Downloading the Source
The Android source tree is located in a Git repository hosted by Google. The Git repository includes metadata for the Android source, including those related to changes to the source and the date they were made. This document describes how to download the source tree for a specific Android code-line.
To instead start with a factory image for a specific device, see Selecting a device build.
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 the Developing section.
To install Repo:
-
Make sure you have a bin/ directory in your home directory and that it is included in your path:
mkdir ~/binPATH=~/bin:$PATH -
Download the Repo tool and ensure that it is executable:
curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repochmod a+x ~/bin/repo
For version 1.21, the SHA-1 checksum for repo is b8bd1804f432ecf1bab730949c82b93b0fc5fede
For version 1.22, the SHA-1 checksum for repo is da0514e484f74648a890c0467d61ca415379f791
For version 1.23, the SHA-256 checksum for repo is e147f0392686c40cfd7d5e6f332c6ee74c4eab4d24e2694b3b0a0c037bf51dc5
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_DIRECTORYcd WORKING_DIRECTORY -
Configure git 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.
git config --global user.name "Your Name"git config --global user.email "[email protected]" -
Run
repo init -u https://android.googlesource.com/platform/manifestrepo initto 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.To check out a branch other than "master", specify it with
repo init -u https://android.googlesource.com/platform/manifest -b android-4.0.1_r1-b. For a list of branches, see Source Code Tags and Builds.
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.
Downloading the Android Source Tree
To pull down the Android source tree 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 the Developing section.
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 with the password generator and follow the instructions on the password generator 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:
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://<proxy_user_id>:<proxy_password>@<proxy_server>:<proxy_port>
export HTTPS_PROXY=http://<proxy_user_id>:<proxy_password>@<proxy_server>:<proxy_port>
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 several 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). The download for a full mirror is smaller than the download of two clients, while containing more information.
These instructions assume that the mirror is created in /usr/local/aosp/mirror.
The first step is to create and sync the mirror itself. Notice the --mirror flag,
which can be specified only 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 --importCopy and paste the key 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+8LLuROSV lFhpHawsVAcFlmi7f7jdSRF+OvtZL9ShPKdLfwBJMNkU66/TZmPewS4m782ndtw7 8tR1cXb197Ob8kOfQB3A9yk2XZ4ei4ZC3i6wVdqHLRxABdncwu5hOF9KXwCgkxMD u4PVgChaAJzTYJ1EG+UYBIUEAJmfearb0qRAN7dEoff0FeXsEaUA6U90sEoVks0Z wNj96SA8BL+a1OoEUUfpMhiHyLuQSftxisJxTh+2QclzDviDyaTrkANjdYY7p2cq /HMdOY7LJlHaqtXmZxXjjtw5Uc2QG8UY8aziU3IE9nTjSwCXeJnuyvoizl9/I1S5 jU5SA/9WwIps4SC84ielIXiGWEqq6i6/sk4I9q1YemZF2XVVKnmI1F4iCMtNKsR4 MGSa1gA8s4iQbsKNWPgp7M3a51JCVCu6l/8zTpA+uUGapw4tWCp4o0dpIvDPBEa9 b/aF/ygcR8mh5hgUfpF9IpXdknOsbKCvM9lSSfRciETykZc4wrRCVGhlIEFuZHJv aWQgT3BlbiBTb3VyY2UgUHJvamVjdCA8aW5pdGlhbC1jb250cmlidXRpb25AYW5k cm9pZC5jb20+iGAEExECACAFAknnWD4CGwMGCwkIBwMCBBUCCAMEFgIDAQIeAQIX gAAKCRDorT+BmrEOeNr+AJ42Xy6tEW7r3KzrJxnRX8mij9z8tgCdFfQYiHpYngkI 2t09Ed+9Bm4gmEO5Ag0ESedYRBAIAKVW1JcMBWvV/0Bo9WiByJ9WJ5swMN36/vAl QN4mWRhfzDOk/Rosdb0csAO/l8Kz0gKQPOfObtyYjvI8JMC3rmi+LIvSUT9806Up hisyEmmHv6U8gUb/xHLIanXGxwhYzjgeuAXVCsv+EvoPIHbY4L/KvP5x+oCJIDbk C2b1TvVk9PryzmE4BPIQL/NtgR1oLWm/uWR9zRUFtBnE411aMAN3qnAHBBMZzKMX LWBGWE0znfRrnczI5p49i2YZJAjyX1P2WzmScK49CV82dzLo71MnrF6fj+Udtb5+ OgTg7Cow+8PRaTkJEW5Y2JIZpnRUq0CYxAmHYX79EMKHDSThf/8AAwUIAJPWsB/M pK+KMs/s3r6nJrnYLTfdZhtmQXimpoDMJg1zxmL8UfNUKiQZ6esoAWtDgpqt7Y7s KZ8laHRARonte394hidZzM5nb6hQvpPjt2OlPRsyqVxw4c/KsjADtAuKW9/d8phb N8bTyOJo856qg4oOEzKG9eeF7oaZTYBy33BTL0408sEBxiMior6b8LrZrAhkqDjA vUXRwm/fFKgpsOysxC6xi553CxBUCH2omNV6Ka1LNMwzSp9ILz8jEGqmUtkBszwo G1S8fXgE0Lq3cdDM/GJ4QXP/p6LiwNF99faDMTV3+2SAOGvytOX6KjKVzKOSsfJQ hN0DlsIw8hqJc0WISQQYEQIACQUCSedYRAIbDAAKCRDorT+BmrEOeCUOAJ9qmR0l EXzeoxcdoafxqf6gZlJZlACgkWF7wi2YLW3Oa+jv2QSTlrx4KLM= =Wi5D -----END PGP PUBLIC KEY BLOCK-----After importing the keys, you can verify any tag with
git tag -v TAG_NAMEIf you haven't set up ccache yet, now would be a good time to do it.