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
14 CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET)
17 ifeq ($(CONFIG_RELOCATABLE), y)
18 # Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour
19 # for relative relocs, since this leads to better Image compression
20 # with the relocation offsets always being zero.
21 LDFLAGS_vmlinux += -shared -Bsymbolic -z notext \
22 $(call ld-option, --no-apply-dynamic-relocs)
25 ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
26 ifeq ($(call ld-option, --fix-cortex-a53-843419),)
27 $(warning ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum)
29 LDFLAGS_vmlinux += --fix-cortex-a53-843419
33 # Check for binutils support for specific extensions
34 lseinstr := $(call as-instr,.arch_extension lse,-DCONFIG_AS_LSE=1)
36 ifeq ($(CONFIG_ARM64_LSE_ATOMICS), y)
38 $(warning LSE atomics not supported by binutils)
42 cc_has_k_constraint := $(call try-run,echo \
44 asm volatile("and w0, w0, %w0" :: "K" (4294967295)); \
46 }' | $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1)
48 ifeq ($(CONFIG_ARM64), y)
49 brokengasinst := $(call as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n,,-DCONFIG_BROKEN_GAS_INST=1)
51 ifneq ($(brokengasinst),)
52 $(warning Detected assembler with broken .inst; disassembly will be unreliable)
56 KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst) \
57 $(compat_vdso) $(cc_has_k_constraint)
58 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
59 KBUILD_CFLAGS += $(call cc-disable-warning, psabi)
60 KBUILD_AFLAGS += $(lseinstr) $(brokengasinst) $(compat_vdso)
62 KBUILD_CFLAGS += $(call cc-option,-mabi=lp64)
63 KBUILD_AFLAGS += $(call cc-option,-mabi=lp64)
65 ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
66 prepare: stack_protector_prepare
67 stack_protector_prepare: prepare0
68 $(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg \
69 -mstack-protector-guard-reg=sp_el0 \
70 -mstack-protector-guard-offset=$(shell \
71 awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
72 include/generated/asm-offsets.h))
75 # Ensure that if the compiler supports branch protection we default it
77 KBUILD_CFLAGS += $(call cc-option,-mbranch-protection=none)
79 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
80 KBUILD_CPPFLAGS += -mbig-endian
81 CHECKFLAGS += -D__AARCH64EB__
83 # Prefer the baremetal ELF build target, but not all toolchains include
84 # it so fall back to the standard linux version if needed.
85 KBUILD_LDFLAGS += -EB $(call ld-option, -maarch64elfb, -maarch64linuxb -z norelro)
86 UTS_MACHINE := aarch64_be
88 KBUILD_CPPFLAGS += -mlittle-endian
89 CHECKFLAGS += -D__AARCH64EL__
91 # Same as above, prefer ELF but fall back to linux target if needed.
92 KBUILD_LDFLAGS += -EL $(call ld-option, -maarch64elf, -maarch64linux -z norelro)
93 UTS_MACHINE := aarch64
96 ifeq ($(CONFIG_LD_IS_LLD), y)
97 KBUILD_LDFLAGS += -z norelro
100 CHECKFLAGS += -D__aarch64__
102 ifeq ($(CONFIG_ARM64_MODULE_PLTS),y)
103 KBUILD_LDS_MODULE += $(srctree)/arch/arm64/kernel/module.lds
107 head-y := arch/arm64/kernel/head.o
109 # The byte offset of the kernel image in RAM from the start of RAM.
110 ifeq ($(CONFIG_ARM64_RANDOMIZE_TEXT_OFFSET), y)
111 TEXT_OFFSET := $(shell awk "BEGIN {srand(); printf \"0x%06x\n\", \
112 int(2 * 1024 * 1024 / (2 ^ $(CONFIG_ARM64_PAGE_SHIFT)) * \
113 rand()) * (2 ^ $(CONFIG_ARM64_PAGE_SHIFT))}")
115 TEXT_OFFSET := 0x00080000
118 ifeq ($(CONFIG_KASAN_SW_TAGS), y)
119 KASAN_SHADOW_SCALE_SHIFT := 4
121 KASAN_SHADOW_SCALE_SHIFT := 3
124 KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
125 KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
126 KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
128 export TEXT_OFFSET GZFLAGS
130 core-y += arch/arm64/
131 libs-y := arch/arm64/lib/ $(libs-y)
132 core-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
134 # Default target when executing plain make
135 boot := arch/arm64/boot
136 KBUILD_IMAGE := $(boot)/Image.gz
142 $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
145 $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
148 $(Q)$(MAKE) $(build)=$(boot) $@
150 PHONY += vdso_install
152 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
153 $(if $(CONFIG_COMPAT_VDSO), \
154 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@)
156 # We use MRPROPER_FILES and CLEAN_FILES now
158 $(Q)$(MAKE) $(clean)=$(boot)
160 ifeq ($(KBUILD_EXTMOD),)
161 # We need to generate vdso-offsets.h before compiling certain files in kernel/.
162 # In order to do that, we should use the archprepare target, but we can't since
163 # asm-offsets.h is included in some files used to generate vdso-offsets.h, and
164 # asm-offsets.h is built in prepare0, for which archprepare is a dependency.
165 # Therefore we need to generate the header after prepare0 has been made, hence
167 prepare: vdso_prepare
168 vdso_prepare: prepare0
169 $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h
170 $(if $(CONFIG_COMPAT_VDSO),$(Q)$(MAKE) \
171 $(build)=arch/arm64/kernel/vdso32 \
172 include/generated/vdso32-offsets.h)
176 echo '* Image.gz - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
177 echo ' Image - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
178 echo ' install - Install uncompressed kernel'
179 echo ' zinstall - Install compressed kernel'
180 echo ' Install using (your) ~/bin/installkernel or'
181 echo ' (distribution) /sbin/installkernel or'
182 echo ' install to $$(INSTALL_PATH) and run lilo'