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, 4 insertions, 0 deletions

diff --git a/erts/emulator/sys/unix/erl_unix_sys_ddll.c b/erts/emulator/sys/unix/erl_unix_sys_ddll.c
index 8760b58839..2659d623c7 100644
--- a/erts/emulator/sys/unix/erl_unix_sys_ddll.c
+++ b/erts/emulator/sys/unix/erl_unix_sys_ddll.c
@@ -123,6 +123,7 @@ int erts_sys_ddll_open(const char *full_name, void **handle, ErtsSysDdllError* e
 
 int erts_sys_ddll_open_noext(char *dlname, void **handle, ErtsSysDdllError* err)
 {
+#if defined(HAVE_DLOPEN)   
     int ret = ERL_DE_NO_ERROR;
     char *str;
     dlerror();
@@ -148,6 +149,9 @@ int erts_sys_ddll_open_noext(char *dlname, void **handle, ErtsSysDdllError* err)
 	ret = ERL_DE_DYNAMIC_ERROR_OFFSET - find_errcode(str, err);
     }
     return ret;
+#else
+    return ERL_DE_ERROR_NO_DDLL_FUNCTIONALITY;
+#endif
 }
 
 /*