Writing a custom Android OS

Question

I hope this is the right place to ask this.

I would like to work on an Android build with a completely custom OS. I was inspired by this project that ported Inferno to Android.

I would like to do this legally (obeying all terms of service and what-not) if possible, and I have no problem with disclosing my source code to a carrier.

Do any of you have experience with this? What are the considerations for getting a custom build to work with a carrier?

Since I am building on Android, I probably won't have to worry about cell/3g/4g hardware drivers, and I would like to buy a phone from the carrier anyway just to make sure it will be supportable.

Answer 1

Head over to the AOSP source, and clone it. Strip out what you don't need in your branch and begin the kernel patching! You'll need to modify the kernel in portions to make it compatible (fairly) with the device you're on. The Android kernel is in fact a very close cousin of the Linux Kernel, and in Linux 3.3, they've begun merging the two. After this is done, write your interfacing mechanisms (be it a display, web interface, etc) and you can test it out on your platform.

Answer 2

I'm one of the creators of the Inferno project you mentioned. Anyway, making a completely custom OS for an Android phone will be difficult; a lot of the hardware will be undocumented or only drivable by Linux binary blobs. What we did (and what Boeing has also done recently for a commercial project) is strip away all the Java from an Android system, leaving a basic Linux upon which you can build your own custom interface. This lets you use all the hardware (since the drivers are in Linux), but everything that the end users see will be your stuff. There are a variety of ways to go from there. Inferno implements a virtual machine, so we can abstract the Linux stuff into our own Inferno-style world.

I don't think there should be any problems with the carriers. We started with a Cyanogenmod ROM and hacked on that; custom ROMs are just fine! I never had any problems, even when I was swapping my little pay-as-you-go SIM card among several phones running Gingerbread, ICS, and Inferno.