# Copyright (C) 2018 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. # 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. # # # Kernel build configuration variables # ==================================== # # These config vars are usually set in BoardConfig.mk: # # TARGET_KERNEL_SOURCE = Kernel source dir, optional, defaults # to kernel/$(TARGET_DEVICE_DIR) # TARGET_KERNEL_ARCH = 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 # # 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 # USE_CCACHE = Enable ccache (global Android flag) BUILD_TOP := $(shell pwd) TARGET_AUTO_KDIR := $(shell echo $(TARGET_DEVICE_DIR) | sed -e 's/^device/kernel/g') TARGET_KERNEL_SOURCE ?= $(TARGET_AUTO_KDIR) ifneq ($(TARGET_PREBUILT_KERNEL),) TARGET_KERNEL_SOURCE := endif TARGET_KERNEL_ARCH := $(strip $(TARGET_KERNEL_ARCH)) ifeq ($(TARGET_KERNEL_ARCH),) KERNEL_ARCH := $(TARGET_ARCH) else KERNEL_ARCH := $(TARGET_KERNEL_ARCH) endif TARGET_KERNEL_CROSS_COMPILE_PREFIX := $(strip $(TARGET_KERNEL_CROSS_COMPILE_PREFIX)) ifneq ($(TARGET_KERNEL_CROSS_COMPILE_PREFIX),) KERNEL_TOOLCHAIN_PREFIX ?= $(TARGET_KERNEL_CROSS_COMPILE_PREFIX) else ifeq ($(KERNEL_ARCH),arm64) ifeq ($(TARGET_KERNEL_CLANG_COMPILE),true) KERNEL_TOOLCHAIN_PREFIX ?= aarch64-linux-android- else KERNEL_TOOLCHAIN_PREFIX ?= aarch64-linux-androidkernel- endif else ifeq ($(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),) KERNEL_TOOLCHAIN_PATH := $(KERNEL_TOOLCHAIN_PREFIX) else ifneq ($(KERNEL_TOOLCHAIN_PREFIX),) KERNEL_TOOLCHAIN_PATH := $(KERNEL_TOOLCHAIN)/$(KERNEL_TOOLCHAIN_PREFIX) endif ifneq ($(USE_CCACHE),) # Detect if the system already has ccache installed to use instead of the prebuilt CCACHE_BIN := $(shell which ccache) ifeq ($(CCACHE_BIN),) CCACHE_BIN := $(BUILD_TOP)/prebuilts/misc/$(HOST_PREBUILT_TAG)/ccache/ccache # Check that the executable is here. CCACHE_BIN := $(strip $(wildcard $(CCACHE_BIN))) endif endif ifeq ($(TARGET_KERNEL_CLANG_COMPILE),true) KERNEL_CROSS_COMPILE := CROSS_COMPILE="$(KERNEL_TOOLCHAIN_PATH)" else KERNEL_CROSS_COMPILE := CROSS_COMPILE="$(CCACHE_BIN) $(KERNEL_TOOLCHAIN_PATH)" endif # Needed for CONFIG_COMPAT_VDSO, safe to set for all arm64 builds ifeq ($(KERNEL_ARCH),arm64) KERNEL_CROSS_COMPILE += CROSS_COMPILE_ARM32="arm-linux-androideabi-" endif # Clear this first to prevent accidental poisoning from env KERNEL_MAKE_FLAGS := # Add back threads, ninja cuts this to $(nproc)/2 KERNEL_MAKE_FLAGS += -j$$(nproc) ifeq ($(KERNEL_ARCH),arm) # Avoid "Unknown symbol _GLOBAL_OFFSET_TABLE_" errors KERNEL_MAKE_FLAGS += CFLAGS_MODULE="-fno-pic" endif ifeq ($(KERNEL_ARCH),arm64) # Avoid "unsupported RELA relocation: 311" errors (R_AARCH64_ADR_GOT_PAGE) KERNEL_MAKE_FLAGS += CFLAGS_MODULE="-fno-pic" endif ifeq ($(HOST_OS),darwin) KERNEL_MAKE_FLAGS += C_INCLUDE_PATH=$(BUILD_TOP)/external/elfutils/libelf:/usr/local/opt/openssl/include KERNEL_MAKE_FLAGS += LIBRARY_PATH=/usr/local/opt/openssl/lib endif # Set DTBO image locations so the build system knows to build them ifeq ($(TARGET_NEEDS_DTBOIMAGE),true) BOARD_PREBUILT_DTBOIMAGE ?= $(PRODUCT_OUT)/dtbo/arch/$(KERNEL_ARCH)/boot/dtbo.img else ifeq ($(BOARD_KERNEL_SEPARATED_DTBO),true) BOARD_PREBUILT_DTBOIMAGE ?= $(PRODUCT_OUT)/dtbo-pre.img endif