arch/arm64/Makefile - linux - Git at Google

 #
 # arch/arm64/Makefile
 #
 # This file is included by the global makefile so that you can add your own
 # architecture-specific flags and dependencies.
 #
 # This file is subject to the terms and conditions of the GNU General Public
 # License.  See the file "COPYING" in the main directory of this archive
 # for more details.
 #
 # Copyright (C) 1995-2001 by Russell King

 LDFLAGS_vmlinux	:=--no-undefined -X -z norelro

 ifeq ($(CONFIG_RELOCATABLE), y)
 # Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour
 # for relative relocs, since this leads to better Image compression
 # with the relocation offsets always being zero.
 LDFLAGS_vmlinux		+= -shared -Bsymbolic -z notext \
 			$(call ld-option, --no-apply-dynamic-relocs)
 endif

 ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
   ifeq ($(call ld-option, --fix-cortex-a53-843419),)
 $(warning ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum)
   else
 LDFLAGS_vmlinux	+= --fix-cortex-a53-843419
   endif
 endif

 # We never want expected sections to be placed heuristically by the
 # linker. All sections should be explicitly named in the linker script.
 LDFLAGS_vmlinux += $(call ld-option, --orphan-handling=warn)

 ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS), y)
   ifneq ($(CONFIG_ARM64_LSE_ATOMICS), y)
 $(warning LSE atomics not supported by binutils)
   endif
 endif

 cc_has_k_constraint := $(call try-run,echo				\
 	'int main(void) {						\
 		asm volatile("and w0, w0, %w0" :: "K" (4294967295));	\
 		return 0;						\
 	}' | $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1)

 ifeq ($(CONFIG_BROKEN_GAS_INST),y)
 $(warning Detected assembler with broken .inst; disassembly will be unreliable)
 endif

 KBUILD_CFLAGS	+= -mgeneral-regs-only	\
 		   $(compat_vdso) $(cc_has_k_constraint)
 KBUILD_CFLAGS	+= $(call cc-disable-warning, psabi)
 KBUILD_AFLAGS	+= $(compat_vdso)

 KBUILD_CFLAGS	+= $(call cc-option,-mabi=lp64)
 KBUILD_AFLAGS	+= $(call cc-option,-mabi=lp64)

 # Avoid generating .eh_frame* sections.
 KBUILD_CFLAGS	+= -fno-asynchronous-unwind-tables -fno-unwind-tables
 KBUILD_AFLAGS	+= -fno-asynchronous-unwind-tables -fno-unwind-tables

 ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
 prepare: stack_protector_prepare
 stack_protector_prepare: prepare0
 	$(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg		  \
 				-mstack-protector-guard-reg=sp_el0	  \
 				-mstack-protector-guard-offset=$(shell	  \
 			awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
 					include/generated/asm-offsets.h))
 endif

 # Ensure that if the compiler supports branch protection we default it
 # off, this will be overridden if we are using branch protection.
 branch-prot-flags-y += $(call cc-option,-mbranch-protection=none)

 ifeq ($(CONFIG_ARM64_PTR_AUTH),y)
 branch-prot-flags-$(CONFIG_CC_HAS_SIGN_RETURN_ADDRESS) := -msign-return-address=all
 # We enable additional protection for leaf functions as there is some
 # narrow potential for ROP protection benefits and no substantial
 # performance impact has been observed.
 ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
 branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protection=pac-ret+leaf+bti
 else
 branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf
 endif
 # -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the
 # compiler to generate them and consequently to break the single image contract
 # we pass it only to the assembler. This option is utilized only in case of non
 # integrated assemblers.
 ifeq ($(CONFIG_AS_HAS_PAC), y)
 asm-arch := armv8.3-a
 endif
 endif

 KBUILD_CFLAGS += $(branch-prot-flags-y)

 ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)
 # make sure to pass the newest target architecture to -march.
 asm-arch := armv8.4-a
 endif

 ifdef asm-arch
 KBUILD_CFLAGS	+= -Wa,-march=$(asm-arch) \
 		   -DARM64_ASM_ARCH='"$(asm-arch)"'
 endif

 ifeq ($(CONFIG_SHADOW_CALL_STACK), y)
 KBUILD_CFLAGS	+= -ffixed-x18
 endif

 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
 KBUILD_CPPFLAGS	+= -mbig-endian
 CHECKFLAGS	+= -D__AARCH64EB__
 # Prefer the baremetal ELF build target, but not all toolchains include
 # it so fall back to the standard linux version if needed.
 KBUILD_LDFLAGS	+= -EB $(call ld-option, -maarch64elfb, -maarch64linuxb)
 UTS_MACHINE	:= aarch64_be
 else
 KBUILD_CPPFLAGS	+= -mlittle-endian
 CHECKFLAGS	+= -D__AARCH64EL__
 # Same as above, prefer ELF but fall back to linux target if needed.
 KBUILD_LDFLAGS	+= -EL $(call ld-option, -maarch64elf, -maarch64linux)
 UTS_MACHINE	:= aarch64
 endif

 CHECKFLAGS	+= -D__aarch64__

 ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
   KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
   CC_FLAGS_FTRACE := -fpatchable-function-entry=2
 endif

 # Default value
 head-y		:= arch/arm64/kernel/head.o

 ifeq ($(CONFIG_KASAN_SW_TAGS), y)
 KASAN_SHADOW_SCALE_SHIFT := 4
 else
 KASAN_SHADOW_SCALE_SHIFT := 3
 endif

 KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
 KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
 KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)

 core-y		+= arch/arm64/
 libs-y		:= arch/arm64/lib/ $(libs-y)
 libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a

 # Default target when executing plain make
 boot		:= arch/arm64/boot
 KBUILD_IMAGE	:= $(boot)/Image.gz

 all:	Image.gz


 Image: vmlinux
 	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@

 Image.%: Image
 	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@

 zinstall install:
 	$(Q)$(MAKE) $(build)=$(boot) $@

 PHONY += vdso_install
 vdso_install:
 	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
 	$(if $(CONFIG_COMPAT_VDSO), \
 		$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@)

 # We use MRPROPER_FILES and CLEAN_FILES now
 archclean:
 	$(Q)$(MAKE) $(clean)=$(boot)

 ifeq ($(KBUILD_EXTMOD),)
 # We need to generate vdso-offsets.h before compiling certain files in kernel/.
 # In order to do that, we should use the archprepare target, but we can't since
 # asm-offsets.h is included in some files used to generate vdso-offsets.h, and
 # asm-offsets.h is built in prepare0, for which archprepare is a dependency.
 # Therefore we need to generate the header after prepare0 has been made, hence
 # this hack.
 prepare: vdso_prepare
 vdso_prepare: prepare0
 	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h
 	$(if $(CONFIG_COMPAT_VDSO),$(Q)$(MAKE) \
 		$(build)=arch/arm64/kernel/vdso32  \
 		include/generated/vdso32-offsets.h)
 endif

 define archhelp
   echo  '* Image.gz      - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
   echo  '  Image         - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
   echo  '  install       - Install uncompressed kernel'
   echo  '  zinstall      - Install compressed kernel'
   echo  '                  Install using (your) ~/bin/installkernel or'
   echo  '                  (distribution) /sbin/installkernel or'
   echo  '                  install to $$(INSTALL_PATH) and run lilo'
 endef
	#
	# arch/arm64/Makefile
	#
	# This file is included by the global makefile so that you can add your own
	# architecture-specific flags and dependencies.
	#
	# This file is subject to the terms and conditions of the GNU General Public
	# License. See the file "COPYING" in the main directory of this archive
	# for more details.
	#
	# Copyright (C) 1995-2001 by Russell King

	LDFLAGS_vmlinux :=--no-undefined -X -z norelro

	ifeq ($(CONFIG_RELOCATABLE), y)
	# Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour
	# for relative relocs, since this leads to better Image compression
	# with the relocation offsets always being zero.
	LDFLAGS_vmlinux += -shared -Bsymbolic -z notext \
	$(call ld-option, --no-apply-dynamic-relocs)
	endif

	ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
	ifeq ($(call ld-option, --fix-cortex-a53-843419),)
	$(warning ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum)
	else
	LDFLAGS_vmlinux += --fix-cortex-a53-843419
	endif
	endif

	# We never want expected sections to be placed heuristically by the
	# linker. All sections should be explicitly named in the linker script.
	LDFLAGS_vmlinux += $(call ld-option, --orphan-handling=warn)

	ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS), y)
	ifneq ($(CONFIG_ARM64_LSE_ATOMICS), y)
	$(warning LSE atomics not supported by binutils)
	endif
	endif

	cc_has_k_constraint := $(call try-run,echo \
	'int main(void) { \
	asm volatile("and w0, w0, %w0" :: "K" (4294967295)); \
	return 0; \
	}' \| $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1)

	ifeq ($(CONFIG_BROKEN_GAS_INST),y)
	$(warning Detected assembler with broken .inst; disassembly will be unreliable)
	endif

	KBUILD_CFLAGS += -mgeneral-regs-only \
	$(compat_vdso) $(cc_has_k_constraint)
	KBUILD_CFLAGS += $(call cc-disable-warning, psabi)
	KBUILD_AFLAGS += $(compat_vdso)

	KBUILD_CFLAGS += $(call cc-option,-mabi=lp64)
	KBUILD_AFLAGS += $(call cc-option,-mabi=lp64)

	# Avoid generating .eh_frame* sections.
	KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables
	KBUILD_AFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables

	ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
	prepare: stack_protector_prepare
	stack_protector_prepare: prepare0
	$(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg \
	-mstack-protector-guard-reg=sp_el0 \
	-mstack-protector-guard-offset=$(shell \
	awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
	include/generated/asm-offsets.h))
	endif

	# Ensure that if the compiler supports branch protection we default it
	# off, this will be overridden if we are using branch protection.
	branch-prot-flags-y += $(call cc-option,-mbranch-protection=none)

	ifeq ($(CONFIG_ARM64_PTR_AUTH),y)
	branch-prot-flags-$(CONFIG_CC_HAS_SIGN_RETURN_ADDRESS) := -msign-return-address=all
	# We enable additional protection for leaf functions as there is some
	# narrow potential for ROP protection benefits and no substantial
	# performance impact has been observed.
	ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
	branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protection=pac-ret+leaf+bti
	else
	branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf
	endif
	# -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the
	# compiler to generate them and consequently to break the single image contract
	# we pass it only to the assembler. This option is utilized only in case of non
	# integrated assemblers.
	ifeq ($(CONFIG_AS_HAS_PAC), y)
	asm-arch := armv8.3-a
	endif
	endif

	KBUILD_CFLAGS += $(branch-prot-flags-y)

	ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)
	# make sure to pass the newest target architecture to -march.
	asm-arch := armv8.4-a
	endif

	ifdef asm-arch
	KBUILD_CFLAGS += -Wa,-march=$(asm-arch) \
	-DARM64_ASM_ARCH='"$(asm-arch)"'
	endif

	ifeq ($(CONFIG_SHADOW_CALL_STACK), y)
	KBUILD_CFLAGS += -ffixed-x18
	endif

	ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
	KBUILD_CPPFLAGS += -mbig-endian
	CHECKFLAGS += -D__AARCH64EB__
	# Prefer the baremetal ELF build target, but not all toolchains include
	# it so fall back to the standard linux version if needed.
	KBUILD_LDFLAGS += -EB $(call ld-option, -maarch64elfb, -maarch64linuxb)
	UTS_MACHINE := aarch64_be
	else
	KBUILD_CPPFLAGS += -mlittle-endian
	CHECKFLAGS += -D__AARCH64EL__
	# Same as above, prefer ELF but fall back to linux target if needed.
	KBUILD_LDFLAGS += -EL $(call ld-option, -maarch64elf, -maarch64linux)
	UTS_MACHINE := aarch64
	endif

	CHECKFLAGS += -D__aarch64__

	ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
	KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
	CC_FLAGS_FTRACE := -fpatchable-function-entry=2
	endif

	# Default value
	head-y := arch/arm64/kernel/head.o

	ifeq ($(CONFIG_KASAN_SW_TAGS), y)
	KASAN_SHADOW_SCALE_SHIFT := 4
	else
	KASAN_SHADOW_SCALE_SHIFT := 3
	endif

	KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
	KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
	KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)

	core-y += arch/arm64/
	libs-y := arch/arm64/lib/ $(libs-y)
	libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a

	# Default target when executing plain make
	boot := arch/arm64/boot
	KBUILD_IMAGE := $(boot)/Image.gz

	all: Image.gz


	Image: vmlinux
	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@

	Image.%: Image
	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@

	zinstall install:
	$(Q)$(MAKE) $(build)=$(boot) $@

	PHONY += vdso_install
	vdso_install:
	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
	$(if $(CONFIG_COMPAT_VDSO), \
	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@)

	# We use MRPROPER_FILES and CLEAN_FILES now
	archclean:
	$(Q)$(MAKE) $(clean)=$(boot)

	ifeq ($(KBUILD_EXTMOD),)
	# We need to generate vdso-offsets.h before compiling certain files in kernel/.
	# In order to do that, we should use the archprepare target, but we can't since
	# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
	# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
	# Therefore we need to generate the header after prepare0 has been made, hence
	# this hack.
	prepare: vdso_prepare
	vdso_prepare: prepare0
	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h
	$(if $(CONFIG_COMPAT_VDSO),$(Q)$(MAKE) \
	$(build)=arch/arm64/kernel/vdso32 \
	include/generated/vdso32-offsets.h)
	endif

	define archhelp
	echo '* Image.gz - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
	echo ' Image - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
	echo ' install - Install uncompressed kernel'
	echo ' zinstall - Install compressed kernel'
	echo ' Install using (your) ~/bin/installkernel or'
	echo ' (distribution) /sbin/installkernel or'
	echo ' install to $$(INSTALL_PATH) and run lilo'
	endef