kernel_definitions.mk - kernel/build - Gitiles

 # Android Kernel compilation/common definitions

 ifeq ($(KERNEL_DEFCONFIG),)
 ifneq ($(TARGET_BOARD_AUTO),true)
      KERNEL_DEFCONFIG := vendor/$(TARGET_BOARD_PLATFORM)-qgki-debug_defconfig
 else
      KERNEL_DEFCONFIG := vendor/gen3auto-qgki-debug_defconfig
 endif
 endif

 TARGET_KERNEL := msm-$(TARGET_KERNEL_VERSION)
 ifeq ($(TARGET_KERNEL_SOURCE),)
      TARGET_KERNEL_SOURCE := kernel/$(TARGET_KERNEL)
 endif

 DTC := $(HOST_OUT_EXECUTABLES)/dtc$(HOST_EXECUTABLE_SUFFIX)
 UFDT_APPLY_OVERLAY := $(HOST_OUT_EXECUTABLES)/ufdt_apply_overlay$(HOST_EXECUTABLE_SUFFIX)

 SOURCE_ROOT := $(shell pwd)
 TARGET_KERNEL_MAKE_ENV := DTC_EXT=$(SOURCE_ROOT)/$(DTC)
 TARGET_KERNEL_MAKE_ENV += DTC_OVERLAY_TEST_EXT=$(SOURCE_ROOT)/$(UFDT_APPLY_OVERLAY)
 TARGET_KERNEL_MAKE_ENV += CONFIG_BUILD_ARM64_DT_OVERLAY=y
 TARGET_KERNEL_MAKE_ENV += HOSTCC=$(SOURCE_ROOT)/$(SOONG_LLVM_PREBUILTS_PATH)/clang
 TARGET_KERNEL_MAKE_ENV += HOSTAR=$(SOURCE_ROOT)/prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.17-4.8/bin/x86_64-linux-ar
 TARGET_KERNEL_MAKE_ENV += HOSTLD=$(SOURCE_ROOT)/prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.17-4.8/bin/x86_64-linux-ld
 TARGET_KERNEL_MAKE_CFLAGS = "-I$(SOURCE_ROOT)/$(TARGET_KERNEL_SOURCE)/include/uapi -I/usr/include -I/usr/include/x86_64-linux-gnu -I$(SOURCE_ROOT)/$(TARGET_KERNEL_SOURCE)/include -L/usr/lib -L/usr/lib/x86_64-linux-gnu -fuse-ld=lld"
 TARGET_KERNEL_MAKE_LDFLAGS = "-L/usr/lib -L/usr/lib/x86_64-linux-gnu -fuse-ld=lld"

 #+ FP5-281. Disable ramdump on mini releases. liquan.zhou.t2m. 20230213.
 ifeq ($(T2M_DISABLE_RAMDUMP), true)
 $(warning "T2M_DISABLE_RAMDUMP is " $(T2M_DISABLE_RAMDUMP))
 TARGET_KERNEL_MAKE_ENV += T2M_DISABLE_RAMDUMP=$(T2M_DISABLE_RAMDUMP)
 endif
 #- FP5-281. Disable ramdump on mini releases. liquan.zhou.t2m. 20230213.

 BUILD_CONFIG := $(TARGET_KERNEL_SOURCE)/build.config.common
 CLANG_VERSION := $(shell IFS="/"; while read LINE; do if [[ $$LINE == *"CLANG_PREBUILT_BIN"* ]]; then read -ra CLANG <<< "$$LINE"; for VERSION in "$${CLANG[@]}"; do if [[ $$VERSION == *"clang-"* ]]; then echo "$$VERSION"; fi; done; fi; done < $(BUILD_CONFIG))
 KERNEL_LLVM_BIN := $(lastword $(sort $(wildcard $(SOURCE_ROOT)/$(LLVM_PREBUILTS_BASE)/$(BUILD_OS)-x86/clang-4*)))/bin/clang
 KERNEL_AOSP_LLVM_BIN := $(SOURCE_ROOT)/$(LLVM_PREBUILTS_BASE)/$(BUILD_OS)-x86/$(CLANG_VERSION)/bin
 KERNEL_AOSP_LLVM_CLANG := $(KERNEL_AOSP_LLVM_BIN)/clang
 USE_KERNEL_AOSP_LLVM := $(shell test -f "$(KERNEL_AOSP_LLVM_CLANG)" && echo "true" || echo "false")

 KERNEL_TARGET := $(strip $(INSTALLED_KERNEL_TARGET))
 ifeq ($(KERNEL_TARGET),)
 INSTALLED_KERNEL_TARGET := $(PRODUCT_OUT)/kernel
 endif

 ifneq ($(TARGET_KERNEL_APPEND_DTB), true)
 $(info Using DTB Image)
 INSTALLED_DTBIMAGE_TARGET := $(PRODUCT_OUT)/dtb.img
 endif

 TARGET_KERNEL_ARCH := $(strip $(TARGET_KERNEL_ARCH))
 ifeq ($(TARGET_KERNEL_ARCH),)
 KERNEL_ARCH := arm
 else
 KERNEL_ARCH := $(TARGET_KERNEL_ARCH)
 endif

 ifeq ($(shell echo $(KERNEL_DEFCONFIG) | grep vendor),)
 KERNEL_DEFCONFIG := vendor/$(KERNEL_DEFCONFIG)
 endif

 # Force 32-bit binder IPC for 64bit kernel with 32bit userspace
 ifeq ($(KERNEL_ARCH),arm64)
 ifeq ($(TARGET_ARCH),arm)
 KERNEL_CONFIG_OVERRIDE := CONFIG_ANDROID_BINDER_IPC_32BIT=y
 endif
 endif

 TARGET_KERNEL_CROSS_COMPILE_PREFIX := $(strip $(TARGET_KERNEL_CROSS_COMPILE_PREFIX))
 ifeq ($(TARGET_KERNEL_CROSS_COMPILE_PREFIX),)
 KERNEL_CROSS_COMPILE := arm-eabi-
 else
 KERNEL_CROSS_COMPILE := $(shell pwd)/$(TARGET_TOOLS_PREFIX)
 endif

 ifeq ($(TARGET_PREBUILT_KERNEL),)

 KERNEL_GCC_NOANDROID_CHK := $(shell (echo "int main() {return 0;}" | $(KERNEL_CROSS_COMPILE)gcc -E -mno-android - > /dev/null 2>&1 ; echo $$?))

 ifeq ($(KERNEL_ARCH),arm64)
 CLANG_ARCH := aarch64-linux-gnu-
 else
 CLANG_ARCH := arm-linux-gnueabi
 endif

 real_cc :=
 ifeq ($(KERNEL_LLVM_SUPPORT),true)
   ifeq ($(KERNEL_SD_LLVM_SUPPORT), true)  #Using sd-llvm compiler
     ifeq ($(shell echo $(SDCLANG_PATH) | head -c 1),/)
        KERNEL_LLVM_BIN := $(SDCLANG_PATH)/clang
     else
        KERNEL_LLVM_BIN := $(shell pwd)/$(SDCLANG_PATH)/clang
     endif
     $(warning "Using sdllvm" $(KERNEL_LLVM_BIN))
   real_cc := REAL_CC=$(KERNEL_LLVM_BIN) CLANG_TRIPLE=aarch64-linux-gnu-
   else
     ifeq ($(USE_KERNEL_AOSP_LLVM), true)  #Using kernel aosp-llvm compiler
        KERNEL_LLVM_BIN := $(KERNEL_AOSP_LLVM_CLANG)
        $(warning "Using latest kernel aosp llvm" $(KERNEL_LLVM_BIN))
     else #Using platform aosp-llvm binaries
        KERNEL_LLVM_BIN := $(shell pwd)/$(CLANG)
        KERNEL_AOSP_LLVM_BIN := $(shell pwd)/$(shell (dirname $(CLANG)))
        $(warning "Not using latest aosp-llvm" $(KERNEL_LLVM_BIN))
     endif
   real_cc := REAL_CC=$(KERNEL_LLVM_BIN) CLANG_TRIPLE=$(CLANG_ARCH) AR=$(KERNEL_AOSP_LLVM_BIN)/llvm-ar LLVM_NM=$(KERNEL_AOSP_LLVM_BIN)/llvm-nm LD=$(KERNEL_AOSP_LLVM_BIN)/ld.lld NM=$(KERNEL_AOSP_LLVM_BIN)/llvm-nm
   endif
 else
 ifeq ($(strip $(KERNEL_GCC_NOANDROID_CHK)),0)
 KERNEL_CFLAGS := KCFLAGS=-mno-android
 endif
 endif

 GKI_KERNEL=0
 ifneq (,$(findstring gki,$(KERNEL_DEFCONFIG)))
 $(info ###### GKI based platform ######)
 ifneq "gki_defconfig" "$(KERNEL_DEFCONFIG)"
 GKI_KERNEL=1
 endif
 endif

 BUILD_ROOT_LOC := ../../..
 KERNEL_OUT := $(TARGET_OUT_INTERMEDIATES)/kernel/$(TARGET_KERNEL)
 KERNEL_SYMLINK := $(TARGET_OUT_INTERMEDIATES)/KERNEL_OBJ
 KERNEL_USR := $(KERNEL_SYMLINK)/usr
 KERNEL_USR_TS := $(TARGET_OUT_INTERMEDIATES)/kernelusr.time

 KERNEL_CONFIG := $(KERNEL_OUT)/.config

 ifeq ($(KERNEL_DEFCONFIG)$(wildcard $(KERNEL_CONFIG)),)
 $(error Kernel configuration not defined, cannot build kernel)
 else

 ifeq ($(GKI_KERNEL),1)
 GKI_PLATFORM_NAME := $(shell echo $(KERNEL_DEFCONFIG) | sed -r "s/(-gki_defconfig|-qgki_defconfig|-qgki-consolidate_defconfig|-qgki-debug_defconfig)$///")
 GKI_PLATFORM_NAME := $(shell echo $(GKI_PLATFORM_NAME) | sed "s/vendor\///g")
 TARGET_USES_UNCOMPRESSED_KERNEL := $(shell grep "CONFIG_BUILD_ARM64_UNCOMPRESSED_KERNEL=y" $(TARGET_KERNEL_SOURCE)/arch/arm64/configs/vendor/$(GKI_PLATFORM_NAME)_GKI.config)

 else
 TARGET_USES_UNCOMPRESSED_KERNEL := $(shell grep "CONFIG_BUILD_ARM64_UNCOMPRESSED_KERNEL=y" $(TARGET_KERNEL_SOURCE)/arch/$(KERNEL_ARCH)/configs/$(KERNEL_DEFCONFIG))
 endif

 # Generate the defconfig file from the fragments
 _x := $(shell ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) KERN_OUT=$(KERNEL_OUT) $(TARGET_KERNEL_MAKE_ENV) MAKE_PATH=$(MAKE_PATH) TARGET_BUILD_VARIANT=${TARGET_BUILD_VARIANT} $(TARGET_KERNEL_SOURCE)/scripts/gki/generate_defconfig.sh $(KERNEL_DEFCONFIG))

 ifeq ($(TARGET_USES_UNCOMPRESSED_KERNEL),)
 ifeq ($(KERNEL_ARCH),arm64)
 TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/Image.gz
 else
 TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/zImage
 endif
 else
 $(info Using uncompressed kernel)
 TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/Image
 endif

 ifeq ($(TARGET_KERNEL_APPEND_DTB), true)
 $(info Using appended DTB)
 TARGET_PREBUILT_INT_KERNEL := $(TARGET_PREBUILT_INT_KERNEL)-dtb
 endif

 KERNEL_HEADERS_INSTALL := $(KERNEL_OUT)/usr
 KERNEL_MODULES_INSTALL ?= system
 KERNEL_MODULES_OUT ?= $(PRODUCT_OUT)/$(KERNEL_MODULES_INSTALL)/lib/modules

 TARGET_PREBUILT_KERNEL := $(TARGET_PREBUILT_INT_KERNEL)

 endif
 endif

 # If the configuration is QGKI, build the GKI kernel as well
 # The build system overrides INSTALLED_KERNEL_TARGET if BOARD_KERNEL_BINARIES is defined
 ifeq ($(GKI_KERNEL),1)
   ifeq "$(KERNEL_DEFCONFIG)" "vendor/$(TARGET_PRODUCT)-qgki_defconfig"
     $(info Additional GKI images will be built)
     INSTALLED_KERNEL_TARGET := $(foreach k,$(BOARD_KERNEL_BINARIES), $(PRODUCT_OUT)/$(k))

     # Create new definitions for building an additional GKI kernel on the side
     GKI_INSTALLED_KERNEL_TARGET := $(PRODUCT_OUT)/kernel-gki
     GKI_KERNEL_DEFCONFIG := vendor/$(TARGET_PRODUCT)-gki_defconfig
     GKI_KERNEL_OUT := $(TARGET_OUT_INTERMEDIATES)/kernel-gki/$(TARGET_KERNEL)
     GKI_KERNEL_MODULES_OUT := $(PRODUCT_OUT)/$(KERNEL_MODULES_INSTALL)/lib/modules/gki
     GKI_KERNEL_HEADERS_INSTALL := $(GKI_KERNEL_OUT)/usr
     GKI_TARGET_PREBUILT_INT_KERNEL := $(subst kernel,kernel-gki,$(TARGET_PREBUILT_INT_KERNEL))
     GKI_TARGET_PREBUILT_KERNEL := $(GKI_TARGET_PREBUILT_INT_KERNEL)
     GKI_TARGET_MODULES_DIR := $(TARGET_KERNEL_VERSION)-gki

     BOARD_KERNEL_MODULE_DIRS := $(GKI_TARGET_MODULES_DIR)
     BOARD_KERNEL-GKI_BOOTIMAGE_PARTITION_SIZE := 0x06000000

     # Generate the GKI defconfig
     _x := $(shell ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) KERN_OUT=$(KERNEL_OUT) $(TARGET_KERNEL_MAKE_ENV) MAKE_PATH=$(MAKE_PATH) TARGET_BUILD_VARIANT=${TARGET_BUILD_VARIANT} $(TARGET_KERNEL_SOURCE)/scripts/gki/generate_defconfig.sh $(GKI_KERNEL_DEFCONFIG))
   endif
 endif

 # Archieve the DLKMs that goes into vendor.img and vendor-ramdisk.
 # Also, make them dependent on the kernel compilation.
 VENDOR_KERNEL_MODULES_ARCHIVE := vendor_modules.zip
 BOARD_VENDOR_KERNEL_MODULES_ARCHIVE := $(KERNEL_MODULES_OUT)/$(VENDOR_KERNEL_MODULES_ARCHIVE)
 $(BOARD_VENDOR_KERNEL_MODULES_ARCHIVE): $(TARGET_PREBUILT_KERNEL)

 ifneq ($(GKI_INSTALLED_KERNEL_TARGET),)
 BOARD_VENDOR_KERNEL_MODULES_ARCHIVE_$(GKI_TARGET_MODULES_DIR) := $(GKI_KERNEL_MODULES_OUT)/$(VENDOR_KERNEL_MODULES_ARCHIVE)
 $(BOARD_VENDOR_KERNEL_MODULES_ARCHIVE_$(GKI_TARGET_MODULES_DIR)): $(GKI_TARGET_PREBUILT_KERNEL)
 endif

 BOARD_VENDOR_KERNEL_MODULES_$(GKI_TARGET_MODULES_DIR) = \
               $(foreach mod, $(BOARD_VENDOR_KERNEL_MODULES), \
                 $(subst $(KERNEL_MODULES_OUT), $(GKI_KERNEL_MODULES_OUT), $(mod)))

 $(warning VENDOR_RAMDISK_KERNEL_MODLUES = $(VENDOR_RAMDISK_KERNEL_MODLUES))

 ifneq ($(VENDOR_RAMDISK_KERNEL_MODULES),)
 VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE := vendor_ramdisk_modules.zip

 ifeq "$(KERNEL_DEFCONFIG)" "vendor/$(TARGET_PRODUCT)-gki_defconfig"
 BOARD_VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE := $(KERNEL_MODULES_OUT)/$(VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE)
 $(BOARD_VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE): $(TARGET_PREBUILT_KERNEL)
 endif

 ifneq ($(GKI_INSTALLED_KERNEL_TARGET),)
 BOARD_VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE_$(GKI_TARGET_MODULES_DIR) := $(GKI_KERNEL_MODULES_OUT)/$(VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE)
 $(BOARD_VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE_$(GKI_TARGET_MODULES_DIR)): $(GKI_TARGET_PREBUILT_KERNEL)
 endif
 endif

 $(BOARD_VENDOR_RAMDISK_KERNEL_MODULES): $(TARGET_PREBUILT_KERNEL)

 # Add RTIC DTB to dtb.img if RTIC MPGen is enabled.
 # Note: unfortunately we can't define RTIC DTS + DTB rule here as the
 # following variable/ tools (needed for DTS generation)
 # are missing - DTB_OBJS, OBJDUMP, KCONFIG_CONFIG, CC, DTC_FLAGS (the only available is DTC).
 # The existing RTIC kernel integration in scripts/link-vmlinux.sh generates RTIC MP DTS
 # that will be compiled with optional rule below.
 # To be safe, we check for MPGen enable.
 ifdef RTIC_MPGEN
 RTIC_DTB := $(KERNEL_SYMLINK)/rtic_mp.dtb
 endif

 MAKE_PATH := $(SOURCE_ROOT)/prebuilts/build-tools/linux-x86/bin/

 # Helper functions

 # Build the kernel
 # $(1): KERNEL_DEFCONFIG to build for
 # $(2): KERNEL_OUT directory
 # $(3): KERNEL_MODULES_OUT directory
 # $(4): KERNEL_HEADERS_INSTALL directory
 # $(5): HEADERS_INSTALL; If 1, the call would just generate the headers and quit
 # $(6): TARGET_PREBUILT_INT_KERNEL: The location to the kernel's binary format (Image, zImage, and so on)
 define build-kernel
 	KERNEL_DIR=$(TARGET_KERNEL_SOURCE) \
 	DEFCONFIG=$(1) \
 	OUT_DIR=$(2) \
 	MAKE_PATH=$(MAKE_PATH)\
 	ARCH=$(KERNEL_ARCH) \
 	CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) \
 	KERNEL_MODULES_OUT=$(3) \
 	KERNEL_HEADERS_INSTALL=$(4) \
 	HEADERS_INSTALL=$(5) \
 	TARGET_PREBUILT_INT_KERNEL=$(6) \
 	TARGET_INCLUDES=$(TARGET_KERNEL_MAKE_CFLAGS) \
 	TARGET_LINCLUDES=$(TARGET_KERNEL_MAKE_LDFLAGS) \
 	VENDOR_KERNEL_MODULES_ARCHIVE=$(VENDOR_KERNEL_MODULES_ARCHIVE) \
 	VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE=$(VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE) \
 	VENDOR_RAMDISK_KERNEL_MODULES="$(VENDOR_RAMDISK_KERNEL_MODULES)" \
 	TARGET_PRODUCT=$(TARGET_PRODUCT) \
 	device/qcom/kernelscripts/buildkernel.sh \
 	$(real_cc) \
 	$(TARGET_KERNEL_MAKE_ENV)
 endef

 # Android Kernel make rules
 # Create kernelusr.time file and use its timestamp later to modify the TS of $(KERNEL_USR). \
 # this will ensure in subsequent builds, i.e. no-op incremental builds, modules depends on $(KERNEL_USR) \
 # will not get recompiled.

 $(KERNEL_HEADERS_INSTALL): $(DTC) $(UFDT_APPLY_OVERLAY) | $(KERNEL_OUT)
 	$(call build-kernel,$(KERNEL_DEFCONFIG),$(KERNEL_OUT),$(KERNEL_MODULES_OUT),$(KERNEL_HEADERS_INSTALL),1,$(TARGET_PREBUILT_INT_KERNEL))
 	touch $(KERNEL_USR_TS)

 $(KERNEL_OUT):
 	mkdir -p $(KERNEL_OUT)

 $(GKI_KERNEL_OUT):
 	mkdir -p $(GKI_KERNEL_OUT)

 $(KERNEL_USR): | $(KERNEL_HEADERS_INSTALL)
 	if [ -d "$(KERNEL_SYMLINK)" ] && [ ! -L "$(KERNEL_SYMLINK)" ]; then \
 	rm -rf $(KERNEL_SYMLINK); \
 	ln -s kernel/$(TARGET_KERNEL) $(KERNEL_SYMLINK); \
 	fi

 $(TARGET_PREBUILT_KERNEL): $(KERNEL_OUT) $(DTC) $(KERNEL_USR)
 	echo "Building the requested kernel.."; \
 	$(call build-kernel,$(KERNEL_DEFCONFIG),$(KERNEL_OUT),$(KERNEL_MODULES_OUT),$(KERNEL_HEADERS_INSTALL),0,$(TARGET_PREBUILT_INT_KERNEL))

 $(GKI_TARGET_PREBUILT_KERNEL): $(DTC) $(UFDT_APPLY_OVERLAY) $(GKI_KERNEL_OUT)
 	echo "Building GKI kernel.."; \
 	$(call build-kernel,$(GKI_KERNEL_DEFCONFIG),$(GKI_KERNEL_OUT),$(GKI_KERNEL_MODULES_OUT),$(GKI_KERNEL_HEADERS_INSTALL),0,$(GKI_TARGET_PREBUILT_INT_KERNEL))

 $(INSTALLED_KERNEL_TARGET): $(TARGET_PREBUILT_KERNEL) $(GKI_TARGET_PREBUILT_KERNEL)
 	cp $(TARGET_PREBUILT_KERNEL) $(PRODUCT_OUT)/kernel
 	if [ ! -z "$(GKI_TARGET_PREBUILT_KERNEL)" ]; then \
 		cp $(GKI_TARGET_PREBUILT_KERNEL) $(PRODUCT_OUT)/kernel-gki; \
 	fi
 	touch $(KERNEL_USR) -r $(KERNEL_USR_TS)

 # RTIC DTS to DTB (if MPGen enabled;
 # and make sure we don't break the build if rtic_mp.dts missing)
 $(RTIC_DTB): $(INSTALLED_KERNEL_TARGET)
 	stat $(KERNEL_SYMLINK)/rtic_mp.dts 2>/dev/null >&2 && \
 	$(DTC) -O dtb -o $(RTIC_DTB) -b 1 $(DTC_FLAGS) $(KERNEL_SYMLINK)/rtic_mp.dts || \
 	touch $(RTIC_DTB)

 # Creating a dtb.img once the kernel is compiled if TARGET_KERNEL_APPEND_DTB is set to be false
 $(INSTALLED_DTBIMAGE_TARGET): $(INSTALLED_KERNEL_TARGET) $(RTIC_DTB)
 	cat $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/dts/vendor/${TARGET_PRODUCT}/*.dtb $(RTIC_DTB) > $@
	# Android Kernel compilation/common definitions

	ifeq ($(KERNEL_DEFCONFIG),)
	ifneq ($(TARGET_BOARD_AUTO),true)
	KERNEL_DEFCONFIG := vendor/$(TARGET_BOARD_PLATFORM)-qgki-debug_defconfig
	else
	KERNEL_DEFCONFIG := vendor/gen3auto-qgki-debug_defconfig
	endif
	endif

	TARGET_KERNEL := msm-$(TARGET_KERNEL_VERSION)
	ifeq ($(TARGET_KERNEL_SOURCE),)
	TARGET_KERNEL_SOURCE := kernel/$(TARGET_KERNEL)
	endif

	DTC := $(HOST_OUT_EXECUTABLES)/dtc$(HOST_EXECUTABLE_SUFFIX)
	UFDT_APPLY_OVERLAY := $(HOST_OUT_EXECUTABLES)/ufdt_apply_overlay$(HOST_EXECUTABLE_SUFFIX)

	SOURCE_ROOT := $(shell pwd)
	TARGET_KERNEL_MAKE_ENV := DTC_EXT=$(SOURCE_ROOT)/$(DTC)
	TARGET_KERNEL_MAKE_ENV += DTC_OVERLAY_TEST_EXT=$(SOURCE_ROOT)/$(UFDT_APPLY_OVERLAY)
	TARGET_KERNEL_MAKE_ENV += CONFIG_BUILD_ARM64_DT_OVERLAY=y
	TARGET_KERNEL_MAKE_ENV += HOSTCC=$(SOURCE_ROOT)/$(SOONG_LLVM_PREBUILTS_PATH)/clang
	TARGET_KERNEL_MAKE_ENV += HOSTAR=$(SOURCE_ROOT)/prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.17-4.8/bin/x86_64-linux-ar
	TARGET_KERNEL_MAKE_ENV += HOSTLD=$(SOURCE_ROOT)/prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.17-4.8/bin/x86_64-linux-ld
	TARGET_KERNEL_MAKE_CFLAGS = "-I$(SOURCE_ROOT)/$(TARGET_KERNEL_SOURCE)/include/uapi -I/usr/include -I/usr/include/x86_64-linux-gnu -I$(SOURCE_ROOT)/$(TARGET_KERNEL_SOURCE)/include -L/usr/lib -L/usr/lib/x86_64-linux-gnu -fuse-ld=lld"
	TARGET_KERNEL_MAKE_LDFLAGS = "-L/usr/lib -L/usr/lib/x86_64-linux-gnu -fuse-ld=lld"

	#+ FP5-281. Disable ramdump on mini releases. liquan.zhou.t2m. 20230213.
	ifeq ($(T2M_DISABLE_RAMDUMP), true)
	$(warning "T2M_DISABLE_RAMDUMP is " $(T2M_DISABLE_RAMDUMP))
	TARGET_KERNEL_MAKE_ENV += T2M_DISABLE_RAMDUMP=$(T2M_DISABLE_RAMDUMP)
	endif
	#- FP5-281. Disable ramdump on mini releases. liquan.zhou.t2m. 20230213.

	BUILD_CONFIG := $(TARGET_KERNEL_SOURCE)/build.config.common
	CLANG_VERSION := $(shell IFS="/"; while read LINE; do if [[ $$LINE == "CLANG_PREBUILT_BIN" ]]; then read -ra CLANG <<< "$$LINE"; for VERSION in "$${CLANG[@]}"; do if [[ $$VERSION == "clang-" ]]; then echo "$$VERSION"; fi; done; fi; done < $(BUILD_CONFIG))
	KERNEL_LLVM_BIN := $(lastword $(sort $(wildcard $(SOURCE_ROOT)/$(LLVM_PREBUILTS_BASE)/$(BUILD_OS)-x86/clang-4*)))/bin/clang
	KERNEL_AOSP_LLVM_BIN := $(SOURCE_ROOT)/$(LLVM_PREBUILTS_BASE)/$(BUILD_OS)-x86/$(CLANG_VERSION)/bin
	KERNEL_AOSP_LLVM_CLANG := $(KERNEL_AOSP_LLVM_BIN)/clang
	USE_KERNEL_AOSP_LLVM := $(shell test -f "$(KERNEL_AOSP_LLVM_CLANG)" && echo "true" \|\| echo "false")

	KERNEL_TARGET := $(strip $(INSTALLED_KERNEL_TARGET))
	ifeq ($(KERNEL_TARGET),)
	INSTALLED_KERNEL_TARGET := $(PRODUCT_OUT)/kernel
	endif

	ifneq ($(TARGET_KERNEL_APPEND_DTB), true)
	$(info Using DTB Image)
	INSTALLED_DTBIMAGE_TARGET := $(PRODUCT_OUT)/dtb.img
	endif

	TARGET_KERNEL_ARCH := $(strip $(TARGET_KERNEL_ARCH))
	ifeq ($(TARGET_KERNEL_ARCH),)
	KERNEL_ARCH := arm
	else
	KERNEL_ARCH := $(TARGET_KERNEL_ARCH)
	endif

	ifeq ($(shell echo $(KERNEL_DEFCONFIG) \| grep vendor),)
	KERNEL_DEFCONFIG := vendor/$(KERNEL_DEFCONFIG)
	endif

	# Force 32-bit binder IPC for 64bit kernel with 32bit userspace
	ifeq ($(KERNEL_ARCH),arm64)
	ifeq ($(TARGET_ARCH),arm)
	KERNEL_CONFIG_OVERRIDE := CONFIG_ANDROID_BINDER_IPC_32BIT=y
	endif
	endif

	TARGET_KERNEL_CROSS_COMPILE_PREFIX := $(strip $(TARGET_KERNEL_CROSS_COMPILE_PREFIX))
	ifeq ($(TARGET_KERNEL_CROSS_COMPILE_PREFIX),)
	KERNEL_CROSS_COMPILE := arm-eabi-
	else
	KERNEL_CROSS_COMPILE := $(shell pwd)/$(TARGET_TOOLS_PREFIX)
	endif

	ifeq ($(TARGET_PREBUILT_KERNEL),)

	KERNEL_GCC_NOANDROID_CHK := $(shell (echo "int main() {return 0;}" \| $(KERNEL_CROSS_COMPILE)gcc -E -mno-android - > /dev/null 2>&1 ; echo $$?))

	ifeq ($(KERNEL_ARCH),arm64)
	CLANG_ARCH := aarch64-linux-gnu-
	else
	CLANG_ARCH := arm-linux-gnueabi
	endif

	real_cc :=
	ifeq ($(KERNEL_LLVM_SUPPORT),true)
	ifeq ($(KERNEL_SD_LLVM_SUPPORT), true) #Using sd-llvm compiler
	ifeq ($(shell echo $(SDCLANG_PATH) \| head -c 1),/)
	KERNEL_LLVM_BIN := $(SDCLANG_PATH)/clang
	else
	KERNEL_LLVM_BIN := $(shell pwd)/$(SDCLANG_PATH)/clang
	endif
	$(warning "Using sdllvm" $(KERNEL_LLVM_BIN))
	real_cc := REAL_CC=$(KERNEL_LLVM_BIN) CLANG_TRIPLE=aarch64-linux-gnu-
	else
	ifeq ($(USE_KERNEL_AOSP_LLVM), true) #Using kernel aosp-llvm compiler
	KERNEL_LLVM_BIN := $(KERNEL_AOSP_LLVM_CLANG)
	$(warning "Using latest kernel aosp llvm" $(KERNEL_LLVM_BIN))
	else #Using platform aosp-llvm binaries
	KERNEL_LLVM_BIN := $(shell pwd)/$(CLANG)
	KERNEL_AOSP_LLVM_BIN := $(shell pwd)/$(shell (dirname $(CLANG)))
	$(warning "Not using latest aosp-llvm" $(KERNEL_LLVM_BIN))
	endif
	real_cc := REAL_CC=$(KERNEL_LLVM_BIN) CLANG_TRIPLE=$(CLANG_ARCH) AR=$(KERNEL_AOSP_LLVM_BIN)/llvm-ar LLVM_NM=$(KERNEL_AOSP_LLVM_BIN)/llvm-nm LD=$(KERNEL_AOSP_LLVM_BIN)/ld.lld NM=$(KERNEL_AOSP_LLVM_BIN)/llvm-nm
	endif
	else
	ifeq ($(strip $(KERNEL_GCC_NOANDROID_CHK)),0)
	KERNEL_CFLAGS := KCFLAGS=-mno-android
	endif
	endif

	GKI_KERNEL=0
	ifneq (,$(findstring gki,$(KERNEL_DEFCONFIG)))
	$(info ###### GKI based platform ######)
	ifneq "gki_defconfig" "$(KERNEL_DEFCONFIG)"
	GKI_KERNEL=1
	endif
	endif

	BUILD_ROOT_LOC := ../../..
	KERNEL_OUT := $(TARGET_OUT_INTERMEDIATES)/kernel/$(TARGET_KERNEL)
	KERNEL_SYMLINK := $(TARGET_OUT_INTERMEDIATES)/KERNEL_OBJ
	KERNEL_USR := $(KERNEL_SYMLINK)/usr
	KERNEL_USR_TS := $(TARGET_OUT_INTERMEDIATES)/kernelusr.time

	KERNEL_CONFIG := $(KERNEL_OUT)/.config

	ifeq ($(KERNEL_DEFCONFIG)$(wildcard $(KERNEL_CONFIG)),)
	$(error Kernel configuration not defined, cannot build kernel)
	else

	ifeq ($(GKI_KERNEL),1)
	GKI_PLATFORM_NAME := $(shell echo $(KERNEL_DEFCONFIG) \| sed -r "s/(-gki_defconfig\|-qgki_defconfig\|-qgki-consolidate_defconfig\|-qgki-debug_defconfig)$///")
	GKI_PLATFORM_NAME := $(shell echo $(GKI_PLATFORM_NAME) \| sed "s/vendor\///g")
	TARGET_USES_UNCOMPRESSED_KERNEL := $(shell grep "CONFIG_BUILD_ARM64_UNCOMPRESSED_KERNEL=y" $(TARGET_KERNEL_SOURCE)/arch/arm64/configs/vendor/$(GKI_PLATFORM_NAME)_GKI.config)

	else
	TARGET_USES_UNCOMPRESSED_KERNEL := $(shell grep "CONFIG_BUILD_ARM64_UNCOMPRESSED_KERNEL=y" $(TARGET_KERNEL_SOURCE)/arch/$(KERNEL_ARCH)/configs/$(KERNEL_DEFCONFIG))
	endif

	# Generate the defconfig file from the fragments
	_x := $(shell ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) KERN_OUT=$(KERNEL_OUT) $(TARGET_KERNEL_MAKE_ENV) MAKE_PATH=$(MAKE_PATH) TARGET_BUILD_VARIANT=${TARGET_BUILD_VARIANT} $(TARGET_KERNEL_SOURCE)/scripts/gki/generate_defconfig.sh $(KERNEL_DEFCONFIG))

	ifeq ($(TARGET_USES_UNCOMPRESSED_KERNEL),)
	ifeq ($(KERNEL_ARCH),arm64)
	TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/Image.gz
	else
	TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/zImage
	endif
	else
	$(info Using uncompressed kernel)
	TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/Image
	endif

	ifeq ($(TARGET_KERNEL_APPEND_DTB), true)
	$(info Using appended DTB)
	TARGET_PREBUILT_INT_KERNEL := $(TARGET_PREBUILT_INT_KERNEL)-dtb
	endif

	KERNEL_HEADERS_INSTALL := $(KERNEL_OUT)/usr
	KERNEL_MODULES_INSTALL ?= system
	KERNEL_MODULES_OUT ?= $(PRODUCT_OUT)/$(KERNEL_MODULES_INSTALL)/lib/modules

	TARGET_PREBUILT_KERNEL := $(TARGET_PREBUILT_INT_KERNEL)

	endif
	endif

	# If the configuration is QGKI, build the GKI kernel as well
	# The build system overrides INSTALLED_KERNEL_TARGET if BOARD_KERNEL_BINARIES is defined
	ifeq ($(GKI_KERNEL),1)
	ifeq "$(KERNEL_DEFCONFIG)" "vendor/$(TARGET_PRODUCT)-qgki_defconfig"
	$(info Additional GKI images will be built)
	INSTALLED_KERNEL_TARGET := $(foreach k,$(BOARD_KERNEL_BINARIES), $(PRODUCT_OUT)/$(k))

	# Create new definitions for building an additional GKI kernel on the side
	GKI_INSTALLED_KERNEL_TARGET := $(PRODUCT_OUT)/kernel-gki
	GKI_KERNEL_DEFCONFIG := vendor/$(TARGET_PRODUCT)-gki_defconfig
	GKI_KERNEL_OUT := $(TARGET_OUT_INTERMEDIATES)/kernel-gki/$(TARGET_KERNEL)
	GKI_KERNEL_MODULES_OUT := $(PRODUCT_OUT)/$(KERNEL_MODULES_INSTALL)/lib/modules/gki
	GKI_KERNEL_HEADERS_INSTALL := $(GKI_KERNEL_OUT)/usr
	GKI_TARGET_PREBUILT_INT_KERNEL := $(subst kernel,kernel-gki,$(TARGET_PREBUILT_INT_KERNEL))
	GKI_TARGET_PREBUILT_KERNEL := $(GKI_TARGET_PREBUILT_INT_KERNEL)
	GKI_TARGET_MODULES_DIR := $(TARGET_KERNEL_VERSION)-gki

	BOARD_KERNEL_MODULE_DIRS := $(GKI_TARGET_MODULES_DIR)
	BOARD_KERNEL-GKI_BOOTIMAGE_PARTITION_SIZE := 0x06000000

	# Generate the GKI defconfig
	_x := $(shell ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) KERN_OUT=$(KERNEL_OUT) $(TARGET_KERNEL_MAKE_ENV) MAKE_PATH=$(MAKE_PATH) TARGET_BUILD_VARIANT=${TARGET_BUILD_VARIANT} $(TARGET_KERNEL_SOURCE)/scripts/gki/generate_defconfig.sh $(GKI_KERNEL_DEFCONFIG))
	endif
	endif

	# Archieve the DLKMs that goes into vendor.img and vendor-ramdisk.
	# Also, make them dependent on the kernel compilation.
	VENDOR_KERNEL_MODULES_ARCHIVE := vendor_modules.zip
	BOARD_VENDOR_KERNEL_MODULES_ARCHIVE := $(KERNEL_MODULES_OUT)/$(VENDOR_KERNEL_MODULES_ARCHIVE)
	$(BOARD_VENDOR_KERNEL_MODULES_ARCHIVE): $(TARGET_PREBUILT_KERNEL)

	ifneq ($(GKI_INSTALLED_KERNEL_TARGET),)
	BOARD_VENDOR_KERNEL_MODULES_ARCHIVE_$(GKI_TARGET_MODULES_DIR) := $(GKI_KERNEL_MODULES_OUT)/$(VENDOR_KERNEL_MODULES_ARCHIVE)
	$(BOARD_VENDOR_KERNEL_MODULES_ARCHIVE_$(GKI_TARGET_MODULES_DIR)): $(GKI_TARGET_PREBUILT_KERNEL)
	endif

	BOARD_VENDOR_KERNEL_MODULES_$(GKI_TARGET_MODULES_DIR) = \
	$(foreach mod, $(BOARD_VENDOR_KERNEL_MODULES), \
	$(subst $(KERNEL_MODULES_OUT), $(GKI_KERNEL_MODULES_OUT), $(mod)))

	$(warning VENDOR_RAMDISK_KERNEL_MODLUES = $(VENDOR_RAMDISK_KERNEL_MODLUES))

	ifneq ($(VENDOR_RAMDISK_KERNEL_MODULES),)
	VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE := vendor_ramdisk_modules.zip

	ifeq "$(KERNEL_DEFCONFIG)" "vendor/$(TARGET_PRODUCT)-gki_defconfig"
	BOARD_VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE := $(KERNEL_MODULES_OUT)/$(VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE)
	$(BOARD_VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE): $(TARGET_PREBUILT_KERNEL)
	endif

	ifneq ($(GKI_INSTALLED_KERNEL_TARGET),)
	BOARD_VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE_$(GKI_TARGET_MODULES_DIR) := $(GKI_KERNEL_MODULES_OUT)/$(VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE)
	$(BOARD_VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE_$(GKI_TARGET_MODULES_DIR)): $(GKI_TARGET_PREBUILT_KERNEL)
	endif
	endif

	$(BOARD_VENDOR_RAMDISK_KERNEL_MODULES): $(TARGET_PREBUILT_KERNEL)

	# Add RTIC DTB to dtb.img if RTIC MPGen is enabled.
	# Note: unfortunately we can't define RTIC DTS + DTB rule here as the
	# following variable/ tools (needed for DTS generation)
	# are missing - DTB_OBJS, OBJDUMP, KCONFIG_CONFIG, CC, DTC_FLAGS (the only available is DTC).
	# The existing RTIC kernel integration in scripts/link-vmlinux.sh generates RTIC MP DTS
	# that will be compiled with optional rule below.
	# To be safe, we check for MPGen enable.
	ifdef RTIC_MPGEN
	RTIC_DTB := $(KERNEL_SYMLINK)/rtic_mp.dtb
	endif

	MAKE_PATH := $(SOURCE_ROOT)/prebuilts/build-tools/linux-x86/bin/

	# Helper functions

	# Build the kernel
	# $(1): KERNEL_DEFCONFIG to build for
	# $(2): KERNEL_OUT directory
	# $(3): KERNEL_MODULES_OUT directory
	# $(4): KERNEL_HEADERS_INSTALL directory
	# $(5): HEADERS_INSTALL; If 1, the call would just generate the headers and quit
	# $(6): TARGET_PREBUILT_INT_KERNEL: The location to the kernel's binary format (Image, zImage, and so on)
	define build-kernel
	KERNEL_DIR=$(TARGET_KERNEL_SOURCE) \
	DEFCONFIG=$(1) \
	OUT_DIR=$(2) \
	MAKE_PATH=$(MAKE_PATH)\
	ARCH=$(KERNEL_ARCH) \
	CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) \
	KERNEL_MODULES_OUT=$(3) \
	KERNEL_HEADERS_INSTALL=$(4) \
	HEADERS_INSTALL=$(5) \
	TARGET_PREBUILT_INT_KERNEL=$(6) \
	TARGET_INCLUDES=$(TARGET_KERNEL_MAKE_CFLAGS) \
	TARGET_LINCLUDES=$(TARGET_KERNEL_MAKE_LDFLAGS) \
	VENDOR_KERNEL_MODULES_ARCHIVE=$(VENDOR_KERNEL_MODULES_ARCHIVE) \
	VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE=$(VENDOR_RAMDISK_KERNEL_MODULES_ARCHIVE) \
	VENDOR_RAMDISK_KERNEL_MODULES="$(VENDOR_RAMDISK_KERNEL_MODULES)" \
	TARGET_PRODUCT=$(TARGET_PRODUCT) \
	device/qcom/kernelscripts/buildkernel.sh \
	$(real_cc) \
	$(TARGET_KERNEL_MAKE_ENV)
	endef

	# Android Kernel make rules
	# Create kernelusr.time file and use its timestamp later to modify the TS of $(KERNEL_USR). \
	# this will ensure in subsequent builds, i.e. no-op incremental builds, modules depends on $(KERNEL_USR) \
	# will not get recompiled.

	$(KERNEL_HEADERS_INSTALL): $(DTC) $(UFDT_APPLY_OVERLAY) \| $(KERNEL_OUT)
	$(call build-kernel,$(KERNEL_DEFCONFIG),$(KERNEL_OUT),$(KERNEL_MODULES_OUT),$(KERNEL_HEADERS_INSTALL),1,$(TARGET_PREBUILT_INT_KERNEL))
	touch $(KERNEL_USR_TS)

	$(KERNEL_OUT):
	mkdir -p $(KERNEL_OUT)

	$(GKI_KERNEL_OUT):
	mkdir -p $(GKI_KERNEL_OUT)

	$(KERNEL_USR): \| $(KERNEL_HEADERS_INSTALL)
	if [ -d "$(KERNEL_SYMLINK)" ] && [ ! -L "$(KERNEL_SYMLINK)" ]; then \
	rm -rf $(KERNEL_SYMLINK); \
	ln -s kernel/$(TARGET_KERNEL) $(KERNEL_SYMLINK); \
	fi

	$(TARGET_PREBUILT_KERNEL): $(KERNEL_OUT) $(DTC) $(KERNEL_USR)
	echo "Building the requested kernel.."; \
	$(call build-kernel,$(KERNEL_DEFCONFIG),$(KERNEL_OUT),$(KERNEL_MODULES_OUT),$(KERNEL_HEADERS_INSTALL),0,$(TARGET_PREBUILT_INT_KERNEL))

	$(GKI_TARGET_PREBUILT_KERNEL): $(DTC) $(UFDT_APPLY_OVERLAY) $(GKI_KERNEL_OUT)
	echo "Building GKI kernel.."; \
	$(call build-kernel,$(GKI_KERNEL_DEFCONFIG),$(GKI_KERNEL_OUT),$(GKI_KERNEL_MODULES_OUT),$(GKI_KERNEL_HEADERS_INSTALL),0,$(GKI_TARGET_PREBUILT_INT_KERNEL))

	$(INSTALLED_KERNEL_TARGET): $(TARGET_PREBUILT_KERNEL) $(GKI_TARGET_PREBUILT_KERNEL)
	cp $(TARGET_PREBUILT_KERNEL) $(PRODUCT_OUT)/kernel
	if [ ! -z "$(GKI_TARGET_PREBUILT_KERNEL)" ]; then \
	cp $(GKI_TARGET_PREBUILT_KERNEL) $(PRODUCT_OUT)/kernel-gki; \
	fi
	touch $(KERNEL_USR) -r $(KERNEL_USR_TS)

	# RTIC DTS to DTB (if MPGen enabled;
	# and make sure we don't break the build if rtic_mp.dts missing)
	$(RTIC_DTB): $(INSTALLED_KERNEL_TARGET)
	stat $(KERNEL_SYMLINK)/rtic_mp.dts 2>/dev/null >&2 && \
	$(DTC) -O dtb -o $(RTIC_DTB) -b 1 $(DTC_FLAGS) $(KERNEL_SYMLINK)/rtic_mp.dts \|\| \
	touch $(RTIC_DTB)

	# Creating a dtb.img once the kernel is compiled if TARGET_KERNEL_APPEND_DTB is set to be false
	$(INSTALLED_DTBIMAGE_TARGET): $(INSTALLED_KERNEL_TARGET) $(RTIC_DTB)
	cat $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/dts/vendor/${TARGET_PRODUCT}/*.dtb $(RTIC_DTB) > $@