TOC1. Introduction2. Installing and setting up the Android
environment3. Getting the source code4. Installing the required
Ubuntu packages5. How to compile6. Installing XBMC in an Android
system7. Running and debugging XBMC in an Android system8.
Architecture9. Useful
Commands-----------------------------------------------------------------------------1.
Introduction-----------------------------------------------------------------------------We
currently recommend Ubuntu Natty (11.04) or later. Current work has
beendone here. Additionally, building from OSX Snow Leopard is
working.NOTE TO NEW USERS: All lines that are prefixed with the
'#'character are commands that need to be typed into a terminal
window /console (similar to the command prompt for Windows). Note
that the '#'character itself should NOT be typed as part of the
command.-----------------------------------------------------------------------------2.
Installing the required Ubuntu
packages-----------------------------------------------------------------------------These
are the minimum packages necessary for building XBMC.
Non-Ubuntuusers will need to get the equivalents. # sudo apt-get
install build-essential default-jdk git curl autoconf \ unzip zip
zlib1g-dev gawk gperf cmakeIf you run a 64bit operating system you
will also need to get ia32-libs # sudo apt-get install
ia32-libs-----------------------------------------------------------------------------3.
Installing and setting up the Android
environment-----------------------------------------------------------------------------To
develop XBMC for Android the Android SDK and NDK are
required.--------------------------------------------------------------------3.1.
Getting the Android SDK and
NDK--------------------------------------------------------------------To
get the Android SDK, go to http://developer.android.com/sdk
anddownload the latest version for your operating system. The
NDKcan be downloaded from
http://developer.android.com/tools/sdk/ndk/[NOTICE] Compiling XBMC
for Android requires at least Android NDK Revision r8e. Android NDK
Revision 7 and earlier do not work properly for our cause.After
downloading the SDK and NDK extract the files contained in
thearchives to your harddisk.Make sure you have a recent JRE and
JDK installed otherwise theAndroid SDK will not
work.--------------------------------------------------------------------3.2.
Installing Android SDK
packages--------------------------------------------------------------------After
having extracted the Android SDK to you need toinstall some android
packages using the Android SDK Manager: # cd /tools # ./android
update sdk -u -t
platform,platform-tool--------------------------------------------------------------------3.3.
Setup the Android
toolchain--------------------------------------------------------------------To
be able to compile XBMC and the libraries it depends on for
theAndroid platform you first need to setup an Android toolchain
usingthe Android NDK which you earlier extracted to . Thefollowing
commands will create a toolchain suitable for the mostcommon
scenario.The --install-dir option (and therefore the
value)specifies where the resulting toolchain should be installed
(your choice). # cd # ls platforms # cd build/tools #
./make-standalone-toolchain.sh --ndk-dir=../../ \
--install-dir=/android-14 --platform=android-14 \
--toolchain=arm-linux-androideabi-4.7Make sure to pick a toolchain
for your desired architecture. Currently onlygcc 4.7 toolchains are
supported, anything else will likely fail to build.ATTENTION FOR
X86 BUILDS - THIS DOES NOT APPLY TO 99% OF BUILDS:If you want to
build for the x86 platform there is a flaw in the mentionedNDK. See
http://code.google.com/p/android/issues/detail?id=19851 which
resultsin linker errors mentioning "sigsetjmp and siglongjmp".In
that case you have to download the libc.tar.bz2 from that google
issueentry:http://android.googlecode.com/issues/attachment?aid=198510003000&name=libc.tar.bz2&token=6uNpHc1v8ixmVOTq3y6-ohUfb0o%3A1341156659947And
extract it to /android-/sysroot/usr/lib/ and overwritethe libc.so
there. (where /android-/ is the path you have given on
the--install-dir option
above)--------------------------------------------------------------------3.4.
Create a (new) debug key to sign debug
APKs--------------------------------------------------------------------
All packages must be signed. The following command will generate a
self-signed debug key. If the result is a cryptic error, it
probably just means a debug key already existed, no cause for
alarm. # keytool -genkey -keystore ~/.android/debug.keystore -v
-alias \ androiddebugkey -dname "CN=Android Debug,O=Android,C=US"
-keypass \ android -storepass android -keyalg RSA -keysize 2048
-validity
10000-----------------------------------------------------------------------------4.
Getting the source
code-----------------------------------------------------------------------------
# cd $HOME # git clone git://github.com/xbmc/xbmc.git xbmc-android
# cd xbmc-android # git submodule update --init
addons/skin.touched-----------------------------------------------------------------------------5.
How to
compile-----------------------------------------------------------------------------Compiling
XBMC for Android consists of compiling the libraries XBMC dependson
with the Android toolchain and creating an Android Application
Package(APK) which can be installed in an Android
system.--------------------------------------------------------------------5.1.
Building
dependencies--------------------------------------------------------------------
# cd $HOME/xbmc-android/tools/depends # ./bootstrap # ./configure
--help Run configure with the correct settings for you local
configuration. See tools/depends/README for examples. Anyone
working on the dependencies themselves will want to set the
environment variables specified in ~/.bashrc or similar, to avoid
having to input these with each configure. # make -j This build was
designed to be massively parallel. Don't be afraid to give it a
'make -j20' or so. Verify that all deps built correctly (it will
tell you so) before continuing. You will get crazy build errors
otherwise.--------------------------------------------------------------------5.2.
Building
XBMC--------------------------------------------------------------------
# cd $HOME/xbmc-android # make -C tools/depends/target/xbmc # make
# make apk After the first build (assuming bootstrap and configure
are successful), subsequent builds can be run with a simple 'make'
and 'make
apk'.-----------------------------------------------------------------------------6.
Installing XBMC in an Android
system-----------------------------------------------------------------------------To
install XBMC through the previously built APK in an Android system
you caneither install it on a real device (smartphone/tablet/...)
running Android >=
2.3.x.--------------------------------------------------------------------6.1.
Installing XBMC on the Android
device--------------------------------------------------------------------Make
sure your Android device is connected to your computer throughUSB.
Furthermore you have to enable the following option in yourdevice's
Android settings: - Applications [X] Unknown sources # cd
$HOME/xbmc-android/tools/android/packaging # adb devices # adb -s
install -r images/xbmcapp-debug.apk The can be retrieved from the
list returned by the"adb devices" command and is the first value in
the row representingyour
device.-----------------------------------------------------------------------------7.
Running and debugging XBMC in an Android
system-----------------------------------------------------------------------------After
installing XBMC's APK in an Android system you can start it using
itsLauncher icon in Android's Application
Launcher.--------------------------------------------------------------------7.1.
Debugging
XBMC--------------------------------------------------------------------To
be able to see what is happening while running XBMC you first
needto enable USB debugging in your Android settings (this is
already donewhen using the emulator): - Applications [X] Unknown
sources - Development [X] USB debuggingTo access the log output of
your Android system run (the -s parameterand the may not be needed
when using the Android emulator) # adb -s
logcat--------------------------------------------------------------------7.2.
GDB--------------------------------------------------------------------GDB
can be used to debug, though the support is rather primitive.
Rather thanusing gdb directly, you will need to use ndk-gdb which
wraps it. Do NOT trustthe -p/--project switches, as of ndk7b they
do not work. Instead you will needto cd to
tools/android/packaging/xbmc and execute it from there. # ndk-gdb
--start --delay=0This will open the installed version of XBMC and
break. The warnings can beignored as we have setup the appropriate
paths
already.--------------------------------------------------------------------8.
Architecture--------------------------------------------------------------------During
the early days of the android port, xbmc was launched via a stub
libthat then dlopen'd libxbmc. This was done to get around bionic's
poor handlingof shared libs. We now compile everything into libxbmc
itself so that it hasno runtime dependencies beyond system libs.
Done this way, we're able to launchinto libxbmc directly.But we
still hit Bionic's loader's deficiencies when we dlopen a lib.
There aretwo main issues to overcome for loading:1. Bionic imports
all symbols for a lib as soon as it is loaded, and it willrefuse to
open a lib if it has a single unresolved symbol2. It does not
search recursively during the resolve. So if liba depends onlibb,
dlopen'ing liba will _not_ pull in missing symbols from libb. This
isparticularly nasty considering #1.To work-around these problems
we use our own recursive loader in place ofdlopen. This loader
mimics expected behavior. Using the example above, loadinglibb
before liba will mean that everything will resolve
correctly.Additionally, Android does not use versioned solibs.
libfoo.so.1 which istypical on linux would not be found by the
loader. This means that we muststrip the SONAME and NEEDED values
out of the libs as well as changing thefilenames themselves. The
cleaner solution would be to patch libtool/cmake/etcto not add
versioning in the first place. For now, we use the
brute-forceapproach of modifying the binary and blanking out the
versions.See here for more
info:http://www.bernawebdesign.ch/byteblog/2011/11/23/creating-non-versioned-shared-libraries-for-android/As
a final gotcha, all libs must be in the form of ^lib.*so$ with
noexceptions (they won't even install otherwise), and the soname
must match.So we have to do some renaming to get some of our
self-built libs loaded.Development:Typical android native
activities are built with ndk-build which is a wrapperaround Make.
It would be a nightmare to port our entire buildsystem over,
soinstead we build as usual then package ourselves. It may be
beneficial to usendk-build to do the actual packaging, but for now
its behavior is emulated.ABI:Presently we are targeting armv7a+neon
for arm, and i686 for x86. Note that x86builds successfully but has
not been
tested.--------------------------------------------------------------------9.
Useful
Commands--------------------------------------------------------------------Below
are a few helpful commands when building/debugging. These assume
that pwdis 'tools/android/packaging' and that the proper sdk/ndk
paths are set.-Install a new build over the existing one # adb -e
install -r images/xbmcapp-debug.apk-Launch XBMC on the emulator
without the GUI # adb shell am start -a android.intent.action.MAIN
-n org.xbmc.xbmc/android.app.NativeActivity-Kill a misbehaving XBMC
# adb shell ps | grep org.xbmc | awk '{print $2}' | xargs adb shell
kill-Filter logcat messages by a specific tag (e.g. "XBMC") # adb
logcat -s XBMC:V -Enable CheckJNI (BEFORE starting the application)
# adb shell setprop debug.checkjni 1
