diff --git a/core/config.mk b/core/config.mk
index 5ff582a13..7ff3b368f 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -383,7 +383,7 @@ ifeq (,$(filter 1 true,$(WITH_TIDY_ONLY)))
 endif
 
 PATH_TO_CLANG_TIDY := \
-    $(LLVM_PREBUILTS_BASE)/$(BUILD_OS)-x86/$(LLVM_PREBUILTS_VERSION)/bin/clang-tidy
+    $(LLVM_PREBUILTS_BASE)/$(BUILD_OS)-$(HOST_PREBUILT_ARCH)/$(LLVM_PREBUILTS_VERSION)/bin/clang-tidy
 ifeq ($(wildcard $(PATH_TO_CLANG_TIDY)),)
   ifneq (,$(filter 1 true,$(WITH_TIDY)))
     $(warning *** Disable WITH_TIDY because $(PATH_TO_CLANG_TIDY) does not exist)
diff --git a/core/envsetup.mk b/core/envsetup.mk
index 43593e63c..acf755f15 100644
--- a/core/envsetup.mk
+++ b/core/envsetup.mk
@@ -116,13 +116,15 @@ HOST_OS_EXTRA:=$(shell python -c "import platform; print(platform.platform())")
 BUILD_OS := $(HOST_OS)
 
 HOST_CROSS_OS :=
-# We can cross-build Windows binaries on Linux
+# We can cross-build Windows binaries on x86 Linux
 ifeq ($(HOST_OS),linux)
+ifeq ($(HOST_ARCH),x86)
 HOST_CROSS_OS := windows
 HOST_CROSS_ARCH := x86
 HOST_CROSS_2ND_ARCH := x86_64
 2ND_HOST_CROSS_IS_64_BIT := true
 endif
+endif
 
 ifeq ($(HOST_OS),)
 $(error Unable to determine HOST_OS from uname -sm: $(UNAME)!)
@@ -134,10 +136,15 @@ ifneq (,$(findstring x86_64,$(UNAME)))
   HOST_2ND_ARCH := x86
   HOST_IS_64_BIT := true
 else
+ifneq (,$(findstring aarch64,$(UNAME)))
+  HOST_ARCH := arm64
+  HOST_IS_64_BIT := true
+else
 ifneq (,$(findstring i686,$(UNAME))$(findstring x86,$(UNAME)))
 $(error Building on a 32-bit x86 host is not supported: $(UNAME)!)
 endif
 endif
+endif
 
 BUILD_ARCH := $(HOST_ARCH)
 BUILD_2ND_ARCH := $(HOST_2ND_ARCH)
@@ -157,8 +164,12 @@ $(error HOST_BUILD_TYPE must be either release or debug, not '$(HOST_BUILD_TYPE)
 endif
 endif
 
+ifneq (,$(findstring x86_64,$(UNAME)))
 # We don't want to move all the prebuilt host tools to a $(HOST_OS)-x86_64 dir.
 HOST_PREBUILT_ARCH := x86
+else
+HOST_PREBUILT_ARCH := $(HOST_ARCH)
+endif
 # This is the standard way to name a directory containing prebuilt host
 # objects. E.g., prebuilt/$(HOST_PREBUILT_TAG)/cc
 HOST_PREBUILT_TAG := $(BUILD_OS)-$(HOST_PREBUILT_ARCH)
diff --git a/core/main.mk b/core/main.mk
index bc4ed0421..34e87f6ec 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -14,6 +14,12 @@ ifndef KATI
 host_prebuilts := linux-x86
 ifeq ($(shell uname),Darwin)
 host_prebuilts := darwin-x86
+else
+ifeq (aarch64,$(shell uname -m))
+host_prebuilts := linux-arm64
+else
+	$(error not arm64)
+endif
 endif
 
 .PHONY: run_soong_ui
diff --git a/core/soong_config.mk b/core/soong_config.mk
index e21083d7c..09d4b5814 100644
--- a/core/soong_config.mk
+++ b/core/soong_config.mk
@@ -71,11 +71,11 @@ $(SOONG_VARIABLES): FORCE
 	echo '    "DeviceSecondaryAbi": ["$(TARGET_2ND_CPU_ABI)", "$(TARGET_2ND_CPU_ABI2)"],'; \
 	echo ''; \
 	echo '    "HostArch": "$(HOST_ARCH)",'; \
-	echo '    "HostSecondaryArch": "$(HOST_2ND_ARCH)",'; \
+	test $(shell uname -m) = aarch64 || echo '    "HostSecondaryArch": "$(HOST_2ND_ARCH)",'; \
 	echo ''; \
-	echo '    "CrossHost": "$(HOST_CROSS_OS)",'; \
-	echo '    "CrossHostArch": "$(HOST_CROSS_ARCH)",'; \
-	echo '    "CrossHostSecondaryArch": "$(HOST_CROSS_2ND_ARCH)",'; \
+	test $(shell uname -m) = aarch64 || echo '    "CrossHost": "$(HOST_CROSS_OS)",'; \
+	test $(shell uname -m) = aarch64 || echo '    "CrossHostArch": "$(HOST_CROSS_ARCH)",'; \
+	test $(shell uname -m) = aarch64 || echo '    "CrossHostSecondaryArch": "$(HOST_CROSS_2ND_ARCH)",'; \
 	echo '    "Safestack": $(if $(filter true,$(USE_SAFESTACK)),true,false),'; \
 	echo '    "EnableCFI": $(if $(filter false,$(ENABLE_CFI)),false,true),'; \
 	echo '    "Device_uses_hwc2": $(if $(filter true,$(TARGET_USES_HWC2)),true,false),'; \
--- /dev/null	2017-05-30 12:59:06.809484016 +0000
+++ core/clang/HOST_arm.mk	2017-06-08 16:05:39.563015342 +0000
@@ -0,0 +1 @@
+$(clang_2nd_arch_prefix)HOST_LIBPROFILE_RT := $(LLVM_RTLIB_PATH)/libclang_rt.profile-armv7.a
--- /dev/null	2017-05-30 12:59:06.809484016 +0000
+++ core/clang/HOST_arm64.mk	2017-06-08 16:05:39.564015311 +0000
@@ -0,0 +1 @@
+HOST_LIBPROFILE_RT := $(LLVM_RTLIB_PATH)/libclang_rt.profile-aarch64.a
--- /dev/null	2017-05-30 12:59:06.809484016 +0000
+++ core/combo/HOST_linux-arm.mk	2017-06-08 16:05:39.564015311 +0000
@@ -0,0 +1,30 @@
+#
+# 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-arm.
+# Included by combo/select.mk
+
+define $(combo_var_prefix)transform-shared-lib-to-toc
+$(call _gen_toc_command_for_elf,$(1),$(2))
+endef
+
+############################################################
+## 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
--- /dev/null	2017-05-30 12:59:06.809484016 +0000
+++ core/combo/HOST_linux-arm64.mk	2017-06-08 16:05:39.564015311 +0000
@@ -0,0 +1,27 @@
+#
+# 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-arm64.
+# Included by combo/select.mk
+
+define $(combo_var_prefix)transform-shared-lib-to-toc
+$(call _gen_toc_command_for_elf,$(1),$(2))
+endef
+
+# $(1): The file to check
+define get-file-size
+stat --format "%s" "$(1)" | tr -d '\n'
+endef