Developer Guide

These are guidelines that should be followed when doing Replicant development.


Developing on Replicant isn't much harder than developing on any other free software project as it doesn't require specific knowledge. In fact, you'll probably learn a lot along the way regarding how hardware works, how the Android system is composed, how the kernel works, etc, but you don't need to know all of this to start. However a basic set of skills is required, among which:

If you think you can cope with the requirements, then developing on Replicant should cause you no particular issue.

Writing free software replacements

Writing free software replacements for non-free components may require more skills depending on what you're trying to achieve, though there may be people with the adequate knowledge to help you and from whom you will likely learn a lot.


When working with Replicant repos, make sure to avoid breaking things. For instance, if you push a commit introducing a compilation error, it will break the whole build process.
It is better to create separate branches (that are not used by the official manifest branches) when your work is still in progress.
Creating branches that add debug infos on a particular topic is usually a good idea since it will save you time next time you want to debug the same component.

When creating a repository

In order to keep repo naming consistent, please name repositories by their name on the tree, replacing the / by _.
For instance, when forking the CyanogenMod repo: android_device_samsung_crespo, rename it to device_samsung_crespo on the Replicant repos.
This creates a more consistent way of naming repositories and makes it easier when pushing: just look at the location in the source tree and replace / by _.

When creating a branch

Official replicant branches are named the following way:

Such as: replicant-2.3 This should be used on the projects repositories as well as the manifest repository.
Any other branch should be considered as Work In Progress (WIP) and thus not be part of any official branch of the manifest.

There is although one exception, with the master branch, that can be used by any project and be in any manifest given that the code held in the master branch will work on any Replicant version.

Upstreaming work

It is generally a good idea to send some changes back to upstream, assuming that they will benefit from it as well.

When it is about the replacement of a non-free component present in the upstream systems, make sure that your replacement is reliable and complete.
Contact the interested developers on the upstream projects before attempting to send your replacement.


The CyanogenMod team uses Gerrit to manage patch submissions. The process to get your patch included in CyanogenMod repos is explained on their wiki: Gerrit

You can push directly using git using the following scheme:

git push ssh://<sshusername> HEAD:refs/for/<branchname>

Writing free software replacements

Here are some tips that may help you achieving a free software replacement for a specific component (some may be more or less relevant regarding the nature of what the component does):

Wiki guidelines

In order the keep the wiki simple and consistent, a few guidelines must be followed when editing:

Commonly-used terminology

In order to keep everything clear and consistent, we use the following terms with a precise meaning in mind:

New images release guide

1. Modify vendor/replicant/CHANGELOG.mkdn, commit and push
2. Update prebuilts (FDroid, Terminal Emulator, etc)
3. Start the build
4. Run the release script and ensure everything is OK
5. Compress the release files

tar -cjf 0005.tar.bz2 0005

6. Upload the release to
scp -v 0005.tar.bz2

7. Unpack the release, fix permissions
8. Modify ReplicantImages, last image on every devices page
9. Update ReplicantStatus with the latest status
10. Announce the release on the blog, mailing list
11. Update the IRC topic

New device documentation guide

1. Create the device main page, following the naming guidelines applied to other devices (e.g. the Samsung Galaxy S II GT-I9100 is called Galaxy S 2 (I9100) and its page is GalaxyS2I9100)
2. Create all the related sub-pages (build guide, install guide and firmwares list at least), following the naming guidelines applied to other devices (e.g. GalaxyS2I9100Build, GalaxyS2I9100Installation and GalaxyS2I9100Firmwares)
3. Link the sub-pages to the main page in the index
4. Update the ReplicantStatus page of the wiki with the current status of the device
5. Modify the WikiStart page of the wiki and add the new device in the following sections:

6. Add new issues categories to the Replicant project redmine