1# SPDX-License-Identifier: GPL-2.0 2# Unified Makefile for i386 and x86_64 3 4# select defconfig based on actual architecture 5ifeq ($(ARCH),x86) 6 ifeq ($(shell uname -m | sed -e 's/i.86/i386/'),i386) 7 KBUILD_DEFCONFIG := i386_defconfig 8 else 9 KBUILD_DEFCONFIG := x86_64_defconfig 10 endif 11else 12 KBUILD_DEFCONFIG := $(ARCH)_defconfig 13endif 14 15ifdef CONFIG_CC_IS_GCC 16RETPOLINE_CFLAGS := $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register) 17RETPOLINE_VDSO_CFLAGS := $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register) 18endif 19ifdef CONFIG_CC_IS_CLANG 20RETPOLINE_CFLAGS := -mretpoline-external-thunk 21RETPOLINE_VDSO_CFLAGS := -mretpoline 22endif 23RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch-cs-prefix) 24 25ifdef CONFIG_RETHUNK 26RETHUNK_CFLAGS := -mfunction-return=thunk-extern 27RETPOLINE_CFLAGS += $(RETHUNK_CFLAGS) 28endif 29 30export RETHUNK_CFLAGS 31export RETPOLINE_CFLAGS 32export RETPOLINE_VDSO_CFLAGS 33 34# For gcc stack alignment is specified with -mpreferred-stack-boundary, 35# clang has the option -mstack-alignment for that purpose. 36ifneq ($(call cc-option, -mpreferred-stack-boundary=4),) 37 cc_stack_align4 := -mpreferred-stack-boundary=2 38 cc_stack_align8 := -mpreferred-stack-boundary=3 39else ifneq ($(call cc-option, -mstack-alignment=16),) 40 cc_stack_align4 := -mstack-alignment=4 41 cc_stack_align8 := -mstack-alignment=8 42endif 43 44# How to compile the 16-bit code. Note we always compile for -march=i386; 45# that way we can complain to the user if the CPU is insufficient. 46REALMODE_CFLAGS := -m16 -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \ 47 -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ 48 -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ 49 -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none) 50 51REALMODE_CFLAGS += -ffreestanding 52REALMODE_CFLAGS += -fno-stack-protector 53REALMODE_CFLAGS += -Wno-address-of-packed-member 54REALMODE_CFLAGS += $(cc_stack_align4) 55REALMODE_CFLAGS += $(CLANG_FLAGS) 56export REALMODE_CFLAGS 57 58# BITS is used as extension for files which are available in a 32 bit 59# and a 64 bit version to simplify shared Makefiles. 60# e.g.: obj-y += foo_$(BITS).o 61export BITS 62 63# 64# Prevent GCC from generating any FP code by mistake. 65# 66# This must happen before we try the -mpreferred-stack-boundary, see: 67# 68# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383 69# 70KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx 71KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2 72 73ifeq ($(CONFIG_X86_KERNEL_IBT),y) 74# 75# Kernel IBT has S_CET.NOTRACK_EN=0, as such the compilers must not generate 76# NOTRACK prefixes. Current generation compilers unconditionally employ NOTRACK 77# for jump-tables, as such, disable jump-tables for now. 78# 79# (jump-tables are implicitly disabled by RETPOLINE) 80# 81# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104816 82# 83KBUILD_CFLAGS += $(call cc-option,-fcf-protection=branch -fno-jump-tables) 84else 85KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none) 86endif 87 88ifeq ($(CONFIG_X86_32),y) 89 BITS := 32 90 UTS_MACHINE := i386 91 CHECKFLAGS += -D__i386__ 92 93 KBUILD_AFLAGS += -m32 94 KBUILD_CFLAGS += -m32 95 96 KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return 97 98 # Never want PIC in a 32-bit kernel, prevent breakage with GCC built 99 # with nonstandard options 100 KBUILD_CFLAGS += -fno-pic 101 102 # Align the stack to the register width instead of using the default 103 # alignment of 16 bytes. This reduces stack usage and the number of 104 # alignment instructions. 105 KBUILD_CFLAGS += $(cc_stack_align4) 106 107 # CPU-specific tuning. Anything which can be shared with UML should go here. 108 include $(srctree)/arch/x86/Makefile_32.cpu 109 KBUILD_CFLAGS += $(cflags-y) 110 111 # temporary until string.h is fixed 112 KBUILD_CFLAGS += -ffreestanding 113 114 ifeq ($(CONFIG_STACKPROTECTOR),y) 115 ifeq ($(CONFIG_SMP),y) 116 KBUILD_CFLAGS += -mstack-protector-guard-reg=fs \ 117 -mstack-protector-guard-symbol=__ref_stack_chk_guard 118 else 119 KBUILD_CFLAGS += -mstack-protector-guard=global 120 endif 121 endif 122else 123 BITS := 64 124 UTS_MACHINE := x86_64 125 CHECKFLAGS += -D__x86_64__ 126 127 KBUILD_AFLAGS += -m64 128 KBUILD_CFLAGS += -m64 129 130 # Align jump targets to 1 byte, not the default 16 bytes: 131 KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1) 132 133 # Pack loops tightly as well: 134 KBUILD_CFLAGS += $(call cc-option,-falign-loops=1) 135 136 # Don't autogenerate traditional x87 instructions 137 KBUILD_CFLAGS += -mno-80387 138 KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387) 139 140 # By default gcc and clang use a stack alignment of 16 bytes for x86. 141 # However the standard kernel entry on x86-64 leaves the stack on an 142 # 8-byte boundary. If the compiler isn't informed about the actual 143 # alignment it will generate extra alignment instructions for the 144 # default alignment which keep the stack *mis*aligned. 145 # Furthermore an alignment to the register width reduces stack usage 146 # and the number of alignment instructions. 147 KBUILD_CFLAGS += $(cc_stack_align8) 148 149 # Use -mskip-rax-setup if supported. 150 KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup) 151 152 # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu) 153 cflags-$(CONFIG_MK8) += -march=k8 154 cflags-$(CONFIG_MPSC) += -march=nocona 155 cflags-$(CONFIG_MCORE2) += -march=core2 156 cflags-$(CONFIG_MATOM) += -march=atom 157 cflags-$(CONFIG_GENERIC_CPU) += -mtune=generic 158 KBUILD_CFLAGS += $(cflags-y) 159 160 rustflags-$(CONFIG_MK8) += -Ctarget-cpu=k8 161 rustflags-$(CONFIG_MPSC) += -Ctarget-cpu=nocona 162 rustflags-$(CONFIG_MCORE2) += -Ctarget-cpu=core2 163 rustflags-$(CONFIG_MATOM) += -Ctarget-cpu=atom 164 rustflags-$(CONFIG_GENERIC_CPU) += -Ztune-cpu=generic 165 KBUILD_RUSTFLAGS += $(rustflags-y) 166 167 KBUILD_CFLAGS += -mno-red-zone 168 KBUILD_CFLAGS += -mcmodel=kernel 169 KBUILD_RUSTFLAGS += -Cno-redzone=y 170 KBUILD_RUSTFLAGS += -Ccode-model=kernel 171endif 172 173# 174# If the function graph tracer is used with mcount instead of fentry, 175# '-maccumulate-outgoing-args' is needed to prevent a GCC bug 176# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109) 177# 178ifdef CONFIG_FUNCTION_GRAPH_TRACER 179 ifndef CONFIG_HAVE_FENTRY 180 ACCUMULATE_OUTGOING_ARGS := 1 181 endif 182endif 183 184ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1) 185 # This compiler flag is not supported by Clang: 186 KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,) 187endif 188 189# Workaround for a gcc prelease that unfortunately was shipped in a suse release 190KBUILD_CFLAGS += -Wno-sign-compare 191# 192KBUILD_CFLAGS += -fno-asynchronous-unwind-tables 193 194# Avoid indirect branches in kernel to deal with Spectre 195ifdef CONFIG_RETPOLINE 196 KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) 197 # Additionally, avoid generating expensive indirect jumps which 198 # are subject to retpolines for small number of switch cases. 199 # clang turns off jump table generation by default when under 200 # retpoline builds, however, gcc does not for x86. This has 201 # only been fixed starting from gcc stable version 8.4.0 and 202 # onwards, but not for older ones. See gcc bug #86952. 203 ifndef CONFIG_CC_IS_CLANG 204 KBUILD_CFLAGS += -fno-jump-tables 205 endif 206endif 207 208ifdef CONFIG_SLS 209 KBUILD_CFLAGS += -mharden-sls=all 210endif 211 212ifdef CONFIG_CALL_PADDING 213PADDING_CFLAGS := -fpatchable-function-entry=$(CONFIG_FUNCTION_PADDING_BYTES),$(CONFIG_FUNCTION_PADDING_BYTES) 214KBUILD_CFLAGS += $(PADDING_CFLAGS) 215export PADDING_CFLAGS 216endif 217 218KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE) 219 220ifdef CONFIG_LTO_CLANG 221ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y) 222KBUILD_LDFLAGS += -plugin-opt=-stack-alignment=$(if $(CONFIG_X86_32),4,8) 223endif 224endif 225 226ifdef CONFIG_X86_NEED_RELOCS 227LDFLAGS_vmlinux := --emit-relocs --discard-none 228else 229LDFLAGS_vmlinux := 230endif 231 232# 233# The 64-bit kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to 234# the linker to force 2MB page size regardless of the default page size used 235# by the linker. 236# 237ifdef CONFIG_X86_64 238LDFLAGS_vmlinux += -z max-page-size=0x200000 239endif 240 241 242archscripts: scripts_basic 243 $(Q)$(MAKE) $(build)=arch/x86/tools relocs 244 245### 246# Syscall table generation 247 248archheaders: 249 $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all 250 251### 252# Kernel objects 253 254libs-y += arch/x86/lib/ 255 256# drivers-y are linked after core-y 257drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/ 258drivers-$(CONFIG_PCI) += arch/x86/pci/ 259 260# suspend and hibernation support 261drivers-$(CONFIG_PM) += arch/x86/power/ 262 263drivers-$(CONFIG_FB_CORE) += arch/x86/video/ 264 265#### 266# boot loader support. Several targets are kept for legacy purposes 267 268boot := arch/x86/boot 269 270BOOT_TARGETS = bzdisk fdimage fdimage144 fdimage288 hdimage isoimage 271 272PHONY += bzImage $(BOOT_TARGETS) 273 274# Default kernel to build 275all: bzImage 276 277# KBUILD_IMAGE specify target image being built 278KBUILD_IMAGE := $(boot)/bzImage 279 280bzImage: vmlinux 281ifeq ($(CONFIG_X86_DECODER_SELFTEST),y) 282 $(Q)$(MAKE) $(build)=arch/x86/tools posttest 283endif 284 $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE) 285 $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot 286 $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@ 287 288$(BOOT_TARGETS): vmlinux 289 $(Q)$(MAKE) $(build)=$(boot) $@ 290 291PHONY += install 292install: 293 $(call cmd,install) 294 295vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg 296vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg 297vdso-install-$(CONFIG_X86_32) += arch/x86/entry/vdso/vdso32.so.dbg 298vdso-install-$(CONFIG_IA32_EMULATION) += arch/x86/entry/vdso/vdso32.so.dbg 299 300archprepare: checkbin 301checkbin: 302ifdef CONFIG_RETPOLINE 303ifeq ($(RETPOLINE_CFLAGS),) 304 @echo "You are building kernel with non-retpoline compiler." >&2 305 @echo "Please update your compiler." >&2 306 @false 307endif 308endif 309 310ifdef CONFIG_UNWINDER_ORC 311orc_hash_h := arch/$(SRCARCH)/include/generated/asm/orc_hash.h 312orc_hash_sh := $(srctree)/scripts/orc_hash.sh 313targets += $(orc_hash_h) 314quiet_cmd_orc_hash = GEN $@ 315 cmd_orc_hash = mkdir -p $(dir $@); \ 316 $(CONFIG_SHELL) $(orc_hash_sh) < $< > $@ 317$(orc_hash_h): $(srctree)/arch/x86/include/asm/orc_types.h $(orc_hash_sh) FORCE 318 $(call if_changed,orc_hash) 319archprepare: $(orc_hash_h) 320endif 321 322archclean: 323 $(Q)rm -rf $(objtree)/arch/i386 324 $(Q)rm -rf $(objtree)/arch/x86_64 325 326define archhelp 327 echo '* bzImage - Compressed kernel image (arch/x86/boot/bzImage)' 328 echo ' install - Install kernel using (your) ~/bin/$(INSTALLKERNEL) or' 329 echo ' (distribution) /sbin/$(INSTALLKERNEL) or install to ' 330 echo ' $$(INSTALL_PATH) and run lilo' 331 echo '' 332 echo ' fdimage - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)' 333 echo ' fdimage144 - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)' 334 echo ' fdimage288 - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)' 335 echo ' hdimage - Create a BIOS/EFI hard disk image (arch/x86/boot/hdimage)' 336 echo ' isoimage - Create a boot CD-ROM image (arch/x86/boot/image.iso)' 337 echo ' bzdisk/fdimage*/hdimage/isoimage also accept:' 338 echo ' FDARGS="..." arguments for the booted kernel' 339 echo ' FDINITRD=file initrd for the booted kernel' 340 341endef 342