xref: /openbmc/linux/arch/arm64/Makefile (revision da1d9caf) 
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
61ifeq ($(CONFIG_AS_HAS_ARMV8_2), y)
62# make sure to pass the newest target architecture to -march.
63asm-arch := armv8.2-a
64endif
65
66# Ensure that if the compiler supports branch protection we default it
67# off, this will be overridden if we are using branch protection.
68branch-prot-flags-y += $(call cc-option,-mbranch-protection=none)
69
70ifeq ($(CONFIG_ARM64_PTR_AUTH_KERNEL),y)
71branch-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.
75ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
76branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protection=pac-ret+leaf+bti
77else
78branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf
79endif
80# -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the
81# compiler to generate them and consequently to break the single image contract
82# we pass it only to the assembler. This option is utilized only in case of non
83# integrated assemblers.
84ifeq ($(CONFIG_AS_HAS_PAC), y)
85asm-arch := armv8.3-a
86endif
87endif
88
89KBUILD_CFLAGS += $(branch-prot-flags-y)
90
91ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)
92# make sure to pass the newest target architecture to -march.
93asm-arch := armv8.4-a
94endif
95
96ifeq ($(CONFIG_AS_HAS_ARMV8_5), y)
97# make sure to pass the newest target architecture to -march.
98asm-arch := armv8.5-a
99endif
100
101ifdef asm-arch
102KBUILD_CFLAGS	+= -Wa,-march=$(asm-arch) \
103		   -DARM64_ASM_ARCH='"$(asm-arch)"'
104endif
105
106ifeq ($(CONFIG_SHADOW_CALL_STACK), y)
107KBUILD_CFLAGS	+= -ffixed-x18
108endif
109
110ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
111KBUILD_CPPFLAGS	+= -mbig-endian
112CHECKFLAGS	+= -D__AARCH64EB__
113# Prefer the baremetal ELF build target, but not all toolchains include
114# it so fall back to the standard linux version if needed.
115KBUILD_LDFLAGS	+= -EB $(call ld-option, -maarch64elfb, -maarch64linuxb -z norelro)
116UTS_MACHINE	:= aarch64_be
117else
118KBUILD_CPPFLAGS	+= -mlittle-endian
119CHECKFLAGS	+= -D__AARCH64EL__
120# Same as above, prefer ELF but fall back to linux target if needed.
121KBUILD_LDFLAGS	+= -EL $(call ld-option, -maarch64elf, -maarch64linux -z norelro)
122UTS_MACHINE	:= aarch64
123endif
124
125ifeq ($(CONFIG_LD_IS_LLD), y)
126KBUILD_LDFLAGS	+= -z norelro
127endif
128
129CHECKFLAGS	+= -D__aarch64__
130
131ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
132  KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
133  CC_FLAGS_FTRACE := -fpatchable-function-entry=2
134endif
135
136# Default value
137head-y		:= arch/arm64/kernel/head.o
138
139ifeq ($(CONFIG_KASAN_SW_TAGS), y)
140KASAN_SHADOW_SCALE_SHIFT := 4
141else ifeq ($(CONFIG_KASAN_GENERIC), y)
142KASAN_SHADOW_SCALE_SHIFT := 3
143endif
144
145KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
146KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
147KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
148
149libs-y		:= arch/arm64/lib/ $(libs-y)
150libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
151
152# Default target when executing plain make
153boot		:= arch/arm64/boot
154KBUILD_IMAGE	:= $(boot)/Image.gz
155
156all:	Image.gz
157
158
159Image: vmlinux
160	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
161
162Image.%: Image
163	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
164
165install: KBUILD_IMAGE := $(boot)/Image
166install zinstall:
167	$(call cmd,install)
168
169PHONY += vdso_install
170vdso_install:
171	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
172	$(if $(CONFIG_COMPAT_VDSO), \
173		$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@)
174
175archprepare:
176	$(Q)$(MAKE) $(build)=arch/arm64/tools kapi
177ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
178  ifneq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
179	@echo "warning: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum" >&2
180  endif
181endif
182ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS),y)
183  ifneq ($(CONFIG_ARM64_LSE_ATOMICS),y)
184	@echo "warning: LSE atomics not supported by binutils" >&2
185  endif
186endif
187
188ifeq ($(KBUILD_EXTMOD),)
189# We need to generate vdso-offsets.h before compiling certain files in kernel/.
190# In order to do that, we should use the archprepare target, but we can't since
191# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
192# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
193# Therefore we need to generate the header after prepare0 has been made, hence
194# this hack.
195prepare: vdso_prepare
196vdso_prepare: prepare0
197	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso \
198	include/generated/vdso-offsets.h arch/arm64/kernel/vdso/vdso.so
199ifdef CONFIG_COMPAT_VDSO
200	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 \
201	include/generated/vdso32-offsets.h arch/arm64/kernel/vdso32/vdso.so
202endif
203endif
204
205define archhelp
206  echo  '* Image.gz      - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
207  echo  '  Image         - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
208  echo  '  install       - Install uncompressed kernel'
209  echo  '  zinstall      - Install compressed kernel'
210  echo  '                  Install using (your) ~/bin/installkernel or'
211  echo  '                  (distribution) /sbin/installkernel or'
212  echo  '                  install to $$(INSTALL_PATH) and run lilo'
213endef
214