xref: /openbmc/linux/arch/arm64/Makefile (revision b296a6d5)
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 -z norelro \
20			$(call ld-option, --no-apply-dynamic-relocs)
21endif
22
23ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
24  ifeq ($(call ld-option, --fix-cortex-a53-843419),)
25$(warning ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum)
26  else
27LDFLAGS_vmlinux	+= --fix-cortex-a53-843419
28  endif
29endif
30
31# We never want expected sections to be placed heuristically by the
32# linker. All sections should be explicitly named in the linker script.
33LDFLAGS_vmlinux += $(call ld-option, --orphan-handling=warn)
34
35ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS), y)
36  ifneq ($(CONFIG_ARM64_LSE_ATOMICS), y)
37$(warning LSE atomics not supported by binutils)
38  endif
39endif
40
41cc_has_k_constraint := $(call try-run,echo				\
42	'int main(void) {						\
43		asm volatile("and w0, w0, %w0" :: "K" (4294967295));	\
44		return 0;						\
45	}' | $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1)
46
47ifeq ($(CONFIG_BROKEN_GAS_INST),y)
48$(warning Detected assembler with broken .inst; disassembly will be unreliable)
49endif
50
51KBUILD_CFLAGS	+= -mgeneral-regs-only	\
52		   $(compat_vdso) $(cc_has_k_constraint)
53KBUILD_CFLAGS	+= $(call cc-disable-warning, psabi)
54KBUILD_AFLAGS	+= $(compat_vdso)
55
56KBUILD_CFLAGS	+= $(call cc-option,-mabi=lp64)
57KBUILD_AFLAGS	+= $(call cc-option,-mabi=lp64)
58
59# Avoid generating .eh_frame* sections.
60KBUILD_CFLAGS	+= -fno-asynchronous-unwind-tables -fno-unwind-tables
61KBUILD_AFLAGS	+= -fno-asynchronous-unwind-tables -fno-unwind-tables
62
63ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
64prepare: stack_protector_prepare
65stack_protector_prepare: prepare0
66	$(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg		  \
67				-mstack-protector-guard-reg=sp_el0	  \
68				-mstack-protector-guard-offset=$(shell	  \
69			awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
70					include/generated/asm-offsets.h))
71endif
72
73# Ensure that if the compiler supports branch protection we default it
74# off, this will be overridden if we are using branch protection.
75branch-prot-flags-y += $(call cc-option,-mbranch-protection=none)
76
77ifeq ($(CONFIG_ARM64_PTR_AUTH),y)
78branch-prot-flags-$(CONFIG_CC_HAS_SIGN_RETURN_ADDRESS) := -msign-return-address=all
79# We enable additional protection for leaf functions as there is some
80# narrow potential for ROP protection benefits and no substantial
81# performance impact has been observed.
82ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
83branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protection=pac-ret+leaf+bti
84else
85branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf
86endif
87# -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the
88# compiler to generate them and consequently to break the single image contract
89# we pass it only to the assembler. This option is utilized only in case of non
90# integrated assemblers.
91ifeq ($(CONFIG_AS_HAS_PAC), y)
92asm-arch := armv8.3-a
93endif
94endif
95
96KBUILD_CFLAGS += $(branch-prot-flags-y)
97
98ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)
99# make sure to pass the newest target architecture to -march.
100asm-arch := armv8.4-a
101endif
102
103ifdef asm-arch
104KBUILD_CFLAGS	+= -Wa,-march=$(asm-arch) \
105		   -DARM64_ASM_ARCH='"$(asm-arch)"'
106endif
107
108ifeq ($(CONFIG_SHADOW_CALL_STACK), y)
109KBUILD_CFLAGS	+= -ffixed-x18
110endif
111
112ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
113KBUILD_CPPFLAGS	+= -mbig-endian
114CHECKFLAGS	+= -D__AARCH64EB__
115# Prefer the baremetal ELF build target, but not all toolchains include
116# it so fall back to the standard linux version if needed.
117KBUILD_LDFLAGS	+= -EB $(call ld-option, -maarch64elfb, -maarch64linuxb)
118UTS_MACHINE	:= aarch64_be
119else
120KBUILD_CPPFLAGS	+= -mlittle-endian
121CHECKFLAGS	+= -D__AARCH64EL__
122# Same as above, prefer ELF but fall back to linux target if needed.
123KBUILD_LDFLAGS	+= -EL $(call ld-option, -maarch64elf, -maarch64linux)
124UTS_MACHINE	:= aarch64
125endif
126
127CHECKFLAGS	+= -D__aarch64__
128
129ifeq ($(CONFIG_ARM64_MODULE_PLTS),y)
130KBUILD_LDS_MODULE	+= $(srctree)/arch/arm64/kernel/module.lds
131endif
132
133ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
134  KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
135  CC_FLAGS_FTRACE := -fpatchable-function-entry=2
136endif
137
138# Default value
139head-y		:= arch/arm64/kernel/head.o
140
141ifeq ($(CONFIG_KASAN_SW_TAGS), y)
142KASAN_SHADOW_SCALE_SHIFT := 4
143else
144KASAN_SHADOW_SCALE_SHIFT := 3
145endif
146
147KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
148KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
149KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
150
151core-y		+= arch/arm64/
152libs-y		:= arch/arm64/lib/ $(libs-y)
153libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
154
155# Default target when executing plain make
156boot		:= arch/arm64/boot
157KBUILD_IMAGE	:= $(boot)/Image.gz
158
159all:	Image.gz
160
161
162Image: vmlinux
163	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
164
165Image.%: Image
166	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
167
168zinstall install:
169	$(Q)$(MAKE) $(build)=$(boot) $@
170
171PHONY += vdso_install
172vdso_install:
173	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
174	$(if $(CONFIG_COMPAT_VDSO), \
175		$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@)
176
177# We use MRPROPER_FILES and CLEAN_FILES now
178archclean:
179	$(Q)$(MAKE) $(clean)=$(boot)
180
181ifeq ($(KBUILD_EXTMOD),)
182# We need to generate vdso-offsets.h before compiling certain files in kernel/.
183# In order to do that, we should use the archprepare target, but we can't since
184# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
185# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
186# Therefore we need to generate the header after prepare0 has been made, hence
187# this hack.
188prepare: vdso_prepare
189vdso_prepare: prepare0
190	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h
191	$(if $(CONFIG_COMPAT_VDSO),$(Q)$(MAKE) \
192		$(build)=arch/arm64/kernel/vdso32  \
193		include/generated/vdso32-offsets.h)
194endif
195
196define archhelp
197  echo  '* Image.gz      - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
198  echo  '  Image         - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
199  echo  '  install       - Install uncompressed kernel'
200  echo  '  zinstall      - Install compressed kernel'
201  echo  '                  Install using (your) ~/bin/installkernel or'
202  echo  '                  (distribution) /sbin/installkernel or'
203  echo  '                  install to $$(INSTALL_PATH) and run lilo'
204endef
205