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Youtube video

A short video demonstrating a bit of what can be done with the Hellaphone: Youtube


We would like to announce the availability of Inferno for Android phones. Because our slogan is "If it ain't broke, break it", we decided to replace the Java stack on Android phones with Inferno. We've dubbed it the Hellaphone--it was originally Hellphone, to keep with the Inferno theme, but then we realized we're in Northern California and the change was obvious.

The Hellaphone runs Inferno directly on top of the basic Linux layer provided by Android. We do not even allow the Java system to start. Instead, emu draws directly to the Linux framebuffer (thanks, Andrey, for the initial code!) and treats the touchscreen like a one-button mouse. Because the Java environment doesn't start, it only takes about 10 seconds to go from power off to a fully-booted Inferno environment.

As of today, we have Inferno running on the Nexus S and the Nook Color. It should also run on the Android emulator, but we haven't tested that in a long time. The cell radio is supported, at least on the Nexus S (the only actual phone we've had), so you can make phone calls, send texts, and use the data network.

The Inferno window manager has been re-worked with cell phone use in mind. Windows are automatically sized to fill the whole screen. The menu has been moved to the top and the menu items have been made significantly larger. Physical buttons on the phone are now used to do many common tasks:

(these keys are for the Nexus S, different bindings are used for the Nook, which has different keys available)

  • Back: Close the current window
  • Menu: Toggle the onscreen keyboard
  • Home: Minimize the current window
  • Power: Turn off the screen
  • Power+Volume Up: Open the screen brightness widget
  • Power+Volume Down: Turn off the phone
  • Power+Home: Restart Inferno

Installation is reasonably simple. You'll need the Android SDK (, with the platform-tools package installed for the adb and fastboot utilities. We also strongly recommend installing CyanogenMod on your phone before proceeding--that's what we use to test.

First, make absolutely sure you have the "adb" and "fastboot" commands in your path--see the previous paragraph regarding the SDK and try running "adb" to be sure. Download the tarball from and unpack it in your root. You should end up with a /data/inferno directory (we put it there because of the Inferno build process). Then, go to the /data/inferno/android directory and run the script (assuming you have a Nexus S. Run if you have a Nook). This will automatically set up the phone to boot into either Inferno or the regular Java environment--during bootup, the screen will go solid white; if you touch the screen at this point, it will boot into the regular Android environment, otherwise it will timeout and go to Inferno. However, at this point you're not yet ready to boot into Inferno, so reboot the phone and touch the screen to go into the regular Android UI. The final task is to run the command "cd /data/inferno; ./". Reboot, let it boot into Inferno, and you're ready to go.

You can also clone the repository ( and build it yourself, but this is a significant effort. I do not recommend it if you wish to simply try the system, but if you want to do development you should get the repository.

Disclaimer: If you break your phone, it's not our fault. Don't email us, don't come knocking on our door, and don't call us--oh wait, you won't be able to do that anyway, your phone is broken!

Credit where credit is due: Ron Minnich came up with the initial idea--we've been kicking the idea of a Plan 9/Inferno phone around for years. Our summer interns, Joel Armstrong and Joshua Landgraf, did the lion's share of the work of making Inferno into a usable cell phone OS--no small feat, considering that neither had any Limbo or Inferno experience before the start of the summer! They re-wrote the UI, puzzled out the undocumented cell radio interface, figured out audio, worked to make Inferno more portable across phones, and generally figured out how to make Inferno and the Android kernel coexist peacefully. Andy Jones, another intern, also did some very early work with Android that helped us figure out the Android init process and how to build for Android. I took care of getting Inferno running on the phone in the first place and have been adding things occasionally since then. We would also like to thank Andrey Mirtchovski for providing the OLPC framebuffer code (which ported to the Android phones relatively easily), and of course Charles Forsyth for keeping the Inferno torch lit all these years (and helping me figure out some puzzling problems throughout the summer)!

More Info

Compiling Inferno

Hellaphone Manual


Freshly-booted Inferno:

Freshly booted Inferno

The application selection menu:


The SMS application, displaying current conversations:

SMS conversations

The SMS application, composing a message:

SMS conversations

The dialer application:


The web browser, Charon: