This is the first of a hopefully weekly series of posts describing the work my team is doing.  This means that this post is probably mostly background about the team’s goals, but in the coming weeks I intend to outline what we’ve done in the past week and plans for the next week.

We’re all about validation obviously – telling whether the code the other Linaro engineers are producing “works” in whatever sense that means.  It could be a simple compile or boot test for the kernel, testing whether the code produced by gcc is smaller or faster, whether a kernel scheduler change reduces power consumption for a certain workload, or many other things.

Beyond simple validation though, what we’re really about is automated validation.  We want to build and test the kernel on all supported boards every day.  We want to build and test proposed android changes in gerrit before they are landed, and the same for the gcc work.

We have built up a validation lab in Cambridge – the boards from the Linaro members we want to test on, but also Cyclades serial console servers, routers, and a few servers.  It looks a bit like this:

The thing that makes our task more complicated than “just install jenkins” is the hardware we run on, of course, and the fact that for many of our tests we need to boot a custom kernel on said hardware.  We’ve written a program (called “lava-dispatcher” or just “the dispatcher”) that knows how to install a custom hwpack and root filesystem by manipulating a board over a serial link, another (“lava-scheduler”) that handles incoming requests to run tests and runs the dispatcher as appropriate and yet another (“lava-dashboard”, aka “launch-control”) that displays the results from the tests.  We’ve also built up a number of infrastructure projects that help us run these main three, and command line clients for most things.  You can see all the code at and the running instance is at

So, what are we working on this week?  The main areas are to improve the UI of the scheduler – currently it runs jobs, but is very opaque about what they are doing, improving the front page to make it clearer to the uninitiated what validation is happening and improving the reliability of the dispatcher.  We’re also hard at work “joining the dots” so that the daily builds of Android that are already being produced can be tested daily, and have the build output and test results all visible from the same page.

Next week I’ll be at Linaro Connect in the UK, but I’ll try to update here on what we get done this week and what our plans are for the Connect.