xref: /openbmc/linux/arch/arm64/Makefile (revision 2f8be0e5) 
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
14CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET)
15
16ifeq ($(CONFIG_RELOCATABLE), y)
17# Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour
18# for relative relocs, since this leads to better Image compression
19# with the relocation offsets always being zero.
20LDFLAGS_vmlinux		+= -shared -Bsymbolic -z notext -z norelro \
21			$(call ld-option, --no-apply-dynamic-relocs)
22endif
23
24ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
25  ifeq ($(call ld-option, --fix-cortex-a53-843419),)
26$(warning ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum)
27  else
28LDFLAGS_vmlinux	+= --fix-cortex-a53-843419
29  endif
30endif
31
32ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS), y)
33  ifneq ($(CONFIG_ARM64_LSE_ATOMICS), y)
34$(warning LSE atomics not supported by binutils)
35  endif
36endif
37
38cc_has_k_constraint := $(call try-run,echo				\
39	'int main(void) {						\
40		asm volatile("and w0, w0, %w0" :: "K" (4294967295));	\
41		return 0;						\
42	}' | $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1)
43
44ifeq ($(CONFIG_BROKEN_GAS_INST),y)
45$(warning Detected assembler with broken .inst; disassembly will be unreliable)
46endif
47
48KBUILD_CFLAGS	+= -mgeneral-regs-only	\
49		   $(compat_vdso) $(cc_has_k_constraint)
50KBUILD_CFLAGS	+= -fno-asynchronous-unwind-tables
51KBUILD_CFLAGS	+= $(call cc-disable-warning, psabi)
52KBUILD_AFLAGS	+= $(compat_vdso)
53
54KBUILD_CFLAGS	+= $(call cc-option,-mabi=lp64)
55KBUILD_AFLAGS	+= $(call cc-option,-mabi=lp64)
56
57ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
58prepare: stack_protector_prepare
59stack_protector_prepare: prepare0
60	$(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg		  \
61				-mstack-protector-guard-reg=sp_el0	  \
62				-mstack-protector-guard-offset=$(shell	  \
63			awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
64					include/generated/asm-offsets.h))
65endif
66
67# Ensure that if the compiler supports branch protection we default it
68# off, this will be overridden if we are using branch protection.
69branch-prot-flags-y += $(call cc-option,-mbranch-protection=none)
70
71ifeq ($(CONFIG_ARM64_PTR_AUTH),y)
72branch-prot-flags-$(CONFIG_CC_HAS_SIGN_RETURN_ADDRESS) := -msign-return-address=all
73# We enable additional protection for leaf functions as there is some
74# narrow potential for ROP protection benefits and no substantial
75# performance impact has been observed.
76ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
77branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protection=pac-ret+leaf+bti
78else
79branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf
80endif
81# -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the
82# compiler to generate them and consequently to break the single image contract
83# we pass it only to the assembler. This option is utilized only in case of non
84# integrated assemblers.
85ifeq ($(CONFIG_AS_HAS_PAC), y)
86asm-arch := armv8.3-a
87endif
88endif
89
90KBUILD_CFLAGS += $(branch-prot-flags-y)
91
92ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)
93# make sure to pass the newest target architecture to -march.
94asm-arch := armv8.4-a
95endif
96
97ifdef asm-arch
98KBUILD_CFLAGS	+= -Wa,-march=$(asm-arch) \
99		   -DARM64_ASM_ARCH='"$(asm-arch)"'
100endif
101
102ifeq ($(CONFIG_SHADOW_CALL_STACK), y)
103KBUILD_CFLAGS	+= -ffixed-x18
104endif
105
106ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
107KBUILD_CPPFLAGS	+= -mbig-endian
108CHECKFLAGS	+= -D__AARCH64EB__
109# Prefer the baremetal ELF build target, but not all toolchains include
110# it so fall back to the standard linux version if needed.
111KBUILD_LDFLAGS	+= -EB $(call ld-option, -maarch64elfb, -maarch64linuxb)
112UTS_MACHINE	:= aarch64_be
113else
114KBUILD_CPPFLAGS	+= -mlittle-endian
115CHECKFLAGS	+= -D__AARCH64EL__
116# Same as above, prefer ELF but fall back to linux target if needed.
117KBUILD_LDFLAGS	+= -EL $(call ld-option, -maarch64elf, -maarch64linux)
118UTS_MACHINE	:= aarch64
119endif
120
121CHECKFLAGS	+= -D__aarch64__
122
123ifeq ($(CONFIG_ARM64_MODULE_PLTS),y)
124KBUILD_LDS_MODULE	+= $(srctree)/arch/arm64/kernel/module.lds
125endif
126
127ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
128  KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
129  CC_FLAGS_FTRACE := -fpatchable-function-entry=2
130endif
131
132# Default value
133head-y		:= arch/arm64/kernel/head.o
134
135# The byte offset of the kernel image in RAM from the start of RAM.
136TEXT_OFFSET := 0x0
137
138ifeq ($(CONFIG_KASAN_SW_TAGS), y)
139KASAN_SHADOW_SCALE_SHIFT := 4
140else
141KASAN_SHADOW_SCALE_SHIFT := 3
142endif
143
144KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
145KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
146KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
147
148export	TEXT_OFFSET
149
150core-y		+= arch/arm64/
151libs-y		:= arch/arm64/lib/ $(libs-y)
152libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
153
154# Default target when executing plain make
155boot		:= arch/arm64/boot
156KBUILD_IMAGE	:= $(boot)/Image.gz
157
158all:	Image.gz
159
160
161Image: vmlinux
162	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
163
164Image.%: Image
165	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
166
167zinstall install:
168	$(Q)$(MAKE) $(build)=$(boot) $@
169
170PHONY += vdso_install
171vdso_install:
172	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
173	$(if $(CONFIG_COMPAT_VDSO), \
174		$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@)
175
176# We use MRPROPER_FILES and CLEAN_FILES now
177archclean:
178	$(Q)$(MAKE) $(clean)=$(boot)
179
180ifeq ($(KBUILD_EXTMOD),)
181# We need to generate vdso-offsets.h before compiling certain files in kernel/.
182# In order to do that, we should use the archprepare target, but we can't since
183# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
184# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
185# Therefore we need to generate the header after prepare0 has been made, hence
186# this hack.
187prepare: vdso_prepare
188vdso_prepare: prepare0
189	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h
190	$(if $(CONFIG_COMPAT_VDSO),$(Q)$(MAKE) \
191		$(build)=arch/arm64/kernel/vdso32  \
192		include/generated/vdso32-offsets.h)
193endif
194
195define archhelp
196  echo  '* Image.gz      - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
197  echo  '  Image         - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
198  echo  '  install       - Install uncompressed kernel'
199  echo  '  zinstall      - Install compressed kernel'
200  echo  '                  Install using (your) ~/bin/installkernel or'
201  echo  '                  (distribution) /sbin/installkernel or'
202  echo  '                  install to $$(INSTALL_PATH) and run lilo'
203endef
204