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
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 ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
25LDFLAGS_vmlinux	+= --fix-cortex-a53-843419
26  endif
27endif
28
29cc_has_k_constraint := $(call try-run,echo				\
30	'int main(void) {						\
31		asm volatile("and w0, w0, %w0" :: "K" (4294967295));	\
32		return 0;						\
33	}' | $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1)
34
35ifeq ($(CONFIG_BROKEN_GAS_INST),y)
36$(warning Detected assembler with broken .inst; disassembly will be unreliable)
37endif
38
39KBUILD_CFLAGS	+= -mgeneral-regs-only	\
40		   $(compat_vdso) $(cc_has_k_constraint)
41KBUILD_CFLAGS	+= $(call cc-disable-warning, psabi)
42KBUILD_AFLAGS	+= $(compat_vdso)
43
44KBUILD_CFLAGS	+= $(call cc-option,-mabi=lp64)
45KBUILD_AFLAGS	+= $(call cc-option,-mabi=lp64)
46
47# Avoid generating .eh_frame* sections.
48KBUILD_CFLAGS	+= -fno-asynchronous-unwind-tables -fno-unwind-tables
49KBUILD_AFLAGS	+= -fno-asynchronous-unwind-tables -fno-unwind-tables
50
51ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
52prepare: stack_protector_prepare
53stack_protector_prepare: prepare0
54	$(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg		  \
55				-mstack-protector-guard-reg=sp_el0	  \
56				-mstack-protector-guard-offset=$(shell	  \
57			awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
58					include/generated/asm-offsets.h))
59endif
60
61# Ensure that if the compiler supports branch protection we default it
62# off, this will be overridden if we are using branch protection.
63branch-prot-flags-y += $(call cc-option,-mbranch-protection=none)
64
65ifeq ($(CONFIG_ARM64_PTR_AUTH_KERNEL),y)
66branch-prot-flags-$(CONFIG_CC_HAS_SIGN_RETURN_ADDRESS) := -msign-return-address=all
67# We enable additional protection for leaf functions as there is some
68# narrow potential for ROP protection benefits and no substantial
69# performance impact has been observed.
70ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
71branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protection=pac-ret+leaf+bti
72else
73branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf
74endif
75# -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the
76# compiler to generate them and consequently to break the single image contract
77# we pass it only to the assembler. This option is utilized only in case of non
78# integrated assemblers.
79ifeq ($(CONFIG_AS_HAS_PAC), y)
80asm-arch := armv8.3-a
81endif
82endif
83
84KBUILD_CFLAGS += $(branch-prot-flags-y)
85
86ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)
87# make sure to pass the newest target architecture to -march.
88asm-arch := armv8.4-a
89endif
90
91ifeq ($(CONFIG_AS_HAS_ARMV8_5), y)
92# make sure to pass the newest target architecture to -march.
93asm-arch := armv8.5-a
94endif
95
96ifdef asm-arch
97KBUILD_CFLAGS	+= -Wa,-march=$(asm-arch) \
98		   -DARM64_ASM_ARCH='"$(asm-arch)"'
99endif
100
101ifeq ($(CONFIG_SHADOW_CALL_STACK), y)
102KBUILD_CFLAGS	+= -ffixed-x18
103endif
104
105ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
106KBUILD_CPPFLAGS	+= -mbig-endian
107CHECKFLAGS	+= -D__AARCH64EB__
108# Prefer the baremetal ELF build target, but not all toolchains include
109# it so fall back to the standard linux version if needed.
110KBUILD_LDFLAGS	+= -EB $(call ld-option, -maarch64elfb, -maarch64linuxb -z norelro)
111UTS_MACHINE	:= aarch64_be
112else
113KBUILD_CPPFLAGS	+= -mlittle-endian
114CHECKFLAGS	+= -D__AARCH64EL__
115# Same as above, prefer ELF but fall back to linux target if needed.
116KBUILD_LDFLAGS	+= -EL $(call ld-option, -maarch64elf, -maarch64linux -z norelro)
117UTS_MACHINE	:= aarch64
118endif
119
120ifeq ($(CONFIG_LD_IS_LLD), y)
121KBUILD_LDFLAGS	+= -z norelro
122endif
123
124CHECKFLAGS	+= -D__aarch64__
125
126ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
127  KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
128  CC_FLAGS_FTRACE := -fpatchable-function-entry=2
129endif
130
131# Default value
132head-y		:= arch/arm64/kernel/head.o
133
134ifeq ($(CONFIG_KASAN_SW_TAGS), y)
135KASAN_SHADOW_SCALE_SHIFT := 4
136else ifeq ($(CONFIG_KASAN_GENERIC), y)
137KASAN_SHADOW_SCALE_SHIFT := 3
138endif
139
140KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
141KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
142KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
143
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
160install: install-image := Image
161zinstall: install-image := Image.gz
162install zinstall:
163	$(CONFIG_SHELL) $(srctree)/$(boot)/install.sh $(KERNELRELEASE) \
164	$(boot)/$(install-image) System.map "$(INSTALL_PATH)"
165
166PHONY += vdso_install
167vdso_install:
168	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
169	$(if $(CONFIG_COMPAT_VDSO), \
170		$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@)
171
172archprepare:
173	$(Q)$(MAKE) $(build)=arch/arm64/tools kapi
174ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
175  ifneq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
176	@echo "warning: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum" >&2
177  endif
178endif
179ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS),y)
180  ifneq ($(CONFIG_ARM64_LSE_ATOMICS),y)
181	@echo "warning: LSE atomics not supported by binutils" >&2
182  endif
183endif
184
185ifeq ($(KBUILD_EXTMOD),)
186# We need to generate vdso-offsets.h before compiling certain files in kernel/.
187# In order to do that, we should use the archprepare target, but we can't since
188# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
189# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
190# Therefore we need to generate the header after prepare0 has been made, hence
191# this hack.
192prepare: vdso_prepare
193vdso_prepare: prepare0
194	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso \
195	include/generated/vdso-offsets.h arch/arm64/kernel/vdso/vdso.so
196ifdef CONFIG_COMPAT_VDSO
197	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 \
198	include/generated/vdso32-offsets.h arch/arm64/kernel/vdso32/vdso.so
199endif
200endif
201
202define archhelp
203  echo  '* Image.gz      - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
204  echo  '  Image         - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
205  echo  '  install       - Install uncompressed kernel'
206  echo  '  zinstall      - Install compressed kernel'
207  echo  '                  Install using (your) ~/bin/installkernel or'
208  echo  '                  (distribution) /sbin/installkernel or'
209  echo  '                  install to $$(INSTALL_PATH) and run lilo'
210endef
211