vendor: build: update kernel.mk

taken from LOS
1fdbf7ad8be3865f07400023ed0ec8ccd16cb869
https://github.com/LineageOS/android_vendor_lineage/commits/lineage-15.1/build/tasks/kernel.mk

Change-Id: Ibf393e8e6ab0189999184fbd8ace2d2c326caaef
diff --git a/build/tasks/kernel.mk b/build/tasks/kernel.mk
index 1404fb3..f00069f 100644
--- a/build/tasks/kernel.mk
+++ b/build/tasks/kernel.mk
@@ -1,4 +1,5 @@
 # Copyright (C) 2012 The CyanogenMod Project
+#           (C) 2017 The LineageOS Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -12,7 +13,64 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+
 # Android makefile to build kernel as a part of Android Build
+#
+# Configuration
+# =============
+#
+# These config vars are usually set in BoardConfig.mk:
+#
+#   TARGET_KERNEL_SOURCE               = Kernel source dir, optional, defaults
+#                                        to kernel/$(TARGET_DEVICE_DIR)
+#   TARGET_KERNEL_CONFIG               = Kernel defconfig
+#   TARGET_KERNEL_VARIANT_CONFIG       = Variant defconfig, optional
+#   TARGET_KERNEL_SELINUX_CONFIG       = SELinux defconfig, optional
+#   TARGET_KERNEL_ADDITIONAL_CONFIG    = Additional defconfig, optional
+#   TARGET_KERNEL_ARCH                 = Kernel Arch
+#   TARGET_KERNEL_HEADER_ARCH          = Optional Arch for kernel headers if
+#                                          different from TARGET_KERNEL_ARCH
+#   TARGET_KERNEL_CROSS_COMPILE_PREFIX = Compiler prefix (e.g. arm-eabi-)
+#                                          defaults to arm-linux-androidkernel- for arm
+#                                                      aarch64-linux-androidkernel- for arm64
+#                                                      x86_64-linux-androidkernel- for x86
+#
+#   TARGET_KERNEL_CLANG_COMPILE        = Compile kernel with clang, defaults to false
+#
+#   TARGET_KERNEL_CLANG_VERSION        = Clang prebuilts version, optional, defaults to clang-stable
+#
+#   TARGET_KERNEL_CLANG_PATH           = Clang prebuilts path, optional
+#
+#   BOARD_KERNEL_IMAGE_NAME            = Built image name
+#                                          for ARM use: zImage
+#                                          for ARM64 use: Image.gz
+#                                          for uncompressed use: Image
+#                                          If using an appended DT, append '-dtb'
+#                                          to the end of the image name.
+#                                          For example, for ARM devices,
+#                                          use zImage-dtb instead of zImage.
+#
+#   KERNEL_TOOLCHAIN_PREFIX            = Overrides TARGET_KERNEL_CROSS_COMPILE_PREFIX,
+#                                          Set this var in shell to override
+#                                          toolchain specified in BoardConfig.mk
+#   KERNEL_TOOLCHAIN                   = Path to toolchain, if unset, assumes
+#                                          TARGET_KERNEL_CROSS_COMPILE_PREFIX
+#                                          is in PATH
+#
+#   KERNEL_CC                          = The C Compiler used. This is automatically set based
+#                                          on whether the clang version is set, optional.
+#
+#   KERNEL_CLANG_TRIPLE                = Target triple for clang (e.g. aarch64-linux-gnu-)
+#                                          defaults to arm-linux-gnu- for arm
+#                                                      aarch64-linux-gnu- for arm64
+#                                                      x86_64-linux-gnu- for x86
+#
+#   USE_CCACHE                         = Enable ccache (global Android flag)
+#
+#   NEED_KERNEL_MODULE_ROOT            = Optional, if true, install kernel
+#                                          modules in root instead of system
+
+ifneq ($(TARGET_NO_KERNEL),true)
 
 -include vendor/omni/config/branding.mk
 
@@ -30,6 +88,7 @@
 ## Internal variables
 KERNEL_OUT := $(TARGET_OUT_INTERMEDIATES)/KERNEL_OBJ
 KERNEL_CONFIG := $(KERNEL_OUT)/.config
+KERNEL_OUT_STAMP := $(KERNEL_OUT)/.mkdir_stamp
 
 TARGET_KERNEL_ARCH := $(strip $(TARGET_KERNEL_ARCH))
 ifeq ($(TARGET_KERNEL_ARCH),)
@@ -38,6 +97,13 @@
 KERNEL_ARCH := $(TARGET_KERNEL_ARCH)
 endif
 
+ifeq ($(KERNEL_ARCH),x86_64)
+KERNEL_DEFCONFIG_ARCH := x86
+else
+KERNEL_DEFCONFIG_ARCH := $(KERNEL_ARCH)
+endif
+KERNEL_DEFCONFIG_SRC := $(KERNEL_SRC)/arch/$(KERNEL_DEFCONFIG_ARCH)/configs/$(KERNEL_DEFCONFIG)
+
 TARGET_KERNEL_HEADER_ARCH := $(strip $(TARGET_KERNEL_HEADER_ARCH))
 ifeq ($(TARGET_KERNEL_HEADER_ARCH),)
 KERNEL_HEADER_ARCH := $(KERNEL_ARCH)
@@ -50,18 +116,16 @@
 KERNEL_HEADER_DEFCONFIG := $(KERNEL_DEFCONFIG)
 endif
 
-
-ifneq ($(BOARD_KERNEL_IMAGE_NAME),)
-  TARGET_PREBUILT_INT_KERNEL_TYPE := $(BOARD_KERNEL_IMAGE_NAME)
-else
-  ifeq ($(TARGET_USES_UNCOMPRESSED_KERNEL),true)
-    TARGET_PREBUILT_INT_KERNEL_TYPE := Image
-  else
-    TARGET_PREBUILT_INT_KERNEL_TYPE := zImage
-  endif
+ifeq ($(BOARD_KERNEL_IMAGE_NAME),)
+$(info BOARD_KERNEL_IMAGE_NAME not defined.)
 endif
-
-TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/$(TARGET_PREBUILT_INT_KERNEL_TYPE)
+ifneq ($(TARGET_USES_UNCOMPRESSED_KERNEL),)
+$(info TARGET_USES_UNCOMPRESSED_KERNEL is deprecated.)
+endif
+ifneq ($(TARGET_KERNEL_APPEND_DTB),)
+$(info TARGET_KERNEL_APPEND_DTB is deprecated.)
+endif
+TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/$(BOARD_KERNEL_IMAGE_NAME)
 
 # Clear this first to prevent accidental poisoning from env
 MAKE_FLAGS :=
@@ -74,23 +138,17 @@
 ifeq ($(KERNEL_ARCH),arm64)
   # Avoid "unsupported RELA relocation: 311" errors (R_AARCH64_ADR_GOT_PAGE)
   MAKE_FLAGS += CFLAGS_MODULE="-fno-pic"
-  ifeq ($(TARGET_ARCH),arm)
-    KERNEL_CONFIG_OVERRIDE := CONFIG_ANDROID_BINDER_IPC_32BIT=y
-  endif
 endif
 
 ifneq ($(TARGET_KERNEL_ADDITIONAL_CONFIG),)
 KERNEL_ADDITIONAL_CONFIG := $(TARGET_KERNEL_ADDITIONAL_CONFIG)
-endif
-
-## Do be discontinued in a future version. Notify builder about target
-## kernel format requirement
-ifeq ($(BOARD_KERNEL_IMAGE_NAME),)
-ifeq ($(BOARD_USES_UBOOT),true)
-        $(error "Please set BOARD_KERNEL_IMAGE_NAME to uImage")
-else ifeq ($(BOARD_USES_UNCOMPRESSED_BOOT),true)
-        $(error "Please set BOARD_KERNEL_IMAGE_NAME to Image")
-endif
+KERNEL_ADDITIONAL_CONFIG_SRC := $(KERNEL_SRC)/arch/$(KERNEL_ARCH)/configs/$(KERNEL_ADDITIONAL_CONFIG)
+    ifeq ("$(wildcard $(KERNEL_ADDITIONAL_CONFIG_SRC))","")
+        $(warning TARGET_KERNEL_ADDITIONAL_CONFIG '$(TARGET_KERNEL_ADDITIONAL_CONFIG)' doesn't exist)
+        KERNEL_ADDITIONAL_CONFIG_SRC := /dev/null
+    endif
+else
+    KERNEL_ADDITIONAL_CONFIG_SRC := /dev/null
 endif
 
 ifeq "$(wildcard $(KERNEL_SRC) )" ""
@@ -111,7 +169,6 @@
         $(warning * THIS IS DEPRECATED, AND WILL BE DISCONTINUED                *)
         $(warning * Please configure your device to download the kernel         *)
         $(warning * source repository to $(KERNEL_SRC))
-        $(warning * See $(URL_INTEGRATED_KERNEL_BUILD))
         $(warning * for more information                                        *)
         $(warning ***************************************************************)
         FULL_KERNEL_BUILD := false
@@ -150,20 +207,29 @@
 ifeq ($(FULL_KERNEL_BUILD),true)
 
 KERNEL_HEADERS_INSTALL := $(KERNEL_OUT)/usr
-KERNEL_MODULES_INSTALL := system
+KERNEL_HEADERS_INSTALL_STAMP := $(KERNEL_OUT)/.headers_install_stamp
+
+ifeq ($(NEED_KERNEL_MODULE_ROOT),true)
+KERNEL_MODULES_INSTALL := root
+KERNEL_MODULES_OUT := $(TARGET_ROOT_OUT)/lib/modules
+KERNEL_DEPMOD_STAGING_DIR := $(call intermediates-dir-for,PACKAGING,depmod_recovery)
+KERNEL_MODULE_MOUNTPOINT :=
+else
+KERNEL_MODULES_INSTALL := $(TARGET_COPY_OUT_SYSTEM)
 KERNEL_MODULES_OUT := $(TARGET_OUT)/lib/modules
+KERNEL_DEPMOD_STAGING_DIR := $(call intermediates-dir-for,PACKAGING,depmod_system)
+KERNEL_MODULE_MOUNTPOINT := system
+endif
 
 TARGET_KERNEL_CROSS_COMPILE_PREFIX := $(strip $(TARGET_KERNEL_CROSS_COMPILE_PREFIX))
-ifeq ($(TARGET_KERNEL_CROSS_COMPILE_PREFIX),)
-ifeq ($(KERNEL_TOOLCHAIN_PREFIX),)
-    ifeq ($(KERNEL_ARCH),arm64)
-	KERNEL_TOOLCHAIN_PREFIX := aarch64-linux-android-
-    else
-	KERNEL_TOOLCHAIN_PREFIX := arm-eabi-
-    endif
-endif
-else
-KERNEL_TOOLCHAIN_PREFIX := $(TARGET_KERNEL_CROSS_COMPILE_PREFIX)
+ifneq ($(TARGET_KERNEL_CROSS_COMPILE_PREFIX),)
+KERNEL_TOOLCHAIN_PREFIX ?= $(TARGET_KERNEL_CROSS_COMPILE_PREFIX)
+else ifeq ($(KERNEL_ARCH),arm64)
+KERNEL_TOOLCHAIN_PREFIX ?= aarch64-linux-androidkernel-
+else ifeq ($(KERNEL_ARCH),arm)
+KERNEL_TOOLCHAIN_PREFIX ?= arm-linux-androidkernel-
+else ifeq ($(KERNEL_ARCH),x86)
+KERNEL_TOOLCHAIN_PREFIX ?= x86_64-linux-androidkernel-
 endif
 
 ifeq ($(KERNEL_TOOLCHAIN),)
@@ -174,117 +240,174 @@
 endif
 endif
 
-ifneq ($(USE_CCACHE),)
-    # Detect if the system already has ccache installed to use instead of the prebuilt
-    ccache := $(shell command -v ccache)
-    ifeq ($(ccache),)
-        ccache := $(ANDROID_BUILD_TOP)/prebuilts/misc/$(HOST_PREBUILT_TAG)/ccache/ccache
+ifeq ($(TARGET_KERNEL_CLANG_COMPILE),true)
+    ifneq ($(TARGET_KERNEL_CLANG_VERSION),)
+        # Find the clang-* directory containing the specified version
+        KERNEL_CLANG_VERSION := $(shell find $(ANDROID_BUILD_TOP)/prebuilts/clang/host/$(HOST_OS)-x86/ -name AndroidVersion.txt -exec grep -l $(TARGET_KERNEL_CLANG_VERSION) "{}" \; | sed -e 's|/AndroidVersion.txt$$||g;s|^.*/||g')
+    else
+        # Only set the latest version of clang if TARGET_KERNEL_CLANG_VERSION hasn't been set by the device config
+        KERNEL_CLANG_VERSION := $(shell ls -d $(ANDROID_BUILD_TOP)/prebuilts/clang/host/$(HOST_OS)-x86/clang-* | xargs -n 1 basename | tail -1)
     endif
-    $(info Using '$(ccache)' binary on '$(HOST_PREBUILT_TAG)')
-    # Check that the executable is here.
-    ccache := $(strip $(wildcard $(ccache)))
+    TARGET_KERNEL_CLANG_PATH ?= $(ANDROID_BUILD_TOP)/prebuilts/clang/host/$(HOST_OS)-x86/$(KERNEL_CLANG_VERSION)/bin
+    ifeq ($(KERNEL_ARCH),arm64)
+        KERNEL_CLANG_TRIPLE ?= CLANG_TRIPLE=aarch64-linux-gnu-
+    else ifeq ($(KERNEL_ARCH),arm)
+        KERNEL_CLANG_TRIPLE ?= CLANG_TRIPLE=arm-linux-gnu-
+    else ifeq ($(KERNEL_ARCH),x86)
+        KERNEL_CLANG_TRIPLE ?= CLANG_TRIPLE=x86_64-linux-gnu-
+    endif
 endif
 
-KERNEL_CROSS_COMPILE := CROSS_COMPILE="$(ccache) $(KERNEL_TOOLCHAIN_PATH)"
+ifneq ($(USE_CCACHE),)
+    # Detect if the system already has ccache installed to use instead of the prebuilt
+    ccache := $(shell which ccache)
+
+    ifeq ($(ccache),)
+        ccache := $(ANDROID_BUILD_TOP)/prebuilts/misc/$(HOST_PREBUILT_TAG)/ccache/ccache
+        # Check that the executable is here.
+        ccache := $(strip $(wildcard $(ccache)))
+    endif
+endif
+
+ifeq ($(TARGET_KERNEL_CLANG_COMPILE),true)
+    KERNEL_CROSS_COMPILE := CROSS_COMPILE="$(KERNEL_TOOLCHAIN_PATH)"
+    ifeq ($(KERNEL_CC),)
+        KERNEL_CC := CC="$(ccache) $(TARGET_KERNEL_CLANG_PATH)/clang"
+    endif
+else
+    KERNEL_CROSS_COMPILE := CROSS_COMPILE="$(ccache) $(KERNEL_TOOLCHAIN_PATH)"
+endif
 ccache =
 
-define mv-modules
-    mdpath=`find $(KERNEL_MODULES_OUT) -type f -name modules.order`;\
-    if [ "$$mdpath" != "" ];then\
-        mpath=`dirname $$mdpath`;\
-        ko=`find $$mpath/kernel -type f -name *.ko`;\
-        for i in $$ko; do $(KERNEL_TOOLCHAIN_PATH)strip --strip-unneeded $$i;\
-        mv $$i $(KERNEL_MODULES_OUT)/; done;\
-    fi
-endef
-
-define clean-module-folder
-    mdpath=`find $(KERNEL_MODULES_OUT) -type f -name modules.order`;\
-    if [ "$$mdpath" != "" ];then\
-        mpath=`dirname $$mdpath`; rm -rf $$mpath;\
-    fi
-endef
-
 ifeq ($(HOST_OS),darwin)
-  MAKE_FLAGS += C_INCLUDE_PATH=$(ANDROID_BUILD_TOP)/external/elfutils/0.153/libelf/
+  MAKE_FLAGS += C_INCLUDE_PATH=$(ANDROID_BUILD_TOP)/external/elfutils/libelf:/usr/local/opt/openssl/include
+  MAKE_FLAGS += LIBRARY_PATH=/usr/local/opt/openssl/lib
 endif
 
 ifeq ($(TARGET_KERNEL_MODULES),)
-    TARGET_KERNEL_MODULES := no-external-modules
+    TARGET_KERNEL_MODULES := INSTALLED_KERNEL_MODULES
 endif
 
-$(KERNEL_OUT):
-	mkdir -p $(KERNEL_OUT)
-	mkdir -p $(KERNEL_MODULES_OUT)
+$(KERNEL_OUT_STAMP):
+	$(hide) mkdir -p $(KERNEL_OUT)
+	$(hide) rm -rf $(KERNEL_MODULES_OUT)
+	$(hide) mkdir -p $(KERNEL_MODULES_OUT)
+	$(hide) rm -rf $(KERNEL_DEPMOD_STAGING_DIR)
+	$(hide) touch $@
 
-$(KERNEL_CONFIG): $(KERNEL_OUT)
-	$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) VARIANT_DEFCONFIG=$(VARIANT_DEFCONFIG) SELINUX_DEFCONFIG=$(SELINUX_DEFCONFIG) $(KERNEL_DEFCONFIG)
+KERNEL_ADDITIONAL_CONFIG_OUT := $(KERNEL_OUT)/.additional_config
+
+.PHONY: force_additional_config
+$(KERNEL_ADDITIONAL_CONFIG_OUT): force_additional_config
+	$(hide) cmp -s $(KERNEL_ADDITIONAL_CONFIG_SRC) $@ || cp $(KERNEL_ADDITIONAL_CONFIG_SRC) $@;
+
+$(KERNEL_CONFIG): $(KERNEL_OUT_STAMP) $(KERNEL_DEFCONFIG_SRC) $(KERNEL_ADDITIONAL_CONFIG_OUT)
+	@echo "Building Kernel Config"
+	$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) VARIANT_DEFCONFIG=$(VARIANT_DEFCONFIG) SELINUX_DEFCONFIG=$(SELINUX_DEFCONFIG) $(KERNEL_DEFCONFIG)
 	$(hide) if [ ! -z "$(KERNEL_CONFIG_OVERRIDE)" ]; then \
 			echo "Overriding kernel config with '$(KERNEL_CONFIG_OVERRIDE)'"; \
 			echo $(KERNEL_CONFIG_OVERRIDE) >> $(KERNEL_OUT)/.config; \
-			$(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) oldconfig; fi
+			$(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) oldconfig; fi
+	# Create defconfig build artifact
+	$(hide) $(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) savedefconfig
 	$(hide) if [ ! -z "$(KERNEL_ADDITIONAL_CONFIG)" ]; then \
 			echo "Using additional config '$(KERNEL_ADDITIONAL_CONFIG)'"; \
-			cat $(KERNEL_SRC)/arch/$(KERNEL_ARCH)/configs/$(KERNEL_ADDITIONAL_CONFIG) >> $(KERNEL_OUT)/.config; \
-			$(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) oldconfig; fi
+			$(KERNEL_SRC)/scripts/kconfig/merge_config.sh -m -O $(KERNEL_OUT) $(KERNEL_OUT)/.config $(KERNEL_SRC)/arch/$(KERNEL_ARCH)/configs/$(KERNEL_ADDITIONAL_CONFIG); \
+			$(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) KCONFIG_ALLCONFIG=$(KERNEL_OUT)/.config alldefconfig; fi
 
-TARGET_KERNEL_BINARIES: $(KERNEL_OUT) $(KERNEL_CONFIG) $(KERNEL_HEADERS_INSTALL)
-	$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(TARGET_PREBUILT_INT_KERNEL_TYPE)
-	$(hide) if grep -q 'CONFIG_OF=y' $(KERNEL_CONFIG) ; \
-			then \
-				echo -e ${CL_GRN}"Building DTBs"${CL_RST} ; \
-				$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) dtbs ; \
-			else \
-				echo "DTBs not enabled" ; \
-			fi ;
-	$(hide) if grep -q 'CONFIG_MODULES=y' $(KERNEL_CONFIG) ; \
-			then \
-				echo -e ${CL_GRN}"Building Kernel Modules"${CL_RST} ; \
-				$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) modules && \
-				$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) INSTALL_MOD_PATH=../../$(KERNEL_MODULES_INSTALL) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) modules_install && \
-				$(mv-modules) && \
-				$(clean-module-folder) ; \
-			else \
-				echo "Kernel Modules not enabled" ; \
-			fi ;
+TARGET_KERNEL_BINARIES: $(KERNEL_OUT_STAMP) $(KERNEL_CONFIG) $(KERNEL_HEADERS_INSTALL_STAMP)
+	@echo "Building Kernel"
+	$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) $(BOARD_KERNEL_IMAGE_NAME)
+	$(hide) if grep -q '^CONFIG_OF=y' $(KERNEL_CONFIG); then \
+			echo "Building DTBs"; \
+			$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) dtbs; \
+		fi
+	$(hide) if grep -q '^CONFIG_MODULES=y' $(KERNEL_CONFIG); then \
+			echo "Building Kernel Modules"; \
+			$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) modules; \
+		fi
 
+.PHONY: INSTALLED_KERNEL_MODULES
+INSTALLED_KERNEL_MODULES: depmod-host
+	$(hide) if grep -q '^CONFIG_MODULES=y' $(KERNEL_CONFIG); then \
+			echo "Installing Kernel Modules"; \
+			$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) INSTALL_MOD_PATH=../../$(KERNEL_MODULES_INSTALL) modules_install && \
+			mofile=$$(find $(KERNEL_MODULES_OUT) -type f -name modules.order) && \
+			mpath=$$(dirname $$mofile) && \
+			for f in $$(find $$mpath/kernel -type f -name '*.ko'); do \
+				$(KERNEL_TOOLCHAIN_PATH)strip --strip-unneeded $$f; \
+				mv $$f $(KERNEL_MODULES_OUT); \
+			done && \
+			rm -rf $$mpath && \
+			mkdir -p $(KERNEL_DEPMOD_STAGING_DIR)/lib/modules/0.0/$(KERNEL_MODULE_MOUNTPOINT)/lib/modules && \
+			find $(KERNEL_MODULES_OUT) -name *.ko -exec cp {} $(KERNEL_DEPMOD_STAGING_DIR)/lib/modules/0.0/$(KERNEL_MODULE_MOUNTPOINT)/lib/modules \; && \
+			$(DEPMOD) -b $(KERNEL_DEPMOD_STAGING_DIR) 0.0 && \
+			sed -e 's/\(.*modules.*\):/\/\1:/g' -e 's/ \([^ ]*modules[^ ]*\)/ \/\1/g' $(KERNEL_DEPMOD_STAGING_DIR)/lib/modules/0.0/modules.dep > $(KERNEL_MODULES_OUT)/modules.dep; \
+		fi
 
 $(TARGET_KERNEL_MODULES): TARGET_KERNEL_BINARIES
 
 $(TARGET_PREBUILT_INT_KERNEL): $(TARGET_KERNEL_MODULES)
-	$(mv-modules)
-	$(clean-module-folder)
 
-$(KERNEL_HEADERS_INSTALL): $(KERNEL_OUT) $(KERNEL_CONFIG)
+$(KERNEL_HEADERS_INSTALL_STAMP): $(KERNEL_OUT_STAMP) $(KERNEL_CONFIG)
+	@echo "Building Kernel Headers"
 	$(hide) if [ ! -z "$(KERNEL_HEADER_DEFCONFIG)" ]; then \
 			rm -f ../$(KERNEL_CONFIG); \
-			$(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_HEADER_ARCH) $(KERNEL_CROSS_COMPILE) VARIANT_DEFCONFIG=$(VARIANT_DEFCONFIG) SELINUX_DEFCONFIG=$(SELINUX_DEFCONFIG) $(KERNEL_HEADER_DEFCONFIG); \
-			$(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_HEADER_ARCH) $(KERNEL_CROSS_COMPILE) headers_install; fi
+			$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_HEADER_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) VARIANT_DEFCONFIG=$(VARIANT_DEFCONFIG) SELINUX_DEFCONFIG=$(SELINUX_DEFCONFIG) $(KERNEL_HEADER_DEFCONFIG); \
+			$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_HEADER_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) headers_install; fi
 	$(hide) if [ "$(KERNEL_HEADER_DEFCONFIG)" != "$(KERNEL_DEFCONFIG)" ]; then \
 			echo "Used a different defconfig for header generation"; \
 			rm -f ../$(KERNEL_CONFIG); \
-			$(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) VARIANT_DEFCONFIG=$(VARIANT_DEFCONFIG) SELINUX_DEFCONFIG=$(SELINUX_DEFCONFIG) $(KERNEL_DEFCONFIG); fi
+			$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) VARIANT_DEFCONFIG=$(VARIANT_DEFCONFIG) SELINUX_DEFCONFIG=$(SELINUX_DEFCONFIG) $(KERNEL_DEFCONFIG); fi
 	$(hide) if [ ! -z "$(KERNEL_CONFIG_OVERRIDE)" ]; then \
 			echo "Overriding kernel config with '$(KERNEL_CONFIG_OVERRIDE)'"; \
 			echo $(KERNEL_CONFIG_OVERRIDE) >> $(KERNEL_OUT)/.config; \
-			$(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) oldconfig; fi
+			$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) oldconfig; fi
 	$(hide) if [ ! -z "$(KERNEL_ADDITIONAL_CONFIG)" ]; then \
 			echo "Using additional config '$(KERNEL_ADDITIONAL_CONFIG)'"; \
-			cat $(KERNEL_SRC)/arch/$(KERNEL_ARCH)/configs/$(KERNEL_ADDITIONAL_CONFIG) >> $(KERNEL_OUT)/.config; \
-			$(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) oldconfig; fi
+			$(KERNEL_SRC)/scripts/kconfig/merge_config.sh -m -O $(KERNEL_OUT) $(KERNEL_OUT)/.config $(KERNEL_SRC)/arch/$(KERNEL_ARCH)/configs/$(KERNEL_ADDITIONAL_CONFIG); \
+			$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) KCONFIG_ALLCONFIG=$(KERNEL_OUT)/.config alldefconfig; fi
+	$(hide) touch $@
 
-kerneltags: $(KERNEL_OUT) $(KERNEL_CONFIG)
-	$(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) tags
+# provide this rule because there are dependencies on this throughout the repo
+$(KERNEL_HEADERS_INSTALL): $(KERNEL_HEADERS_INSTALL_STAMP)
 
-kernelconfig: $(KERNEL_OUT) $(KERNEL_CONFIG)
+kerneltags: $(KERNEL_OUT_STAMP) $(KERNEL_CONFIG)
+	$(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) tags
+
+kernelconfig:  KERNELCONFIG_MODE := menuconfig
+kernelxconfig: KERNELCONFIG_MODE := xconfig
+kernelxconfig kernelconfig: $(KERNEL_OUT_STAMP)
+	$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) $(KERNEL_DEFCONFIG)
 	env KCONFIG_NOTIMESTAMP=true \
-		 $(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) menuconfig
+		 $(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) $(KERNELCONFIG_MODE)
 	env KCONFIG_NOTIMESTAMP=true \
-		 $(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) savedefconfig
-	cp $(KERNEL_OUT)/defconfig $(KERNEL_SRC)/arch/$(KERNEL_ARCH)/configs/$(KERNEL_DEFCONFIG)
+		 $(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) savedefconfig
+	cp $(KERNEL_OUT)/defconfig $(KERNEL_DEFCONFIG_SRC)
+
+kernelsavedefconfig: $(KERNEL_OUT_STAMP)
+	$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) $(KERNEL_DEFCONFIG)
+	env KCONFIG_NOTIMESTAMP=true \
+		 $(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) savedefconfig
+	cp $(KERNEL_OUT)/defconfig $(KERNEL_DEFCONFIG_SRC)
+
+alldefconfig: $(KERNEL_OUT_STAMP)
+	env KCONFIG_NOTIMESTAMP=true \
+		 $(MAKE) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) alldefconfig
 
 endif # FULL_KERNEL_BUILD
 
+TARGET_PREBUILT_DTBO = $(PRODUCT_OUT)/dtbo/arch/$(KERNEL_ARCH)/boot/dtbo.img
+$(TARGET_PREBUILT_DTBO): $(AVBTOOL)
+	echo -e ${CL_GRN}"Building DTBO.img"${CL_RST}
+	$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(PRODUCT_OUT)/dtbo ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) $(KERNEL_DEFCONFIG)
+	$(MAKE) $(MAKE_FLAGS) -C $(KERNEL_SRC) O=$(PRODUCT_OUT)/dtbo ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) dtbo.img
+	$(AVBTOOL) add_hash_footer \
+		--image $@ \
+		--partition_size $(BOARD_DTBOIMG_PARTITION_SIZE) \
+		--partition_name dtbo $(INTERNAL_AVB_DTBO_SIGNING_ARGS) \
+		$(BOARD_AVB_DTBO_ADD_HASH_FOOTER_ARGS)
+
 ## Install it
 
 ifeq ($(NEEDS_KERNEL_COPY),true)
@@ -295,3 +418,20 @@
 
 ALL_PREBUILT += $(INSTALLED_KERNEL_TARGET)
 endif
+
+ifeq ($(TARGET_NEEDS_DTBOIMAGE),true)
+file := $(INSTALLED_DTBOIMAGE_TARGET)
+ALL_PREBUILT += $(file)
+$(file) : $(TARGET_PREBUILT_DTBO) | $(ACP)
+	$(transform-prebuilt-to-target)
+
+ALL_PREBUILT += $(INSTALLED_DTBOIMAGE_TARGET)
+endif
+
+.PHONY: kernel
+kernel: $(INSTALLED_KERNEL_TARGET)
+
+.PHONY: dtbo
+dtbo: $(INSTALLED_DTBOIMAGE_TARGET)
+
+endif # TARGET_NO_KERNEL