com/a/platform/manifest Troubleshooting network issues When downloading from behind a proxy (which is common in some corporate environments), it might be necessary to explicitly specify the proxy that is then used by repo: $ export HTTP_PROXY=http://:@: $ export HTTPS_PROXY=http://:@: More rarely, Linux clients experience connectivity issues, getting stuck in the middle of downloads (typically during "Receiving objects"). It has been reported that tweaking the settings of the TCP/IP stack and using non-parallel commands can improve the situation. You need root access to modify the TCP setting: $ sudo sysctl -w net.ipv4.tcp_window_scaling=0 $ repo sync -j1 Using a local mirror When using many clients, especially in situations where bandwidth is scarce, it is better to create a local mirror of the entire server content, and to sync clients from that mirror (which requires no network access). These instructions assume that the mirror is created in /usr/local/aosp/mirror. The first step is to create and sync the mirror itself, which uses close to 10GB of network bandwidth and a similar amount of disk space. Notice the --mirror flag, which can only be specified when creating a new client: $ mkdir -p /usr/local/aosp/mirror $ cd /usr/local/aosp/mirror $ repo init -u https://android.googlesource.com/mirror/manifest --mirror $ repo sync Once the mirror is synced, new clients can be created from it. Note that it's important to specify an absolute path: $ mkdir -p /usr/local/aosp/master $ cd /usr/local/aosp/master $ repo init -u /usr/local/aosp/mirror/platform/manifest.git $ repo sync Finally, to sync a client against the server, the mirror needs to be synced against the server, then the client against the mirror: $ cd /usr/local/aosp/mirror $ repo sync $ cd /usr/local/aosp/master $ repo sync It's possible to store the mirror on a LAN server and to access it over NFS, SSH or Git. It's also possible to store it on a removable drive and to pass that drive around between users or between machines. Verifying Git Tags Load the following public key into your GnuPG key database. The key is used to sign annotated tags that represent releases. $ gpg --import Copy and paste the key(s) below, then enter EOF (Ctrl-D) to end the input and process the keys. -----BEGIN PGP PUBLIC KEY BLOCK----- Version: GnuPG v1.4.2.2 (GNU/Linux) mQGiBEnnWD4RBACt9/h4v9xnnGDou13y3dvOx6/t43LPPIxeJ8eX9WB+8 LLuROSV lFhpHawsVAcFlmi7f7jdSRF+OvtZL9ShPKdLfwBJMNkU66/TZmPewS4m7 82ndtw7 8tR1cXb197Ob8kOfQB3A9yk2XZ4ei4ZC3i6wVdqHLRxABdncwu5hOF9KX wCgkxMD u4PVgChaAJzTYJ1EG+UYBIUEAJmfearb0qRAN7dEoff0FeXsEaUA6U90s EoVks0Z wNj96SA8BL+a1OoEUUfpMhiHyLuQSftxisJxTh+2QclzDviDyaTrkANjd YY7p2cq /HMdOY7LJlHaqtXmZxXjjtw5Uc2QG8UY8aziU3IE9nTjSwCXeJnuyvoiz l9/I1S5 jU5SA/9WwIps4SC84ielIXiGWEqq6i6/sk4I9q1YemZF2XVVKnmI1F4iC MtNKsR4 MGSa1gA8s4iQbsKNWPgp7M3a51JCVCu6l/8zTpA+uUGapw4tWCp4o0dpI vDPBEa9 b/aF/ygcR8mh5hgUfpF9IpXdknOsbKCvM9lSSfRciETykZc4wrRCVGhlI EFuZHJv aWQgT3BlbiBTb3VyY2UgUHJvamVjdCA8aW5pdGlhbC1jb250cmlidXRpb 25AYW5k cm9pZC5jb20+iGAEExECACAFAknnWD4CGwMGCwkIBwMCBBUCCAMEFgIDA QIeAQIX gAAKCRDorT+BmrEOeNr+AJ42Xy6tEW7r3KzrJxnRX8mij9z8tgCdFfQYi HpYngkI 2t09Ed+9Bm4gmEO5Ag0ESedYRBAIAKVW1JcMBWvV/0Bo9WiByJ9WJ5swM N36/vAl QN4mWRhfzDOk/Rosdb0csAO/l8Kz0gKQPOfObtyYjvI8JMC3rmi+LIvSU T9806Up hisyEmmHv6U8gUb/xHLIanXGxwhYzjgeuAXVCsv+EvoPIHbY4L/KvP5x+ oCJIDbk C2b1TvVk9PryzmE4BPIQL/NtgR1oLWm/uWR9zRUFtBnE411aMAN3qnAHB BMZzKMX LWBGWE0znfRrnczI5p49i2YZJAjyX1P2WzmScK49CV82dzLo71MnrF6fj +Udtb5+ OgTg7Cow+8PRaTkJEW5Y2JIZpnRUq0CYxAmHYX79EMKHDSThf/8AAwUIA JPWsB/M pK+KMs/s3r6nJrnYLTfdZhtmQXimpoDMJg1zxmL8UfNUKiQZ6esoAWtDg pqt7Y7s KZ8laHRARonte394hidZzM5nb6hQvpPjt2OlPRsyqVxw4c/KsjADtAuKW 9/d8phb N8bTyOJo856qg4oOEzKG9eeF7oaZTYBy33BTL0408sEBxiMior6b8LrZr AhkqDjA vUXRwm/fFKgpsOysxC6xi553CxBUCH2omNV6Ka1LNMwzSp9ILz8jEGqmU tkBszwo G1S8fXgE0Lq3cdDM/GJ4QXP/p6LiwNF99faDMTV3+2SAOGvytOX6KjKVz KOSsfJQ hN0DlsIw8hqJc0WISQQYEQIACQUCSedYRAIbDAAKCRDorT+BmrEOeCUOA J9qmR0l EXzeoxcdoafxqf6gZlJZlACgkWF7wi2YLW3Oa+jv2QSTlrx4KLM= =Wi5D -----END PGP PUBLIC KEY BLOCK----- After importing the keys, you can verify any tag with $ git tag -v TAG_NAME If you haven't set up ccache yet, now would be a good time to do it.     Building the System The basic sequence of build commands is as follows: Initialize Initialize the environment with the envsetup.sh script. Note that replacing "source" with a single dot saves a few characters, and the short form is more commonly used in documentation. $ source build/envsetup.sh or $ . build/envsetup.sh Choose a Target Choose which target to build with lunch. The exact configuration can be passed as an argument, e.g. $ lunch full-eng The example above refers to a complete build for the emulator, with all debugging enabled. If run with no arguments lunch will prompt you to choose a target from the menu. All build targets take the form BUILD-BUILDTYPE, where the BUILD is a codename referring to the particular feature combination: Build name Device Notes full emulator fully configured with all languages, apps, input methods full_maguro maguro full build running on Galaxy Nexus GSM/HSPA+ ("maguro") full_panda panda full build running on PandaBoard ("panda") and the BUILDTYPE is one of the following: Buildtype Use user limited access; suited for production userdebug like "user" but with root access and debuggability; preferred for debugging eng development configuration with additional debugging tools For more information about building for and running on actual hardware, see Building for devices Build the Code Build everything with make. GNU make can handle parallel tasks with a -jN argument, and it's common to use a number of tasks N that's between 1 and 2 times the number of hardware threads on the computer being used for the build. E.g. on a dual-E5520 machine (2 CPUs, 4 cores per CPU, 2 threads per core), the fastest builds are made with commands between make -j16 and make -j32. $ make -j4 Run It! You can either run your build on an emulator or flash it on a device. Please note that you have already selected your build target with lunch, and it is unlikely at best to run on a different target than it was built for. Flash a Device To flash a device, you will need to use fastboot, which should be included in your path after a successful build. Place the device in fastboot mode either manually by holding the appropriate key combination at boot, or from the shell with $ adb reboot bootloader Once the device is in fastboot mode, run $ fastboot flashall -w The -w option wipes the /data partition on the device; this is useful for your first time flashing a particular device, but is otherwise unnecessary. For more information about building for and running on actual hardware, see Building for devices Emulate an Android Device The emulator is added to your path automatically by the build process. To run the emulator, type $ emulator Using ccache ccache is a compiler cache for C and C++ that can help make builds faster. In the root of the source tree, do the following: $ export USE_CCACHE=1 $ export CCACHE_DIR=//.ccache $ prebuilt/linux-x86/ccache/ccache -M 20G You can watch ccache being used by doing the following: $ watch -n1 -d prebuilt/linux-x86/ccache/ccache -s On OSX, you should replace linux-x86 with darwin-x86. Troubleshooting Common Build Errors Wrong Java Version If you are attempting to build froyo or earlier with Java 1.6, or gingerbread or later with Java 1.5, make will abort with a message such as ********************************************************* *** You are attempting to build with the incorrect version of java. Your version is: WRONG_VERSION. The correct version is: RIGHT_VERSION. Please follow the machine setup instructions at http://source.android.com/download ********************************************************* *** This may be caused by • failing to install the correct JDK as specified on the Initializing page. Building Android requires Sun JDK 5 or 6 depending on which release you are building. • another JDK that you previously installed appearing in your path. You can remove the offending JDK from your path with: • $ export PATH=${PATH/\/path\/to\/jdk\/dir:/} Python Version 3 Repo is built on particular functionality from Python 2.x and is unfortunately incompatible with Python 3. In order to use repo, please install Python 2.x: $ apt-get install python Gmake Version 3.82 There is a bug in make version 3.82 on Mac OS that prevents building Android. TODO: what the error looks like with GNU make 3.82 on older builds that don't explicitly detect it. Follow the instructions on the Initializing page for reverting GNU make from 3.82 to 3.81. Case Insensitive Filesystem If you are building on an HFS filesystem on Mac OS X, you may encounter an error such as ********************************************************* *** You are building on a case-insensitive filesystem. Please move your source tree to a case-sensitive filesystem. ********************************************************* *** Please follow the instructions on the Initializing page for creating a case-sensitive disk image. No USB Permission On most Linux systems, unprivileged users cannot access USB ports by default. If you see a permission denied error, follow the instructions on the Initializing page for configuring USB access. If adb was already running and cannot connect to the device after getting those rules set up, it can be killed with adb kill-server. That will cause adb to restart with the new configuration.