--- a/b2g/Makefile.in
+++ b/b2g/Makefile.in
@@ -4,22 +4,10 @@
 
 DEPTH      = @DEPTH@
 topsrcdir  = @top_srcdir@
 srcdir     = @srcdir@
 VPATH      = @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
-DIRS = chrome components locales
-
-ifeq ($(OS_ARCH),WINNT)
-DIRS += $(DEPTH)/xulrunner/tools/redit
-endif
-
-ifneq ($(GAIADIR),)
-DIRS += gaia
-endif
-
-DIRS += app
-
 include $(topsrcdir)/config/rules.mk
 include $(topsrcdir)/testing/testsuite-targets.mk

new file mode 100644
--- /dev/null
+++ b/b2g/app.mozbuild
@@ -0,0 +1,16 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+if not CONFIG['LIBXUL_SDK']:
+    app_libxul_dirs = []
+    include('/toolkit/toolkit.mozbuild')
+elif CONFIG['ENABLE_TESTS']:
+    add_tier_dir('testharness', 'testing/mochitest')
+
+if CONFIG['MOZ_EXTENSIONS']:
+    add_tier_dir('app', 'extensions')
+
+add_tier_dir('app', CONFIG['MOZ_BRANDING_DIRECTORY'])
+add_tier_dir('app', 'b2g')

new file mode 100644
--- /dev/null
+++ b/b2g/app/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

--- a/b2g/branding/official/Makefile.in
+++ b/b2g/branding/official/Makefile.in
@@ -4,14 +4,9 @@
 
 DEPTH = @DEPTH@
 topsrcdir = @top_srcdir@
 srcdir = @srcdir@
 VPATH = @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
-DIRS = \
-	content \
-	locales \
-	$(NULL)
-
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/b2g/branding/official/content/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/b2g/branding/official/locales/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/b2g/branding/official/moz.build
@@ -0,0 +1,6 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DIRS += ['content', 'locales']

--- a/b2g/branding/unofficial/Makefile.in
+++ b/b2g/branding/unofficial/Makefile.in
@@ -4,14 +4,9 @@
 
 DEPTH = @DEPTH@
 topsrcdir = @top_srcdir@
 srcdir = @srcdir@
 VPATH = @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
-DIRS = \
-	content \
-	locales \
-	$(NULL)
-
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/b2g/branding/unofficial/content/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/b2g/branding/unofficial/locales/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/b2g/branding/unofficial/moz.build
@@ -0,0 +1,6 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DIRS += ['content', 'locales']

--- a/b2g/build.mk
+++ b/b2g/build.mk
@@ -1,34 +1,12 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-ifndef LIBXUL_SDK
-include $(topsrcdir)/toolkit/toolkit-tiers.mk
-else
-ifdef ENABLE_TESTS
-tier_testharness_dirs += \
-  testing/mochitest \
-  $(NULL)
-endif
-endif
-
-TIERS += app
-
-ifdef MOZ_EXTENSIONS
-tier_app_dirs += extensions
-endif
-
-tier_app_dirs += \
-  $(MOZ_BRANDING_DIRECTORY) \
-  b2g \
-  $(NULL)
-
-
 installer: 
 	@$(MAKE) -C b2g/installer installer
 
 package:
 	@$(MAKE) -C b2g/installer
 
 install::
 	@echo "B2G can't be installed directly."

new file mode 100644
--- /dev/null
+++ b/b2g/chrome/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

--- a/b2g/components/Makefile.in
+++ b/b2g/components/Makefile.in
@@ -35,17 +35,13 @@ EXTRA_PP_COMPONENTS = \
         $(NULL)
 
 EXTRA_JS_MODULES = \
 	Keyboard.jsm \
 	TelURIParser.jsm \
 	SignInToWebsite.jsm \
 	$(NULL)
 
-TEST_DIRS = \
-	test \
-	$(NULL)
-
 ifdef MOZ_UPDATER
 EXTRA_PP_COMPONENTS += UpdatePrompt.js
 endif
 
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/b2g/components/moz.build
@@ -0,0 +1,6 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+TEST_DIRS += ['test']

new file mode 100644
--- /dev/null
+++ b/b2g/components/test/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/b2g/gaia/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

--- a/b2g/installer/Makefile.in
+++ b/b2g/installer/Makefile.in
@@ -3,16 +3,19 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DEPTH     = @DEPTH@
 topsrcdir = @top_srcdir@
 srcdir    = @srcdir@
 VPATH     = @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
+
+STANDALONE_MAKEFILE := 1
+
 include $(topsrcdir)/config/rules.mk
 
 MOZ_PKG_REMOVALS = $(srcdir)/removed-files.in
 
 MOZ_PKG_MANIFEST_P = $(srcdir)/package-manifest.in
 
 MOZ_NONLOCALIZED_PKG_LIST = \
 	xpcom \

new file mode 100644
--- /dev/null
+++ b/b2g/installer/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/b2g/locales/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/b2g/moz.build
@@ -0,0 +1,17 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+CONFIGURE_SUBST_FILES += ['installer/Makefile']
+
+DIRS += ['chrome', 'components', 'locales']
+
+if CONFIG['OS_ARCH'] == 'WINNT':
+    DIRS += ['/xulrunner/tools/redit']
+
+if CONFIG['GAIADIR']:
+    DIRS += ['gaia']
+
+DIRS += ['app']
+