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_MITIGATION_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 := -std=gnu11 -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 += $(CLANG_FLAGS) 56ifdef CONFIG_CC_IS_CLANG 57REALMODE_CFLAGS += -Wno-gnu 58endif 59export REALMODE_CFLAGS 60 61# BITS is used as extension for files which are available in a 32 bit 62# and a 64 bit version to simplify shared Makefiles. 63# e.g.: obj-y += foo_$(BITS).o 64export BITS 65 66# 67# Prevent GCC from generating any FP code by mistake. 68# 69# This must happen before we try the -mpreferred-stack-boundary, see: 70# 71# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383 72# 73KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx 74KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2 75 76ifeq ($(CONFIG_X86_KERNEL_IBT),y) 77# 78# Kernel IBT has S_CET.NOTRACK_EN=0, as such the compilers must not generate 79# NOTRACK prefixes. Current generation compilers unconditionally employ NOTRACK 80# for jump-tables, as such, disable jump-tables for now. 81# 82# (jump-tables are implicitly disabled by RETPOLINE) 83# 84# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104816 85# 86KBUILD_CFLAGS += $(call cc-option,-fcf-protection=branch -fno-jump-tables) 87KBUILD_RUSTFLAGS += -Zcf-protection=branch -Zno-jump-tables 88else 89KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none) 90endif 91 92ifeq ($(CONFIG_X86_32),y) 93 BITS := 32 94 UTS_MACHINE := i386 95 CHECKFLAGS += -D__i386__ 96 97 KBUILD_AFLAGS += -m32 98 KBUILD_CFLAGS += -m32 99 100 KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return 101 102 # Never want PIC in a 32-bit kernel, prevent breakage with GCC built 103 # with nonstandard options 104 KBUILD_CFLAGS += -fno-pic 105 106 # Align the stack to the register width instead of using the default 107 # alignment of 16 bytes. This reduces stack usage and the number of 108 # alignment instructions. 109 KBUILD_CFLAGS += $(cc_stack_align4) 110 111 # CPU-specific tuning. Anything which can be shared with UML should go here. 112 include $(srctree)/arch/x86/Makefile_32.cpu 113 KBUILD_CFLAGS += $(cflags-y) 114 115 # temporary until string.h is fixed 116 KBUILD_CFLAGS += -ffreestanding 117 118 ifeq ($(CONFIG_STACKPROTECTOR),y) 119 ifeq ($(CONFIG_SMP),y) 120 KBUILD_CFLAGS += -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard 121 else 122 KBUILD_CFLAGS += -mstack-protector-guard=global 123 endif 124 endif 125else 126 BITS := 64 127 UTS_MACHINE := x86_64 128 CHECKFLAGS += -D__x86_64__ 129 130 KBUILD_AFLAGS += -m64 131 KBUILD_CFLAGS += -m64 132 133 # Align jump targets to 1 byte, not the default 16 bytes: 134 KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1) 135 136 # Pack loops tightly as well: 137 KBUILD_CFLAGS += $(call cc-option,-falign-loops=1) 138 139 # Don't autogenerate traditional x87 instructions 140 KBUILD_CFLAGS += -mno-80387 141 KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387) 142 143 # By default gcc and clang use a stack alignment of 16 bytes for x86. 144 # However the standard kernel entry on x86-64 leaves the stack on an 145 # 8-byte boundary. If the compiler isn't informed about the actual 146 # alignment it will generate extra alignment instructions for the 147 # default alignment which keep the stack *mis*aligned. 148 # Furthermore an alignment to the register width reduces stack usage 149 # and the number of alignment instructions. 150 KBUILD_CFLAGS += $(cc_stack_align8) 151 152 # Use -mskip-rax-setup if supported. 153 KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup) 154 155 # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu) 156 cflags-$(CONFIG_MK8) += -march=k8 157 cflags-$(CONFIG_MPSC) += -march=nocona 158 cflags-$(CONFIG_MCORE2) += -march=core2 159 cflags-$(CONFIG_MATOM) += -march=atom 160 cflags-$(CONFIG_GENERIC_CPU) += -mtune=generic 161 KBUILD_CFLAGS += $(cflags-y) 162 163 rustflags-$(CONFIG_MK8) += -Ctarget-cpu=k8 164 rustflags-$(CONFIG_MPSC) += -Ctarget-cpu=nocona 165 rustflags-$(CONFIG_MCORE2) += -Ctarget-cpu=core2 166 rustflags-$(CONFIG_MATOM) += -Ctarget-cpu=atom 167 rustflags-$(CONFIG_GENERIC_CPU) += -Ztune-cpu=generic 168 KBUILD_RUSTFLAGS += $(rustflags-y) 169 170 KBUILD_CFLAGS += -mno-red-zone 171 KBUILD_CFLAGS += -mcmodel=kernel 172 KBUILD_RUSTFLAGS += -Cno-redzone=y 173 KBUILD_RUSTFLAGS += -Ccode-model=kernel 174endif 175 176# 177# If the function graph tracer is used with mcount instead of fentry, 178# '-maccumulate-outgoing-args' is needed to prevent a GCC bug 179# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109) 180# 181ifdef CONFIG_FUNCTION_GRAPH_TRACER 182 ifndef CONFIG_HAVE_FENTRY 183 ACCUMULATE_OUTGOING_ARGS := 1 184 endif 185endif 186 187ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1) 188 # This compiler flag is not supported by Clang: 189 KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,) 190endif 191 192# Workaround for a gcc prelease that unfortunately was shipped in a suse release 193KBUILD_CFLAGS += -Wno-sign-compare 194# 195KBUILD_CFLAGS += -fno-asynchronous-unwind-tables 196 197# Avoid indirect branches in kernel to deal with Spectre 198ifdef CONFIG_MITIGATION_RETPOLINE 199 KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) 200 # Additionally, avoid generating expensive indirect jumps which 201 # are subject to retpolines for small number of switch cases. 202 # clang turns off jump table generation by default when under 203 # retpoline builds, however, gcc does not for x86. This has 204 # only been fixed starting from gcc stable version 8.4.0 and 205 # onwards, but not for older ones. See gcc bug #86952. 206 ifndef CONFIG_CC_IS_CLANG 207 KBUILD_CFLAGS += -fno-jump-tables 208 endif 209endif 210 211ifdef CONFIG_MITIGATION_SLS 212 KBUILD_CFLAGS += -mharden-sls=all 213endif 214 215ifdef CONFIG_CALL_PADDING 216PADDING_CFLAGS := -fpatchable-function-entry=$(CONFIG_FUNCTION_PADDING_BYTES),$(CONFIG_FUNCTION_PADDING_BYTES) 217KBUILD_CFLAGS += $(PADDING_CFLAGS) 218export PADDING_CFLAGS 219endif 220 221KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE) 222 223ifdef CONFIG_LTO_CLANG 224ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y) 225KBUILD_LDFLAGS += -plugin-opt=-stack-alignment=$(if $(CONFIG_X86_32),4,8) 226endif 227endif 228 229ifdef CONFIG_X86_NEED_RELOCS 230LDFLAGS_vmlinux := --emit-relocs --discard-none 231else 232LDFLAGS_vmlinux := 233endif 234 235# 236# The 64-bit kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to 237# the linker to force 2MB page size regardless of the default page size used 238# by the linker. 239# 240ifdef CONFIG_X86_64 241LDFLAGS_vmlinux += -z max-page-size=0x200000 242endif 243 244 245archscripts: scripts_basic 246 $(Q)$(MAKE) $(build)=arch/x86/tools relocs 247 248### 249# Syscall table generation 250 251archheaders: 252 $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all 253 254### 255# Kernel objects 256 257libs-y += arch/x86/lib/ 258 259core-y += arch/x86/virt/ 260 261# drivers-y are linked after core-y 262drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/ 263drivers-$(CONFIG_PCI) += arch/x86/pci/ 264 265# suspend and hibernation support 266drivers-$(CONFIG_PM) += arch/x86/power/ 267 268drivers-$(CONFIG_FB_CORE) += arch/x86/video/ 269 270#### 271# boot loader support. Several targets are kept for legacy purposes 272 273boot := arch/x86/boot 274 275BOOT_TARGETS = bzdisk fdimage fdimage144 fdimage288 hdimage isoimage 276 277PHONY += bzImage $(BOOT_TARGETS) 278 279# Default kernel to build 280all: bzImage 281 282# KBUILD_IMAGE specify target image being built 283KBUILD_IMAGE := $(boot)/bzImage 284 285bzImage: vmlinux 286ifeq ($(CONFIG_X86_DECODER_SELFTEST),y) 287 $(Q)$(MAKE) $(build)=arch/x86/tools posttest 288endif 289 $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE) 290 $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot 291 $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@ 292 293$(BOOT_TARGETS): vmlinux 294 $(Q)$(MAKE) $(build)=$(boot) $@ 295 296PHONY += install 297install: 298 $(call cmd,install) 299 300vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg 301vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg 302vdso-install-$(CONFIG_COMPAT_32) += arch/x86/entry/vdso/vdso32.so.dbg 303 304archprepare: checkbin 305checkbin: 306ifdef CONFIG_MITIGATION_RETPOLINE 307ifeq ($(RETPOLINE_CFLAGS),) 308 @echo "You are building kernel with non-retpoline compiler." >&2 309 @echo "Please update your compiler." >&2 310 @false 311endif 312endif 313 314ifdef CONFIG_UNWINDER_ORC 315orc_hash_h := arch/$(SRCARCH)/include/generated/asm/orc_hash.h 316orc_hash_sh := $(srctree)/scripts/orc_hash.sh 317targets += $(orc_hash_h) 318quiet_cmd_orc_hash = GEN $@ 319 cmd_orc_hash = mkdir -p $(dir $@); \ 320 $(CONFIG_SHELL) $(orc_hash_sh) < $< > $@ 321$(orc_hash_h): $(srctree)/arch/x86/include/asm/orc_types.h $(orc_hash_sh) FORCE 322 $(call if_changed,orc_hash) 323archprepare: $(orc_hash_h) 324endif 325 326archclean: 327 $(Q)rm -rf $(objtree)/arch/i386 328 $(Q)rm -rf $(objtree)/arch/x86_64 329 330define archhelp 331 echo '* bzImage - Compressed kernel image (arch/x86/boot/bzImage)' 332 echo ' install - Install kernel using (your) ~/bin/$(INSTALLKERNEL) or' 333 echo ' (distribution) /sbin/$(INSTALLKERNEL) or install to ' 334 echo ' $$(INSTALL_PATH) and run lilo' 335 echo '' 336 echo ' fdimage - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)' 337 echo ' fdimage144 - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)' 338 echo ' fdimage288 - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)' 339 echo ' hdimage - Create a BIOS/EFI hard disk image (arch/x86/boot/hdimage)' 340 echo ' isoimage - Create a boot CD-ROM image (arch/x86/boot/image.iso)' 341 echo ' bzdisk/fdimage*/hdimage/isoimage also accept:' 342 echo ' FDARGS="..." arguments for the booted kernel' 343 echo ' FDINITRD=file initrd for the booted kernel' 344 345endef 346