Repo is a tool provided by Google that simplifies using Git in the context of the Android source.

Many different Linux distributions exist, and here we will outline a few of the popular ones The suggested [guide] (http://forum.xda-developers.com/showthread.php?t=2464683) for [Ubuntu] (http://www.ubuntu.com/) works on versions 13.10 and above.

Our guide for [Arch] (https://www.archlinux.org/) is in development.

# Make a directory where Repo will be stored and add it to the path
$ mkdir ~/bin
$ PATH=~/bin:$PATH

# Download Repo itself
$ curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo

# Make Repo executable
$ chmod a+x ~/bin/repo

# Create a directory for the source files
# This can be located anywhere (as long as the fs is case-sensitive)
$ mkdir android
$ cd android

# Install Repo in the created directory
# Use a real name/email combination, if you intend to submit patches
$ repo init -u https://github.com/VentureROM/manifest -b kitkat

You may be prompted to enter some ID if youa re running this for the first time.

# Give your ID so we can identify if you try to help us with code
$ git config --global user.email "<enter email>"
$ git config --global user.name "<enter your name>"

Then re-run the repo initialization.

This is what you will run each time you want to pull in upstream changes. Keep in mind that on your first run, it is expected to take a while as it will download all the required Android source files and their change histories. Afterwatrds, only changed files.

# Let Repo take care of all the hard work
$ repo sync

In case you are not interested in syncing all the projects, you can specify what projects you do want to sync. This can help if, for example, you want to make a quick change and quickly push it back for review. You should note that this can sometimes cause issues when building if there is a large change that spans across multiple projects.

# Specify one or more projects by either name or path

# For example, enter VentureROM/android_frameworks_base or
# frameworks/base to sync the frameworks/base repository

$ repo sync PROJECT

The bundled builder tool ./rom-build.sh handles all the building steps for the specified device automatically. As the device value, you just feed it with the device codename (for example, 'hammerhead' for the Nexus 5).

# Go to the root of the source tree, in our case "android"...
$ cd android
# ...and run the builder tool.
$ ./rom-build.sh <device>

# Start by going to the repo on Github and forking it to your own profile

# Clone that project to your machine
$ git clone git://www.github.com/<URL of the forked project>.git

# Make your changes
...

# Commit all your changes
$ git add -A
$ git commit -a

# Push your changes to your Github account
$ git push

# Send it to us for review
# Go to the Pull Requests tab on your forked repo and create a new pull request
# Give us a description of it, leave a comment or two perhaps.

If your code is good and benefitial, we can gladly consider including it!

You will be asked a commit message when you run git commit. Writing a good commit message is often hard, but it is also essential as these messages will stay around with your changes and will be seen by others when looking back at the project history.

A few general pointers to keep in mind when writing the commit message are that you should use imperative as it matches the style used by the git merge and git revert commands (that means "Fix bug" is preferred over "Fixes bug", "Fixed bug" and others) and that you should write the first line of the commit message as a summary of the commit. It should always be capitalized and followed by an empty line. You might optionally include the project name at the start and try to keep it to 50 characters when possible as it is used in various logs, including "one line" logs.