So I’ve been interested in the Boot2Gecko project for awhile and wanted to see if I could get an app running on Steroids that would run under B2G.

To accomplish this I needed to get the B2G desktop emulator up and running so I could actually develop something.

Below is the method I had to use to get it up and running with OSX (Mountain Lion).


You will need the following installed to get started.

  • Git
  • Brew
  • Autoconf
  • Yasm

For this to build properly you’re going to have to force brew to download and install autoconf-2.13. This can be accomplished by placing the autoconf.rb code listed below into your Formula folder located at /usr/local/Library/Formula/.

require 'formula'

class Autoconf < Formula
  url ''
  homepage ''
  md5 '9de56d4a161a723228220b0f425dc711'`

  def install
    system "./configure", "--program-suffix=213",
    system "make install"

Once this is accomplished just use brew to install both autoconf and yasm

brew install autoconf

brew install yasm

Getting the code

There are two different pieces needed to get the desktop emulator up and running. First there is Mozilla-central. This will contain the b2g executable. The second component needed is gaia. This is the user interface for the b2g phone.

// Get mozilla-central repo and save it to folder called mozilla-central
git clone

// Get gaia repo and save to folder called gaia
git clone gaia

Building Mozilla Central

Create a mozconfig

You will need to create a mozconfig file before building. cd into the mozilla-central directory and create a file called “mozconfig”. Then add the following to it and save.

mk_add_options MOZ_OBJDIR=../build
mk_add_options MOZ_MAKE_FLAGS="-j9 -s"

ac_add_options --enable-application=b2g
ac_add_options --disable-libjpeg-turbo

# This option is required if you want to be able to run Gaia's tests
ac_add_options --enable-tests

# turn on mozTelephony/mozSms interfaces
ac_add_options --enable-b2g-ril


While still in the mozilla-central directory build the source code. Now go get a beer or some coffee as this will take a long time.

make -f build

When complete you should see a build folder outside of your mozilla-central directory.

Building Gaia

Now that we have mozilla-central working we need to build a profile for gaia. Navigate into the gaia directory that was created when doing a git clone from above. Now we can build with the following command.


A lot of stuff will happen but if everything works out you should have a “profile” folder in your gaia directory.

Running the emulator

To run thhe b2g emulator you’re going to need to pass in the profile generated in the gaia folder.

cd build/dist/

./b2g -profile /path/to/gaia/profile


It really wasn’t that hard to get this up and running under OSX. In a future blog post I’ll discuss getting a Steroids application un and running under B2G but for now here are a few screenshots.

B2G Lock Screen

B2G Home Screen

B2G Marketplace