1# 2# arch/arm64/Makefile 3# 4# This file is included by the global makefile so that you can add your own 5# architecture-specific flags and dependencies. 6# 7# This file is subject to the terms and conditions of the GNU General Public 8# License. See the file "COPYING" in the main directory of this archive 9# for more details. 10# 11# Copyright (C) 1995-2001 by Russell King 12 13LDFLAGS_vmlinux :=--no-undefined -X -z norelro 14 15ifeq ($(CONFIG_RELOCATABLE), y) 16# Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour 17# for relative relocs, since this leads to better Image compression 18# with the relocation offsets always being zero. 19LDFLAGS_vmlinux += -shared -Bsymbolic -z notext \ 20 $(call ld-option, --no-apply-dynamic-relocs) 21endif 22 23ifeq ($(CONFIG_ARM64_ERRATUM_843419),y) 24 ifeq ($(call ld-option, --fix-cortex-a53-843419),) 25$(warning ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum) 26 else 27LDFLAGS_vmlinux += --fix-cortex-a53-843419 28 endif 29endif 30 31ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS), y) 32 ifneq ($(CONFIG_ARM64_LSE_ATOMICS), y) 33$(warning LSE atomics not supported by binutils) 34 endif 35endif 36 37cc_has_k_constraint := $(call try-run,echo \ 38 'int main(void) { \ 39 asm volatile("and w0, w0, %w0" :: "K" (4294967295)); \ 40 return 0; \ 41 }' | $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1) 42 43ifeq ($(CONFIG_BROKEN_GAS_INST),y) 44$(warning Detected assembler with broken .inst; disassembly will be unreliable) 45endif 46 47KBUILD_CFLAGS += -mgeneral-regs-only \ 48 $(compat_vdso) $(cc_has_k_constraint) 49KBUILD_CFLAGS += $(call cc-disable-warning, psabi) 50KBUILD_AFLAGS += $(compat_vdso) 51 52KBUILD_CFLAGS += $(call cc-option,-mabi=lp64) 53KBUILD_AFLAGS += $(call cc-option,-mabi=lp64) 54 55# Avoid generating .eh_frame* sections. 56KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables 57KBUILD_AFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables 58 59ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y) 60prepare: stack_protector_prepare 61stack_protector_prepare: prepare0 62 $(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg \ 63 -mstack-protector-guard-reg=sp_el0 \ 64 -mstack-protector-guard-offset=$(shell \ 65 awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \ 66 include/generated/asm-offsets.h)) 67endif 68 69# Ensure that if the compiler supports branch protection we default it 70# off, this will be overridden if we are using branch protection. 71branch-prot-flags-y += $(call cc-option,-mbranch-protection=none) 72 73ifeq ($(CONFIG_ARM64_PTR_AUTH),y) 74branch-prot-flags-$(CONFIG_CC_HAS_SIGN_RETURN_ADDRESS) := -msign-return-address=all 75# We enable additional protection for leaf functions as there is some 76# narrow potential for ROP protection benefits and no substantial 77# performance impact has been observed. 78ifeq ($(CONFIG_ARM64_BTI_KERNEL),y) 79branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protection=pac-ret+leaf+bti 80else 81branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf 82endif 83# -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the 84# compiler to generate them and consequently to break the single image contract 85# we pass it only to the assembler. This option is utilized only in case of non 86# integrated assemblers. 87ifeq ($(CONFIG_AS_HAS_PAC), y) 88asm-arch := armv8.3-a 89endif 90endif 91 92KBUILD_CFLAGS += $(branch-prot-flags-y) 93 94ifeq ($(CONFIG_AS_HAS_ARMV8_4), y) 95# make sure to pass the newest target architecture to -march. 96asm-arch := armv8.4-a 97endif 98 99ifdef asm-arch 100KBUILD_CFLAGS += -Wa,-march=$(asm-arch) \ 101 -DARM64_ASM_ARCH='"$(asm-arch)"' 102endif 103 104ifeq ($(CONFIG_SHADOW_CALL_STACK), y) 105KBUILD_CFLAGS += -ffixed-x18 106endif 107 108ifeq ($(CONFIG_CPU_BIG_ENDIAN), y) 109KBUILD_CPPFLAGS += -mbig-endian 110CHECKFLAGS += -D__AARCH64EB__ 111# Prefer the baremetal ELF build target, but not all toolchains include 112# it so fall back to the standard linux version if needed. 113KBUILD_LDFLAGS += -EB $(call ld-option, -maarch64elfb, -maarch64linuxb) 114UTS_MACHINE := aarch64_be 115else 116KBUILD_CPPFLAGS += -mlittle-endian 117CHECKFLAGS += -D__AARCH64EL__ 118# Same as above, prefer ELF but fall back to linux target if needed. 119KBUILD_LDFLAGS += -EL $(call ld-option, -maarch64elf, -maarch64linux) 120UTS_MACHINE := aarch64 121endif 122 123CHECKFLAGS += -D__aarch64__ 124 125ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y) 126 KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY 127 CC_FLAGS_FTRACE := -fpatchable-function-entry=2 128endif 129 130# Default value 131head-y := arch/arm64/kernel/head.o 132 133ifeq ($(CONFIG_KASAN_SW_TAGS), y) 134KASAN_SHADOW_SCALE_SHIFT := 4 135else 136KASAN_SHADOW_SCALE_SHIFT := 3 137endif 138 139KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT) 140KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT) 141KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT) 142 143core-y += arch/arm64/ 144libs-y := arch/arm64/lib/ $(libs-y) 145libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a 146 147# Default target when executing plain make 148boot := arch/arm64/boot 149KBUILD_IMAGE := $(boot)/Image.gz 150 151all: Image.gz 152 153 154Image: vmlinux 155 $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@ 156 157Image.%: Image 158 $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@ 159 160zinstall install: 161 $(Q)$(MAKE) $(build)=$(boot) $@ 162 163PHONY += vdso_install 164vdso_install: 165 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@ 166 $(if $(CONFIG_COMPAT_VDSO), \ 167 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@) 168 169# We use MRPROPER_FILES and CLEAN_FILES now 170archclean: 171 $(Q)$(MAKE) $(clean)=$(boot) 172 173ifeq ($(KBUILD_EXTMOD),) 174# We need to generate vdso-offsets.h before compiling certain files in kernel/. 175# In order to do that, we should use the archprepare target, but we can't since 176# asm-offsets.h is included in some files used to generate vdso-offsets.h, and 177# asm-offsets.h is built in prepare0, for which archprepare is a dependency. 178# Therefore we need to generate the header after prepare0 has been made, hence 179# this hack. 180prepare: vdso_prepare 181vdso_prepare: prepare0 182 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h 183 $(if $(CONFIG_COMPAT_VDSO),$(Q)$(MAKE) \ 184 $(build)=arch/arm64/kernel/vdso32 \ 185 include/generated/vdso32-offsets.h) 186endif 187 188define archhelp 189 echo '* Image.gz - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)' 190 echo ' Image - Uncompressed kernel image (arch/$(ARCH)/boot/Image)' 191 echo ' install - Install uncompressed kernel' 192 echo ' zinstall - Install compressed kernel' 193 echo ' Install using (your) ~/bin/installkernel or' 194 echo ' (distribution) /sbin/installkernel or' 195 echo ' install to $$(INSTALL_PATH) and run lilo' 196endef 197