For some of our projects, FreeRTOS specifically, we need to track a SVN upstream repository that is hosted on Source Forge. As we’re only interested in pulling upstream changes and not pushing anything upstream, this simplifies our workflow a bit.

The first thing that is needed is to configure the upstream SVN repository. In our case, we already have an existing git repository. Therefore, instead of cloning the actual SVN tree, we’ll only pull in the necessary changes.

$ cd freertos-port.git
$ git svn init -s https://freertos.svn.sourceforge.net/svnroot/freertos


Fetching the entire SVN history would take ages. Therefore, we’re limiting the fetch to only the more recent releases (r1611 onwards). This operation will take a little time. Time to grab a coffee break.

$ git svn fetch -r 1611:HEAD


Next, we need to merge in the upstream code. We only work of stable upstream releases, which are tracked as specific SVN branches. This can be done by merging the remote branches directly.

$ git branch -a
$ git checkout develop
$ git merge remotes/tags/V7.0.2


Periodically, new code needs to be pulled from the upstream repository. This will only be done to track a new stable upstream release. This can be accomplished using the following method:

$ git svn fetch
$ git checkout develop
$ git branch -a
$ git merge remotes/tags/V7.1.0


Otherwise, we use git-flow as usual. Once things are done, push any changes up to github.

$ git push -u origin master
$ git push -u origin develop


We’ve recently added a number of git repositories at github to track ports of various software tools to our platform. These are the steps that we used to get things working. We will use the binutils port as an example.

Create
For consistency, we’ll name all our upstream code as upstream for obvious reasons.
Instead of tracking everything, it might be more beneficial to just track the upstream master branch as we only want to track the main development code.
To create the initial repository, these steps are used:

$ mkdir binutils-port.git
$ cd binutils-port.git
$ git flow init
$ git remote add upstream -t master git://sourceware.org/git/binutils.git
$ git remote add origin [email protected]:aeste/newlib-port.git
$ git push -u origin master
$ git push -u origin develop


Upstream
We would like to only work off stable releases.
Therefore, instead of merging the complete upstream branch, we’ll only merge in stable code tagged as official releases.
To fetch and merge stable upstream code, use these steps:

$ git fetch upstream
$ git fetch upstream --tags
$ git tag
$ git show-ref binutils-2_22
$ git checkout develop
$ git merge XXXXXXXX


Modifications
Use the standard git-flow model to make modifications to the code. To merge the code from future upstream stable releases:

$ git fetch upstream
$ git fetch upstream --tags
$ git tag
$ git show-ref binutils-X_XX
$ git checkout develop
$ git merge XXXXXXXX


Push
Once the code is ready it needs to be pushed up to github.
This should be done as and when necessary, particularly after major releases or hotfixes.
For this example, we’ll push up two public branches and a tag (12.02).

$ git push -u origin master
$ git push -u origin develop
$ git push origin 12.02


That’s it.