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 ifneq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
25 $(warning ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum)
27 LDFLAGS_vmlinux += --fix-cortex-a53-843419
31 ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS), y)
32 ifneq ($(CONFIG_ARM64_LSE_ATOMICS), y)
33 $(warning LSE atomics not supported by binutils)
37 cc_has_k_constraint := $(call try-run,echo \
39 asm volatile("and w0, w0, %w0" :: "K" (4294967295)); \
41 }' | $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1)
43 ifeq ($(CONFIG_BROKEN_GAS_INST),y)
44 $(warning Detected assembler with broken .inst; disassembly will be unreliable)
47 KBUILD_CFLAGS += -mgeneral-regs-only \
48 $(compat_vdso) $(cc_has_k_constraint)
49 KBUILD_CFLAGS += $(call cc-disable-warning, psabi)
50 KBUILD_AFLAGS += $(compat_vdso)
52 KBUILD_CFLAGS += $(call cc-option,-mabi=lp64)
53 KBUILD_AFLAGS += $(call cc-option,-mabi=lp64)
55 # Avoid generating .eh_frame* sections.
56 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables
57 KBUILD_AFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables
59 ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
60 prepare: stack_protector_prepare
61 stack_protector_prepare: prepare0
62 $(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg \
63 -mstack-protector-guard-reg=sp_el0 \
64 -mstack-protector-guard-offset=$(shell \
65 awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
66 include/generated/asm-offsets.h))
69 # Ensure that if the compiler supports branch protection we default it
70 # off, this will be overridden if we are using branch protection.
71 branch-prot-flags-y += $(call cc-option,-mbranch-protection=none)
73 ifeq ($(CONFIG_ARM64_PTR_AUTH),y)
74 branch-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.
78 ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
79 branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protection=pac-ret+leaf+bti
81 branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf
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.
87 ifeq ($(CONFIG_AS_HAS_PAC), y)
92 KBUILD_CFLAGS += $(branch-prot-flags-y)
94 ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)
95 # make sure to pass the newest target architecture to -march.
99 ifeq ($(CONFIG_AS_HAS_ARMV8_5), y)
100 # make sure to pass the newest target architecture to -march.
101 asm-arch := armv8.5-a
105 KBUILD_CFLAGS += -Wa,-march=$(asm-arch) \
106 -DARM64_ASM_ARCH='"$(asm-arch)"'
109 ifeq ($(CONFIG_SHADOW_CALL_STACK), y)
110 KBUILD_CFLAGS += -ffixed-x18
113 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
114 KBUILD_CPPFLAGS += -mbig-endian
115 CHECKFLAGS += -D__AARCH64EB__
116 # Prefer the baremetal ELF build target, but not all toolchains include
117 # it so fall back to the standard linux version if needed.
118 KBUILD_LDFLAGS += -EB $(call ld-option, -maarch64elfb, -maarch64linuxb -z norelro)
119 UTS_MACHINE := aarch64_be
121 KBUILD_CPPFLAGS += -mlittle-endian
122 CHECKFLAGS += -D__AARCH64EL__
123 # Same as above, prefer ELF but fall back to linux target if needed.
124 KBUILD_LDFLAGS += -EL $(call ld-option, -maarch64elf, -maarch64linux -z norelro)
125 UTS_MACHINE := aarch64
128 ifeq ($(CONFIG_LD_IS_LLD), y)
129 KBUILD_LDFLAGS += -z norelro
132 CHECKFLAGS += -D__aarch64__
134 ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
135 KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
136 CC_FLAGS_FTRACE := -fpatchable-function-entry=2
140 head-y := arch/arm64/kernel/head.o
142 ifeq ($(CONFIG_KASAN_SW_TAGS), y)
143 KASAN_SHADOW_SCALE_SHIFT := 4
144 else ifeq ($(CONFIG_KASAN_GENERIC), y)
145 KASAN_SHADOW_SCALE_SHIFT := 3
148 KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
149 KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
150 KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
152 core-y += arch/arm64/
153 libs-y := arch/arm64/lib/ $(libs-y)
154 libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
156 # Default target when executing plain make
157 boot := arch/arm64/boot
158 KBUILD_IMAGE := $(boot)/Image.gz
164 $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
167 $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
170 $(Q)$(MAKE) $(build)=$(boot) $@
172 PHONY += vdso_install
174 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
175 $(if $(CONFIG_COMPAT_VDSO), \
176 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@)
179 $(Q)$(MAKE) $(build)=arch/arm64/tools kapi
181 # We use MRPROPER_FILES and CLEAN_FILES now
183 $(Q)$(MAKE) $(clean)=$(boot)
184 $(Q)$(MAKE) $(clean)=arch/arm64/kernel/vdso
185 $(Q)$(MAKE) $(clean)=arch/arm64/kernel/vdso32
187 ifeq ($(KBUILD_EXTMOD),)
188 # We need to generate vdso-offsets.h before compiling certain files in kernel/.
189 # In order to do that, we should use the archprepare target, but we can't since
190 # asm-offsets.h is included in some files used to generate vdso-offsets.h, and
191 # asm-offsets.h is built in prepare0, for which archprepare is a dependency.
192 # Therefore we need to generate the header after prepare0 has been made, hence
194 prepare: vdso_prepare
195 vdso_prepare: prepare0
196 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso \
197 include/generated/vdso-offsets.h arch/arm64/kernel/vdso/vdso.so
198 ifdef CONFIG_COMPAT_VDSO
199 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 \
200 include/generated/vdso32-offsets.h arch/arm64/kernel/vdso32/vdso.so
205 echo '* Image.gz - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
206 echo ' Image - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
207 echo ' install - Install uncompressed kernel'
208 echo ' zinstall - Install compressed kernel'
209 echo ' Install using (your) ~/bin/installkernel or'
210 echo ' (distribution) /sbin/installkernel or'
211 echo ' install to $$(INSTALL_PATH) and run lilo'