Add generic aarch64 board config and build rules.

Change-Id: I8b4a377596705dfa0a3bd234162d183ec2ae9530
diff --git a/core/combo/TARGET_linux-aarch64.mk b/core/combo/TARGET_linux-aarch64.mk
new file mode 100644
index 0000000..bb328c5
--- /dev/null
+++ b/core/combo/TARGET_linux-aarch64.mk
@@ -0,0 +1,232 @@
+#
+# Copyright (C) 2013 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 Linux on ARM.
+# Included by combo/select.mk
+
+# You can set TARGET_ARCH_VARIANT to use an arch version other
+# than ARMv5TE. Each value should correspond to a file named
+# $(BUILD_COMBOS)/arch/<name>.mk which must contain
+# makefile variable definitions similar to the preprocessor
+# defines in build/core/combo/include/arch/<combo>/AndroidConfig.h. Their
+# purpose is to allow module Android.mk files to selectively compile
+# different versions of code based upon the funtionality and
+# instructions available in a given architecture version.
+#
+# The blocks also define specific arch_variant_cflags, which
+# include defines, and compiler settings for the given architecture
+# version.
+#
+ifeq ($(strip $(TARGET_ARCH_VARIANT)),)
+TARGET_ARCH_VARIANT := armv8
+endif
+
+ifeq ($(strip $(TARGET_GCC_VERSION_EXP)),)
+TARGET_GCC_VERSION := 4.8
+else
+TARGET_GCC_VERSION := $(TARGET_GCC_VERSION_EXP)
+endif
+
+TARGET_ARCH_SPECIFIC_MAKEFILE := $(BUILD_COMBOS)/arch/$(TARGET_ARCH)/$(TARGET_ARCH_VARIANT).mk
+ifeq ($(strip $(wildcard $(TARGET_ARCH_SPECIFIC_MAKEFILE))),)
+$(error Unknown ARM architecture version: $(TARGET_ARCH_VARIANT))
+endif
+
+include $(TARGET_ARCH_SPECIFIC_MAKEFILE)
+
+# You can set TARGET_TOOLS_PREFIX to get gcc from somewhere else
+ifeq ($(strip $(TARGET_TOOLS_PREFIX)),)
+TARGET_TOOLCHAIN_ROOT := prebuilts/gcc/$(HOST_PREBUILT_TAG)/aarch64/aarch64-linux-android-$(TARGET_GCC_VERSION)
+TARGET_TOOLS_PREFIX := $(TARGET_TOOLCHAIN_ROOT)/bin/aarch64-linux-android-
+endif
+
+TARGET_CC := $(TARGET_TOOLS_PREFIX)gcc$(HOST_EXECUTABLE_SUFFIX)
+TARGET_CXX := $(TARGET_TOOLS_PREFIX)g++$(HOST_EXECUTABLE_SUFFIX)
+TARGET_AR := $(TARGET_TOOLS_PREFIX)ar$(HOST_EXECUTABLE_SUFFIX)
+TARGET_OBJCOPY := $(TARGET_TOOLS_PREFIX)objcopy$(HOST_EXECUTABLE_SUFFIX)
+TARGET_LD := $(TARGET_TOOLS_PREFIX)ld$(HOST_EXECUTABLE_SUFFIX)
+TARGET_STRIP := $(TARGET_TOOLS_PREFIX)strip$(HOST_EXECUTABLE_SUFFIX)
+ifeq ($(TARGET_BUILD_VARIANT),user)
+    TARGET_STRIP_COMMAND = $(TARGET_STRIP) --strip-all $< -o $@
+else
+    TARGET_STRIP_COMMAND = $(TARGET_STRIP) --strip-all $< -o $@ && \
+        $(TARGET_OBJCOPY) --add-gnu-debuglink=$< $@
+endif
+
+TARGET_NO_UNDEFINED_LDFLAGS := -Wl,--no-undefined
+
+android_config_h := $(call select-android-config-h,linux-aarch64)
+
+TARGET_GLOBAL_CFLAGS += \
+			-fpic -fPIE \
+			$(arch_variant_cflags) \
+			-include $(android_config_h) \
+			-I $(dir $(android_config_h))
+
+TARGET_GLOBAL_CFLAGS += \
+			-fpic -fPIE \
+			-ffunction-sections \
+			-fdata-sections \
+			-funwind-tables \
+			-Wa,--noexecstack \
+			-Werror=format-security \
+			-D_FORTIFY_SOURCE=2 \
+			-fno-short-enums \
+			$(arch_variant_cflags) \
+			-include $(android_config_h) \
+			-I $(dir $(android_config_h))
+
+TARGET_GLOBAL_CFLAGS += -fno-strict-volatile-bitfields
+
+# This is to avoid the dreaded warning compiler message:
+#   note: the mangling of 'va_list' has changed in GCC 4.4
+#
+# The fact that the mangling changed does not affect the NDK ABI
+# very fortunately (since none of the exposed APIs used va_list
+# in their exported C++ functions). Also, GCC 4.5 has already
+# removed the warning from the compiler.
+#
+TARGET_GLOBAL_CFLAGS += -Wno-psabi
+
+TARGET_GLOBAL_LDFLAGS += \
+			-Wl,-z,noexecstack \
+			-Wl,-z,relro \
+			-Wl,-z,now \
+			-Wl,--warn-shared-textrel \
+			-Wl,--fatal-warnings \
+			$(arch_variant_ldflags)
+
+TARGET_GLOBAL_CPPFLAGS += -fvisibility-inlines-hidden
+
+# More flags/options can be added here
+TARGET_RELEASE_CFLAGS := \
+			-DNDEBUG \
+			-O2 -g \
+			-Wstrict-aliasing=2 \
+			-fgcse-after-reload \
+			-frerun-cse-after-loop \
+			-frename-registers
+
+libc_root := bionic/libc
+libm_root := bionic/libm
+libstdc++_root := bionic/libstdc++
+libthread_db_root := bionic/libthread_db
+
+
+# unless CUSTOM_KERNEL_HEADERS is defined, we're going to use
+# symlinks located in out/ to point to the appropriate kernel
+# headers. see 'config/kernel_headers.make' for more details
+#
+ifneq ($(CUSTOM_KERNEL_HEADERS),)
+    KERNEL_HEADERS_COMMON := $(CUSTOM_KERNEL_HEADERS)
+    KERNEL_HEADERS_ARCH   := $(CUSTOM_KERNEL_HEADERS)
+else
+    KERNEL_HEADERS_COMMON := $(libc_root)/kernel/common
+    KERNEL_HEADERS_ARCH   := $(libc_root)/kernel/arch-$(TARGET_ARCH)
+endif
+KERNEL_HEADERS := $(KERNEL_HEADERS_COMMON) $(KERNEL_HEADERS_ARCH)
+
+TARGET_C_INCLUDES := \
+	$(libc_root)/arch-aarch64/include \
+	$(libc_root)/include \
+	$(libstdc++_root)/include \
+	$(KERNEL_HEADERS) \
+	$(libm_root)/include \
+	$(libm_root)/include/aarch64 \
+	$(libthread_db_root)/include
+
+# FIXME
+# CRT* objects to be added later
+TARGET_CRTBEGIN_STATIC_O :=
+TARGET_CRTBEGIN_DYNAMIC_O :=
+TARGET_CRTEND_O :=
+
+TARGET_CRTBEGIN_SO_O :=
+TARGET_CRTEND_SO_O :=
+
+TARGET_STRIP_MODULE:=true
+
+TARGET_DEFAULT_SYSTEM_SHARED_LIBRARIES := libc libstdc++ libm
+
+TARGET_CUSTOM_LD_COMMAND := true
+
+define transform-o-to-shared-lib-inner
+$(hide) $(PRIVATE_CXX) \
+	-nostdlib -Wl,-soname,$(notdir $@) \
+	-Wl,-shared,-Bsymbolic \
+	$(PRIVATE_TARGET_GLOBAL_LD_DIRS) \
+	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTBEGIN_SO_O)) \
+	$(PRIVATE_ALL_OBJECTS) \
+	-Wl,--whole-archive \
+	$(call normalize-target-libraries,$(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES)) \
+	-Wl,--no-whole-archive \
+	$(if $(PRIVATE_GROUP_STATIC_LIBRARIES),-Wl$(comma)--start-group) \
+	$(call normalize-target-libraries,$(PRIVATE_ALL_STATIC_LIBRARIES)) \
+	$(if $(PRIVATE_GROUP_STATIC_LIBRARIES),-Wl$(comma)--end-group) \
+	$(if $(TARGET_BUILD_APPS),$(PRIVATE_TARGET_LIBGCC)) \
+	$(PRIVATE_TARGET_FDO_LIB) \
+	$(call normalize-target-libraries,$(PRIVATE_ALL_SHARED_LIBRARIES)) \
+	-o $@ \
+	$(PRIVATE_TARGET_GLOBAL_LDFLAGS) \
+	$(PRIVATE_LDFLAGS) \
+	$(PRIVATE_TARGET_LIBGCC) \
+	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTEND_SO_O))
+endef
+
+define transform-o-to-executable-inner
+$(hide) $(PRIVATE_CXX) -nostdlib -Bdynamic -fPIE -pie \
+	-Wl,-dynamic-linker,/system/bin/linker \
+	-Wl,-z,nocopyreloc \
+	$(PRIVATE_TARGET_GLOBAL_LD_DIRS) \
+	-Wl,-rpath-link=$(TARGET_OUT_INTERMEDIATE_LIBRARIES) \
+	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTBEGIN_DYNAMIC_O)) \
+	$(PRIVATE_ALL_OBJECTS) \
+	-Wl,--whole-archive \
+	$(call normalize-target-libraries,$(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES)) \
+	-Wl,--no-whole-archive \
+	$(if $(PRIVATE_GROUP_STATIC_LIBRARIES),-Wl$(comma)--start-group) \
+	$(call normalize-target-libraries,$(PRIVATE_ALL_STATIC_LIBRARIES)) \
+	$(if $(PRIVATE_GROUP_STATIC_LIBRARIES),-Wl$(comma)--end-group) \
+	$(if $(TARGET_BUILD_APPS),$(PRIVATE_TARGET_LIBGCC)) \
+	$(PRIVATE_TARGET_FDO_LIB) \
+	$(call normalize-target-libraries,$(PRIVATE_ALL_SHARED_LIBRARIES)) \
+	-o $@ \
+	$(PRIVATE_TARGET_GLOBAL_LDFLAGS) \
+	$(PRIVATE_LDFLAGS) \
+	$(PRIVATE_TARGET_LIBGCC) \
+	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTEND_O))
+endef
+
+define transform-o-to-static-executable-inner
+$(hide) $(PRIVATE_CXX) -Bstatic \
+	-o $@ \
+	$(PRIVATE_TARGET_GLOBAL_LD_DIRS) \
+	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTBEGIN_STATIC_O)) \
+	$(PRIVATE_TARGET_GLOBAL_LDFLAGS) \
+	$(PRIVATE_LDFLAGS) \
+	$(PRIVATE_ALL_OBJECTS) \
+	-Wl,--whole-archive \
+	$(call normalize-target-libraries,$(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES)) \
+	-Wl,--no-whole-archive \
+	$(call normalize-target-libraries,$(filter-out %libc_nomalloc.a,$(filter-out %libc.a,$(PRIVATE_ALL_STATIC_LIBRARIES)))) \
+	-Wl,--start-group \
+	$(call normalize-target-libraries,$(filter %libc.a,$(PRIVATE_ALL_STATIC_LIBRARIES))) \
+	$(call normalize-target-libraries,$(filter %libc_nomalloc.a,$(PRIVATE_ALL_STATIC_LIBRARIES))) \
+	$(PRIVATE_TARGET_FDO_LIB) \
+	$(PRIVATE_TARGET_LIBGCC) \
+	-Wl,--end-group \
+	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTEND_O))
+endef