Raspberry PI / Android a minimal cross-compile configuration

Enable a cross compile Erlang/OTP platform to Android or Raspberry PI
using Android NDK. Port emulator and core application to support target
HW platform. Exclude any add-on services required for OTP platform deployment
into target hardware due to device fragmentation and jail-break requirements.

 * fix erts/emulator/beam/sys.h
   Disable redefinition of __noreturn macro

 * port erts/emulator/sys/unix/erl_child_setup.c
   Use techniques proposed by https://code.google.com/p/erlang4android to
   access system properties

 * fix erts/emulator/sys/unix/erl_unix_sys_ddll.c
   The static linking of emulator cannot find dlerror(), dlopen() symbols

 * port erts/emulator/sys/unix/sys.c
   make path to shell configurable at build time

 * port erts/etc/common/Makefile.in
   disable librt for *-linux-androideabi

 * port erts/lib_src/pthread/ethread.c
   Use techniques proposed by https://code.google.com/p/erlang4android to
   disable emulator crash if kernel threads are on. Replace unreliable
   pthread_sigmask() by sigprocmask()

 * port lib/erl_interface/src/connect/ei_connect.c
   Disable call to undefined gethostid()

 * port lib/erl_interface/src/connect/ei_resolve.c
   Use gethostbyname_r() on Android platform

1 files changed, 52 insertions, 0 deletions

diff --git a/HOWTO/INSTALL-ANDROID.md b/HOWTO/INSTALL-ANDROID.md
new file mode 100644
index 0000000000..31698d4ce3
--- /dev/null
+++ b/HOWTO/INSTALL-ANDROID.md
@@ -0,0 +1,52 @@
+Cross Compiling Erlang/OTP - ANDROID
+====================================
+
+Introduction
+------------
+
+This document describes how to cross compile Erlang OTP to Android/Rasberry Pi platforms.
+
+### Download and Install Android NDK ###
+
+https://developer.android.com/tools/sdk/ndk/index.html
+
+### Define System Variables ###
+
+export NDK_ROOT=/usr/local/android
+export NDK_PLAT=android-9
+export PATH=$NDK_ROOT/toolchains/arm-linux-androideabi-4.8/prebuilt/darwin-x86_64/bin:$PATH
+
+### Configure OTP ###
+
+./otp_build configure \
+   --xcomp-conf=./xcomp/erl-xcomp-arm-android.conf  \
+   --without-ssl
+
+### Compile OTP ###
+
+make noboot [-j4]
+
+### Make Release ###
+
+./otp_build release -a /usr/local/otp_R16B03_arm
+
+### Target Deployment ###
+
+Make a tarball out of /usr/local/otp_R16B03_arm and copy it to target device
+(e.g. Raspberry Pi). Extract it and install
+
+./Install /usr/local/otp_R16B03_arm
+
+Android SDK (adb tool) is used to deploy OTP/Erlang to target device for 
+evaluation purpose only.
+
+adb push /usr/local/otp_R16B03_arm /mnt/sdcard/otp_R16B03_arm
+adb shell
+
+### Known Issues ###
+
+ * native inet:gethostbyname/1 return {error, nxdomain} on Raspberry PI. Use dns resolver to by-pass the issue (see http://www.erlang.org/doc/apps/erts/inet_cfg.html) 
+
+### References ###
+
+  The port derives some solutions from https://code.google.com/p/erlang4android/