4 # This file is included by the global makefile so that you can add your own
5 # architecture-specific flags and dependencies.
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
11 # Copyright (C) 1995-2001 by Russell King
13 LDFLAGS_vmlinux :=--no-undefined -X
15 ifeq ($(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.
19 LDFLAGS_vmlinux += -shared -Bsymbolic -z notext \
20 $(call ld-option, --no-apply-dynamic-relocs)
23 ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
24 ifeq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
25 LDFLAGS_vmlinux += --fix-cortex-a53-843419
29 cc_has_k_constraint := $(call try-run,echo \
31 asm volatile("and w0, w0, %w0" :: "K" (4294967295)); \
33 }' | $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1)
35 ifeq ($(CONFIG_BROKEN_GAS_INST),y)
36 $(warning Detected assembler with broken .inst; disassembly will be unreliable)
39 KBUILD_CFLAGS += -mgeneral-regs-only \
40 $(compat_vdso) $(cc_has_k_constraint)
41 KBUILD_CFLAGS += $(call cc-disable-warning, psabi)
42 KBUILD_AFLAGS += $(compat_vdso)
44 KBUILD_CFLAGS += $(call cc-option,-mabi=lp64)
45 KBUILD_AFLAGS += $(call cc-option,-mabi=lp64)
47 # Avoid generating .eh_frame* sections.
48 ifneq ($(CONFIG_UNWIND_TABLES),y)
49 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables
50 KBUILD_AFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables
52 KBUILD_CFLAGS += -fasynchronous-unwind-tables
53 KBUILD_AFLAGS += -fasynchronous-unwind-tables
56 ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
57 prepare: stack_protector_prepare
58 stack_protector_prepare: prepare0
59 $(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg \
60 -mstack-protector-guard-reg=sp_el0 \
61 -mstack-protector-guard-offset=$(shell \
62 awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
63 include/generated/asm-offsets.h))
66 # Ensure that if the compiler supports branch protection we default it
67 # off, this will be overridden if we are using branch protection.
68 branch-prot-flags-y += $(call cc-option,-mbranch-protection=none)
70 ifeq ($(CONFIG_ARM64_PTR_AUTH_KERNEL),y)
71 branch-prot-flags-$(CONFIG_CC_HAS_SIGN_RETURN_ADDRESS) := -msign-return-address=all
72 # We enable additional protection for leaf functions as there is some
73 # narrow potential for ROP protection benefits and no substantial
74 # performance impact has been observed.
75 PACRET-y := pac-ret+leaf
77 # Using a shadow call stack in leaf functions is too costly, so avoid PAC there
78 # as well when we may be patching PAC into SCS
79 PACRET-$(CONFIG_UNWIND_PATCH_PAC_INTO_SCS) := pac-ret
81 ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
82 branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protection=$(PACRET-y)+bti
84 branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=$(PACRET-y)
88 KBUILD_CFLAGS += $(branch-prot-flags-y)
90 # Tell the assembler to support instructions from the latest target
93 # For non-integrated assemblers we'll pass this on the command line, and for
94 # integrated assemblers we'll define ARM64_ASM_ARCH and ARM64_ASM_PREAMBLE for
97 # We cannot pass the same arch flag to the compiler as this would allow it to
98 # freely generate instructions which are not supported by earlier architecture
99 # versions, which would prevent a single kernel image from working on earlier
101 ifeq ($(CONFIG_AS_HAS_ARMV8_5), y)
102 asm-arch := armv8.5-a
103 else ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)
104 asm-arch := armv8.4-a
105 else ifeq ($(CONFIG_AS_HAS_ARMV8_3), y)
106 asm-arch := armv8.3-a
107 else ifeq ($(CONFIG_AS_HAS_ARMV8_2), y)
108 asm-arch := armv8.2-a
112 KBUILD_CFLAGS += -Wa,-march=$(asm-arch) \
113 -DARM64_ASM_ARCH='"$(asm-arch)"'
116 ifeq ($(CONFIG_SHADOW_CALL_STACK), y)
117 KBUILD_CFLAGS += -ffixed-x18
120 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
121 KBUILD_CPPFLAGS += -mbig-endian
122 CHECKFLAGS += -D__AARCH64EB__
123 # Prefer the baremetal ELF build target, but not all toolchains include
124 # it so fall back to the standard linux version if needed.
125 KBUILD_LDFLAGS += -EB $(call ld-option, -maarch64elfb, -maarch64linuxb -z norelro)
126 UTS_MACHINE := aarch64_be
128 KBUILD_CPPFLAGS += -mlittle-endian
129 CHECKFLAGS += -D__AARCH64EL__
130 # Same as above, prefer ELF but fall back to linux target if needed.
131 KBUILD_LDFLAGS += -EL $(call ld-option, -maarch64elf, -maarch64linux -z norelro)
132 UTS_MACHINE := aarch64
135 ifeq ($(CONFIG_LD_IS_LLD), y)
136 KBUILD_LDFLAGS += -z norelro
139 CHECKFLAGS += -D__aarch64__
141 ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_ARGS),y)
142 KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
143 CC_FLAGS_FTRACE := -fpatchable-function-entry=2
146 ifeq ($(CONFIG_KASAN_SW_TAGS), y)
147 KASAN_SHADOW_SCALE_SHIFT := 4
148 else ifeq ($(CONFIG_KASAN_GENERIC), y)
149 KASAN_SHADOW_SCALE_SHIFT := 3
152 KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
153 KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
154 KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
156 libs-y := arch/arm64/lib/ $(libs-y)
157 libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
159 # Default target when executing plain make
160 boot := arch/arm64/boot
162 ifeq ($(CONFIG_EFI_ZBOOT),)
163 KBUILD_IMAGE := $(boot)/Image.gz
165 KBUILD_IMAGE := $(boot)/vmlinuz.efi
168 all: $(notdir $(KBUILD_IMAGE))
171 Image vmlinuz.efi: vmlinux
172 $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
175 $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
177 install: KBUILD_IMAGE := $(boot)/Image
181 PHONY += vdso_install
183 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
184 $(if $(CONFIG_COMPAT_VDSO), \
185 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@)
188 $(Q)$(MAKE) $(build)=arch/arm64/tools kapi
189 ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
190 ifneq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
191 @echo "warning: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum" >&2
194 ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS),y)
195 ifneq ($(CONFIG_ARM64_LSE_ATOMICS),y)
196 @echo "warning: LSE atomics not supported by binutils" >&2
200 ifeq ($(KBUILD_EXTMOD),)
201 # We need to generate vdso-offsets.h before compiling certain files in kernel/.
202 # In order to do that, we should use the archprepare target, but we can't since
203 # asm-offsets.h is included in some files used to generate vdso-offsets.h, and
204 # asm-offsets.h is built in prepare0, for which archprepare is a dependency.
205 # Therefore we need to generate the header after prepare0 has been made, hence
207 prepare: vdso_prepare
208 vdso_prepare: prepare0
209 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso \
210 include/generated/vdso-offsets.h arch/arm64/kernel/vdso/vdso.so
211 ifdef CONFIG_COMPAT_VDSO
212 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 \
213 include/generated/vdso32-offsets.h arch/arm64/kernel/vdso32/vdso.so
218 echo '* Image.gz - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
219 echo ' Image - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
220 echo ' install - Install uncompressed kernel'
221 echo ' zinstall - Install compressed kernel'
222 echo ' Install using (your) ~/bin/installkernel or'
223 echo ' (distribution) /sbin/installkernel or'
224 echo ' install to $$(INSTALL_PATH) and run lilo'