GIT Examples
Contributing Code to PX4
Adding a feature to PX4 follows a defined workflow. In order to share your contributions on PX4, you can follow this example.
Sign up for github if you haven't already
Fork the PX4-Autopilot re[p (see here)
Clone your forked repository to your local computer
Go into the new directory, initialize and update the submodules, and add the original upstream PX4-Autopilot
You should have now two remote repositories: One repository is called upstream that points to PX4/PX4-Autopilot, and one repository that points to your forked repository of the PX4 repository.
This can be checked with the following command:
Make the changes that you want to add to the current master.
Create a new branch with a meaningful name that represents your feature
you can use the command
git branch
to make sure you're on the right branch.Add your changes that you want to be part of the commit by adding the respective files
If you prefer having a GUI to add your files see Gitk or
git add -p
.Commit the added files with a meaningful message explaining your changes
For a good commit message, please refer to Contributing section.
Some time might have passed and the upstream master has changed. PX4 prefers a linear commit history and uses git rebase. To include the newest changes from upstream in your local branch, switch to your master branch
Then pull the newest commits from upstream master
Now your local master is up to date. Switch back to your feature branch
and rebase on your updated master
Now you can push your local commits to your forked repository
You can verify that the push was successful by going to your forked repository in your browser:
https://github.com/<your git name>/PX4-Autopilot.git
There you should see the message that a new branch has been pushed to your forked repository.Now it's time to create a pull request (PR). On the right hand side of the "new branch message" (see one step before), you should see a green button saying "Compare & Create Pull Request". Then it should list your changes and you can (must) add a meaningful title (in case of a one commit PR, it's usually the commit message) and message (explain what you did for what reason. Check other pull requests for comparison)
You're done! Responsible members of PX4 will now have a look at your contribution and decide if they want to integrate it. Check if they have questions on your changes every once in a while.
Get a Specific Release
To get the source code for a specific older release:
Clone the PX4-Autopilot repo and navigate into PX4-Autopilot directory:
List all releases (tags)
Checkout code for particular tag (e.g. for tag 1.7.4beta)
Update Submodule
There are several ways to update a submodule. Either you clone the repository or you go in the submodule directory and follow the same procedure as in Contributing code to PX4.
Do a PR for a submodule update
This is required after you have done a PR for a submodule X repository and the bug-fix / feature-add is in the current master of submodule X. Since the Firmware still points to a commit before your update, a submodule pull request is required such that the submodule used by the Firmware points to the newest commit.
Make a new branch that describes the fix / feature for the submodule update:
Go to submodule subdirectory
PX4 submodule might not necessarily point to the newest commit. Therefore, first checkout master and pull the newest upstream code.
Go back to Firmware directory, and as usual add, commit and push the changes.
Checkout pull requests
You can test someone's pull request (changes are not yet merged) even if the branch to merge only exists on the fork from that person. Do the following:
PR ID
is the number right next to the PR's title (without the #) and the <branch name>
can also be found right below the PR ID
, e.g. <the other persons git name>:<branch name>
. After that you can see the newly created branch locally with
Then switch to that branch
Common pitfalls
Force push to forked repository
After having done the first PR, people from the PX4 community will review your changes. In most cases this means that you have to fix your local branch according to the review. After changing the files locally, the feature branch needs to be rebased again with the most recent upstream/master. However, after the rebase, it is no longer possible to push the feature branch to your forked repository directly, but instead you need to use a force push:
Rebase merge conflicts
If a conflict occurs during a git rebase
, please refer to this guide.
Pull merge conflicts
If a conflict occurs during a git pull
, please refer to this guide.
Build error due to git tags out of date
The build error Error: PX4 version too low, expected at least vx.x.x
occurs if git tags are out of date.
This can be solved by fetching the upstream repository tags:
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