The Android Root source code is the code that developers use to create custom ROMs and kernels for Android devices. If you’re a developer, then you probably already know what this is and how to use it. But if you’re new to the world of Android development, then you might be wondering what all the fuss is about.
In this blog post, we’ll take a look at what the Android Root source code is and why it’s so important.
Table of Content
Things You Should Know To Download Android Root Source Code
- You have Git or Git Bash installed on your computer.
- You can clone your existing repository or clone another person’s existing repository to collaborate on a project.
- You need to follow the steps carefully to be able to download the Android root source code.
What is the Android Root Source Code?
The Android Root source code is the code that developers use to create custom ROMs (Read Only Memory) and kernels for Android devices. A ROM is a custom version of the Android operating system that can be installed on an Android device. A kernel is the core of an operating system that controls how the hardware and software of a device interact.
Why is the Android Root Source Code Important?
The Android Root source code is important because it allows developers to create custom ROMs and kernels for Android devices. By doing this, developers can add new features and functionality to their devices that would not be possible with stock firmware. Custom ROMs and kernels can also improve the performance of a device by optimizing how the hardware and software interact.
Method 1: Initializing a Repo client
Set up your client to access the Android source repository after installing the Repo Launcher:
- Make an empty directory to store your work files. Give it whatever name you want:
mkdir WORKING_DIRECTORY
cd WORKING_DIRECTORY |
- Set up Git using your real name and email address. To use the Gerrit code-review tool, you must have an email address associated with a Google account. Make sure this is a working address where you can receive messages. The name you enter here appears in the attributions for your code submissions.
git config –global user.name Your Name
git config –global user.email you@example.com |
- Run repo init to get the most recent version of Repo with bug fixes. The manifest must have a URL that specifies where the various repositories included in the Android source are located within your working directory.
repo init -u https://android.googlesource.com/platform/manifest |
To check out the master branch:
repo init -u https://android.googlesource.com/platform/manifest -b master |
Specify -b to check out a branch other than master. See Source code tags and builds for a list of branches.
For Python 2
Warning: Python 2 support was sunset on Jan 1, 2020, as detailed in Sunsetting Python 2. All major Linux distributions are deprecating support for the Python 2 package. Google strongly recommends that you migrate all your scripts over to Python 3.
Note: AOSP ships with its own copies of the Python 2 and Python 3 packages, and you can use the version (such as SEPolicy) that’s included in the source tree. Google is migrating all scripts in the Android source tree to Python 3, and the embedded copy of Python 2 might be deprecated.
For additional details, see Porting Python 2 Code to Python 3, and advice on sunsetting your Python 2 code.
For Python 3
If you receive the error message “/usr/bin/env ‘python‘ no such file or directory,” try one of the following solutions:
If you’ve just installed (rather than upgraded) Ubuntu 20.04.2 LTS:
sudo ln -s /usr/bin/python3 /usr/bin/python |
When performing repo init with Git version 2.19 or higher, you can specify —partial-clone. This uses Git’s partial clone capability to download Git objects only when needed, rather than downloading everything. Because using partial clones requires many operations to communicate with the server, if you’re a developer and you’re using a low-latency network, use the following:
repo init -u https://android.googlesource.com/platform/manifest -b master –partial-clone –clone-filter=blob:limit=10M |
If you receive an error message indicating that symbolic links could not be created, causing repo init to fail, refer to the GitHub Symbolic Links documentation to create these or enable their support. See the section Allowing non-administrators to create symbolic links for more information.
A successful initialization results in a message stating that Repo has been successfully initialized in your working directory. Your client directory now includes a.repo directory that stores files like the manifest.
Method 2: Downloading the Android source tree
- Run the following command to download the Android source tree to your working directory from the repositories specified in the default manifest:
repo sync |
- To speed syncs, pass the -c (current branch) and -jthreadcount flags:
repo sync -c -j8 |
- The Android source files are downloaded to your working directory and named after the project.
- Pass the -q (quiet) flag to suppress output. All options are listed in the Repo Command Reference.
Method 3: Using authentication
Access to the Android source code is anonymous by default. Each IP address is assigned a quota to protect the servers from overuse.
Quotas can be triggered even for regular use patterns when an IP address is shared with other users (for example, when accessing the source repositories from outside a NAT firewall) (for example, if many users sync new clients from the same IP address within a short period).
In that case, authenticated access can be used, which uses a separate quota for each user regardless of IP address.
First, use the password generator to generate a password, and then follow the instructions on the password generator page.
Next, use the manifest URI https://android.googlesource.com/a/platform/manifest to force authenticated access. Take note of how the /a/ directory prefix forces mandatory authentication. With the following command, you can convert an existing client to use mandatory authentication:
repo init -u https://android.googlesource.com/a/platform/manifest |
Method 4: Using authentication
When downloading from behind a proxy (as is common in some corporate environments), you may need to specify the proxy explicitly for Repo to use:
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, causing downloads to stall. Adjusting the TCP/IP stack settings and using non-parallel commands can help improve the situation. To change the TCP setting, you must have root privileges:
sudo sysctl -w net.ipv4.tcp_window_scaling=0
repo sync -j1 |
Method 5: Using a local mirror
When using multiple clients, especially when bandwidth is limited, it is preferable to create a local mirror of the entire server content and sync clients from that mirror (which requires no network access). The download for a full mirror is smaller and contains more information than the download for two clients.
These instructions are based on the mirror being created in /usr/local/aosp/mirror. Create and sync the mirror first. Take note of the —mirror flag, which is only available 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 |
When the mirror is synced, you can use it to create new clients. It is important to note that you must 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 with the server, first sync the mirror with the server, then the client with the mirror:
cd /usr/local/aosp/mirror
repo sync cd /usr/local/aosp/master repo sync |
The mirror can be stored on a LAN server and accessed via NFS, SSH, or Git. It is also possible to store it on a removable drive and transfer it between users or machines.
Load the public key listed below into your GnuPG key database. The key is used to sign release-related annotated tags.
gpg –import |
Copy and paste the key below, then press the EOF (Ctrl-D) keyboard shortcut 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—– |
You can verify any tag after importing the keys with:
git tag -v TAG_NAME |
Tips
The Android Root source code is an important tool for developers who want to create custom ROMs and kernels for their devices. By allowing developers to add new features and optimize how the hardware and software interact, the Android Root source code makes it possible for users to get more out of their devices.