android: Add README file with instructions

This file cotains help on how BlueZ for Android should be build, run
and test. Some hints and examples on how BlueZ can be intergrated into
Android are present as well.

android/Makefile.am

@@ -96,7 +96,7 @@ EXTRA_DIST += android/client/terminal.c \
 		android/client/history.h \
 		android/client/terminal.h
 
-EXTRA_DIST += android/hal-ipc-api.txt
+EXTRA_DIST += android/hal-ipc-api.txt android/README
 
 EXTRA_DIST += android/hardware/bluetooth.h \
 		android/hardware/bt_av.h \

android/README

@@ -0,0 +1,90 @@
+BlueZ for Android
+*****************
+
+Since Android 4.2 there exists a well standardized HAL interface that the
+Bluetooth stack is expected to provide and which enables the easy replacement
+of the stack of choice on Android. Android BlueZ is intended as a drop-in
+replacement to Android provided Bluetooth stack.
+
+More details about BlueZ for Android architecture and components can be found
+in android/hal-apc-api.txt file.
+
+===============================
+Building and running on Android
+===============================
+
+Build requirements
+==================
+
+- GLib - Android 4.2 or later don't provide GLib and one must provide it in
+'external/bluetooth/glib' folder of Android tree. Sample Android GLib port
+is available at https://code.google.com/p/android-bluez.glib/
+
+- Bionic support - BlueZ requires signalfd and timerfd APIs to be provided
+by libc library. Currently only 'master' branch available at
+https://android.googlesource.com/platform/bionic provides all required
+functionality and running BlueZ on older branch requires backporting missing
+features. Sample Bionic for Android on Intel Architecture (Android-IA) with all
+required features backported is available at
+https://code.google.com/p/android-bluez.bionic/
+
+Runtime requirements
+====================
+
+BlueZ HAL library requires 'bluetoothd' service to be available on Android
+system. This can be done by defining service in init.rc file of targeted board:
+
+service bluetoothd /system/bin/logwrapper /system/bin/bluetoothd
+  class main
+  group bluetooth net_admin
+  disabled
+  oneshot
+
+It is required that bluetooth user could start and stop bluetoothd service by
+setting 'ctl.start' or 'ctl.stop' property. This can be achieved by
+whitelisting bluetooth user and bluetoothd service in init source code.
+
+Required Android init system modifications can be found at
+https://code.google.com/p/android-bluez.system-core/
+
+Downloading and building
+========================
+
+Building for Android requires full Android AOSP source tree. Sample Android-IA
+tree with all required components present is available at
+http://code.google.com/p/android-bluez/
+
+Downloading:
+repo init -u https://code.google.com/p/android-bluez.manifest/ -m topics/bluez
+repo sync
+
+Build for Intel ultrabook:
+'source build/envsetup.sh'
+'lunch core_mesa-eng'
+'make allimages -j8'
+
+After full build is done it is possible to rebuild only BlueZ:
+'cd external/bluetooth/bluez/android/'
+'mm' (or 'mm -B' to force rebuilding of all files)
+'adb sync' to update target device.
+
+=============================
+Building and running on Linux
+=============================
+
+It is possible to build and test BlueZ for Android daemon on Linux (eg. PC).
+Simply follow instructions available at README file in BlueZ top directory.
+Android daemon binary is located at android/bluetoothd. See next section on
+how to test Android daemon on Linux.
+
+============
+Testing tool
+============
+
+BT HAL test tools located in android/haltest is provided for HAL level testing
+of both Android daemon and HAL library. Start it and type 'adapter init' in
+prompt to initialize HAL library. On Android required bluetoothd service will
+be started automatically. On Linux it is required to start android/bluetoothd
+manually before init command timeout. To deinitialize HAL library and stop
+daemon type 'adapter cleanup'. Type 'help' for more information. Tab completion
+is also supported.