Merge masterlinaro-juno-master

* aosp/master: (34 commits)
  set a prebuilt directory name for the 2nd arch
  add vendor directories to gdb shared library search path
  add 2nd arch gcc to the path
  fix paths when 2nd arch gcc is a different version
  Clarify multiarch warnings
  Split the rules to build the odex file
  libctest: zap
  Remove netd_client. It has moved to the internal tree.
  Add HOST_PREFER_32_BIT to support 32-bit-by-default multilib build
  Support to extract JNI libs from prebuilt APK
  The generic_arm64 system image is full.
  Fix extra/missing : in path setup.
  Use aarch64-linux-android-4.9 for arm64 build (attempt #4)
  Allow qemu_device read-write access to various processes
  Multilib support for odex
  Increase system image size to 650M for generic_arm64
  Default TARGET_CPU_SMP to true.
  Fix the missing 2nd arch prefix.
  Use libc++ versions of gtest libs when needed
  Use libc++ versions of gtest libs when needed
  ...

Conflicts:
	core/combo/HOST_linux-x86.mk

Change-Id: Icf1ec5bee19547ad0c96a7dd221aecebf4ac6ad5
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

67 files changed, 1221 insertions, 572 deletions

diff --git a/core/base_rules.mk b/core/base_rules.mk
index c68fba7076..8b3614a3c8 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -98,16 +98,10 @@ ifneq ($(words $(LOCAL_MODULE_CLASS)),1)
   $(error $(LOCAL_PATH): LOCAL_MODULE_CLASS must contain exactly one word, not "$(LOCAL_MODULE_CLASS)")
 endif
 
-ifndef LOCAL_IS_HOST_MODULE
-my_32_64_bit_suffix := $(if $($(LOCAL_2ND_ARCH_VAR_PREFIX)TARGET_IS_64_BIT),64,32)
-endif
+my_32_64_bit_suffix := $(if $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)IS_64_BIT),64,32)
 
 ifneq (true,$(LOCAL_UNINSTALLABLE_MODULE))
-ifndef LOCAL_IS_HOST_MODULE
 my_multilib_module_path := $(strip $(LOCAL_MODULE_PATH_$(my_32_64_bit_suffix)))
-else
-my_multilib_module_path :=
-endif
 ifdef my_multilib_module_path
 my_module_path := $(my_multilib_module_path)
 else
@@ -148,7 +142,7 @@ endif
 my_register_name := $(LOCAL_MODULE)
 ifdef LOCAL_2ND_ARCH_VAR_PREFIX
 ifndef LOCAL_NO_2ND_ARCH_MODULE_SUFFIX
-my_register_name := $(LOCAL_MODULE)$(TARGET_2ND_ARCH_MODULE_SUFFIX)
+my_register_name := $(LOCAL_MODULE)$($(my_prefix)2ND_ARCH_MODULE_SUFFIX)
 endif
 endif
 # Make sure that this IS_HOST/CLASS/MODULE combination is unique.
@@ -179,11 +173,11 @@ ifdef OVERRIDE_BUILT_MODULE_PATH
 else
   built_module_path := $(intermediates)
 endif
-LOCAL_BUILT_MODULE := $(built_module_path)/$(LOCAL_BUILT_MODULE_STEM)
+LOCAL_BUILT_MODULE := $(built_module_path)/$(my_built_module_stem)
 built_module_path :=
 
 ifneq (true,$(LOCAL_UNINSTALLABLE_MODULE))
-  LOCAL_INSTALLED_MODULE := $(my_module_path)/$(LOCAL_INSTALLED_MODULE_STEM)
+  LOCAL_INSTALLED_MODULE := $(my_module_path)/$(my_installed_module_stem)
 endif
 
 # Assemble the list of targets to create PRIVATE_ variables for.
@@ -516,6 +510,8 @@ $(LOCAL_INTERMEDIATE_TARGETS) : PRIVATE_HOST:= $(my_host)
 
 $(LOCAL_INTERMEDIATE_TARGETS) : PRIVATE_INTERMEDIATES_DIR:= $(intermediates)
 
+$(LOCAL_INTERMEDIATE_TARGETS) : PRIVATE_2ND_ARCH_VAR_PREFIX := $(LOCAL_2ND_ARCH_VAR_PREFIX)
+
 # Tell the module and all of its sub-modules who it is.
 $(LOCAL_INTERMEDIATE_TARGETS) : PRIVATE_MODULE:= $(my_register_name)
 
@@ -573,10 +569,12 @@ endif
 ifdef LOCAL_DONT_CHECK_MODULE
   LOCAL_CHECKED_MODULE :=
 endif
-# Don't check build the module defined for the 2nd arch
+# Don't check build target module defined for the 2nd arch
+ifndef LOCAL_IS_HOST_MODULE
 ifdef LOCAL_2ND_ARCH_VAR_PREFIX
   LOCAL_CHECKED_MODULE :=
 endif
+endif
 
 ###########################################################
 ## Register with ALL_MODULES
diff --git a/core/binary.mk b/core/binary.mk
index 9dab23f125..4af3da1168 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -113,22 +113,20 @@ my_cxx := $(LOCAL_CXX)
 my_c_includes := $(LOCAL_C_INCLUDES)
 my_generated_sources := $(LOCAL_GENERATED_SOURCES)
 
-ifndef LOCAL_IS_HOST_MODULE
-my_src_files += $(LOCAL_SRC_FILES_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_SRC_FILES_$(my_32_64_bit_suffix))
-my_shared_libraries += $(LOCAL_SHARED_LIBRARIES_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_SHARED_LIBRARIES_$(my_32_64_bit_suffix))
-my_cflags += $(LOCAL_CFLAGS_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_CFLAGS_$(my_32_64_bit_suffix))
-my_cppflags += $(LOCAL_CPPFLAGS_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_CPPFLAGS_$(my_32_64_bit_suffix))
-my_ldflags += $(LOCAL_LDFLAGS_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_LDFLAGS_$(my_32_64_bit_suffix))
-my_asflags += $(LOCAL_ASFLAGS_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_ASFLAGS_$(my_32_64_bit_suffix))
-my_c_includes += $(LOCAL_C_INCLUDES_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_C_INCLUDES_$(my_32_64_bit_suffix))
-my_generated_sources += $(LOCAL_GENERATED_SOURCES_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_GENERATED_SOURCES_$(my_32_64_bit_suffix))
+my_src_files += $(LOCAL_SRC_FILES_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_SRC_FILES_$(my_32_64_bit_suffix))
+my_shared_libraries += $(LOCAL_SHARED_LIBRARIES_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_SHARED_LIBRARIES_$(my_32_64_bit_suffix))
+my_cflags += $(LOCAL_CFLAGS_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_CFLAGS_$(my_32_64_bit_suffix))
+my_cppflags += $(LOCAL_CPPFLAGS_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_CPPFLAGS_$(my_32_64_bit_suffix))
+my_ldflags += $(LOCAL_LDFLAGS_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_LDFLAGS_$(my_32_64_bit_suffix))
+my_asflags += $(LOCAL_ASFLAGS_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_ASFLAGS_$(my_32_64_bit_suffix))
+my_c_includes += $(LOCAL_C_INCLUDES_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_C_INCLUDES_$(my_32_64_bit_suffix))
+my_generated_sources += $(LOCAL_GENERATED_SOURCES_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_GENERATED_SOURCES_$(my_32_64_bit_suffix))
 
 # arch-specific static libraries go first so that generic ones can depend on them
-my_static_libraries := $(LOCAL_STATIC_LIBRARIES_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_STATIC_LIBRARIES_$(my_32_64_bit_suffix)) $(my_static_libraries)
-my_whole_static_libraries := $(LOCAL_WHOLE_STATIC_LIBRARIES_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_WHOLE_STATIC_LIBRARIES_$(my_32_64_bit_suffix)) $(my_whole_static_libraries)
+my_static_libraries := $(LOCAL_STATIC_LIBRARIES_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_STATIC_LIBRARIES_$(my_32_64_bit_suffix)) $(my_static_libraries)
+my_whole_static_libraries := $(LOCAL_WHOLE_STATIC_LIBRARIES_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_WHOLE_STATIC_LIBRARIES_$(my_32_64_bit_suffix)) $(my_whole_static_libraries)
 
-my_cflags := $(filter-out $($(LOCAL_2ND_ARCH_VAR_PREFIX)TARGET_GLOBAL_UNSUPPORTED_CFLAGS),$(my_cflags))
-endif
+my_cflags := $(filter-out $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)GLOBAL_UNSUPPORTED_CFLAGS),$(my_cflags))
 
 # Add static HAL libraries
 ifdef LOCAL_HAL_STATIC_LIBRARIES
@@ -234,15 +232,15 @@ $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_TARGET_GLOBAL_LDFLAGS := $(my_target_glob
 else # LOCAL_IS_HOST_MODULE
 
 ifeq ($(LOCAL_CLANG),true)
-my_host_global_cflags := $(CLANG_HOST_GLOBAL_CFLAGS)
-my_host_global_cppflags := $(CLANG_HOST_GLOBAL_CPPFLAGS)
-my_host_global_ldflags := $(CLANG_HOST_GLOBAL_LDFLAGS)
-my_host_c_includes := $(HOST_C_INCLUDES) $(CLANG_CONFIG_EXTRA_HOST_C_INCLUDES)
+my_host_global_cflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)CLANG_HOST_GLOBAL_CFLAGS)
+my_host_global_cppflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)CLANG_HOST_GLOBAL_CPPFLAGS)
+my_host_global_ldflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)CLANG_HOST_GLOBAL_LDFLAGS)
+my_host_c_includes := $($(LOCAL_2ND_ARCH_VAR_PREFIX)HOST_C_INCLUDES) $(CLANG_CONFIG_EXTRA_HOST_C_INCLUDES)
 else
-my_host_global_cflags := $(HOST_GLOBAL_CFLAGS)
-my_host_global_cppflags := $(HOST_GLOBAL_CPPFLAGS)
-my_host_global_ldflags := $(HOST_GLOBAL_LDFLAGS)
-my_host_c_includes := $(HOST_C_INCLUDES)
+my_host_global_cflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_CFLAGS)
+my_host_global_cppflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_CPPFLAGS)
+my_host_global_ldflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_LDFLAGS)
+my_host_c_includes := $($(LOCAL_2ND_ARCH_VAR_PREFIX)HOST_C_INCLUDES)
 endif # LOCAL_CLANG
 
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_HOST_C_INCLUDES := $(my_host_c_includes)
diff --git a/core/clang/HOST_x86.mk b/core/clang/HOST_x86.mk
index ee61e5e028..510a74dc30 100644
--- a/core/clang/HOST_x86.mk
+++ b/core/clang/HOST_x86.mk
@@ -1,6 +1,6 @@
 
 include $(BUILD_SYSTEM)/clang/x86.mk
-include $(BUILD_SYSTEM)/clang/x86_common.mk
+include $(BUILD_SYSTEM)/clang/HOST_x86_common.mk
 
 ifeq ($(HOST_OS),linux)
 CLANG_CONFIG_x86_HOST_TRIPLE := i686-linux-gnu
@@ -44,21 +44,21 @@ CLANG_CONFIG_x86_HOST_EXTRA_LDFLAGS := \
   $(CLANG_CONFIG_x86_HOST_COMBO_EXTRA_LDFLAGS) \
   -target $(CLANG_CONFIG_x86_HOST_TRIPLE)
 
-define convert-to-host-clang-flags
+define $(clang_2nd_arch_prefix)convert-to-host-clang-flags
   $(strip \
   $(call subst-clang-incompatible-x86-flags,\
   $(filter-out $(CLANG_CONFIG_x86_UNKNOWN_CFLAGS),\
   $(1))))
 endef
 
-CLANG_HOST_GLOBAL_CFLAGS := \
-  $(call convert-to-host-clang-flags,$(HOST_GLOBAL_CFLAGS)) \
+$(clang_2nd_arch_prefix)CLANG_HOST_GLOBAL_CFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-host-clang-flags,$($(clang_2nd_arch_prefix)HOST_GLOBAL_CFLAGS)) \
   $(CLANG_CONFIG_x86_HOST_EXTRA_CFLAGS)
 
-CLANG_HOST_GLOBAL_CPPFLAGS := \
-  $(call convert-to-host-clang-flags,$(HOST_GLOBAL_CPPFLAGS)) \
+$(clang_2nd_arch_prefix)CLANG_HOST_GLOBAL_CPPFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-host-clang-flags,$($(clang_2nd_arch_prefix)HOST_GLOBAL_CPPFLAGS)) \
   $(CLANG_CONFIG_x86_HOST_EXTRA_CPPFLAGS)
 
-CLANG_HOST_GLOBAL_LDFLAGS := \
-  $(call convert-to-host-clang-flags,$(HOST_GLOBAL_LDFLAGS)) \
+$(clang_2nd_arch_prefix)CLANG_HOST_GLOBAL_LDFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-host-clang-flags,$($(clang_2nd_arch_prefix)HOST_GLOBAL_LDFLAGS)) \
   $(CLANG_CONFIG_x86_HOST_EXTRA_LDFLAGS)
diff --git a/core/clang/HOST_x86_64.mk b/core/clang/HOST_x86_64.mk
index d60e15fea3..6b945258d9 100644
--- a/core/clang/HOST_x86_64.mk
+++ b/core/clang/HOST_x86_64.mk
@@ -1,6 +1,6 @@
 
 include $(BUILD_SYSTEM)/clang/x86_64.mk
-include $(BUILD_SYSTEM)/clang/x86_common.mk
+include $(BUILD_SYSTEM)/clang/HOST_x86_common.mk
 
 ifeq ($(HOST_OS),linux)
 CLANG_CONFIG_x86_64_HOST_TRIPLE := x86_64-linux-gnu
diff --git a/core/clang/HOST_x86_common.mk b/core/clang/HOST_x86_common.mk
new file mode 100644
index 0000000000..0241cb6636
--- /dev/null
+++ b/core/clang/HOST_x86_common.mk
@@ -0,0 +1,56 @@
+# Shared by HOST_x86.mk and HOST_x86_64.mk.
+
+ifeq ($(HOST_OS),darwin)
+# nothing required here yet
+endif
+
+ifeq ($(HOST_OS),linux)
+CLANG_CONFIG_x86_LINUX_HOST_EXTRA_ASFLAGS := \
+  --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
+  --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
+  -no-integrated-as
+
+CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CFLAGS := \
+  --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
+  -no-integrated-as
+
+ifneq ($(strip $($(clang_2nd_arch_prefix)HOST_IS_64_BIT)),)
+CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CPPFLAGS := \
+  --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
+  --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
+  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6 \
+  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/x86_64-linux \
+  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/backward \
+  -no-integrated-as
+
+CLANG_CONFIG_x86_LINUX_HOST_EXTRA_LDFLAGS := \
+  --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
+  --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
+  -B$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/bin \
+  -B$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6 \
+  -L$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6 \
+  -L$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/lib64/ \
+  -no-integrated-as
+else
+CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CPPFLAGS := \
+  --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
+  --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
+  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6 \
+  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/x86_64-linux/32 \
+  -isystem $($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/backward \
+  -no-integrated-as
+
+CLANG_CONFIG_x86_LINUX_HOST_EXTRA_LDFLAGS := \
+  --gcc-toolchain=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG) \
+  --sysroot=$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
+  -B$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/bin \
+  -B$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6/32 \
+  -L$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6/32 \
+  -L$($(clang_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/lib32/ \
+  -no-integrated-as
+endif
+endif  # Linux
+
+ifeq ($(HOST_OS),windows)
+# nothing required here yet
+endif
diff --git a/core/clang/config.mk b/core/clang/config.mk
index c598e7daba..9c5311d0f1 100644
--- a/core/clang/config.mk
+++ b/core/clang/config.mk
@@ -6,6 +6,11 @@ WITHOUT_TARGET_CLANG := true
 WITHOUT_HOST_CLANG := true
 endif
 
+# We don't have 64-bit host prebuilts yet.
+ifeq (true,$(HOST_IS_64_BIT))
+FORCE_BUILD_LLVM_COMPONENTS := true
+endif
+
 LLVM_PREBUILTS_PATH := prebuilts/clang/$(BUILD_OS)-x86/host/3.5/bin
 LLVM_PREBUILTS_HEADER_PATH := prebuilts/clang/$(BUILD_OS)-x86/host/3.5/lib/clang/3.5/include/
 
@@ -29,9 +34,14 @@ CLANG_CONFIG_EXTRA_CFLAGS := \
 
 CLANG_CONFIG_UNKNOWN_CFLAGS := \
   -funswitch-loops \
+  -fno-tree-sra \
+  -finline-limit=64 \
   -Wno-psabi \
   -Wno-unused-but-set-variable \
   -Wno-unused-but-set-parameter \
+  -Wmaybe-uninitialized \
+  -Wno-maybe-uninitialized \
+  -Wno-error=maybe-uninitialized \
   -fno-canonical-system-headers
 
 # Clang flags for all host rules
@@ -47,10 +57,13 @@ CLANG_CONFIG_TARGET_EXTRA_CPPFLAGS := -nostdlibinc
 CLANG_CONFIG_TARGET_EXTRA_LDFLAGS :=
 
 # HOST config
-ifneq ($(strip $(BUILD_HOST_64bit)),)
-include $(BUILD_SYSTEM)/clang/HOST_x86_64.mk
-else
+clang_2nd_arch_prefix :=
 include $(BUILD_SYSTEM)/clang/HOST_$(HOST_ARCH).mk
+
+# HOST_2ND_ARCH config
+ifdef HOST_2ND_ARCH
+clang_2nd_arch_prefix := $(HOST_2ND_ARCH_VAR_PREFIX)
+include $(BUILD_SYSTEM)/clang/HOST_$(HOST_2ND_ARCH).mk
 endif
 
 # TARGET config
diff --git a/core/clang/x86_common.mk b/core/clang/x86_common.mk
deleted file mode 100644
index 0bb565f52c..0000000000
--- a/core/clang/x86_common.mk
+++ /dev/null
@@ -1,54 +0,0 @@
-ifeq ($(HOST_OS),darwin)
-# nothing required here yet
-endif
-
-ifeq ($(HOST_OS),linux)
-CLANG_CONFIG_x86_LINUX_HOST_EXTRA_ASFLAGS := \
-  --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG) \
-  --sysroot=$(HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
-  -no-integrated-as
-
-CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CFLAGS := \
-  --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG) \
-  -no-integrated-as
-
-ifneq ($(strip $(BUILD_HOST_64bit)),)
-CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CPPFLAGS :=   \
-  --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG) \
-  --sysroot=$(HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
-  -isystem $(HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6 \
-  -isystem $(HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/x86_64-linux \
-  -isystem $(HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/backward \
-  -no-integrated-as
-
-CLANG_CONFIG_x86_LINUX_HOST_EXTRA_LDFLAGS := \
-  --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG) \
-  --sysroot=$(HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
-  -B$(HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/bin \
-  -B$(HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6 \
-  -L$(HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6 \
-  -L$(HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/lib64/ \
-  -no-integrated-as
-else
-CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CPPFLAGS :=   \
-  --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG) \
-  --sysroot=$(HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
-  -isystem $(HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6 \
-  -isystem $(HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/x86_64-linux/32 \
-  -isystem $(HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/include/c++/4.6/backward \
-  -no-integrated-as
-
-CLANG_CONFIG_x86_LINUX_HOST_EXTRA_LDFLAGS := \
-  --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG) \
-  --sysroot=$(HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
-  -B$(HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/bin \
-  -B$(HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6/32 \
-  -L$(HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/x86_64-linux/4.6/32 \
-  -L$(HOST_TOOLCHAIN_FOR_CLANG)/x86_64-linux/lib32/ \
-  -no-integrated-as
-endif
-endif
-
-ifeq ($(HOST_OS),windows)
-# nothing required here yet
-endif
\ No newline at end of file
diff --git a/core/cleanbuild.mk b/core/cleanbuild.mk
index fa673320c9..46a312ab14 100644
--- a/core/cleanbuild.mk
+++ b/core/cleanbuild.mk
@@ -179,11 +179,13 @@ installclean_files := \
 	$(HOST_OUT)/obj/NOTICE_FILES \
 	$(HOST_OUT)/sdk \
 	$(PRODUCT_OUT)/*.img \
+	$(PRODUCT_OUT)/*.ini \
 	$(PRODUCT_OUT)/*.txt \
 	$(PRODUCT_OUT)/*.xlb \
 	$(PRODUCT_OUT)/*.zip \
 	$(PRODUCT_OUT)/kernel \
 	$(PRODUCT_OUT)/data \
+	$(PRODUCT_OUT)/skin \
 	$(PRODUCT_OUT)/obj/APPS \
 	$(PRODUCT_OUT)/obj/NOTICE_FILES \
 	$(PRODUCT_OUT)/obj/PACKAGING \
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index 5342fd2d24..be1def1aae 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -88,6 +88,7 @@ LOCAL_COMPRESS_MODULE_SYMBOLS:=
 LOCAL_STRIP_MODULE:=
 LOCAL_JNI_SHARED_LIBRARIES:=
 LOCAL_JNI_SHARED_LIBRARIES_ABI:=
+LOCAL_PREBUILT_JNI_LIBS:=
 LOCAL_JAR_MANIFEST:=
 LOCAL_INSTRUMENTATION_FOR:=
 LOCAL_APK_LIBRARIES:=
@@ -118,7 +119,7 @@ LOCAL_RENDERSCRIPT_SKIP_INSTALL:=
 LOCAL_RENDERSCRIPT_TARGET_API:=
 LOCAL_BUILD_HOST_DEX:=
 LOCAL_DEX_PREOPT:= # '',true,false,nostripping
-LOCAL_DEX_PREOPT_IMAGE:=
+LOCAL_DEX_PREOPT_IMAGE_LOCATION:=
 LOCAL_PROTOC_OPTIMIZE_TYPE:= # lite(default),micro,nano,full
 LOCAL_PROTOC_FLAGS:=
 LOCAL_PROTO_JAVA_OUTPUT_PARAMS:=
@@ -148,6 +149,10 @@ LOCAL_MODULE_TARGET_ARCH:=
 LOCAL_MODULE_TARGET_ARCH_WARN:=
 LOCAL_MODULE_UNSUPPORTED_TARGET_ARCH:=
 LOCAL_MODULE_UNSUPPORTED_TARGET_ARCH_WARN:=
+LOCAL_MODULE_HOST_ARCH:=
+LOCAL_MODULE_HOST_ARCH_WARN:=
+LOCAL_MODULE_UNSUPPORTED_HOST_ARCH:=
+LOCAL_MODULE_UNSUPPORTED_HOST_ARCH_WARN:=
 
 # arch specific variables
 LOCAL_SRC_FILES_$(TARGET_ARCH):=
@@ -176,6 +181,32 @@ LOCAL_WHOLE_STATIC_LIBRARIES_$(TARGET_2ND_ARCH):=
 LOCAL_GENERATED_SOURCES_$(TARGET_2ND_ARCH):=
 LOCAL_REQUIRED_MODULES_$(TARGET_2ND_ARCH):=
 endif
+LOCAL_SRC_FILES_$(HOST_ARCH):=
+LOCAL_CFLAGS_$(HOST_ARCH):=
+LOCAL_CPPFLAGS_$(HOST_ARCH):=
+LOCAL_C_INCLUDES_$(HOST_ARCH):=
+LOCAL_ASFLAGS_$(HOST_ARCH):=
+LOCAL_NO_CRT_$(HOST_ARCH):=
+LOCAL_LDFLAGS_$(HOST_ARCH):=
+LOCAL_SHARED_LIBRARIES_$(HOST_ARCH):=
+LOCAL_STATIC_LIBRARIES_$(HOST_ARCH):=
+LOCAL_WHOLE_STATIC_LIBRARIES_$(HOST_ARCH):=
+LOCAL_GENERATED_SOURCES_$(HOST_ARCH):=
+LOCAL_REQUIRED_MODULES_$(HOST_ARCH):=
+ifdef HOST_2ND_ARCH
+LOCAL_SRC_FILES_$(HOST_2ND_ARCH):=
+LOCAL_CFLAGS_$(HOST_2ND_ARCH):=
+LOCAL_CPPFLAGS_$(HOST_2ND_ARCH):=
+LOCAL_C_INCLUDES_$(HOST_2ND_ARCH):=
+LOCAL_ASFLAGS_$(HOST_2ND_ARCH):=
+LOCAL_NO_CRT_$(HOST_2ND_ARCH):=
+LOCAL_LDFLAGS_$(HOST_2ND_ARCH):=
+LOCAL_SHARED_LIBRARIES_$(HOST_2ND_ARCH):=
+LOCAL_STATIC_LIBRARIES_$(HOST_2ND_ARCH):=
+LOCAL_WHOLE_STATIC_LIBRARIES_$(HOST_2ND_ARCH):=
+LOCAL_GENERATED_SOURCES_$(HOST_2ND_ARCH):=
+LOCAL_REQUIRED_MODULES_$(HOST_2ND_ARCH):=
+endif
 
 LOCAL_SRC_FILES_32:=
 LOCAL_SRC_FILES_64:=
diff --git a/core/combo/HOST_darwin-x86.mk b/core/combo/HOST_darwin-x86.mk
index b819f36cb3..4a2bfe3be2 100644
--- a/core/combo/HOST_darwin-x86.mk
+++ b/core/combo/HOST_darwin-x86.mk
@@ -17,115 +17,75 @@
 # Configuration for Darwin (Mac OS X) on x86.
 # Included by combo/select.mk
 
-ifneq ($(strip $(BUILD_HOST_64bit)),)
-# By default we build everything in 32-bit, because it gives us
-# more consistency between the host tools and the target.
-# BUILD_HOST_64bit=1 overrides it for tool like emulator
-# which can benefit from 64-bit host arch.
-HOST_GLOBAL_CFLAGS += -m64
-HOST_GLOBAL_LDFLAGS += -m64
-else
-HOST_GLOBAL_CFLAGS += -m32
-HOST_GLOBAL_LDFLAGS += -m32
-endif # BUILD_HOST_64bit
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -m32
+$(combo_2nd_arch_prefix)HOST_GLOBAL_LDFLAGS += -m32
 
 ifneq ($(strip $(BUILD_HOST_static)),)
 # Statically-linked binaries are desirable for sandboxed environment
-HOST_GLOBAL_LDFLAGS += -static
+$(combo_2nd_arch_prefix)HOST_GLOBAL_LDFLAGS += -static
 endif # BUILD_HOST_static
 
 # Workaround differences in inttypes.h between host and target.
 # See bug 12708004.
-HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS
-
-build_mac_version := $(shell sw_vers -productVersion)
-
-mac_sdk_versions_supported :=  10.6 10.7 10.8
-ifneq ($(strip $(MAC_SDK_VERSION)),)
-mac_sdk_version := $(MAC_SDK_VERSION)
-ifeq ($(filter $(mac_sdk_version),$(mac_sdk_versions_supported)),)
-$(warning ****************************************************************)
-$(warning * MAC_SDK_VERSION $(MAC_SDK_VERSION) isn't one of the supported $(mac_sdk_versions_supported))
-$(warning ****************************************************************)
-$(error Stop.)
-endif
-else
-mac_sdk_versions_installed := $(shell xcodebuild -showsdks | grep macosx | sort | sed -e "s/.*macosx//g")
-mac_sdk_version := $(firstword $(filter $(mac_sdk_versions_installed), $(mac_sdk_versions_supported)))
-ifeq ($(mac_sdk_version),)
-mac_sdk_version := $(firstword $(mac_sdk_versions_supported))
-endif
-endif
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS
 
-mac_sdk_path := $(shell xcode-select -print-path)
-# try /Applications/Xcode*.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.?.sdk
-#  or /Volume/Xcode/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.?.sdk
-mac_sdk_root := $(mac_sdk_path)/Platforms/MacOSX.platform/Developer/SDKs/MacOSX$(mac_sdk_version).sdk
-ifeq ($(wildcard $(mac_sdk_root)),)
-# try legacy /Developer/SDKs/MacOSX10.?.sdk
-mac_sdk_root := /Developer/SDKs/MacOSX$(mac_sdk_version).sdk
-endif
-ifeq ($(wildcard $(mac_sdk_root)),)
-$(warning *****************************************************)
-$(warning * Can not find SDK $(mac_sdk_version) at $(mac_sdk_root))
-$(warning *****************************************************)
-$(error Stop.)
-endif
-
-ifeq ($(mac_sdk_version),10.6)
-  gcc_darwin_version := 10
-else
-  gcc_darwin_version := 11
-endif
+include $(BUILD_COMBOS)/mac_version.mk
 
-HOST_TOOLCHAIN_ROOT := prebuilts/gcc/darwin-x86/host/i686-apple-darwin-4.2.1
-HOST_TOOLCHAIN_PREFIX := $(HOST_TOOLCHAIN_ROOT)/bin/i686-apple-darwin$(gcc_darwin_version)
+$(combo_2nd_arch_prefix)HOST_TOOLCHAIN_ROOT := prebuilts/gcc/darwin-x86/host/i686-apple-darwin-4.2.1
+$(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX := $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_ROOT)/bin/i686-apple-darwin$(gcc_darwin_version)
 # Don't do anything if the toolchain is not there
-ifneq (,$(strip $(wildcard $(HOST_TOOLCHAIN_PREFIX)-gcc)))
-HOST_CC  := $(HOST_TOOLCHAIN_PREFIX)-gcc
-HOST_CXX := $(HOST_TOOLCHAIN_PREFIX)-g++
+ifneq (,$(strip $(wildcard $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)-gcc)))
+$(combo_2nd_arch_prefix)HOST_CC  := $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)-gcc
+$(combo_2nd_arch_prefix)HOST_CXX := $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)-g++
 ifeq ($(mac_sdk_version),10.8)
 # Mac SDK 10.8 no longer has stdarg.h, etc
-host_toolchain_header := $(HOST_TOOLCHAIN_ROOT)/lib/gcc/i686-apple-darwin$(gcc_darwin_version)/4.2.1/include
-HOST_GLOBAL_CFLAGS += -isystem $(host_toolchain_header)
+host_toolchain_header := $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_ROOT)/lib/gcc/i686-apple-darwin$(gcc_darwin_version)/4.2.1/include
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -isystem $(host_toolchain_header)
 endif
 else
-HOST_CC := gcc
-HOST_CXX := g++
+$(combo_2nd_arch_prefix)HOST_CC := gcc
+$(combo_2nd_arch_prefix)HOST_CXX := g++
 endif # $(HOST_TOOLCHAIN_PREFIX)-gcc exists
-HOST_AR := $(AR)
-HOST_STRIP := $(STRIP)
-HOST_STRIP_COMMAND = $(HOST_STRIP) --strip-all $< -o $@
 
-HOST_GLOBAL_CFLAGS += -isysroot $(mac_sdk_root) -mmacosx-version-min=$(mac_sdk_version) -DMACOSX_DEPLOYMENT_TARGET=$(mac_sdk_version)
-HOST_GLOBAL_LDFLAGS += -isysroot $(mac_sdk_root) -Wl,-syslibroot,$(mac_sdk_root) -mmacosx-version-min=$(mac_sdk_version)
+# gcc location for clang; to be updated when clang is updated
+# HOST_TOOLCHAIN_ROOT is a Darwin-specific define
+$(combo_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG := $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_ROOT)
+
+$(combo_2nd_arch_prefix)HOST_AR := $(AR)
 
-HOST_GLOBAL_CFLAGS += -fPIC -funwind-tables
-HOST_NO_UNDEFINED_LDFLAGS := -Wl,-undefined,error
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -isysroot $(mac_sdk_root) -mmacosx-version-min=$(mac_sdk_version) -DMACOSX_DEPLOYMENT_TARGET=$(mac_sdk_version)
+$(combo_2nd_arch_prefix)HOST_GLOBAL_LDFLAGS += -isysroot $(mac_sdk_root) -Wl,-syslibroot,$(mac_sdk_root) -mmacosx-version-min=$(mac_sdk_version)
 
-HOST_SHLIB_SUFFIX := .dylib
-HOST_JNILIB_SUFFIX := .jnilib
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -fPIC -funwind-tables
+$(combo_2nd_arch_prefix)HOST_NO_UNDEFINED_LDFLAGS := -Wl,-undefined,error
 
-HOST_GLOBAL_CFLAGS += \
+$(combo_2nd_arch_prefix)HOST_SHLIB_SUFFIX := .dylib
+$(combo_2nd_arch_prefix)HOST_JNILIB_SUFFIX := .jnilib
+
+# TODO: add AndroidConfig.h for darwin-x86_64
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += \
     -include $(call select-android-config-h,darwin-x86)
 
 ifneq ($(filter 10.7 10.7.% 10.8 10.8.%, $(build_mac_version)),)
-       HOST_RUN_RANLIB_AFTER_COPYING := false
+       $(combo_2nd_arch_prefix)HOST_RUN_RANLIB_AFTER_COPYING := false
 else
-       HOST_RUN_RANLIB_AFTER_COPYING := true
+       $(combo_2nd_arch_prefix)HOST_RUN_RANLIB_AFTER_COPYING := true
        PRE_LION_DYNAMIC_LINKER_OPTIONS := -Wl,-dynamic
 endif
-HOST_GLOBAL_ARFLAGS := cqs
+$(combo_2nd_arch_prefix)HOST_GLOBAL_ARFLAGS := cqs
+
+############################################################
+## Macros after this line are shared by the 64-bit config.
 
 HOST_CUSTOM_LD_COMMAND := true
 
 define transform-host-o-to-shared-lib-inner
 $(hide) $(PRIVATE_CXX) \
         -dynamiclib -single_module -read_only_relocs suppress \
-        $(HOST_GLOBAL_LD_DIRS) \
-	$(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),, \
-	   $(PRIVATE_HOST_GLOBAL_LDFLAGS) \
-	) \
+        $($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_LD_DIRS) \
+        $(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),, \
+            $(PRIVATE_HOST_GLOBAL_LDFLAGS) \
+        ) \
         $(PRIVATE_ALL_OBJECTS) \
         $(addprefix -force_load , $(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES)) \
         $(call normalize-host-libraries,$(PRIVATE_ALL_SHARED_LIBRARIES)) \
@@ -133,34 +93,28 @@ $(hide) $(PRIVATE_CXX) \
         $(PRIVATE_LDLIBS) \
         -o $@ \
         -install_name @rpath/$(notdir $@) \
-        -Wl,-rpath,@loader_path/../lib \
-        $(PRIVATE_LDFLAGS) \
-        $(HOST_LIBGCC)
+        -Wl,-rpath,@loader_path/../$(notdir $($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_OUT_SHARED_LIBRARIES)) \
+        $(PRIVATE_LDFLAGS)
 endef
 
 define transform-host-o-to-executable-inner
 $(hide) $(PRIVATE_CXX) \
-        -Wl,-rpath,@loader_path/../lib \
+        -Wl,-rpath,@loader_path/../$(notdir $($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_OUT_SHARED_LIBRARIES)) \
         -o $@ \
         $(PRE_LION_DYNAMIC_LINKER_OPTIONS) -Wl,-headerpad_max_install_names \
-        $(HOST_GLOBAL_LD_DIRS) \
-	$(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),, \
-	   $(PRIVATE_HOST_GLOBAL_LDFLAGS) \
-	) \
+        $($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_LD_DIRS) \
+        $(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),, \
+           $(PRIVATE_HOST_GLOBAL_LDFLAGS) \
+        ) \
         $(call normalize-host-libraries,$(PRIVATE_ALL_SHARED_LIBRARIES)) \
         $(PRIVATE_ALL_OBJECTS) \
         $(call normalize-host-libraries,$(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES)) \
         $(call normalize-host-libraries,$(PRIVATE_ALL_STATIC_LIBRARIES)) \
         $(PRIVATE_LDFLAGS) \
-        $(PRIVATE_LDLIBS) \
-        $(HOST_LIBGCC)
+        $(PRIVATE_LDLIBS)
 endef
 
 # $(1): The file to check
 define get-file-size
 stat -f "%z" $(1)
 endef
-
-# gcc location for clang; to be updated when clang is updated
-# HOST_TOOLCHAIN_ROOT is a Darwin-specific define
-HOST_TOOLCHAIN_FOR_CLANG := $(HOST_TOOLCHAIN_ROOT)
\ No newline at end of file
diff --git a/core/combo/HOST_darwin-x86_64.mk b/core/combo/HOST_darwin-x86_64.mk
new file mode 100644
index 0000000000..8ad3ba76f1
--- /dev/null
+++ b/core/combo/HOST_darwin-x86_64.mk
@@ -0,0 +1,80 @@
+#
+# Copyright (C) 2006 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Configuration for Darwin (Mac OS X) on x86_64.
+# Included by combo/select.mk
+
+HOST_IS_64_BIT := true
+
+HOST_GLOBAL_CFLAGS += -m64
+HOST_GLOBAL_LDFLAGS += -m64
+
+ifneq ($(strip $(BUILD_HOST_static)),)
+# Statically-linked binaries are desirable for sandboxed environment
+HOST_GLOBAL_LDFLAGS += -static
+endif # BUILD_HOST_static
+
+# Workaround differences in inttypes.h between host and target.
+# See bug 12708004.
+HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS
+
+include $(BUILD_COMBOS)/mac_version.mk
+
+HOST_TOOLCHAIN_ROOT := prebuilts/gcc/darwin-x86/host/i686-apple-darwin-4.2.1
+HOST_TOOLCHAIN_PREFIX := $(HOST_TOOLCHAIN_ROOT)/bin/i686-apple-darwin$(gcc_darwin_version)
+# Don't do anything if the toolchain is not there
+ifneq (,$(strip $(wildcard $(HOST_TOOLCHAIN_PREFIX)-gcc)))
+HOST_CC  := $(HOST_TOOLCHAIN_PREFIX)-gcc
+HOST_CXX := $(HOST_TOOLCHAIN_PREFIX)-g++
+ifeq ($(mac_sdk_version),10.8)
+# Mac SDK 10.8 no longer has stdarg.h, etc
+host_toolchain_header := $(HOST_TOOLCHAIN_ROOT)/lib/gcc/i686-apple-darwin$(gcc_darwin_version)/4.2.1/include
+HOST_GLOBAL_CFLAGS += -isystem $(host_toolchain_header)
+endif
+else
+HOST_CC := gcc
+HOST_CXX := g++
+endif # $(HOST_TOOLCHAIN_PREFIX)-gcc exists
+
+# gcc location for clang; to be updated when clang is updated
+# HOST_TOOLCHAIN_ROOT is a Darwin-specific define
+HOST_TOOLCHAIN_FOR_CLANG := $(HOST_TOOLCHAIN_ROOT)
+
+HOST_AR := $(AR)
+
+HOST_GLOBAL_CFLAGS += -isysroot $(mac_sdk_root) -mmacosx-version-min=$(mac_sdk_version) -DMACOSX_DEPLOYMENT_TARGET=$(mac_sdk_version)
+HOST_GLOBAL_LDFLAGS += -isysroot $(mac_sdk_root) -Wl,-syslibroot,$(mac_sdk_root) -mmacosx-version-min=$(mac_sdk_version)
+
+HOST_GLOBAL_CFLAGS += -fPIC -funwind-tables
+HOST_NO_UNDEFINED_LDFLAGS := -Wl,-undefined,error
+
+HOST_SHLIB_SUFFIX := .dylib
+HOST_JNILIB_SUFFIX := .jnilib
+
+HOST_GLOBAL_CFLAGS += \
+    -include $(call select-android-config-h,darwin-x86)
+
+ifneq ($(filter 10.7 10.7.% 10.8 10.8.%, $(build_mac_version)),)
+       HOST_RUN_RANLIB_AFTER_COPYING := false
+else
+       HOST_RUN_RANLIB_AFTER_COPYING := true
+endif
+HOST_GLOBAL_ARFLAGS := cqs
+
+# We Reuse the following functions with the same name from HOST_darwin-x86.mk:
+# transform-host-o-to-shared-lib-inner
+# transform-host-o-to-executable-inner
+# get-file-size
diff --git a/core/combo/HOST_linux-x86.mk b/core/combo/HOST_linux-x86.mk
index 3c44d93cf0..c931937d85 100644
--- a/core/combo/HOST_linux-x86.mk
+++ b/core/combo/HOST_linux-x86.mk
@@ -17,55 +17,46 @@
 # Configuration for builds hosted on linux-x86.
 # Included by combo/select.mk
 
-# $(1): The file to check
-define get-file-size
-stat --format "%s" "$(1)" | tr -d '\n'
-endef
-
-ifeq ($(strip $(HOST_TOOLCHAIN_PREFIX)),)
-HOST_TOOLCHAIN_PREFIX := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.6/bin/x86_64-linux-
+ifeq ($(strip $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)),)
+$(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.6/bin/x86_64-linux-
 endif
 # Don't do anything if the toolchain is not there
-ifneq (,$(strip $(wildcard $(HOST_TOOLCHAIN_PREFIX)gcc)))
-HOST_CC  := $(HOST_TOOLCHAIN_PREFIX)gcc
-HOST_CXX := $(HOST_TOOLCHAIN_PREFIX)g++
-HOST_AR  := $(HOST_TOOLCHAIN_PREFIX)ar
-endif # $(HOST_TOOLCHAIN_PREFIX)gcc exists
+ifneq (,$(strip $(wildcard $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)gcc)))
+$(combo_2nd_arch_prefix)HOST_CC  := $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)gcc
+$(combo_2nd_arch_prefix)HOST_CXX := $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)g++
+$(combo_2nd_arch_prefix)HOST_AR  := $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)ar
+endif # $($(combo_2nd_arch_prefix)HOST_TOOLCHAIN_PREFIX)gcc exists
 
-HOST_TOOLCHAIN_FOR_CLANG := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.6/
-# By default we build everything in 32-bit if the target is 32-bit or
-# in 64-bit if the target is 64-bit. This gives more consistency
-# between the host tools and the target.
-# BUILD_HOST_64bit can also be set to 1 to override this behaviour
-# for tools like the emulator which can benefit from 64-bit host arch
-# (even when emulating 32-bit targets).
-ifneq ($(filter %64,$(TARGET_ARCH)),)
-BUILD_HOST_64bit=1
-endif
+# gcc location for clang; to be updated when clang is updated
+$(combo_2nd_arch_prefix)HOST_TOOLCHAIN_FOR_CLANG := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.6/
 
-ifneq ($(strip $(BUILD_HOST_64bit)),)
-HOST_GLOBAL_CFLAGS += -m64 -Wa,--noexecstack
-HOST_GLOBAL_LDFLAGS += -m64 -Wl,-z,noexecstack
-else
 # We expect SSE3 floating point math.
-HOST_GLOBAL_CFLAGS += -mstackrealign -msse3 -mfpmath=sse -m32 -Wa,--noexecstack
-HOST_GLOBAL_LDFLAGS += -m32 -Wl,-z,noexecstack
-endif # BUILD_HOST_64bit
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -mstackrealign -msse3 -mfpmath=sse -m32 -Wa,--noexecstack
+$(combo_2nd_arch_prefix)HOST_GLOBAL_LDFLAGS += -m32 -Wl,-z,noexecstack
 
 ifneq ($(strip $(BUILD_HOST_static)),)
 # Statically-linked binaries are desirable for sandboxed environment
-HOST_GLOBAL_LDFLAGS += -static
+$(combo_2nd_arch_prefix)HOST_GLOBAL_LDFLAGS += -static
 endif # BUILD_HOST_static
 
-HOST_GLOBAL_CFLAGS += -fPIC \
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -fPIC \
   -no-canonical-prefixes \
   -include $(call select-android-config-h,linux-x86)
 
 # Disable new longjmp in glibc 2.11 and later. See bug 2967937.
-HOST_GLOBAL_CFLAGS += -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0
 
 # Workaround differences in inttypes.h between host and target.
 # See bug 12708004.
-HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS
+
+$(combo_2nd_arch_prefix)HOST_NO_UNDEFINED_LDFLAGS := -Wl,--no-undefined
 
-HOST_NO_UNDEFINED_LDFLAGS := -Wl,--no-undefined
+
+############################################################
+## Macros after this line are shared by the 64-bit config.
+
+# $(1): The file to check
+define get-file-size
+stat --format "%s" "$(1)" | tr -d '\n'
+endef
diff --git a/core/combo/HOST_linux-x86_64.mk b/core/combo/HOST_linux-x86_64.mk
new file mode 100644
index 0000000000..8f3a31106f
--- /dev/null
+++ b/core/combo/HOST_linux-x86_64.mk
@@ -0,0 +1,55 @@
+#
+# Copyright (C) 2006 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Configuration for builds hosted on linux-x86_64.
+# Included by combo/select.mk
+
+HOST_IS_64_BIT := true
+
+ifeq ($(strip $(HOST_TOOLCHAIN_PREFIX)),)
+HOST_TOOLCHAIN_PREFIX := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.6/bin/x86_64-linux-
+endif
+# Don't do anything if the toolchain is not there
+ifneq (,$(strip $(wildcard $(HOST_TOOLCHAIN_PREFIX)gcc)))
+HOST_CC  := $(HOST_TOOLCHAIN_PREFIX)gcc
+HOST_CXX := $(HOST_TOOLCHAIN_PREFIX)g++
+HOST_AR  := $(HOST_TOOLCHAIN_PREFIX)ar
+endif # $(HOST_TOOLCHAIN_PREFIX)gcc exists
+
+# gcc location for clang; to be updated when clang is updated
+HOST_TOOLCHAIN_FOR_CLANG := prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.6/
+
+HOST_GLOBAL_CFLAGS += -m64 -Wa,--noexecstack
+HOST_GLOBAL_LDFLAGS += -m64 -Wl,-z,noexecstack
+
+ifneq ($(strip $(BUILD_HOST_static)),)
+# Statically-linked binaries are desirable for sandboxed environment
+HOST_GLOBAL_LDFLAGS += -static
+endif # BUILD_HOST_static
+
+# TODO: Add AndroidConfig.h for linux-x86_64
+HOST_GLOBAL_CFLAGS += -fPIC \
+  -no-canonical-prefixes \
+  -include $(call select-android-config-h,linux-x86)
+
+# Disable new longjmp in glibc 2.11 and later. See bug 2967937.
+HOST_GLOBAL_CFLAGS += -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0
+
+# Workaround differences in inttypes.h between host and target.
+# See bug 12708004.
+HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS
+
+HOST_NO_UNDEFINED_LDFLAGS := -Wl,--no-undefined
diff --git a/core/combo/HOST_windows-x86.mk b/core/combo/HOST_windows-x86.mk
index cd047a1283..4d871d879d 100644
--- a/core/combo/HOST_windows-x86.mk
+++ b/core/combo/HOST_windows-x86.mk
@@ -27,32 +27,29 @@ ifneq ($(findstring Linux,$(UNAME)),)
 ifneq ($(strip $(USE_MINGW)),)
 HOST_ACP_UNAVAILABLE := true
 TOOLS_EXE_SUFFIX :=
-HOST_GLOBAL_CFLAGS += -DUSE_MINGW
-ifneq ($(strip $(BUILD_HOST_64bit)),)
-TOOLS_PREFIX := /usr/bin/amd64-mingw32msvc-
-HOST_C_INCLUDES += /usr/lib/gcc/amd64-mingw32msvc/4.4.2/include
-HOST_GLOBAL_LD_DIRS += -L/usr/amd64-mingw32msvc/lib
-else
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -DUSE_MINGW
 TOOLS_PREFIX := /usr/bin/i586-mingw32msvc-
-HOST_C_INCLUDES += /usr/lib/gcc/i586-mingw32msvc/3.4.4/include
-HOST_GLOBAL_LD_DIRS += -L/usr/i586-mingw32msvc/lib
-endif # BUILD_HOST_64bit
+$(combo_2nd_arch_prefix)HOST_C_INCLUDES += /usr/lib/gcc/i586-mingw32msvc/3.4.4/include
+$(combo_2nd_arch_prefix)HOST_GLOBAL_LD_DIRS += -L/usr/i586-mingw32msvc/lib
 endif # USE_MINGW
 endif # Linux
 
 # Workaround differences in inttypes.h between host and target.
 # See bug 12708004.
-HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS -D__USE_MINGW_ANSI_STDIO
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS -D__USE_MINGW_ANSI_STDIO
 
-HOST_CC := $(TOOLS_PREFIX)gcc$(TOOLS_EXE_SUFFIX)
-HOST_CXX := $(TOOLS_PREFIX)g++$(TOOLS_EXE_SUFFIX)
-HOST_AR := $(TOOLS_PREFIX)ar$(TOOLS_EXE_SUFFIX)
+$(combo_2nd_arch_prefix)HOST_CC := $(TOOLS_PREFIX)gcc$(TOOLS_EXE_SUFFIX)
+$(combo_2nd_arch_prefix)HOST_CXX := $(TOOLS_PREFIX)g++$(TOOLS_EXE_SUFFIX)
+$(combo_2nd_arch_prefix)HOST_AR := $(TOOLS_PREFIX)ar$(TOOLS_EXE_SUFFIX)
+
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += \
+    -include $(call select-android-config-h,windows)
+$(combo_2nd_arch_prefix)HOST_GLOBAL_LDFLAGS += \
+    --enable-stdcall-fixup
 
-HOST_GLOBAL_CFLAGS += -include $(call select-android-config-h,windows)
-HOST_GLOBAL_LDFLAGS += --enable-stdcall-fixup
 ifneq ($(strip $(BUILD_HOST_static)),)
 # Statically-linked binaries are desirable for sandboxed environment
-HOST_GLOBAL_LDFLAGS += -static
+$(combo_2nd_arch_prefix)HOST_GLOBAL_LDFLAGS += -static
 endif # BUILD_HOST_static
 
 # when building under Cygwin, ensure that we use Mingw compilation by default.
@@ -66,11 +63,14 @@ endif # BUILD_HOST_static
 #
 ifneq ($(findstring CYGWIN,$(UNAME)),)
 ifeq ($(strip $(USE_CYGWIN)),)
-HOST_GLOBAL_CFLAGS += -mno-cygwin
-HOST_GLOBAL_LDFLAGS += -mno-cygwin -mconsole
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -mno-cygwin
+$(combo_2nd_arch_prefix)HOST_GLOBAL_LDFLAGS += -mno-cygwin -mconsole
 endif
 endif
 
+############################################################
+## Macros after this line are shared by the 64-bit config.
+
 HOST_SHLIB_SUFFIX := .dll
 HOST_EXECUTABLE_SUFFIX := .exe
 
diff --git a/core/combo/HOST_windows-x86_64.mk b/core/combo/HOST_windows-x86_64.mk
new file mode 100644
index 0000000000..9edc6195a1
--- /dev/null
+++ b/core/combo/HOST_windows-x86_64.mk
@@ -0,0 +1,68 @@
+#
+# Copyright (C) 2006 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Configuration for Windows on x86_64.
+# Included by combo/select.make
+
+# right now we get these from the environment, but we should
+# pick them from the tree somewhere
+TOOLS_PREFIX := #prebuilt/windows/host/bin/
+TOOLS_EXE_SUFFIX := .exe
+
+HOST_IS_64_BIT := true
+
+# Settings to use MinGW has a cross-compiler under Linux
+ifneq ($(findstring Linux,$(UNAME)),)
+ifneq ($(strip $(USE_MINGW)),)
+HOST_ACP_UNAVAILABLE := true
+TOOLS_EXE_SUFFIX :=
+HOST_GLOBAL_CFLAGS += -DUSE_MINGW
+TOOLS_PREFIX := /usr/bin/amd64-mingw32msvc-
+HOST_C_INCLUDES += /usr/lib/gcc/amd64-mingw32msvc/4.4.2/include
+HOST_GLOBAL_LD_DIRS += -L/usr/amd64-mingw32msvc/lib
+endif # USE_MINGW
+endif # Linux
+
+# Workaround differences in inttypes.h between host and target.
+# See bug 12708004.
+HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS -D__USE_MINGW_ANSI_STDIO
+
+HOST_CC := $(TOOLS_PREFIX)gcc$(TOOLS_EXE_SUFFIX)
+HOST_CXX := $(TOOLS_PREFIX)g++$(TOOLS_EXE_SUFFIX)
+HOST_AR := $(TOOLS_PREFIX)ar$(TOOLS_EXE_SUFFIX)
+
+HOST_GLOBAL_CFLAGS += -include $(call select-android-config-h,windows)
+HOST_GLOBAL_LDFLAGS += --enable-stdcall-fixup
+ifneq ($(strip $(BUILD_HOST_static)),)
+# Statically-linked binaries are desirable for sandboxed environment
+HOST_GLOBAL_LDFLAGS += -static
+endif # BUILD_HOST_static
+
+# when building under Cygwin, ensure that we use Mingw compilation by default.
+# you can disable this (i.e. to generate Cygwin executables) by defining the
+# USE_CYGWIN variable in your environment, e.g.:
+#
+#   export USE_CYGWIN=1
+#
+# note that the -mno-cygwin flags are not needed when cross-compiling the
+# Windows host tools on Linux
+#
+ifneq ($(findstring CYGWIN,$(UNAME)),)
+ifeq ($(strip $(USE_CYGWIN)),)
+HOST_GLOBAL_CFLAGS += -mno-cygwin
+HOST_GLOBAL_LDFLAGS += -mno-cygwin -mconsole
+endif
+endif
diff --git a/core/combo/TARGET_linux-arm64.mk b/core/combo/TARGET_linux-arm64.mk
index 6515eb5094..9518ba7da4 100644
--- a/core/combo/TARGET_linux-arm64.mk
+++ b/core/combo/TARGET_linux-arm64.mk
@@ -38,7 +38,7 @@ endif
 TARGET_NDK_GCC_VERSION := 4.8
 
 ifeq ($(strip $(TARGET_GCC_VERSION_EXP)),)
-TARGET_GCC_VERSION := 4.8
+TARGET_GCC_VERSION := 4.9
 else
 TARGET_GCC_VERSION := $(TARGET_GCC_VERSION_EXP)
 endif
@@ -73,13 +73,9 @@ TARGET_GLOBAL_CFLAGS += \
 
 android_config_h := $(call select-android-config-h,linux-arm64)
 
-# HACK: globally disable -fstack-protector until the toolchain supports it
-TARGET_GLOBAL_UNSUPPORTED_CFLAGS := \
-    -fstack-protector \
-    -fstack-protector-all \
-
 TARGET_GLOBAL_CFLAGS += \
 			-fpic -fPIE \
+			-fstack-protector \
 			-ffunction-sections \
 			-fdata-sections \
 			-funwind-tables \
@@ -165,6 +161,7 @@ TARGET_CUSTOM_LD_COMMAND := true
 define transform-o-to-shared-lib-inner
 $(hide) $(PRIVATE_CXX) \
 	-nostdlib -Wl,-soname,$(notdir $@) \
+	-Wl,--gc-sections \
 	-Wl,-shared,-Bsymbolic \
 	$(PRIVATE_TARGET_GLOBAL_LD_DIRS) \
 	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTBEGIN_SO_O)) \
@@ -189,6 +186,7 @@ endef
 define transform-o-to-executable-inner
 $(hide) $(PRIVATE_CXX) -nostdlib -Bdynamic -fPIE -pie \
 	-Wl,-dynamic-linker,/system/bin/linker64 \
+	-Wl,--gc-sections \
 	-Wl,-z,nocopyreloc \
 	$(PRIVATE_TARGET_GLOBAL_LD_DIRS) \
 	-Wl,-rpath-link=$(PRIVATE_TARGET_OUT_INTERMEDIATE_LIBRARIES) \
@@ -213,6 +211,7 @@ endef
 
 define transform-o-to-static-executable-inner
 $(hide) $(PRIVATE_CXX) -nostdlib -Bstatic \
+	-Wl,--gc-sections \
 	-o $@ \
 	$(PRIVATE_TARGET_GLOBAL_LD_DIRS) \
 	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTBEGIN_STATIC_O)) \
diff --git a/core/combo/mac_version.mk b/core/combo/mac_version.mk
new file mode 100644
index 0000000000..b49feeefbe
--- /dev/null
+++ b/core/combo/mac_version.mk
@@ -0,0 +1,50 @@
+# Detect Mac OS X and SDK versions.
+# Output variables:
+#   build_mac_version
+#   mac_sdk_version
+#   mac_sdk_root
+#   gcc_darwin_version
+
+ifndef build_mac_version
+
+build_mac_version := $(shell sw_vers -productVersion)
+
+mac_sdk_versions_supported :=  10.6 10.7 10.8
+ifneq ($(strip $(MAC_SDK_VERSION)),)
+mac_sdk_version := $(MAC_SDK_VERSION)
+ifeq ($(filter $(mac_sdk_version),$(mac_sdk_versions_supported)),)
+$(warning ****************************************************************)
+$(warning * MAC_SDK_VERSION $(MAC_SDK_VERSION) isn't one of the supported $(mac_sdk_versions_supported))
+$(warning ****************************************************************)
+$(error Stop.)
+endif
+else
+mac_sdk_versions_installed := $(shell xcodebuild -showsdks | grep macosx | sort | sed -e "s/.*macosx//g")
+mac_sdk_version := $(firstword $(filter $(mac_sdk_versions_installed), $(mac_sdk_versions_supported)))
+ifeq ($(mac_sdk_version),)
+mac_sdk_version := $(firstword $(mac_sdk_versions_supported))
+endif
+endif
+
+mac_sdk_path := $(shell xcode-select -print-path)
+# try /Applications/Xcode*.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.?.sdk
+#  or /Volume/Xcode/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.?.sdk
+mac_sdk_root := $(mac_sdk_path)/Platforms/MacOSX.platform/Developer/SDKs/MacOSX$(mac_sdk_version).sdk
+ifeq ($(wildcard $(mac_sdk_root)),)
+# try legacy /Developer/SDKs/MacOSX10.?.sdk
+mac_sdk_root := /Developer/SDKs/MacOSX$(mac_sdk_version).sdk
+endif
+ifeq ($(wildcard $(mac_sdk_root)),)
+$(warning *****************************************************)
+$(warning * Can not find SDK $(mac_sdk_version) at $(mac_sdk_root))
+$(warning *****************************************************)
+$(error Stop.)
+endif
+
+ifeq ($(mac_sdk_version),10.6)
+  gcc_darwin_version := 10
+else
+  gcc_darwin_version := 11
+endif
+
+endif  # ifndef build_mac_version
diff --git a/core/combo/select.mk b/core/combo/select.mk
index c1a7cc05a6..8234a8fcb1 100644
--- a/core/combo/select.mk
+++ b/core/combo/select.mk
@@ -18,15 +18,11 @@
 #
 # Inputs:
 #	combo_target -- prefix for final variables (HOST_ or TARGET_)
-#	combo_2nd_arch_prefix -- it's defined if this is loaded for TARGET_2ND_ARCH.
+#	combo_2nd_arch_prefix -- it's defined if this is loaded for the 2nd arch.
 #
 
 # Build a target string like "linux-arm" or "darwin-x86".
-ifdef combo_2nd_arch_prefix
-combo_os_arch := $($(combo_target)OS)-$(TARGET_2ND_ARCH)
-else
-combo_os_arch := $($(combo_target)OS)-$($(combo_target)ARCH)
-endif
+combo_os_arch := $($(combo_target)OS)-$($(combo_target)$(combo_2nd_arch_prefix)ARCH)
 
 combo_var_prefix := $(combo_2nd_arch_prefix)$(combo_target)
 
@@ -90,7 +86,7 @@ ifneq ($(USE_CCACHE),)
   # If we are cross-compiling Windows binaries on Linux
   # then use the linux ccache binary instead.
   ifeq ($(HOST_OS)-$(BUILD_OS),windows-linux)
-    CCACHE_HOST_TAG := linux-$(BUILD_ARCH)
+    CCACHE_HOST_TAG := linux-$(HOST_PREBUILT_ARCH)
   endif
   ccache := prebuilts/misc/$(CCACHE_HOST_TAG)/ccache/ccache
   # Check that the executable is here.
diff --git a/core/config.mk b/core/config.mk
index 322f258803..715038053c 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -217,6 +217,13 @@ combo_target := HOST_
 combo_2nd_arch_prefix :=
 include $(BUILD_SYSTEM)/combo/select.mk
 
+# Load the 2nd host arch if it's needed.
+ifdef HOST_2ND_ARCH
+combo_target := HOST_
+combo_2nd_arch_prefix := $(HOST_2ND_ARCH_VAR_PREFIX)
+include $(BUILD_SYSTEM)/combo/select.mk
+endif
+
 # on windows, the tools have .exe at the end, and we depend on the
 # host config stuff being done first
 
@@ -351,13 +358,13 @@ endif
 # ---------------------------------------------------------------
 # Generic tools.
 
-LEX := prebuilts/misc/$(BUILD_OS)-$(BUILD_ARCH)/flex/flex-2.5.39
+LEX := prebuilts/misc/$(BUILD_OS)-$(HOST_PREBUILT_ARCH)/flex/flex-2.5.39
 # The default PKGDATADIR built in the prebuilt bison is a relative path
 # external/bison/data.
 # To run bison from elsewhere you need to set up enviromental variable
 # BISON_PKGDATADIR.
 BISON_PKGDATADIR := $(PWD)/external/bison/data
-BISON := prebuilts/misc/$(BUILD_OS)-$(BUILD_ARCH)/bison/bison
+BISON := prebuilts/misc/$(BUILD_OS)-$(HOST_PREBUILT_ARCH)/bison/bison
 YACC := $(BISON) -d
 
 DOXYGEN:= doxygen
@@ -501,29 +508,39 @@ $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_GLOBAL_CFLAGS += $($(TARGET_2ND_ARCH_VAR_PRE
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_GLOBAL_CPPFLAGS += $($(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_RELEASE_CPPFLAGS)
 endif
 
+ifdef HOST_2ND_ARCH
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_CFLAGS += $(COMMON_GLOBAL_CFLAGS)
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_RELEASE_CFLAGS += $(COMMON_RELEASE_CFLAGS)
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_CPPFLAGS += $(COMMON_GLOBAL_CPPFLAGS)
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_RELEASE_CPPFLAGS += $(COMMON_RELEASE_CPPFLAGS)
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_LD_DIRS += -L$($(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_INTERMEDIATE_LIBRARIES)
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_PROJECT_INCLUDES := $(HOST_PROJECT_INCLUDES)
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_CFLAGS += $($(HOST_2ND_ARCH_VAR_PREFIX)HOST_RELEASE_CFLAGS)
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_CPPFLAGS += $($(HOST_2ND_ARCH_VAR_PREFIX)HOST_RELEASE_CPPFLAGS)
+endif
+
 # allow overriding default Java libraries on a per-target basis
 ifeq ($(TARGET_DEFAULT_JAVA_LIBRARIES),)
   TARGET_DEFAULT_JAVA_LIBRARIES := core core-junit ext framework framework2
 endif
 
+TARGET_CPU_SMP ?= true
+
 # Flags for DEX2OAT
 DEX2OAT_TARGET_ARCH := $(TARGET_ARCH)
 DEX2OAT_TARGET_CPU_VARIANT := $(TARGET_CPU_VARIANT)
 DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES := default
+ifneq (,$(filter $(DEX2OAT_TARGET_CPU_VARIANT),cortex-a7 cortex-a15 krait denver))
+  DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES := div
+endif
 
-# If for a 64bit build we have a 2nd architecture but the zygote isn't 64bit,
-# assume DEX2OAT should DEXPREOPT for the 2nd architecture.
 ifdef TARGET_2ND_ARCH
-  ifeq (true,$(TARGET_IS_64_BIT))
-    ifeq ($(filter ro.zygote=zygote64,$(PRODUCT_DEFAULT_PROPERTY_OVERRIDES)),)
-      DEX2OAT_TARGET_ARCH := $(TARGET_2ND_ARCH)
-      DEX2OAT_TARGET_CPU_VARIANT := $(TARGET_2ND_CPU_VARIANT)
-    endif
-  endif
+$(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_ARCH := $(TARGET_2ND_ARCH)
+$(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_CPU_VARIANT := $(TARGET_2ND_CPU_VARIANT)
+$(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES := default
+ifneq (,$(filter $($(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_CPU_VARIANT),cortex-a7 cortex-a15 krait denver))
+  $(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES := div
 endif
-
-ifneq (,$(filter $(DEX2OAT_TARGET_CPU_VARIANT),cortex-a7 cortex-a15 krait))
-  DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES := div
 endif
 
 # define clang/llvm tools and global flags
@@ -562,6 +579,9 @@ INTERNAL_PLATFORM_API_FILE := $(TARGET_OUT_COMMON_INTERMEDIATES)/PACKAGING/publi
 # This is the standard way to name a directory containing prebuilt target
 # objects. E.g., prebuilt/$(TARGET_PREBUILT_TAG)/libc.so
 TARGET_PREBUILT_TAG := android-$(TARGET_ARCH)
+ifdef TARGET_2ND_ARCH
+TARGET_2ND_PREBUILT_TAG := android-$(TARGET_2ND_ARCH)
+endif
 
 # Set up RS prebuilt variables for compatibility library
 
diff --git a/core/configure_module_stem.mk b/core/configure_module_stem.mk
index 2823e3758d..48b77871a0 100644
--- a/core/configure_module_stem.mk
+++ b/core/configure_module_stem.mk
@@ -1,16 +1,20 @@
-my_multilib_stem := $(LOCAL_MODULE_STEM_$(if $($(LOCAL_2ND_ARCH_VAR_PREFIX)TARGET_IS_64_BIT),64,32))
+my_multilib_stem := $(LOCAL_MODULE_STEM_$(if $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)IS_64_BIT),64,32))
 ifdef my_multilib_stem
-LOCAL_MODULE_STEM := $(my_multilib_stem)
+  my_module_stem := $(my_multilib_stem)
+else ifdef LOCAL_MODULE_STEM
+  my_module_stem := $(LOCAL_MODULE_STEM)
+else
+  my_module_stem := $(LOCAL_MODULE)
 endif
 
-ifndef LOCAL_MODULE_STEM
-  LOCAL_MODULE_STEM := $(LOCAL_MODULE)
+ifdef LOCAL_BUILT_MODULE_STEM
+  my_built_module_stem := $(LOCAL_BUILT_MODULE_STEM)
+else
+  my_built_module_stem := $(my_module_stem)$(LOCAL_MODULE_SUFFIX)
 endif
 
-ifndef LOCAL_BUILT_MODULE_STEM
-  LOCAL_BUILT_MODULE_STEM := $(LOCAL_MODULE_STEM)$(LOCAL_MODULE_SUFFIX)
-endif
-
-ifndef LOCAL_INSTALLED_MODULE_STEM
-  LOCAL_INSTALLED_MODULE_STEM := $(LOCAL_MODULE_STEM)$(LOCAL_MODULE_SUFFIX)
+ifdef LOCAL_INSTALLED_MODULE_STEM
+  my_installed_module_stem := $(LOCAL_INSTALLED_MODULE_STEM)
+else
+  my_installed_module_stem := $(my_module_stem)$(LOCAL_MODULE_SUFFIX)
 endif
diff --git a/core/definitions.mk b/core/definitions.mk
index adf8d40df5..e35d36fec5 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -84,8 +84,9 @@ ALL_GPL_MODULE_LICENSE_FILES:=
 # Target and host installed module's dependencies on shared libraries.
 # They are list of "<module_name>:<installed_file>:lib1,lib2...".
 TARGET_DEPENDENCIES_ON_SHARED_LIBRARIES :=
-2ND_TARGET_DEPENDENCIES_ON_SHARED_LIBRARIES :=
+$(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_DEPENDENCIES_ON_SHARED_LIBRARIES :=
 HOST_DEPENDENCIES_ON_SHARED_LIBRARIES :=
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_DEPENDENCIES_ON_SHARED_LIBRARIES :=
 
 # Generated class file names for Android resource.
 # They are escaped and quoted so can be passed safely to a bash command.
@@ -426,7 +427,7 @@ $(strip \
     $(eval _idf2ndArchPrefix := $(if $(call directory_is_64_bit_blacklisted,$(LOCAL_PATH))$(strip $(5)),$(TARGET_2ND_ARCH_VAR_PREFIX))) \
     $(if $(filter $(_idfPrefix)-$(_idfClass),$(COMMON_MODULE_CLASSES))$(4), \
         $(eval _idfIntBase := $($(_idfPrefix)_OUT_COMMON_INTERMEDIATES)) \
-      ,$(if $(filter $(_idfPrefix)-$(_idfClass),TARGET-SHARED_LIBRARIES TARGET-STATIC_LIBRARIES TARGET-EXECUTABLES TARGET-GYP),\
+      ,$(if $(filter $(_idfClass),SHARED_LIBRARIES STATIC_LIBRARIES EXECUTABLES GYP),\
           $(eval _idfIntBase := $($(_idf2ndArchPrefix)$(_idfPrefix)_OUT_INTERMEDIATES)) \
        ,$(eval _idfIntBase := $($(_idfPrefix)_OUT_INTERMEDIATES)) \
        ) \
@@ -1170,7 +1171,7 @@ $(hide) ldir=$(PRIVATE_INTERMEDIATES_DIR)/WHOLE/$(basename $(notdir $(1)))_objs;
     rm -rf $$ldir; \
     mkdir -p $$ldir; \
     filelist=; \
-    for f in `$(TARGET_AR) t $(1)`; do \
+    for f in `$($(PRIVATE_2ND_ARCH_VAR_PREFIX)TARGET_AR) t $(1)`; do \
         $($(PRIVATE_2ND_ARCH_VAR_PREFIX)TARGET_AR) p $(1) $$f > $$ldir/$$f; \
         filelist="$$filelist $$ldir/$$f"; \
     done ; \
@@ -1191,7 +1192,8 @@ define transform-o-to-static-lib
 @rm -f $@
 $(extract-and-include-target-whole-static-libs)
 @echo "target StaticLib: $(PRIVATE_MODULE) ($@)"
-$(call split-long-arguments,$($(PRIVATE_2ND_ARCH_VAR_PREFIX)TARGET_AR) $($(PRIVATE_2ND_ARCH_VAR_PREFIX)TARGET_GLOBAL_ARFLAGS) \
+$(call split-long-arguments,$($(PRIVATE_2ND_ARCH_VAR_PREFIX)TARGET_AR) \
+    $($(PRIVATE_2ND_ARCH_VAR_PREFIX)TARGET_GLOBAL_ARFLAGS) \
     $(PRIVATE_ARFLAGS) $@,$(filter %.o, $^))
 endef
 
@@ -1206,11 +1208,12 @@ $(hide) ldir=$(PRIVATE_INTERMEDIATES_DIR)/WHOLE/$(basename $(notdir $(1)))_objs;
     rm -rf $$ldir; \
     mkdir -p $$ldir; \
     filelist=; \
-    for f in `$(HOST_AR) t $(1) | \grep '\.o$$'`; do \
-        $(HOST_AR) p $(1) $$f > $$ldir/$$f; \
+    for f in `$($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_AR) t $(1) | \grep '\.o$$'`; do \
+        $($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_AR) p $(1) $$f > $$ldir/$$f; \
         filelist="$$filelist $$ldir/$$f"; \
     done ; \
-    $(HOST_AR) $(HOST_GLOBAL_ARFLAGS) $(PRIVATE_ARFLAGS) $@ $$filelist
+    $($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_AR) $($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_ARFLAGS) \
+        $(PRIVATE_ARFLAGS) $@ $$filelist
 
 endef
 
@@ -1226,7 +1229,9 @@ define transform-host-o-to-static-lib
 @rm -f $@
 $(extract-and-include-host-whole-static-libs)
 @echo "host StaticLib: $(PRIVATE_MODULE) ($@)"
-$(call split-long-arguments,$(HOST_AR) $(HOST_GLOBAL_ARFLAGS) $(PRIVATE_ARFLAGS) $@,$(filter %.o, $^))
+$(call split-long-arguments,$($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_AR) \
+    $($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_ARFLAGS) \
+    $(PRIVATE_ARFLAGS) $@,$(filter %.o, $^))
 endef
 
 
@@ -1239,10 +1244,10 @@ endef
 ifneq ($(HOST_CUSTOM_LD_COMMAND),true)
 define transform-host-o-to-shared-lib-inner
 $(hide) $(PRIVATE_CXX) \
-	-Wl,-rpath-link=$(HOST_OUT_INTERMEDIATE_LIBRARIES) \
-	-Wl,-rpath,\$$ORIGIN/../lib \
+	-Wl,-rpath-link=$($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_OUT_INTERMEDIATE_LIBRARIES) \
+	-Wl,-rpath,\$$ORIGIN/../$(notdir $($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_OUT_SHARED_LIBRARIES)) \
 	-shared -Wl,-soname,$(notdir $@) \
-	$(HOST_GLOBAL_LD_DIRS) \
+	$($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_LD_DIRS) \
 	$(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),, \
 	   $(PRIVATE_HOST_GLOBAL_LDFLAGS) \
 	) \
@@ -1412,9 +1417,9 @@ $(hide) $(PRIVATE_CXX) \
 	$(call normalize-host-libraries,$(PRIVATE_ALL_STATIC_LIBRARIES)) \
 	$(if $(PRIVATE_GROUP_STATIC_LIBRARIES),-Wl$(comma)--end-group) \
 	$(call normalize-host-libraries,$(PRIVATE_ALL_SHARED_LIBRARIES)) \
-	-Wl,-rpath-link=$(HOST_OUT_INTERMEDIATE_LIBRARIES) \
-	-Wl,-rpath,\$$ORIGIN/../lib \
-	$(HOST_GLOBAL_LD_DIRS) \
+	-Wl,-rpath-link=$($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_OUT_INTERMEDIATE_LIBRARIES) \
+	-Wl,-rpath,\$$ORIGIN/../$(notdir $($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_OUT_SHARED_LIBRARIES)) \
+	$($(PRIVATE_2ND_ARCH_VAR_PREFIX)HOST_GLOBAL_LD_DIRS) \
 	$(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),, \
 		$(PRIVATE_HOST_GLOBAL_LDFLAGS) \
 		$(HOST_FPIE_FLAGS) \
@@ -1675,10 +1680,10 @@ endef
 # so we need to give it something.
 define create-empty-package
 @mkdir -p $(dir $@)
-$(hide) touch $(dir $@)/dummy
+$(hide) touch $(dir $@)dummy
 $(hide) (cd $(dir $@) && jar cf $(notdir $@) dummy)
 $(hide) zip -qd $@ dummy
-$(hide) rm $(dir $@)/dummy
+$(hide) rm $(dir $@)dummy
 endef
 
 #TODO: we kinda want to build different asset packages for
diff --git a/core/dex_preopt.mk b/core/dex_preopt.mk
index 46a6479b36..ab970f917a 100644
--- a/core/dex_preopt.mk
+++ b/core/dex_preopt.mk
@@ -49,25 +49,26 @@ endif
 include $(BUILD_SYSTEM)/dex_preopt_libart.mk
 
 # Define dexpreopt-one-file based on current default runtime.
-# $(1): the boot image to use (unused for libdvm)
-# $(2): the input .jar or .apk file
-# $(3): the input .jar or .apk target location (unused for libdvm)
-# $(4): the output .odex file
+# $(1): the input .jar or .apk file
+# $(2): the output .odex file
 ifeq ($(DALVIK_VM_LIB),libdvm.so)
 define dexpreopt-one-file
-$(call dexopt-one-file,$(2),$(4))
+$(call dexopt-one-file,$(1),$(2))
 endef
 
 DEXPREOPT_ONE_FILE_DEPENDENCY_TOOLS := $(DEXOPT_DEPENDENCY)
 DEXPREOPT_ONE_FILE_DEPENDENCY_BUILT_BOOT_PREOPT := $(DEXPREOPT_BOOT_ODEXS)
 else
 define dexpreopt-one-file
-$(call dex2oat-one-file,$(1),$(2),$(3),$(4))
+$(call dex2oat-one-file,$(1),$(2))
 endef
 
 DEXPREOPT_ONE_FILE_DEPENDENCY_TOOLS := $(DEX2OATD_DEPENDENCY)
-DEXPREOPT_ONE_FILE_DEPENDENCY_BUILT_BOOT_PREOPT := $(DEFAULT_DEX_PREOPT_BUILT_IMAGE)
-endif
+DEXPREOPT_ONE_FILE_DEPENDENCY_BUILT_BOOT_PREOPT := $(DEFAULT_DEX_PREOPT_BUILT_IMAGE_FILENAME)
+ifdef TARGET_2ND_ARCH
+$(TARGET_2ND_ARCH_VAR_PREFIX)DEXPREOPT_ONE_FILE_DEPENDENCY_BUILT_BOOT_PREOPT := $($(TARGET_2ND_ARCH_VAR_PREFIX)DEFAULT_DEX_PREOPT_BUILT_IMAGE_FILENAME)
+endif  # TARGET_2ND_ARCH
+endif  # DALVIK_VM_LIB
 else
 $(warning No DALVIK_VM_LIB, disable dexpreopt.)
 WITH_DEXPREOPT := false
diff --git a/core/dex_preopt_libart.mk b/core/dex_preopt_libart.mk
index 7f3285ce16..411af7513d 100644
--- a/core/dex_preopt_libart.mk
+++ b/core/dex_preopt_libart.mk
@@ -6,37 +6,18 @@
 DEX2OAT := $(HOST_OUT_EXECUTABLES)/dex2oat$(HOST_EXECUTABLE_SUFFIX)
 DEX2OATD := $(HOST_OUT_EXECUTABLES)/dex2oatd$(HOST_EXECUTABLE_SUFFIX)
 
-LIBART_COMPILER := $(HOST_OUT_SHARED_LIBRARIES)/libart-compiler$(HOST_SHLIB_SUFFIX)
-LIBARTD_COMPILER := $(HOST_OUT_SHARED_LIBRARIES)/libartd-compiler$(HOST_SHLIB_SUFFIX)
-
 # By default, do not run rerun dex2oat if the tool changes.
 # Comment out the | to force dex2oat to rerun on after all changes.
 DEX2OAT_DEPENDENCY := art/runtime/oat.cc # dependency on oat version number
 DEX2OAT_DEPENDENCY += art/runtime/image.cc # dependency on image version number
 DEX2OAT_DEPENDENCY += |
 DEX2OAT_DEPENDENCY += $(DEX2OAT)
-DEX2OAT_DEPENDENCY += $(LIBART_COMPILER)
 
 DEX2OATD_DEPENDENCY := $(DEX2OAT_DEPENDENCY)
 DEX2OATD_DEPENDENCY += $(DEX2OATD)
-DEX2OATD_DEPENDENCY += $(LIBARTD_COMPILER)
 
 PRELOADED_CLASSES := frameworks/base/preloaded-classes
 
-LIBART_BOOT_IMAGE := /$(DEXPREOPT_BOOT_JAR_DIR)/boot-$(DEX2OAT_TARGET_ARCH).art
-
-DEFAULT_DEX_PREOPT_BUILT_IMAGE := $(DEXPREOPT_BOOT_JAR_DIR_FULL_PATH)/boot-$(DEX2OAT_TARGET_ARCH).art
-
-DEFAULT_DEX_PREOPT_INSTALLED_IMAGE :=
-ifneq ($(PRODUCT_DEX_PREOPT_IMAGE_IN_DATA),true)
-DEFAULT_DEX_PREOPT_INSTALLED_IMAGE := $(PRODUCT_OUT)$(LIBART_BOOT_IMAGE)
-
-# The rule to install boot.art and boot.oat
-$(DEFAULT_DEX_PREOPT_INSTALLED_IMAGE) : $(DEFAULT_DEX_PREOPT_BUILT_IMAGE) | $(ACP)
-	$(call copy-file-to-target)
-	$(hide) $(ACP) -fp $(patsubst %.art,%.oat,$<) $(patsubst %.art,%.oat,$@)
-endif
-
 # start of image reserved address space
 LIBART_IMG_HOST_BASE_ADDRESS   := 0x60000000
 
@@ -49,48 +30,50 @@ endif
 ########################################################################
 # The full system boot classpath
 
+# Returns the path to the .odex file
+# $(1): the arch name.
+# $(2): the full path (including file name) of the corresponding .jar or .apk.
+define get-odex-file-path
+$(dir $(2))$(1)/$(basename $(notdir $(2))).odex
+endef
+
+# Returns the path to the image file (such as "/system/framework/<arch>/boot.art"
+# $(1): the arch name (such as "arm")
+# $(2): the image location (such as "/system/framework/boot.art")
+define get-image-file-path
+$(dir $(2))$(1)/$(notdir $(2))
+endef
+
 # note we use core-libart.jar in place of core.jar for ART.
 LIBART_TARGET_BOOT_JARS := $(patsubst core, core-libart,$(DEXPREOPT_BOOT_JARS_MODULES))
 LIBART_TARGET_BOOT_DEX_LOCATIONS := $(foreach jar,$(LIBART_TARGET_BOOT_JARS),/$(DEXPREOPT_BOOT_JAR_DIR)/$(jar).jar)
 LIBART_TARGET_BOOT_DEX_FILES := $(foreach jar,$(LIBART_TARGET_BOOT_JARS),$(call intermediates-dir-for,JAVA_LIBRARIES,$(jar),,COMMON)/javalib.jar)
 
-# The .oat with symbols
-LIBART_TARGET_BOOT_OAT_UNSTRIPPED := $(TARGET_OUT_UNSTRIPPED)$(patsubst %.art,%.oat,$(LIBART_BOOT_IMAGE))
+my_2nd_arch_prefix :=
+include $(BUILD_SYSTEM)/dex_preopt_libart_boot.mk
 
-# Use dex2oat debug version for better error reporting
-$(DEFAULT_DEX_PREOPT_BUILT_IMAGE): $(LIBART_TARGET_BOOT_DEX_FILES) $(DEX2OATD_DEPENDENCY)
-	@echo "target dex2oat: $@ ($?)"
-	@mkdir -p $(dir $@)
-	@mkdir -p $(dir $(LIBART_TARGET_BOOT_OAT_UNSTRIPPED))
-	$(hide) $(DEX2OATD) --runtime-arg -Xms256m --runtime-arg -Xmx256m --image-classes=$(PRELOADED_CLASSES) \
-		$(addprefix --dex-file=,$(LIBART_TARGET_BOOT_DEX_FILES)) \
-		$(addprefix --dex-location=,$(LIBART_TARGET_BOOT_DEX_LOCATIONS)) \
-		--oat-symbols=$(LIBART_TARGET_BOOT_OAT_UNSTRIPPED) \
-		--oat-file=$(patsubst %.art,%.oat,$@) \
-		--oat-location=$(patsubst %.art,%.oat,$(LIBART_BOOT_IMAGE)) \
-		--image=$@ --base=$(LIBART_IMG_TARGET_BASE_ADDRESS) \
-		--instruction-set=$(DEX2OAT_TARGET_ARCH) \
-		--instruction-set-features=$(DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES) \
-		--android-root=$(PRODUCT_OUT)/system
+ifdef TARGET_2ND_ARCH
+my_2nd_arch_prefix := $(TARGET_2ND_ARCH_VAR_PREFIX)
+include $(BUILD_SYSTEM)/dex_preopt_libart_boot.mk
+my_2nd_arch_prefix :=
+endif
 
 
 ########################################################################
 # For a single jar or APK
 
-# $(1): the boot image to use
-# $(2): the input .jar or .apk file
-# $(3): the input .jar or .apk target location
-# $(4): the output .odex file
+# $(1): the input .jar or .apk file
+# $(2): the output .odex file
 define dex2oat-one-file
-$(hide) rm -f $(4)
-$(hide) mkdir -p $(dir $(4))
+$(hide) rm -f $(2)
+$(hide) mkdir -p $(dir $(2))
 $(hide) $(DEX2OATD) \
 	--runtime-arg -Xms64m --runtime-arg -Xmx64m \
-	--boot-image=$(1) \
-	--dex-file=$(2) \
-	--dex-location=$(3) \
-	--oat-file=$(4) \
+	--boot-image=$(PRIVATE_DEX_PREOPT_IMAGE_LOCATION) \
+	--dex-file=$(1) \
+	--dex-location=$(PRIVATE_DEX_LOCATION) \
+	--oat-file=$(2) \
 	--android-root=$(PRODUCT_OUT)/system \
-	--instruction-set=$(DEX2OAT_TARGET_ARCH) \
-	--instruction-set-features=$(DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES)
+	--instruction-set=$($(PRIVATE_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_ARCH) \
+	--instruction-set-features=$($(PRIVATE_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES)
 endef
diff --git a/core/dex_preopt_libart_boot.mk b/core/dex_preopt_libart_boot.mk
new file mode 100644
index 0000000000..70130b62fd
--- /dev/null
+++ b/core/dex_preopt_libart_boot.mk
@@ -0,0 +1,55 @@
+# Rules to build boot.art
+# Input variables:
+#   my_2nd_arch_prefix: indicates if this is to build for the 2nd arch.
+
+# The image "location" is a symbolic path that with multiarchitecture
+# support doesn't really exist on the device. Typically it is
+# /system/framework/boot.art and should be the same for all supported
+# architectures on the device. The concrete architecture specific
+# content actually ends up in a "filename" that contains an
+# architecture specific directory name such as arm, arm64, mips,
+# mips64, x86, x86_64.
+#
+# Here are some example values for an x86_64 / x86 configuration:
+#
+# DEFAULT_DEX_PREOPT_BUILT_IMAGE_LOCATION=out/target/product/generic_x86_64/dex_bootjars/system/framework/boot.art
+# DEFAULT_DEX_PREOPT_BUILT_IMAGE_FILENAME=out/target/product/generic_x86_64/dex_bootjars/system/framework/x86_64/boot.art
+# LIBART_BOOT_IMAGE=/system/framework/x86_64/boot.art
+#
+# 2ND_DEFAULT_DEX_PREOPT_BUILT_IMAGE_LOCATION=out/target/product/generic_x86_64/dex_bootjars/system/framework/boot.art
+# 2ND_DEFAULT_DEX_PREOPT_BUILT_IMAGE_FILENAME=out/target/product/generic_x86_64/dex_bootjars/system/framework/x86/boot.art
+# 2ND_LIBART_BOOT_IMAGE=/system/framework/x86/boot.art
+
+$(my_2nd_arch_prefix)DEFAULT_DEX_PREOPT_BUILT_IMAGE_LOCATION := $(DEXPREOPT_BOOT_JAR_DIR_FULL_PATH)/boot.art
+$(my_2nd_arch_prefix)DEFAULT_DEX_PREOPT_BUILT_IMAGE_FILENAME := $(DEXPREOPT_BOOT_JAR_DIR_FULL_PATH)/$($(my_2nd_arch_prefix)DEX2OAT_TARGET_ARCH)/boot.art
+$(my_2nd_arch_prefix)LIBART_BOOT_IMAGE_FILENAME := /$(DEXPREOPT_BOOT_JAR_DIR)/$($(my_2nd_arch_prefix)DEX2OAT_TARGET_ARCH)/boot.art
+
+# The .oat with symbols
+$(my_2nd_arch_prefix)LIBART_TARGET_BOOT_OAT_UNSTRIPPED := $(TARGET_OUT_UNSTRIPPED)$(patsubst %.art,%.oat,$($(my_2nd_arch_prefix)LIBART_BOOT_IMAGE_FILENAME))
+
+$(my_2nd_arch_prefix)DEFAULT_DEX_PREOPT_INSTALLED_IMAGE :=
+ifneq ($(PRODUCT_DEX_PREOPT_IMAGE_IN_DATA),true)
+$(my_2nd_arch_prefix)DEFAULT_DEX_PREOPT_INSTALLED_IMAGE := $(PRODUCT_OUT)$($(my_2nd_arch_prefix)LIBART_BOOT_IMAGE_FILENAME)
+endif
+
+# The rule to install boot.art and boot.oat
+$($(my_2nd_arch_prefix)DEFAULT_DEX_PREOPT_INSTALLED_IMAGE) : $($(my_2nd_arch_prefix)DEFAULT_DEX_PREOPT_BUILT_IMAGE_FILENAME) | $(ACP)
+	$(call copy-file-to-target)
+	$(hide) $(ACP) -fp $(patsubst %.art,%.oat,$<) $(patsubst %.art,%.oat,$@)
+
+$($(my_2nd_arch_prefix)DEFAULT_DEX_PREOPT_BUILT_IMAGE_FILENAME): PRIVATE_2ND_ARCH_VAR_PREFIX := $(my_2nd_arch_prefix)
+# Use dex2oat debug version for better error reporting
+$($(my_2nd_arch_prefix)DEFAULT_DEX_PREOPT_BUILT_IMAGE_FILENAME) : $(LIBART_TARGET_BOOT_DEX_FILES) $(DEX2OATD_DEPENDENCY)
+	@echo "target dex2oat: $@ ($?)"
+	@mkdir -p $(dir $@)
+	@mkdir -p $(dir $($(PRIVATE_2ND_ARCH_VAR_PREFIX)LIBART_TARGET_BOOT_OAT_UNSTRIPPED))
+	$(hide) $(DEX2OATD) --runtime-arg -Xms256m --runtime-arg -Xmx256m --image-classes=$(PRELOADED_CLASSES) \
+		$(addprefix --dex-file=,$(LIBART_TARGET_BOOT_DEX_FILES)) \
+		$(addprefix --dex-location=,$(LIBART_TARGET_BOOT_DEX_LOCATIONS)) \
+		--oat-symbols=$($(PRIVATE_2ND_ARCH_VAR_PREFIX)LIBART_TARGET_BOOT_OAT_UNSTRIPPED) \
+		--oat-file=$(patsubst %.art,%.oat,$@) \
+		--oat-location=$(patsubst %.art,%.oat,$($(PRIVATE_2ND_ARCH_VAR_PREFIX)LIBART_BOOT_IMAGE_FILENAME)) \
+		--image=$@ --base=$(LIBART_IMG_TARGET_BASE_ADDRESS) \
+		--instruction-set=$($(PRIVATE_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_ARCH) \
+		--instruction-set-features=$($(PRIVATE_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES) \
+		--android-root=$(PRODUCT_OUT)/system
diff --git a/core/dex_preopt_odex_install.mk b/core/dex_preopt_odex_install.mk
index b0b73afaf2..db2314076e 100644
--- a/core/dex_preopt_odex_install.mk
+++ b/core/dex_preopt_odex_install.mk
@@ -43,22 +43,83 @@ else # libdvm.so
 # For libart, the boot jars' odex files are replaced by $(DEFAULT_DEX_PREOPT_INSTALLED_IMAGE).
 # We use this installed_odex trick to get boot.art installed.
 installed_odex := $(DEFAULT_DEX_PREOPT_INSTALLED_IMAGE)
+# Append the odex for the 2nd arch if we have one.
+installed_odex += $($(TARGET_2ND_ARCH_VAR_PREFIX)DEFAULT_DEX_PREOPT_INSTALLED_IMAGE)
 endif # libdvm.so
 else  # boot jar
+ifeq ($(DALVIK_VM_LIB),libdvm.so)
 built_odex := $(basename $(LOCAL_BUILT_MODULE)).odex
 installed_odex := $(basename $(LOCAL_INSTALLED_MODULE)).odex
 
-ifneq ($(DALVIK_VM_LIB),libdvm.so) # libart
-ifndef LOCAL_DEX_PREOPT_IMAGE
-LOCAL_DEX_PREOPT_IMAGE := $(DEFAULT_DEX_PREOPT_BUILT_IMAGE)
+$(built_odex) : $(DEXPREOPT_ONE_FILE_DEPENDENCY_BUILT_BOOT_PREOPT) \
+                $(DEXPREOPT_ONE_FILE_DEPENDENCY_TOOLS)
+else # libart
+ifeq ($(LOCAL_MODULE_CLASS),JAVA_LIBRARIES)
+# For a Java library, we build odex for both 1st arch and 2nd arch, if we have one.
+# #################################################
+# Odex for the 1st arch
+built_odex := $(call get-odex-file-path,$(DEX2OAT_TARGET_ARCH),$(LOCAL_BUILT_MODULE))
+ifdef LOCAL_DEX_PREOPT_IMAGE_LOCATION
+my_dex_preopt_image_location := $(LOCAL_DEX_PREOPT_IMAGE_LOCATION)
+else
+my_dex_preopt_image_location := $(DEFAULT_DEX_PREOPT_BUILT_IMAGE_LOCATION)
+endif
+my_dex_preopt_image_filename := $(call get-image-file-path,$(DEX2OAT_TARGET_ARCH),$(my_dex_preopt_image_location))
+$(built_odex): PRIVATE_2ND_ARCH_VAR_PREFIX :=
+$(built_odex): PRIVATE_DEX_LOCATION := $(patsubst $(PRODUCT_OUT)%,%,$(LOCAL_INSTALLED_MODULE))
+$(built_odex): PRIVATE_DEX_PREOPT_IMAGE_LOCATION := $(my_dex_preopt_image_location)
+$(built_odex) : $(DEXPREOPT_ONE_FILE_DEPENDENCY_BUILT_BOOT_PREOPT) \
+                $(DEXPREOPT_ONE_FILE_DEPENDENCY_TOOLS) \
+                $(my_dex_preopt_image_filename)
+installed_odex := $(call get-odex-file-path,$(DEX2OAT_TARGET_ARCH),$(LOCAL_INSTALLED_MODULE))
+
+# #################################################
+# Odex for the 2nd arch
+ifdef TARGET_2ND_ARCH
+built_odex2 := $(call get-odex-file-path,$($(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_ARCH),$(LOCAL_BUILT_MODULE))
+ifdef LOCAL_DEX_PREOPT_IMAGE_LOCATION
+my_dex_preopt_image_location := $(LOCAL_DEX_PREOPT_IMAGE_LOCATION)
+else
+my_dex_preopt_image_location := $($(TARGET_2ND_ARCH_VAR_PREFIX)DEFAULT_DEX_PREOPT_BUILT_IMAGE_LOCATION)
+endif
+my_dex_preopt_image_filename := $(call get-image-file-path,$($(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_ARCH),$(my_dex_preopt_image_location))
+$(built_odex2): PRIVATE_2ND_ARCH_VAR_PREFIX := $(TARGET_2ND_ARCH_VAR_PREFIX)
+$(built_odex2): PRIVATE_DEX_LOCATION := $(patsubst $(PRODUCT_OUT)%,%,$(LOCAL_INSTALLED_MODULE))
+$(built_odex2): PRIVATE_DEX_PREOPT_IMAGE_LOCATION := $(my_dex_preopt_image_location)
+$(built_odex2) : $($(TARGET_2ND_ARCH_VAR_PREFIX)DEXPREOPT_ONE_FILE_DEPENDENCY_BUILT_BOOT_PREOPT) \
+                 $(DEXPREOPT_ONE_FILE_DEPENDENCY_TOOLS) \
+                 $(my_dex_preopt_image_filename)
+
+built_odex += $(built_odex2)
+installed_odex += $(call get-odex-file-path,$($(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_ARCH),$(LOCAL_INSTALLED_MODULE))
+endif  # TARGET_2ND_ARCH
+# #################################################
+else  # must be APPS
+# For an app, we build for the multilib arch it's targeted for.
+built_odex := $(call get-odex-file-path,$($(LOCAL_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_ARCH),$(LOCAL_BUILT_MODULE))
+ifdef LOCAL_DEX_PREOPT_IMAGE_LOCATION
+my_dex_preopt_image_location := $(LOCAL_DEX_PREOPT_IMAGE_LOCATION)
+else
+my_dex_preopt_image_location := $($(LOCAL_2ND_ARCH_VAR_PREFIX)DEFAULT_DEX_PREOPT_BUILT_IMAGE_LOCATION)
 endif
+my_dex_preopt_image_filename := $(call get-image-file-path,$($(LOCAL_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_ARCH),$(my_dex_preopt_image_location))
+$(built_odex): PRIVATE_2ND_ARCH_VAR_PREFIX := $(LOCAL_2ND_ARCH_VAR_PREFIX)
+$(built_odex): PRIVATE_DEX_LOCATION := $(patsubst $(PRODUCT_OUT)%,%,$(LOCAL_INSTALLED_MODULE))
+$(built_odex): PRIVATE_DEX_PREOPT_IMAGE_LOCATION := $(my_dex_preopt_image_location)
+$(built_odex) : $($(LOCAL_2ND_ARCH_VAR_PREFIX)DEXPREOPT_ONE_FILE_DEPENDENCY_BUILT_BOOT_PREOPT) \
+                $(DEXPREOPT_ONE_FILE_DEPENDENCY_TOOLS) \
+                $(my_dex_preopt_image_filename)
+installed_odex := $(call get-odex-file-path,$($(LOCAL_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_ARCH),$(LOCAL_INSTALLED_MODULE))
+endif  # LOCAL_MODULE_CLASS
 endif # libart
 endif # boot jar
 
 ifdef built_odex
-# We need $(LOCAL_BUILT_MODULE) in the deps to enforce reinstallation
-# even if $(built_odex) is byproduct of $(LOCAL_BUILT_MODULE), such as in package.mk.
-$(installed_odex) : $(built_odex) $(LOCAL_BUILT_MODULE) | $(ACP)
+# Use pattern rule - we may have multiple installed odex files.
+# Ugly syntax - See the definition get-odex-file-path.
+$(installed_odex) : $(dir $(LOCAL_INSTALLED_MODULE))%/$(notdir $(word 1,$(installed_odex))) \
+                  : $(dir $(LOCAL_BUILT_MODULE))%/$(notdir $(word 1,$(built_odex))) \
+    | $(ACP)
 	@echo "Install: $@"
 	$(copy-file-to-target)
 endif
diff --git a/core/dumpvar.mk b/core/dumpvar.mk
index d3f3969115..510bc7d082 100644
--- a/core/dumpvar.mk
+++ b/core/dumpvar.mk
@@ -72,9 +72,11 @@ $(info   TARGET_BUILD_VARIANT=$(TARGET_BUILD_VARIANT))
 $(info   TARGET_BUILD_TYPE=$(TARGET_BUILD_TYPE))
 $(info   TARGET_BUILD_APPS=$(TARGET_BUILD_APPS))
 $(info   TARGET_ARCH=$(TARGET_ARCH))
-$(info   TARGET_2ND_ARCH=$(TARGET_2ND_ARCH))
 $(info   TARGET_ARCH_VARIANT=$(TARGET_ARCH_VARIANT))
 $(info   TARGET_CPU_VARIANT=$(TARGET_CPU_VARIANT))
+$(info   TARGET_2ND_ARCH=$(TARGET_2ND_ARCH))
+$(info   TARGET_2ND_ARCH_VARIANT=$(TARGET_2ND_ARCH_VARIANT))
+$(info   TARGET_2ND_CPU_VARIANT=$(TARGET_2ND_CPU_VARIANT))
 $(info   HOST_ARCH=$(HOST_ARCH))
 $(info   HOST_OS=$(HOST_OS))
 $(info   HOST_OS_EXTRA=$(HOST_OS_EXTRA))
diff --git a/core/dynamic_binary.mk b/core/dynamic_binary.mk
index b3ca4fcbd5..396199c1a9 100644
--- a/core/dynamic_binary.mk
+++ b/core/dynamic_binary.mk
@@ -26,7 +26,7 @@ guessed_intermediates := $(call local-intermediates-dir,,$(LOCAL_2ND_ARCH_VAR_PR
 # The basename of this target must be the same as the final output
 # binary name, because it's used to set the "soname" in the binary.
 # The includer of this file will define a rule to build this target.
-linked_module := $(guessed_intermediates)/LINKED/$(LOCAL_BUILT_MODULE_STEM)
+linked_module := $(guessed_intermediates)/LINKED/$(my_built_module_stem)
 
 ALL_ORIGINAL_DYNAMIC_BINARIES += $(linked_module)
 
@@ -41,8 +41,6 @@ LOCAL_INTERMEDIATE_TARGETS := $(linked_module)
 include $(BUILD_SYSTEM)/binary.mk
 ###################################
 
-$(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_2ND_ARCH_VAR_PREFIX := $(LOCAL_2ND_ARCH_VAR_PREFIX)
-
 # Make sure that our guess at the value of intermediates was correct.
 ifneq ($(intermediates),$(guessed_intermediates))
 $(error Internal error: guessed path '$(guessed_intermediates)' doesn't match '$(intermediates))
@@ -59,7 +57,7 @@ endif
 
 ifeq ($(LOCAL_COMPRESS_MODULE_SYMBOLS),true)
 $(error Symbol compression not yet supported.)
-compress_output := $(intermediates)/COMPRESSED-$(LOCAL_BUILT_MODULE_STEM)
+compress_output := $(intermediates)/COMPRESSED-$(my_built_module_stem)
 
 #TODO: write the real $(STRIPPER) rule.
 #TODO: define a rule to build TARGET_SYMBOL_FILTER_FILE, and
@@ -81,7 +79,7 @@ else
 my_unstripped_path := $(LOCAL_UNSTRIPPED_PATH)
 endif
 symbolic_input := $(compress_output)
-symbolic_output := $(my_unstripped_path)/$(LOCAL_INSTALLED_MODULE_STEM)
+symbolic_output := $(my_unstripped_path)/$(my_installed_module_stem)
 $(symbolic_output) : $(symbolic_input) | $(ACP)
 	@echo "target Symbolic: $(PRIVATE_MODULE) ($@)"
 	$(copy-file-to-target)
diff --git a/core/envsetup.mk b/core/envsetup.mk
index 4cb389bf4e..a228fc7cd8 100644
--- a/core/envsetup.mk
+++ b/core/envsetup.mk
@@ -40,16 +40,16 @@ UNAME := $(shell uname -sm)
 
 # HOST_OS
 ifneq (,$(findstring Linux,$(UNAME)))
-	HOST_OS := linux
+  HOST_OS := linux
 endif
 ifneq (,$(findstring Darwin,$(UNAME)))
-	HOST_OS := darwin
+  HOST_OS := darwin
 endif
 ifneq (,$(findstring Macintosh,$(UNAME)))
-	HOST_OS := darwin
+  HOST_OS := darwin
 endif
 ifneq (,$(findstring CYGWIN,$(UNAME)))
-	HOST_OS := windows
+  HOST_OS := windows
 endif
 
 # BUILD_OS is the real host doing the build.
@@ -59,7 +59,7 @@ BUILD_OS := $(HOST_OS)
 # Windows SDK. Only a subset of tools and SDK will manage to build properly.
 ifeq ($(HOST_OS),linux)
 ifneq ($(USE_MINGW),)
-	HOST_OS := windows
+  HOST_OS := windows
 endif
 endif
 
@@ -67,17 +67,30 @@ ifeq ($(HOST_OS),)
 $(error Unable to determine HOST_OS from uname -sm: $(UNAME)!)
 endif
 
-
-# HOST_ARCH
-ifneq (,$(findstring 86,$(UNAME)))
-	HOST_ARCH := x86
+ifeq ($(HOST_PREFER_32_BIT),true)
+# User asks for multilib build, but use 32-bit as preferred arch.
+BUILD_HOST_64bit := true
 endif
 
-ifneq (,$(findstring Power,$(UNAME)))
-	HOST_ARCH := ppc
+# HOST_ARCH
+ifneq (,$(findstring x86_64,$(UNAME)))
+  # TODO: Replace BUILD_HOST_64bit with a flag that forces 32-bit build,
+  # after we default to 64-bit host build.
+  ifeq (,$(BUILD_HOST_64bit))
+    HOST_ARCH := x86
+    HOST_2ND_ARCH :=
+  else
+    HOST_ARCH := x86_64
+    HOST_2ND_ARCH := x86
+  endif
+else ifneq (,$(findstring 86,$(UNAME)))
+  # It's not officially supported!
+  HOST_ARCH := x86
+  HOST_2ND_ARCH :=
 endif
 
 BUILD_ARCH := $(HOST_ARCH)
+BUILD_2ND_ARCH := $(HOST_2ND_ARCH)
 
 ifeq ($(HOST_ARCH),)
 $(error Unable to determine HOST_ARCH from uname -sm: $(UNAME)!)
@@ -94,12 +107,14 @@ $(error HOST_BUILD_TYPE must be either release or debug, not '$(HOST_BUILD_TYPE)
 endif
 endif
 
+# We don't want to move all the prebuilt host tools to a $(HOST_OS)-x86_64 dir.
+HOST_PREBUILT_ARCH := x86
 # This is the standard way to name a directory containing prebuilt host
 # objects. E.g., prebuilt/$(HOST_PREBUILT_TAG)/cc
 ifeq ($(HOST_OS),windows)
   HOST_PREBUILT_TAG := windows
 else
-  HOST_PREBUILT_TAG := $(HOST_OS)-$(HOST_ARCH)
+  HOST_PREBUILT_TAG := $(HOST_OS)-$(HOST_PREBUILT_ARCH)
 endif
 
 # TARGET_COPY_OUT_* are all relative to the staging directory, ie PRODUCT_OUT.
@@ -180,11 +195,12 @@ HOST_OUT_ROOT_release := $(OUT_DIR)/host
 HOST_OUT_ROOT_debug := $(DEBUG_OUT_DIR)/host
 HOST_OUT_ROOT := $(HOST_OUT_ROOT_$(HOST_BUILD_TYPE))
 
-HOST_OUT_release := $(HOST_OUT_ROOT_release)/$(HOST_OS)-$(HOST_ARCH)
-HOST_OUT_debug := $(HOST_OUT_ROOT_debug)/$(HOST_OS)-$(HOST_ARCH)
+# We want to avoid two host bin directories in multilib build.
+HOST_OUT_release := $(HOST_OUT_ROOT_release)/$(HOST_OS)-$(HOST_PREBUILT_ARCH)
+HOST_OUT_debug := $(HOST_OUT_ROOT_debug)/$(HOST_OS)-$(HOST_PREBUILT_ARCH)
 HOST_OUT := $(HOST_OUT_$(HOST_BUILD_TYPE))
 
-BUILD_OUT := $(OUT_DIR)/host/$(BUILD_OS)-$(BUILD_ARCH)
+BUILD_OUT := $(OUT_DIR)/host/$(BUILD_OS)-$(HOST_PREBUILT_ARCH)
 
 TARGET_PRODUCT_OUT_ROOT := $(TARGET_OUT_ROOT)/product
 
@@ -211,6 +227,21 @@ HOST_OUT_COMMON_INTERMEDIATES := $(HOST_COMMON_OUT_ROOT)/obj
 HOST_OUT_GEN := $(HOST_OUT)/gen
 HOST_OUT_COMMON_GEN := $(HOST_COMMON_OUT_ROOT)/gen
 
+# Out for HOST_2ND_ARCH
+HOST_2ND_ARCH_VAR_PREFIX := 2ND_
+HOST_2ND_ARCH_MODULE_SUFFIX := _32
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_INTERMEDIATES := $(HOST_OUT)/obj32
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_INTERMEDIATE_LIBRARIES := $($(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_INTERMEDIATES)/lib
+ifeq ($(HOST_PREFER_32_BIT),true)
+# To keep path compatibility, put 32-bit libs in lib/ and 64-bit libs in lib64/.
+HOST_OUT_SHARED_LIBRARIES := $(HOST_OUT)/lib64
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_SHARED_LIBRARIES := $(HOST_OUT)/lib
+else
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_SHARED_LIBRARIES := $(HOST_OUT)/lib32
+endif
+$(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_EXECUTABLES := $(HOST_OUT_EXECUTABLES)
+
+
 TARGET_OUT_INTERMEDIATES := $(PRODUCT_OUT)/obj
 TARGET_OUT_HEADERS := $(TARGET_OUT_INTERMEDIATES)/include
 TARGET_OUT_INTERMEDIATE_LIBRARIES := $(TARGET_OUT_INTERMEDIATES)/lib
diff --git a/core/executable.mk b/core/executable.mk
index 7a3e08e0d7..4dd9a2349a 100644
--- a/core/executable.mk
+++ b/core/executable.mk
@@ -6,6 +6,7 @@
 # LOCAL_MODULE_PATH_32 and LOCAL_MODULE_PATH_64 or LOCAL_MODULE_STEM_32 and
 # LOCAL_MODULE_STEM_64
 
+my_prefix := TARGET_
 include $(BUILD_SYSTEM)/multilib.mk
 
 ifeq ($(my_module_multilib),both)
diff --git a/core/executable_prefer_symlink.mk b/core/executable_prefer_symlink.mk
index c6abed4172..2f04d0dab6 100644
--- a/core/executable_prefer_symlink.mk
+++ b/core/executable_prefer_symlink.mk
@@ -5,12 +5,20 @@
 # Note: now only limited to the binaries that will be installed under system/bin directory
 
 my_symlink := $(addprefix $(TARGET_OUT)/bin/, $(LOCAL_MODULE))
-# create link to the one used for prefer version
+# Create link to the one used depending on the target
+# configuration. Note that we require the TARGET_IS_64_BIT
+# check because 32 bit targets may not define TARGET_PREFER_32_BIT_APPS
+# et al. since those variables make no sense in that context.
+ifeq ($(TARGET_IS_64_BIT),true)
 ifneq ($(TARGET_PREFER_32_BIT_APPS),true)
   $(my_symlink): PRIVATE_SRC_BINARY_NAME := $(LOCAL_MODULE_STEM_64)
 else
   $(my_symlink): PRIVATE_SRC_BINARY_NAME := $(LOCAL_MODULE_STEM_32)
 endif
+else
+  $(my_symlink): PRIVATE_SRC_BINARY_NAME := $(LOCAL_MODULE_STEM_32)
+endif
+
 
 $(my_symlink): $(LOCAL_INSTALLED_MODULE) $(LOCAL_MODULE_MAKEFILE)
 	@echo "Symlink: $@ -> $(PRIVATE_SRC_BINARY_NAME)"
diff --git a/core/host_executable.mk b/core/host_executable.mk
index ffb35d2a13..53b5fd1a34 100644
--- a/core/host_executable.mk
+++ b/core/host_executable.mk
@@ -1,33 +1,48 @@
-###########################################################
-## Standard rules for building an executable file.
-##
-## Additional inputs from base_rules.make:
-## None.
-###########################################################
-
-LOCAL_IS_HOST_MODULE := true
-ifeq ($(strip $(LOCAL_MODULE_CLASS)),)
-LOCAL_MODULE_CLASS := EXECUTABLES
+
+my_prefix := HOST_
+include $(BUILD_SYSTEM)/multilib.mk
+
+ifndef my_module_multilib
+ifeq ($(HOST_PREFER_32_BIT),true)
+my_module_multilib := 32
+else
+# By default we only build host module for the first arch.
+my_module_multilib := first
 endif
-ifeq ($(strip $(LOCAL_MODULE_SUFFIX)),)
-LOCAL_MODULE_SUFFIX := $(HOST_EXECUTABLE_SUFFIX)
 endif
 
-$(call host-executable-hook)
-
-skip_build_from_source :=
-ifdef LOCAL_PREBUILT_MODULE_FILE
-ifeq (,$(call if-build-from-source,$(LOCAL_MODULE),$(LOCAL_PATH)))
-include $(BUILD_SYSTEM)/prebuilt_internal.mk
-skip_build_from_source := true
+ifeq ($(my_module_multilib),both)
+ifeq ($(LOCAL_MODULE_PATH_32)$(LOCAL_MODULE_STEM_32),)
+$(error $(LOCAL_PATH): LOCAL_MODULE_STEM_32 or LOCAL_MODULE_PATH_32 is required for LOCAL_MULTILIB := both for module $(LOCAL_MODULE))
+endif
+ifeq ($(LOCAL_MODULE_PATH_64)$(LOCAL_MODULE_STEM_64),)
+$(error $(LOCAL_PATH): LOCAL_MODULE_STEM_64 or LOCAL_MODULE_PATH_64 is required for LOCAL_MULTILIB := both for module $(LOCAL_MODULE))
 endif
+else #!LOCAL_MULTILIB == both
+LOCAL_NO_2ND_ARCH_MODULE_SUFFIX := true
 endif
 
-ifndef skip_build_from_source
+LOCAL_2ND_ARCH_VAR_PREFIX :=
+include $(BUILD_SYSTEM)/module_arch_supported.mk
 
-include $(BUILD_SYSTEM)/binary.mk
+ifeq ($(my_module_arch_supported),true)
+include $(BUILD_SYSTEM)/host_executable_internal.mk
+endif
+
+ifdef HOST_2ND_ARCH
+LOCAL_2ND_ARCH_VAR_PREFIX := $(HOST_2ND_ARCH_VAR_PREFIX)
+include $(BUILD_SYSTEM)/module_arch_supported.mk
+ifeq ($(my_module_arch_supported),true)
+# Build for HOST_2ND_ARCH
+OVERRIDE_BUILT_MODULE_PATH :=
+LOCAL_BUILT_MODULE :=
+LOCAL_INSTALLED_MODULE :=
+LOCAL_INTERMEDIATE_TARGETS :=
 
-$(LOCAL_BUILT_MODULE): $(all_objects) $(all_libraries)
-	$(transform-host-o-to-executable)
+include $(BUILD_SYSTEM)/host_executable_internal.mk
+endif
+LOCAL_2ND_ARCH_VAR_PREFIX :=
+endif  # HOST_2ND_ARCH
 
-endif  # skip_build_from_source
+LOCAL_NO_2ND_ARCH_MODULE_SUFFIX :=
+my_module_arch_supported :=
diff --git a/core/host_executable_internal.mk b/core/host_executable_internal.mk
new file mode 100644
index 0000000000..ffb35d2a13
--- /dev/null
+++ b/core/host_executable_internal.mk
@@ -0,0 +1,33 @@
+###########################################################
+## Standard rules for building an executable file.
+##
+## Additional inputs from base_rules.make:
+## None.
+###########################################################
+
+LOCAL_IS_HOST_MODULE := true
+ifeq ($(strip $(LOCAL_MODULE_CLASS)),)
+LOCAL_MODULE_CLASS := EXECUTABLES
+endif
+ifeq ($(strip $(LOCAL_MODULE_SUFFIX)),)
+LOCAL_MODULE_SUFFIX := $(HOST_EXECUTABLE_SUFFIX)
+endif
+
+$(call host-executable-hook)
+
+skip_build_from_source :=
+ifdef LOCAL_PREBUILT_MODULE_FILE
+ifeq (,$(call if-build-from-source,$(LOCAL_MODULE),$(LOCAL_PATH)))
+include $(BUILD_SYSTEM)/prebuilt_internal.mk
+skip_build_from_source := true
+endif
+endif
+
+ifndef skip_build_from_source
+
+include $(BUILD_SYSTEM)/binary.mk
+
+$(LOCAL_BUILT_MODULE): $(all_objects) $(all_libraries)
+	$(transform-host-o-to-executable)
+
+endif  # skip_build_from_source
diff --git a/core/host_shared_library.mk b/core/host_shared_library.mk
index 56ced01e45..2fdf61f86a 100644
--- a/core/host_shared_library.mk
+++ b/core/host_shared_library.mk
@@ -1,49 +1,38 @@
-###########################################################
-## Standard rules for building a normal shared library.
-##
-## Additional inputs from base_rules.make:
-## None.
-##
-## LOCAL_MODULE_SUFFIX will be set for you.
-###########################################################
-
-LOCAL_IS_HOST_MODULE := true
-
-ifeq ($(strip $(LOCAL_MODULE_CLASS)),)
-LOCAL_MODULE_CLASS := SHARED_LIBRARIES
-endif
-ifeq ($(strip $(LOCAL_MODULE_SUFFIX)),)
-LOCAL_MODULE_SUFFIX := $(HOST_SHLIB_SUFFIX)
-endif
-ifneq ($(strip $(OVERRIDE_BUILT_MODULE_PATH)),)
-$(error $(LOCAL_PATH): Illegal use of OVERRIDE_BUILT_MODULE_PATH)
+my_prefix := HOST_
+include $(BUILD_SYSTEM)/multilib.mk
+
+ifndef my_module_multilib
+ifeq ($(HOST_PREFER_32_BIT),true)
+my_module_multilib := 32
+else
+# By default we only build host module for the first arch.
+my_module_multilib := first
 endif
-ifneq ($(strip $(LOCAL_MODULE_STEM)$(LOCAL_BUILT_MODULE_STEM)),)
-$(error $(LOCAL_PATH): Cannot set module stem for a library)
 endif
 
-$(call host-shared-library-hook)
+LOCAL_2ND_ARCH_VAR_PREFIX :=
+include $(BUILD_SYSTEM)/module_arch_supported.mk
 
-skip_build_from_source :=
-ifdef LOCAL_PREBUILT_MODULE_FILE
-ifeq (,$(call if-build-from-source,$(LOCAL_MODULE),$(LOCAL_PATH)))
-include $(BUILD_SYSTEM)/prebuilt_internal.mk
-skip_build_from_source := true
+ifeq ($(my_module_arch_supported),true)
+include $(BUILD_SYSTEM)/host_shared_library_internal.mk
 endif
-endif
-
-ifndef skip_build_from_source
-
-# Put the built modules of all shared libraries in a common directory
-# to simplify the link line.
-OVERRIDE_BUILT_MODULE_PATH := $(HOST_OUT_INTERMEDIATE_LIBRARIES)
 
-include $(BUILD_SYSTEM)/binary.mk
-
-$(LOCAL_BUILT_MODULE): $(all_objects) $(all_libraries) $(LOCAL_ADDITIONAL_DEPENDENCIES)
-	$(transform-host-o-to-shared-lib)
+ifdef HOST_2ND_ARCH
+LOCAL_2ND_ARCH_VAR_PREFIX := $(HOST_2ND_ARCH_VAR_PREFIX)
+include $(BUILD_SYSTEM)/module_arch_supported.mk
+ifeq ($(my_module_arch_supported),true)
+# Build for HOST_2ND_ARCH
+OVERRIDE_BUILT_MODULE_PATH :=
+LOCAL_BUILT_MODULE :=
+LOCAL_INSTALLED_MODULE :=
+LOCAL_INTERMEDIATE_TARGETS :=
+
+include $(BUILD_SYSTEM)/host_shared_library_internal.mk
+endif
+LOCAL_2ND_ARCH_VAR_PREFIX :=
+endif  # HOST_2ND_ARCH
 
-endif  # skip_build_from_source
+my_module_arch_supported :=
 
 ###########################################################
 ## Copy headers to the install tree
diff --git a/core/host_shared_library_internal.mk b/core/host_shared_library_internal.mk
new file mode 100644
index 0000000000..d9769d3846
--- /dev/null
+++ b/core/host_shared_library_internal.mk
@@ -0,0 +1,46 @@
+###########################################################
+## Standard rules for building a normal shared library.
+##
+## Additional inputs from base_rules.make:
+## None.
+##
+## LOCAL_MODULE_SUFFIX will be set for you.
+###########################################################
+
+LOCAL_IS_HOST_MODULE := true
+
+ifeq ($(strip $(LOCAL_MODULE_CLASS)),)
+LOCAL_MODULE_CLASS := SHARED_LIBRARIES
+endif
+ifeq ($(strip $(LOCAL_MODULE_SUFFIX)),)
+LOCAL_MODULE_SUFFIX := $(HOST_SHLIB_SUFFIX)
+endif
+ifneq ($(strip $(OVERRIDE_BUILT_MODULE_PATH)),)
+$(error $(LOCAL_PATH): Illegal use of OVERRIDE_BUILT_MODULE_PATH)
+endif
+ifneq ($(strip $(LOCAL_MODULE_STEM)$(LOCAL_BUILT_MODULE_STEM)),)
+$(error $(LOCAL_PATH): Cannot set module stem for a library)
+endif
+
+$(call host-shared-library-hook)
+
+skip_build_from_source :=
+ifdef LOCAL_PREBUILT_MODULE_FILE
+ifeq (,$(call if-build-from-source,$(LOCAL_MODULE),$(LOCAL_PATH)))
+include $(BUILD_SYSTEM)/prebuilt_internal.mk
+skip_build_from_source := true
+endif
+endif
+
+ifndef skip_build_from_source
+
+# Put the built modules of all shared libraries in a common directory
+# to simplify the link line.
+OVERRIDE_BUILT_MODULE_PATH := $($(LOCAL_2ND_ARCH_VAR_PREFIX)HOST_OUT_INTERMEDIATE_LIBRARIES)
+
+include $(BUILD_SYSTEM)/binary.mk
+
+$(LOCAL_BUILT_MODULE): $(all_objects) $(all_libraries) $(LOCAL_ADDITIONAL_DEPENDENCIES)
+	$(transform-host-o-to-shared-lib)
+
+endif  # skip_build_from_source
diff --git a/core/host_static_library.mk b/core/host_static_library.mk
index 7d9b3750f8..c40cf7d29f 100644
--- a/core/host_static_library.mk
+++ b/core/host_static_library.mk
@@ -1,30 +1,38 @@
-###########################################################
-## Standard rules for building a static library for the host.
-##
-## Additional inputs from base_rules.make:
-## None.
-##
-## LOCAL_MODULE_SUFFIX will be set for you.
-###########################################################
+my_prefix := HOST_
+include $(BUILD_SYSTEM)/multilib.mk
 
-ifeq ($(strip $(LOCAL_MODULE_CLASS)),)
-LOCAL_MODULE_CLASS := STATIC_LIBRARIES
+ifndef my_module_multilib
+ifeq ($(HOST_PREFER_32_BIT),true)
+my_module_multilib := 32
+else
+# By default we only build host module for the first arch.
+my_module_multilib := first
 endif
-ifeq ($(strip $(LOCAL_MODULE_SUFFIX)),)
-LOCAL_MODULE_SUFFIX := .a
 endif
-ifneq ($(strip $(LOCAL_MODULE_STEM)$(LOCAL_BUILT_MODULE_STEM)),)
-$(error $(LOCAL_PATH): Cannot set module stem for a library)
+
+LOCAL_2ND_ARCH_VAR_PREFIX :=
+include $(BUILD_SYSTEM)/module_arch_supported.mk
+
+ifeq ($(my_module_arch_supported),true)
+include $(BUILD_SYSTEM)/host_static_library_internal.mk
 endif
-LOCAL_UNINSTALLABLE_MODULE := true
 
-LOCAL_IS_HOST_MODULE := true
+ifdef HOST_2ND_ARCH
+LOCAL_2ND_ARCH_VAR_PREFIX := $(HOST_2ND_ARCH_VAR_PREFIX)
+include $(BUILD_SYSTEM)/module_arch_supported.mk
+ifeq ($(my_module_arch_supported),true)
+# Build for HOST_2ND_ARCH
+OVERRIDE_BUILT_MODULE_PATH :=
+LOCAL_BUILT_MODULE :=
+LOCAL_INSTALLED_MODULE :=
+LOCAL_INTERMEDIATE_TARGETS :=
 
-include $(BUILD_SYSTEM)/binary.mk
+include $(BUILD_SYSTEM)/host_static_library_internal.mk
+endif
+LOCAL_2ND_ARCH_VAR_PREFIX :=
+endif  # HOST_2ND_ARCH
 
-$(LOCAL_BUILT_MODULE): $(built_whole_libraries)
-$(LOCAL_BUILT_MODULE): $(all_objects)
-	$(transform-host-o-to-static-lib)
+my_module_arch_supported :=
 
 ###########################################################
 ## Copy headers to the install tree
diff --git a/core/host_static_library_internal.mk b/core/host_static_library_internal.mk
new file mode 100644
index 0000000000..a533cf5ddf
--- /dev/null
+++ b/core/host_static_library_internal.mk
@@ -0,0 +1,27 @@
+###########################################################
+## Standard rules for building a static library for the host.
+##
+## Additional inputs from base_rules.make:
+## None.
+##
+## LOCAL_MODULE_SUFFIX will be set for you.
+###########################################################
+
+ifeq ($(strip $(LOCAL_MODULE_CLASS)),)
+LOCAL_MODULE_CLASS := STATIC_LIBRARIES
+endif
+ifeq ($(strip $(LOCAL_MODULE_SUFFIX)),)
+LOCAL_MODULE_SUFFIX := .a
+endif
+ifneq ($(strip $(LOCAL_MODULE_STEM)$(LOCAL_BUILT_MODULE_STEM)),)
+$(error $(LOCAL_PATH): Cannot set module stem for a library)
+endif
+LOCAL_UNINSTALLABLE_MODULE := true
+
+LOCAL_IS_HOST_MODULE := true
+
+include $(BUILD_SYSTEM)/binary.mk
+
+$(LOCAL_BUILT_MODULE): $(built_whole_libraries)
+$(LOCAL_BUILT_MODULE): $(all_objects)
+	$(transform-host-o-to-static-lib)
diff --git a/core/host_test_internal.mk b/core/host_test_internal.mk
index 650b9c6f5c..426c400ad2 100644
--- a/core/host_test_internal.mk
+++ b/core/host_test_internal.mk
@@ -5,7 +5,11 @@
 LOCAL_CFLAGS += -DGTEST_OS_LINUX -DGTEST_HAS_STD_STRING -O0 -g
 LOCAL_C_INCLUDES +=  external/gtest/include
 
+ifneq ($(filter libc++,$(LOCAL_SHARED_LIBRARIES)),)
+LOCAL_STATIC_LIBRARIES += libgtest_libc++_host libgtest_main_libc++_host
+else
 LOCAL_STATIC_LIBRARIES += libgtest_host libgtest_main_host
 LOCAL_SHARED_LIBRARIES +=
+endif
 
 LOCAL_LDLIBS += -lpthread
diff --git a/core/install_jni_libs.mk b/core/install_jni_libs.mk
index 464a2a20ee..700d106c81 100644
--- a/core/install_jni_libs.mk
+++ b/core/install_jni_libs.mk
@@ -5,9 +5,11 @@
 #   rs_compatibility_jni_libs (from java.mk)
 #   my_module_path (from base_rules.mk)
 #   partition_tag (from base_rules.mk)
+#   my_prebuilt_src_file (from prebuilt_internal.mk)
 #
 # Output variables:
-#   jni_shared_libraries, jni_shared_libraries_abi, if we are going to embed the libraries into the apk.
+#   jni_shared_libraries, jni_shared_libraries_abi, if we are going to embed the libraries into the apk;
+#   my_extracted_jni_libs, if we extract jni libs from prebuilt apk.
 #
 
 jni_shared_libraries := \
@@ -33,6 +35,10 @@ ifeq ($(filter $(TARGET_OUT)/% $(TARGET_OUT_VENDOR)/% $(TARGET_OUT_OEM)/%, $(my_
 my_embed_jni := true
 endif
 
+# App-specific lib path.
+my_app_lib_path :=  $($(LOCAL_2ND_ARCH_VAR_PREFIX)TARGET$(partition_tag)_OUT_SHARED_LIBRARIES)/$(basename $(my_installed_module_stem))
+my_extracted_jni_libs :=
+
 ifdef my_embed_jni
 # App explicitly requires the prebuilt NDK stl shared libraies.
 # The NDK stl shared libraries should never go to the system image.
@@ -74,12 +80,42 @@ my_leading_separator := ;
 else
 my_leading_separator :=
 endif
-my_app_lib_path :=  $($(LOCAL_2ND_ARCH_VAR_PREFIX)TARGET$(partition_tag)_OUT_SHARED_LIBRARIES)/$(basename $(LOCAL_INSTALLED_MODULE_STEM))
 $(LOCAL_INSTALLED_MODULE): PRIVATE_POST_INSTALL_CMD += \
   $(my_leading_separator)mkdir -p $(my_app_lib_path) \
   $(foreach lib, $(my_jni_filenames), ;ln -sf ../$(lib) $(my_app_lib_path)/$(lib))
 
 # Clear jni_shared_libraries to not embed it into the apk.
 jni_shared_libraries :=
-endif # $(jni_shared_libraries) not empty
+endif  # $(jni_shared_libraries) not empty
 endif  # my_embed_jni
+
+ifdef LOCAL_PREBUILT_JNI_LIBS
+# Install prebuilt JNI libs to the app specific lib path.
+# Files like @path/to/libfoo.so (path inside the apk) are JNI libs extracted from the prebuilt apk;
+# Files like path/to/libfoo.so (path relative to LOCAL_PATH) are prebuilts in the source tree.
+my_extracted_jni_libs := $(patsubst @%,%, \
+    $(filter @%, $(LOCAL_PREBUILT_JNI_LIBS)))
+ifdef my_extracted_jni_libs
+ifndef my_prebuilt_src_file
+$(error No prebuilt apk to extract prebuilt jni libraries $(my_extracted_jni_libs))
+endif
+# We use the first jni lib file as dependency.
+my_installed_prebuilt_jni := $(my_app_lib_path)/$(notdir $(firstword $(my_extracted_jni_libs)))
+$(my_installed_prebuilt_jni): PRIVATE_JNI_LIBS := $(my_extracted_jni_libs)
+$(my_installed_prebuilt_jni): $(my_prebuilt_src_file)
+	@echo "Extract JNI libs ($@ <- $<)"
+	@mkdir -p $(dir $@)
+	$(hide) unzip -j -o -d $(dir $@) $< $(PRIVATE_JNI_LIBS) && touch $@
+
+$(LOCAL_INSTALLED_MODULE) : | $(my_installed_prebuilt_jni)
+endif
+
+my_prebulit_jni_libs := $(addprefix $(LOCAL_PATH)/, \
+    $(filter-out @%, $(LOCAL_PREBUILT_JNI_LIBS)))
+ifdef my_prebulit_jni_libs
+$(foreach lib, $(my_prebulit_jni_libs), \
+    $(eval $(call copy-one-file, $(lib), $(my_app_lib_path)/$(notdir $(lib)))))
+
+$(LOCAL_INSTALLED_MODULE) : | $(addprefix $(my_app_lib_path)/, $(notdir $(my_prebulit_jni_libs)))
+endif
+endif  # LOCAL_PREBULT_JNI_LIBS
diff --git a/core/java_library.mk b/core/java_library.mk
index 343b27e38b..dffc7d90aa 100644
--- a/core/java_library.mk
+++ b/core/java_library.mk
@@ -93,15 +93,10 @@ endif
 
 else # ! boot jar
 $(built_odex): PRIVATE_MODULE := $(LOCAL_MODULE)
-$(built_odex): PRIVATE_DEX_LOCATION := $(patsubst $(PRODUCT_OUT)%,%,$(LOCAL_INSTALLED_MODULE))
-$(built_odex): PRIVATE_DEX_PREOPT_IMAGE := $(LOCAL_DEX_PREOPT_IMAGE)
-# Make sure the boot jars get dex-preopt-ed first
-$(built_odex) : $(DEXPREOPT_ONE_FILE_DEPENDENCY_BUILT_BOOT_PREOPT)
-$(built_odex) : $(DEXPREOPT_ONE_FILE_DEPENDENCY_TOOLS)
-$(built_odex) : $(LOCAL_DEX_PREOPT_IMAGE)
-$(built_odex) : $(common_javalib.jar)
+# Use pattern rule - we may have multiple built odex files.
+$(built_odex) : $(dir $(LOCAL_BUILT_MODULE))% : $(common_javalib.jar)
 	@echo "Dexpreopt Jar: $(PRIVATE_MODULE) ($@)"
-	$(call dexpreopt-one-file,$(PRIVATE_DEX_PREOPT_IMAGE),$<,$(PRIVATE_DEX_LOCATION),$@)
+	$(call dexpreopt-one-file,$<,$@)
 
 $(LOCAL_BUILT_MODULE) : $(common_javalib.jar) | $(ACP)
 	$(call copy-file-to-target)
diff --git a/core/main.mk b/core/main.mk
index 6a8bb636c5..e0817a3f01 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -111,7 +111,6 @@ ifneq ($(VERSION_CHECK_SEQUENCE_NUMBER),$(VERSIONS_CHECKED))
 $(info Checking build tools versions...)
 
 ifneq ($(HOST_OS),windows)
-ifneq ($(HOST_OS)-$(HOST_ARCH),darwin-ppc)
 # check for a case sensitive file system
 ifneq (a,$(shell mkdir -p $(OUT_DIR) ; \
                 echo a > $(OUT_DIR)/casecheck.txt; \
@@ -124,7 +123,6 @@ $(warning ************************************************************)
 $(error Case-insensitive filesystems not supported)
 endif
 endif
-endif
 
 # Make sure that there are no spaces in the absolute path; the
 # build system can't deal with them.
@@ -451,12 +449,6 @@ $(INTERNAL_MODIFIER_TARGETS): $(DEFAULT_GOAL)
 endif
 
 # Bring in all modules that need to be built.
-ifeq ($(HOST_OS)-$(HOST_ARCH),darwin-ppc)
-SDK_ONLY := true
-$(info Building the SDK under darwin-ppc is actually obsolete and unsupported.)
-$(error stop)
-endif
-
 ifeq ($(HOST_OS),windows)
 SDK_ONLY := true
 endif
@@ -656,6 +648,14 @@ $(foreach m,$($(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_DEPENDENCIES_ON_SHARED_LIBRARI
       $(subst $(comma),$(space),$(lastword $(p))))))) \
   $(eval $(call add-required-deps,$(word 2,$(p)),$(r))))
 endif
+ifdef HOST_2ND_ARCH
+$(foreach m,$($(HOST_2ND_ARCH_VAR_PREFIX)HOST_DEPENDENCIES_ON_SHARED_LIBRARIES), \
+  $(eval p := $(subst :,$(space),$(m))) \
+  $(eval r := $(filter $(HOST_OUT_ROOT)/%,$(call module-installed-files,\
+    $(addsuffix $(HOST_2ND_ARCH_MODULE_SUFFIX), \
+      $(subst $(comma),$(space),$(lastword $(p))))))) \
+  $(eval $(call add-required-deps,$(word 2,$(p)),$(r))))
+endif
 
 m :=
 r :=
diff --git a/core/module_arch_supported.mk b/core/module_arch_supported.mk
index 542f3f2bff..d677e39fc3 100644
--- a/core/module_arch_supported.mk
+++ b/core/module_arch_supported.mk
@@ -2,14 +2,15 @@
 ## Determine if a module can be built for an arch
 ##
 ## Inputs from module makefile:
+## my_prefix   TARGET_ or HOST_
 ## my_module_multilib
-## LOCAL_MODULE_TARGET_ARCH
-## LOCAL_MODULE_TARGET_ARCH_WARN
-## LOCAL_MODULE_UNSUPPORTED_TARGET_ARCH
-## LOCAL_MODULE_UNSUPPORTED_TARGET_ARCH_WARN
+## LOCAL_MODULE_$(my_prefix)ARCH
+## LOCAL_MODULE_$(my_prefix)ARCH_WARN
+## LOCAL_MODULE_UNSUPPORTED_$(my_prefix)ARCH
+## LOCAL_MODULE_UNSUPPORTED_$(my_prefix)ARCH_WARN
 ##
 ## Inputs from build system:
-## TARGET_IS_64_BIT
+## $(my_prefix)IS_64_BIT
 ## LOCAL_2ND_ARCH_VAR_PREFIX
 ##
 ## Outputs:
@@ -23,9 +24,9 @@ my_module_arch_supported := false
 endif
 
 ifeq ($(LOCAL_2ND_ARCH_VAR_PREFIX),)
-ifeq ($(TARGET_IS_64_BIT)|$(my_module_multilib),true|32)
+ifeq ($($(my_prefix)IS_64_BIT)|$(my_module_multilib),true|32)
 my_module_arch_supported := false
-else ifeq ($(TARGET_IS_64_BIT)|$(my_module_multilib),|64)
+else ifeq ($($(my_prefix)IS_64_BIT)|$(my_module_multilib),|64)
 my_module_arch_supported := false
 else ifeq ($(call directory_is_64_bit_blacklisted,$(LOCAL_PATH)),true)
 my_module_arch_supported := false
@@ -38,26 +39,26 @@ my_module_arch_supported := false
 endif
 endif # LOCAL_2ND_ARCH_VAR_PREFIX
 
-ifneq (,$(LOCAL_MODULE_TARGET_ARCH))
-ifeq (,$(filter $(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH),$(LOCAL_MODULE_TARGET_ARCH)))
+ifneq (,$(LOCAL_MODULE_$(my_prefix)ARCH))
+ifeq (,$(filter $($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH),$(LOCAL_MODULE_$(my_prefix)ARCH)))
 my_module_arch_supported := false
 endif
 endif
 
-ifneq (,$(LOCAL_MODULE_TARGET_ARCH_WARN))
-ifeq (,$(filter $(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH),$(LOCAL_MODULE_TARGET_ARCH_WARN)))
+ifneq (,$(LOCAL_MODULE_$(my_prefix)ARCH_WARN))
+ifeq (,$(filter $($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH),$(LOCAL_MODULE_$(my_prefix)ARCH_WARN)))
 my_module_arch_supported := false
-$(warning $(LOCAL_MODULE): architecture $(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH) not supported)
+$(warning $(LOCAL_MODULE): architecture $($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH) not supported)
 endif
 endif
 
-ifneq (,$(filter $(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH),$(LOCAL_MODULE_UNSUPPORTED_TARGET_ARCH)))
+ifneq (,$(filter $($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH),$(LOCAL_MODULE_UNSUPPORTED_$(my_prefix)ARCH)))
 my_module_arch_supported := false
 endif
 
-ifneq (,$(filter $(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH),$(LOCAL_MODULE_UNSUPPORTED_TARGET_ARCH_WARN)))
+ifneq (,$(filter $($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH),$(LOCAL_MODULE_UNSUPPORTED_$(my_prefix)ARCH_WARN)))
 my_module_arch_supported := false
-$(warning $(LOCAL_MODULE): architecture $(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH) unsupported)
+$(warning $(LOCAL_MODULE): architecture $($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH) unsupported)
 endif
 
 ifeq ($(call directory_is_in_project_blacklist,$(LOCAL_PATH)),true)
diff --git a/core/multilib.mk b/core/multilib.mk
index f630c94430..a3ced65d2c 100644
--- a/core/multilib.mk
+++ b/core/multilib.mk
@@ -1,4 +1,4 @@
-# Translate LOCAL_32_BIT_ONLY and LOCAL_NO_2ND_ARCH to LOCAL_MULTILIB,
+# Translate LOCAL_32_BIT_ONLY to LOCAL_MULTILIB,
 # and check LOCAL_MULTILIB is a valid value.  Returns module's multilib
 # setting in my_module_multilib, or empty if not set.
 
diff --git a/core/package.mk b/core/package.mk
index c7d68d95e5..78b65db107 100644
--- a/core/package.mk
+++ b/core/package.mk
@@ -1,8 +1,8 @@
 # We don't automatically set up rules to build packages for both
 # TARGET_ARCH and TARGET_2ND_ARCH.
-# By default, an package is built for TARGET_ARCH.
 # To build it for TARGET_2ND_ARCH in a 64bit product, use "LOCAL_MULTILIB := 32".
 
+my_prefix := TARGET_
 include $(BUILD_SYSTEM)/multilib.mk
 
 ifeq ($(TARGET_SUPPORTS_32_BIT_APPS)|$(TARGET_SUPPORTS_64_BIT_APPS),true|true)
diff --git a/core/package_internal.mk b/core/package_internal.mk
index 768032ebd4..cb1e4244a5 100644
--- a/core/package_internal.mk
+++ b/core/package_internal.mk
@@ -336,18 +336,6 @@ $(LOCAL_BUILT_MODULE): PRIVATE_ADDITIONAL_CERTIFICATES := $(foreach c,\
 
 # Define the rule to build the actual package.
 $(LOCAL_BUILT_MODULE): $(AAPT) | $(ZIPALIGN)
-ifdef LOCAL_DEX_PREOPT
-$(LOCAL_BUILT_MODULE): PRIVATE_DEX_LOCATION := $(patsubst $(PRODUCT_OUT)%,%,$(LOCAL_INSTALLED_MODULE))
-$(LOCAL_BUILT_MODULE): PRIVATE_BUILT_ODEX := $(built_odex)
-$(LOCAL_BUILT_MODULE): PRIVATE_DEX_PREOPT_IMAGE := $(LOCAL_DEX_PREOPT_IMAGE)
-# Make sure the boot jars get dexpreopt-ed first
-$(LOCAL_BUILT_MODULE) : $(DEXPREOPT_ONE_FILE_DEPENDENCY_BUILT_BOOT_PREOPT)
-$(LOCAL_BUILT_MODULE) : $(DEXPREOPT_ONE_FILE_DEPENDENCY_TOOLS)
-$(LOCAL_BUILT_MODULE) : $(LOCAL_DEX_PREOPT_IMAGE)
-
-# built_odex is byproduct of LOCAL_BUILT_MODULE without its own build recipe.
-$(built_odex) : $(LOCAL_BUILT_MODULE)
-endif
 $(LOCAL_BUILT_MODULE): PRIVATE_JNI_SHARED_LIBRARIES := $(jni_shared_libraries)
 $(LOCAL_BUILT_MODULE): PRIVATE_JNI_SHARED_LIBRARIES_ABI := $(jni_shared_libraries_abi)
 ifneq ($(TARGET_BUILD_APPS),)
@@ -377,7 +365,6 @@ ifneq ($(extra_jar_args),)
 endif
 	$(sign-package)
 ifdef LOCAL_DEX_PREOPT
-	$(call dexpreopt-one-file,$(PRIVATE_DEX_PREOPT_IMAGE),$@,$(PRIVATE_DEX_LOCATION),$(PRIVATE_BUILT_ODEX))
 ifneq (nostripping,$(LOCAL_DEX_PREOPT))
 	$(call dexpreopt-remove-classes.dex,$@)
 endif
@@ -385,6 +372,18 @@ endif
 	@# Alignment must happen after all other zip operations.
 	$(align-package)
 
+###############################
+## Rule to build the odex file
+ifdef LOCAL_DEX_PREOPT
+$(built_odex): PRIVATE_DEX_FILE := $(built_dex)
+$(built_odex) : $(built_dex)
+	$(create-empty-package)
+	$(add-dex-to-package)
+	$(hide) mv $@ $@.input
+	$(call dexpreopt-one-file,$@.input,$@)
+	$(hide) rm $@.input
+endif
+
 # Save information about this package
 PACKAGES.$(LOCAL_PACKAGE_NAME).OVERRIDES := $(strip $(LOCAL_OVERRIDES_PACKAGES))
 PACKAGES.$(LOCAL_PACKAGE_NAME).RESOURCE_FILES := $(all_resources)
diff --git a/core/prebuilt.mk b/core/prebuilt.mk
index 5f91110cf6..33f5dc6c2f 100644
--- a/core/prebuilt.mk
+++ b/core/prebuilt.mk
@@ -7,32 +7,43 @@
 ###########################################################
 
 ifdef LOCAL_IS_HOST_MODULE
-include $(BUILD_SYSTEM)/prebuilt_internal.mk
-else #!LOCAL_IS_HOST_MODULE
+  my_prefix := HOST_
+else
+  my_prefix := TARGET_
+endif
 
 include $(BUILD_SYSTEM)/multilib.mk
 
-ifndef my_module_multilib
-# prebuilts default to building for either architecture,
-# the first if its supported, otherwise the second.
-my_module_multilib := both
-endif
+my_skip_non_preferred_arch :=
 
 # check if first arch is supported
 include $(BUILD_SYSTEM)/module_arch_supported.mk
 ifeq ($(my_module_arch_supported),true)
 # first arch is supported
 include $(BUILD_SYSTEM)/prebuilt_internal.mk
-else ifneq (,$(TARGET_2ND_ARCH))
+ifneq ($(my_module_multilib),both)
+my_skip_non_preferred_arch := true
+endif # $(my_module_multilib)
+endif # $(my_module_arch_supported)
+
+ifndef my_skip_non_preferred_arch
+ifneq (,$($(my_prefix)2ND_ARCH))
 # check if secondary arch is supported
-LOCAL_2ND_ARCH_VAR_PREFIX := $(TARGET_2ND_ARCH_VAR_PREFIX)
+LOCAL_2ND_ARCH_VAR_PREFIX := $($(my_prefix)2ND_ARCH_VAR_PREFIX)
 include $(BUILD_SYSTEM)/module_arch_supported.mk
 ifeq ($(my_module_arch_supported),true)
 # secondary arch is supported
+OVERRIDE_BUILT_MODULE_PATH :=
+LOCAL_BUILT_MODULE :=
+LOCAL_INSTALLED_MODULE :=
+LOCAL_MODULE_STEM :=
+LOCAL_BUILT_MODULE_STEM :=
+LOCAL_INSTALLED_MODULE_STEM :=
+LOCAL_INTERMEDIATE_TARGETS :=
 include $(BUILD_SYSTEM)/prebuilt_internal.mk
-endif
-endif # TARGET_2ND_ARCH
-endif # !LOCAL_IS_HOST_MODULE
+endif # $(my_module_arch_supported)
+endif # $($(my_prefix)2ND_ARCH)
+endif # $(my_skip_non_preferred_arch) not true
 
 LOCAL_2ND_ARCH_VAR_PREFIX :=
 
diff --git a/core/prebuilt_internal.mk b/core/prebuilt_internal.mk
index 8efb89e773..7229b3a467 100644
--- a/core/prebuilt_internal.mk
+++ b/core/prebuilt_internal.mk
@@ -19,21 +19,22 @@ endif
 # Not much sense to check build prebuilts
 LOCAL_DONT_CHECK_MODULE := true
 
+my_32_64_bit_suffix := $(if $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)IS_64_BIT),64,32)
+
 ifdef LOCAL_PREBUILT_MODULE_FILE
   my_prebuilt_src_file := $(LOCAL_PREBUILT_MODULE_FILE)
 else
-  ifdef LOCAL_SRC_FILES_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)
-    my_prebuilt_src_file := $(LOCAL_PATH)/$(LOCAL_SRC_FILES_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH))
+  ifdef LOCAL_SRC_FILES_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)
+    my_prebuilt_src_file := $(LOCAL_PATH)/$(LOCAL_SRC_FILES_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH))
   else
-    my_prebuilt_src_file := $(LOCAL_PATH)/$(LOCAL_SRC_FILES)
+    ifdef LOCAL_SRC_FILES_$(my_32_64_bit_suffix)
+      my_prebuilt_src_file := $(LOCAL_PATH)/$(LOCAL_SRC_FILES_$(my_32_64_bit_suffix))
+    else
+      my_prebuilt_src_file := $(LOCAL_PATH)/$(LOCAL_SRC_FILES)
+    endif
   endif
 endif
 
-ifdef LOCAL_IS_HOST_MODULE
-  my_prefix := HOST_
-else
-  my_prefix := TARGET_
-endif
 ifeq (SHARED_LIBRARIES,$(LOCAL_MODULE_CLASS))
   # Put the built targets of all shared libraries in a common directory
   # to simplify the link line.
@@ -161,28 +162,29 @@ LOCAL_DEX_PREOPT := false
 # defines built_odex along with rule to install odex
 include $(BUILD_SYSTEM)/dex_preopt_odex_install.mk
 #######################################
-ifdef LOCAL_DEX_PREOPT
-$(built_module): PRIVATE_DEX_PREOPT_IMAGE := $(LOCAL_DEX_PREOPT_IMAGE)
-$(built_module): PRIVATE_DEX_LOCATION := $(patsubst $(PRODUCT_OUT)%,%,$(LOCAL_INSTALLED_MODULE))
-$(built_module): PRIVATE_BUILT_ODEX := $(built_odex)
-# Make sure the boot jars get dexpreopt-ed first
-$(built_module) : $(DEXPREOPT_ONE_FILE_DEPENDENCY_BUILT_BOOT_PREOPT)
-$(built_module) : $(DEXPREOPT_ONE_FILE_DEPENDENCY_TOOLS)
-(built_module) : $(LOCAL_DEX_PREOPT_IMAGE)
-# built_odex is byproduct of LOCAL_BUILT_MODULE without its own build recipe.
-$(built_odex) : $(LOCAL_BUILT_MODULE)
-endif # LOCAL_DEX_PREOPT
 # Sign and align non-presigned .apks.
 $(built_module) : $(my_prebuilt_src_file) | $(ACP) $(ZIPALIGN) $(SIGNAPK_JAR)
 	$(transform-prebuilt-to-target)
+ifdef my_extracted_jni_libs
+	$(hide) zip -d $@ 'lib/*.so'  # strip embedded JNI libraries.
+endif
 ifneq ($(LOCAL_CERTIFICATE),PRESIGNED)
 	$(sign-package)
 endif
 ifdef LOCAL_DEX_PREOPT
-	$(call dexpreopt-one-file,$(PRIVATE_DEX_PREOPT_IMAGE),$@,$(PRIVATE_DEX_LOCATION),$(PRIVATE_BUILT_ODEX))
+ifneq (nostripping,$(LOCAL_DEX_PREOPT))
+	$(call dexpreopt-remove-classes.dex,$@)
+endif
 endif
 	$(align-package)
 
+###############################
+## Rule to build the odex file
+ifdef LOCAL_DEX_PREOPT
+$(built_odex) : $(my_prebuilt_src_file)
+	$(call dexpreopt-one-file,$<,$@)
+endif
+
 else # LOCAL_MODULE_CLASS != APPS
 ifneq ($(LOCAL_PREBUILT_STRIP_COMMENTS),)
 $(built_module) : $(my_prebuilt_src_file)
diff --git a/core/product_config.mk b/core/product_config.mk
index 61bdfb40e7..cb488c0af8 100644
--- a/core/product_config.mk
+++ b/core/product_config.mk
@@ -164,7 +164,7 @@ endif # unbundled_goals
 
 # Default to building dalvikvm on hosts that support it...
 ifeq ($(HOST_OS),linux)
-ifeq ($(BUILD_HOST_64bit),)
+ifneq ($(HOST_ARCH),x86_64)
 # ... or if the if the option is already set
 ifeq ($(WITH_HOST_DALVIK),)
   WITH_HOST_DALVIK := true
diff --git a/core/shared_library.mk b/core/shared_library.mk
index 95a8d7b0e7..71a3bb2681 100644
--- a/core/shared_library.mk
+++ b/core/shared_library.mk
@@ -1,3 +1,12 @@
+my_prefix := TARGET_
+include $(BUILD_SYSTEM)/multilib.mk
+
+ifndef my_module_multilib
+# libraries default to building for both architecturess
+my_module_multilib := both
+endif
+
+ifeq ($(my_module_multilib),both)
 ifneq ($(LOCAL_MODULE_PATH),)
 ifneq ($(TARGET_2ND_ARCH),)
 $(warning $(LOCAL_MODULE): LOCAL_MODULE_PATH for shared libraries is unsupported in multiarch builds, use LOCAL_MODULE_RELATIVE_PATH instead)
@@ -9,13 +18,8 @@ ifneq ($(TARGET_2ND_ARCH),)
 $(warning $(LOCAL_MODULE): LOCAL_UNSTRIPPED_PATH for shared libraries is unsupported in multiarch builds)
 endif
 endif
+endif # my_module_multilib == both
 
-include $(BUILD_SYSTEM)/multilib.mk
-
-ifndef my_module_multilib
-# libraries default to building for both architecturess
-my_module_multilib := both
-endif
 
 LOCAL_2ND_ARCH_VAR_PREFIX :=
 include $(BUILD_SYSTEM)/module_arch_supported.mk
diff --git a/core/static_library.mk b/core/static_library.mk
index bedefd0993..854cbfcb96 100644
--- a/core/static_library.mk
+++ b/core/static_library.mk
@@ -1,3 +1,4 @@
+my_prefix := TARGET_
 include $(BUILD_SYSTEM)/multilib.mk
 
 ifndef my_module_multilib
diff --git a/core/static_library_internal.mk b/core/static_library_internal.mk
index 2d3468c949..cabe823220 100644
--- a/core/static_library_internal.mk
+++ b/core/static_library_internal.mk
@@ -28,7 +28,6 @@ $(all_objects) : PRIVATE_TARGET_GLOBAL_CFLAGS :=
 $(all_objects) : PRIVATE_TARGET_GLOBAL_CPPFLAGS :=
 endif
 
-$(LOCAL_BUILT_MODULE): PRIVATE_2ND_ARCH_VAR_PREFIX := $(LOCAL_2ND_ARCH_VAR_PREFIX)
 $(LOCAL_BUILT_MODULE) : $(built_whole_libraries)
 $(LOCAL_BUILT_MODULE) : $(all_objects)
 	$(transform-o-to-static-lib)
diff --git a/core/target_test_internal.mk b/core/target_test_internal.mk
index 7b99678f9b..49ea518cfe 100644
--- a/core/target_test_internal.mk
+++ b/core/target_test_internal.mk
@@ -5,6 +5,9 @@
 LOCAL_CFLAGS += -DGTEST_OS_LINUX_ANDROID -DGTEST_HAS_STD_STRING
 
 LOCAL_C_INCLUDES += external/gtest/include
+ifneq ($(filter libc++,$(LOCAL_SHARED_LIBRARIES)),)
+LOCAL_STATIC_LIBRARIES += libgtest_libc++ libgtest_main_libc++
+else
 LOCAL_STATIC_LIBRARIES += libgtest libgtest_main
 
 ifndef LOCAL_SDK_VERSION
@@ -14,6 +17,7 @@ LOCAL_C_INCLUDES += bionic \
 LOCAL_SHARED_LIBRARIES += libstlport
 LOCAL_STATIC_LIBRARIES += libstdc++
 endif
+endif
 
 ifndef LOCAL_MODULE_PATH
 LOCAL_MODULE_PATH := $(TARGET_OUT_DATA_NATIVE_TESTS)/$(LOCAL_MODULE)
diff --git a/envsetup.sh b/envsetup.sh
index d02646630a..6c25ebe91e 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -120,6 +120,7 @@ function setpaths()
 
     # defined in core/config.mk
     targetgccversion=$(get_build_var TARGET_GCC_VERSION)
+    targetgccversion2=$(get_build_var 2ND_TARGET_GCC_VERSION)
     export TARGET_GCC_VERSION=$targetgccversion
 
     # The gcc toolchain does not exists for windows/cygwin. In this case, do not reference it.
@@ -134,7 +135,7 @@ function setpaths()
         arm) toolchaindir=arm/arm-linux-androideabi-$targetgccversion/bin
             ;;
         arm64) toolchaindir=aarch64/aarch64-linux-android-$targetgccversion/bin;
-               toolchaindir2=arm/arm-linux-androideabi-$targetgccversion/bin
+               toolchaindir2=arm/arm-linux-androideabi-$targetgccversion2/bin
             ;;
         mips) toolchaindir=mips/mipsel-linux-android-$targetgccversion/bin
             ;;
@@ -170,7 +171,7 @@ function setpaths()
 
     export ANDROID_QTOOLS=$T/development/emulator/qtools
     export ANDROID_DEV_SCRIPTS=$T/development/scripts:$T/prebuilts/devtools/tools
-    export ANDROID_BUILD_PATHS=$(get_build_var ANDROID_BUILD_PATHS):$ANDROID_QTOOLS:$ANDROID_TOOLCHAIN:$ANDROID_KERNEL_TOOLCHAIN_PATH$ANDROID_DEV_SCRIPTS:
+    export ANDROID_BUILD_PATHS=$(get_build_var ANDROID_BUILD_PATHS):$ANDROID_QTOOLS:$ANDROID_TOOLCHAIN:$ANDROID_TOOLCHAIN_2ND_ARCH:$ANDROID_KERNEL_TOOLCHAIN_PATH$ANDROID_DEV_SCRIPTS:
 
     # If prebuilts/android-emulator/<system>/ exists, prepend it to our PATH
     # to ensure that the corresponding 'emulator' binaries are used.
@@ -186,7 +187,7 @@ function setpaths()
             ;;
     esac
     if [ -n "$ANDROID_EMULATOR_PREBUILTS" -a -d "$ANDROID_EMULATOR_PREBUILTS" ]; then
-        ANDROID_BUILD_PATHS=$ANDROID_EMULATOR_PREBUILTS:$ANDROID_BUILD_PATHS
+        ANDROID_BUILD_PATHS=$ANDROID_BUILD_PATHS$ANDROID_EMULATOR_PREBUILTS:
         export ANDROID_EMULATOR_PREBUILTS
     fi
 
@@ -976,6 +977,7 @@ function gdbclient()
    local OUT_ROOT=$(get_abs_build_var PRODUCT_OUT)
    local OUT_SYMBOLS=$(get_abs_build_var TARGET_OUT_UNSTRIPPED)
    local OUT_SO_SYMBOLS=$(get_abs_build_var TARGET_OUT_SHARED_LIBRARIES_UNSTRIPPED)
+   local OUT_VENDOR_SO_SYMBOLS=$(get_abs_build_var TARGET_OUT_VENDOR_SHARED_LIBRARIES_UNSTRIPPED)
    local OUT_EXE_SYMBOLS=$(get_abs_build_var TARGET_OUT_EXECUTABLES_UNSTRIPPED)
    local PREBUILTS=$(get_abs_build_var ANDROID_PREBUILTS)
    local ARCH=$(get_build_var TARGET_ARCH)
@@ -1040,7 +1042,7 @@ function gdbclient()
        OUT_SO_SYMBOLS=$OUT_SO_SYMBOLS$USE64BIT
 
        echo >|"$OUT_ROOT/gdbclient.cmds" "set solib-absolute-prefix $OUT_SYMBOLS"
-       echo >>"$OUT_ROOT/gdbclient.cmds" "set solib-search-path $OUT_SO_SYMBOLS:$OUT_SO_SYMBOLS/hw:$OUT_SO_SYMBOLS/ssl/engines:$OUT_SO_SYMBOLS/drm:$OUT_SO_SYMBOLS/egl:$OUT_SO_SYMBOLS/soundfx"
+       echo >>"$OUT_ROOT/gdbclient.cmds" "set solib-search-path $OUT_SO_SYMBOLS:$OUT_SO_SYMBOLS/hw:$OUT_SO_SYMBOLS/ssl/engines:$OUT_SO_SYMBOLS/drm:$OUT_SO_SYMBOLS/egl:$OUT_SO_SYMBOLS/soundfx:$OUT_VENDOR_SO_SYMBOLS:$OUT_VENDOR_SO_SYMBOLS/hw:$OUT_VENDOR_SO_SYMBOLS/egl"
        echo >>"$OUT_ROOT/gdbclient.cmds" "source $ANDROID_BUILD_TOP/development/scripts/gdb/dalvik.gdb"
        echo >>"$OUT_ROOT/gdbclient.cmds" "target remote $PORT"
        echo >>"$OUT_ROOT/gdbclient.cmds" ""
diff --git a/libs/host/Android.mk b/libs/host/Android.mk
index 74afa5562f..c67afbbcd9 100644
--- a/libs/host/Android.mk
+++ b/libs/host/Android.mk
@@ -2,7 +2,7 @@ LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES:= \
-	CopyFile.c
+    CopyFile.c
 
 ifeq ($(HOST_OS),cygwin)
 LOCAL_CFLAGS += -DWIN32_EXE
diff --git a/target/board/generic/BoardConfig.mk b/target/board/generic/BoardConfig.mk
index c30cc75862..6d58b1c86b 100644
--- a/target/board/generic/BoardConfig.mk
+++ b/target/board/generic/BoardConfig.mk
@@ -78,6 +78,7 @@ TARGET_USERIMAGES_SPARSE_EXT_DISABLED := true
 BOARD_SEPOLICY_DIRS += build/target/board/generic/sepolicy
 BOARD_SEPOLICY_UNION += \
         adbd.te \
+        app.te \
         bootanim.te \
         device.te \
         domain.te \
@@ -88,4 +89,5 @@ BOARD_SEPOLICY_UNION += \
         rild.te \
         shell.te \
         surfaceflinger.te \
-        system_server.te
+        system_server.te \
+        zygote.te
diff --git a/target/board/generic/sepolicy/app.te b/target/board/generic/sepolicy/app.te
new file mode 100644
index 0000000000..fd33453e6c
--- /dev/null
+++ b/target/board/generic/sepolicy/app.te
@@ -0,0 +1 @@
+allow appdomain qemu_device:chr_file rw_file_perms;
diff --git a/target/board/generic/sepolicy/bootanim.te b/target/board/generic/sepolicy/bootanim.te
index d6506e11dd..a5a84f9fbb 100644
--- a/target/board/generic/sepolicy/bootanim.te
+++ b/target/board/generic/sepolicy/bootanim.te
@@ -1,2 +1,3 @@
 allow bootanim self:process execmem;
 allow bootanim ashmem_device:chr_file execute;
+allow bootanim qemu_device:chr_file rw_file_perms;
diff --git a/target/board/generic/sepolicy/surfaceflinger.te b/target/board/generic/sepolicy/surfaceflinger.te
index 4c354697ab..671278919d 100644
--- a/target/board/generic/sepolicy/surfaceflinger.te
+++ b/target/board/generic/sepolicy/surfaceflinger.te
@@ -1,2 +1,3 @@
 allow surfaceflinger self:process execmem;
 allow surfaceflinger ashmem_device:chr_file execute;
+allow surfaceflinger qemu_device:chr_file rw_file_perms;
diff --git a/target/board/generic/sepolicy/zygote.te b/target/board/generic/sepolicy/zygote.te
new file mode 100644
index 0000000000..a5da574060
--- /dev/null
+++ b/target/board/generic/sepolicy/zygote.te
@@ -0,0 +1 @@
+allow zygote qemu_device:chr_file rw_file_perms;
diff --git a/target/board/generic_arm64/BoardConfig.mk b/target/board/generic_arm64/BoardConfig.mk
index 9d3bcc035c..c383f87069 100644
--- a/target/board/generic_arm64/BoardConfig.mk
+++ b/target/board/generic_arm64/BoardConfig.mk
@@ -48,7 +48,7 @@ BUILD_EMULATOR_OPENGL := true
 USE_OPENGL_RENDERER := true
 
 TARGET_USERIMAGES_USE_EXT4 := true
-BOARD_SYSTEMIMAGE_PARTITION_SIZE := 576716800
+BOARD_SYSTEMIMAGE_PARTITION_SIZE := 786432000
 BOARD_USERDATAIMAGE_PARTITION_SIZE := 576716800
 BOARD_CACHEIMAGE_PARTITION_SIZE := 69206016
 BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE := ext4
diff --git a/target/board/generic_x86/BoardConfig.mk b/target/board/generic_x86/BoardConfig.mk
index 67f0ecff12..727d3db734 100644
--- a/target/board/generic_x86/BoardConfig.mk
+++ b/target/board/generic_x86/BoardConfig.mk
@@ -35,7 +35,7 @@ BUILD_EMULATOR_OPENGL := true
 USE_OPENGL_RENDERER := true
 
 TARGET_USERIMAGES_USE_EXT4 := true
-BOARD_SYSTEMIMAGE_PARTITION_SIZE := 576716800
+BOARD_SYSTEMIMAGE_PARTITION_SIZE := 681574400
 BOARD_USERDATAIMAGE_PARTITION_SIZE := 576716800
 BOARD_CACHEIMAGE_PARTITION_SIZE := 69206016
 BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE := ext4
@@ -44,7 +44,9 @@ TARGET_USERIMAGES_SPARSE_EXT_DISABLED := true
 
 BOARD_SEPOLICY_DIRS += build/target/board/generic_x86/sepolicy
 BOARD_SEPOLICY_UNION += \
+        app.te \
         adbd.te \
+        bootanim.te \
         device.te \
         domain.te \
         file.te \
@@ -55,5 +57,6 @@ BOARD_SEPOLICY_UNION += \
         qemud.te \
         rild.te \
         shell.te \
+        surfaceflinger.te \
         system_server.te \
         zygote.te
diff --git a/target/board/generic_x86/sepolicy/app.te b/target/board/generic_x86/sepolicy/app.te
new file mode 100644
index 0000000000..fd33453e6c
--- /dev/null
+++ b/target/board/generic_x86/sepolicy/app.te
@@ -0,0 +1 @@
+allow appdomain qemu_device:chr_file rw_file_perms;
diff --git a/target/board/generic_x86/sepolicy/bootanim.te b/target/board/generic_x86/sepolicy/bootanim.te
new file mode 100644
index 0000000000..762a57387f
--- /dev/null
+++ b/target/board/generic_x86/sepolicy/bootanim.te
@@ -0,0 +1 @@
+allow bootanim qemu_device:chr_file rw_file_perms;
diff --git a/target/board/generic_x86/sepolicy/surfaceflinger.te b/target/board/generic_x86/sepolicy/surfaceflinger.te
new file mode 100644
index 0000000000..865405ce55
--- /dev/null
+++ b/target/board/generic_x86/sepolicy/surfaceflinger.te
@@ -0,0 +1 @@
+allow surfaceflinger qemu_device:chr_file rw_file_perms;
diff --git a/target/board/generic_x86/sepolicy/zygote.te b/target/board/generic_x86/sepolicy/zygote.te
index 93993a47f1..d34c4a1f9c 100644
--- a/target/board/generic_x86/sepolicy/zygote.te
+++ b/target/board/generic_x86/sepolicy/zygote.te
@@ -1,2 +1,3 @@
 allow zygote self:process execmem;
 allow zygote self:capability sys_nice;
+allow zygote qemu_device:chr_file rw_file_perms;
diff --git a/target/product/embedded.mk b/target/product/embedded.mk
index 60a19da794..5d868615e4 100644
--- a/target/product/embedded.mk
+++ b/target/product/embedded.mk
@@ -38,7 +38,6 @@ PRODUCT_PACKAGES += \
     libGLESv2 \
     libbinder \
     libc \
-    libctest \
     libcutils \
     libdl \
     libgui \
diff --git a/tools/acp/Android.mk b/tools/acp/Android.mk
index 5e0e2e461e..33c55675f1 100644
--- a/tools/acp/Android.mk
+++ b/tools/acp/Android.mk
@@ -6,7 +6,7 @@ LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := \
-	acp.c
+    acp.c
 
 ifeq ($(HOST_OS),cygwin)
 LOCAL_CFLAGS += -DWIN32_EXE
@@ -23,4 +23,3 @@ LOCAL_MODULE := acp
 LOCAL_ACP_UNAVAILABLE := true
 
 include $(BUILD_HOST_EXECUTABLE)
-
diff --git a/tools/signapk/SignApk.java b/tools/signapk/SignApk.java
index b2470722c8..e661e506f4 100644
--- a/tools/signapk/SignApk.java
+++ b/tools/signapk/SignApk.java
@@ -461,24 +461,75 @@ class SignApk {
      * reduce variation in the output file and make incremental OTAs
      * more efficient.
      */
-    private static void copyFiles(Manifest manifest,
-                                  JarFile in, JarOutputStream out, long timestamp) throws IOException {
+    private static void copyFiles(Manifest manifest, JarFile in, JarOutputStream out,
+                                  long timestamp, int alignment) throws IOException {
         byte[] buffer = new byte[4096];
         int num;
 
         Map<String, Attributes> entries = manifest.getEntries();
         ArrayList<String> names = new ArrayList<String>(entries.keySet());
         Collections.sort(names);
+
+        boolean firstEntry = true;
+        long offset = 0L;
+
+        // We do the copy in two passes -- first copying all the
+        // entries that are STORED, then copying all the entries that
+        // have any other compression flag (which in practice means
+        // DEFLATED).  This groups all the stored entries together at
+        // the start of the file and makes it easier to do alignment
+        // on them (since only stored entries are aligned).
+
         for (String name : names) {
             JarEntry inEntry = in.getJarEntry(name);
             JarEntry outEntry = null;
-            if (inEntry.getMethod() == JarEntry.STORED) {
-                // Preserve the STORED method of the input entry.
-                outEntry = new JarEntry(inEntry);
-            } else {
-                // Create a new entry so that the compressed len is recomputed.
-                outEntry = new JarEntry(name);
+            if (inEntry.getMethod() != JarEntry.STORED) continue;
+            // Preserve the STORED method of the input entry.
+            outEntry = new JarEntry(inEntry);
+            outEntry.setTime(timestamp);
+
+            // 'offset' is the offset into the file at which we expect
+            // the file data to begin.  This is the value we need to
+            // make a multiple of 'alignement'.
+            offset += JarFile.LOCHDR + outEntry.getName().length();
+            if (firstEntry) {
+                // The first entry in a jar file has an extra field of
+                // four bytes that you can't get rid of; any extra
+                // data you specify in the JarEntry is appended to
+                // these forced four bytes.  This is JAR_MAGIC in
+                // JarOutputStream; the bytes are 0xfeca0000.
+                offset += 4;
+                firstEntry = false;
+            }
+            if (alignment > 0 && (offset % alignment != 0)) {
+                // Set the "extra data" of the entry to between 1 and
+                // alignment-1 bytes, to make the file data begin at
+                // an aligned offset.
+                int needed = alignment - (int)(offset % alignment);
+                outEntry.setExtra(new byte[needed]);
+                offset += needed;
+            }
+
+            out.putNextEntry(outEntry);
+
+            InputStream data = in.getInputStream(inEntry);
+            while ((num = data.read(buffer)) > 0) {
+                out.write(buffer, 0, num);
+                offset += num;
             }
+            out.flush();
+        }
+
+        // Copy all the non-STORED entries.  We don't attempt to
+        // maintain the 'offset' variable past this point; we don't do
+        // alignment on these entries.
+
+        for (String name : names) {
+            JarEntry inEntry = in.getJarEntry(name);
+            JarEntry outEntry = null;
+            if (inEntry.getMethod() == JarEntry.STORED) continue;
+            // Create a new entry so that the compressed len is recomputed.
+            outEntry = new JarEntry(name);
             outEntry.setTime(timestamp);
             out.putNextEntry(outEntry);
 
@@ -589,7 +640,7 @@ class SignApk {
                 long timestamp = publicKey.getNotBefore().getTime() + 3600L * 1000;
 
                 Manifest manifest = addDigestsToManifest(inputJar, hash);
-                copyFiles(manifest, inputJar, outputJar, timestamp);
+                copyFiles(manifest, inputJar, outputJar, timestamp, 0);
                 addOtacert(outputJar, publicKeyFile, timestamp, manifest, hash);
 
                 signFile(manifest, inputJar,
@@ -778,6 +829,7 @@ class SignApk {
 
     private static void usage() {
         System.err.println("Usage: signapk [-w] " +
+                           "[-a <alignment>] " +
                            "[-providerClass <className>] " +
                            "publickey.x509[.pem] privatekey.pk8 " +
                            "[publickey2.x509[.pem] privatekey2.pk8 ...] " +
@@ -794,6 +846,7 @@ class SignApk {
         boolean signWholeFile = false;
         String providerClass = null;
         String providerArg = null;
+        int alignment = 4;
 
         int argstart = 0;
         while (argstart < args.length && args[argstart].startsWith("-")) {
@@ -806,6 +859,9 @@ class SignApk {
                 }
                 providerClass = args[++argstart];
                 ++argstart;
+            } else if ("-a".equals(args[argstart])) {
+                alignment = Integer.parseInt(args[++argstart]);
+                ++argstart;
             } else {
                 usage();
             }
@@ -872,7 +928,7 @@ class SignApk {
                 outputJar.setLevel(9);
 
                 Manifest manifest = addDigestsToManifest(inputJar, hashes);
-                copyFiles(manifest, inputJar, outputJar, timestamp);
+                copyFiles(manifest, inputJar, outputJar, timestamp, alignment);
                 signFile(manifest, inputJar, publicKey, privateKey, outputJar);
                 outputJar.close();
             }