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),x86_64) 7 KBUILD_DEFCONFIG := x86_64_defconfig 8 else 9 KBUILD_DEFCONFIG := i386_defconfig 10 endif 11else 12 KBUILD_DEFCONFIG := $(ARCH)_defconfig 13endif 14 15# For gcc stack alignment is specified with -mpreferred-stack-boundary, 16# clang has the option -mstack-alignment for that purpose. 17ifneq ($(call cc-option, -mpreferred-stack-boundary=4),) 18 cc_stack_align4 := -mpreferred-stack-boundary=2 19 cc_stack_align8 := -mpreferred-stack-boundary=3 20else ifneq ($(call cc-option, -mstack-alignment=16),) 21 cc_stack_align4 := -mstack-alignment=4 22 cc_stack_align8 := -mstack-alignment=8 23endif 24 25# How to compile the 16-bit code. Note we always compile for -march=i386; 26# that way we can complain to the user if the CPU is insufficient. 27# 28# The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For 29# older versions of GCC, include an *assembly* header to make sure that 30# gcc doesn't play any games behind our back. 31CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h 32M16_CFLAGS := $(call cc-option, -m16, $(CODE16GCC_CFLAGS)) 33 34REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -D__KERNEL__ \ 35 -DDISABLE_BRANCH_PROFILING \ 36 -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ 37 -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ 38 -mno-mmx -mno-sse 39 40REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding) 41REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector) 42REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member) 43REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4)) 44export REALMODE_CFLAGS 45 46# BITS is used as extension for files which are available in a 32 bit 47# and a 64 bit version to simplify shared Makefiles. 48# e.g.: obj-y += foo_$(BITS).o 49export BITS 50 51ifdef CONFIG_X86_NEED_RELOCS 52 LDFLAGS_vmlinux := --emit-relocs --discard-none 53endif 54 55# 56# Prevent GCC from generating any FP code by mistake. 57# 58# This must happen before we try the -mpreferred-stack-boundary, see: 59# 60# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383 61# 62KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow 63KBUILD_CFLAGS += $(call cc-option,-mno-avx,) 64 65ifeq ($(CONFIG_X86_32),y) 66 BITS := 32 67 UTS_MACHINE := i386 68 CHECKFLAGS += -D__i386__ 69 70 biarch := $(call cc-option,-m32) 71 KBUILD_AFLAGS += $(biarch) 72 KBUILD_CFLAGS += $(biarch) 73 74 KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return 75 76 # Never want PIC in a 32-bit kernel, prevent breakage with GCC built 77 # with nonstandard options 78 KBUILD_CFLAGS += -fno-pic 79 80 # Align the stack to the register width instead of using the default 81 # alignment of 16 bytes. This reduces stack usage and the number of 82 # alignment instructions. 83 KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align4)) 84 85 # Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use 86 # a lot more stack due to the lack of sharing of stacklots: 87 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0400, \ 88 $(call cc-option,-fno-unit-at-a-time)) 89 90 # CPU-specific tuning. Anything which can be shared with UML should go here. 91 include arch/x86/Makefile_32.cpu 92 KBUILD_CFLAGS += $(cflags-y) 93 94 # temporary until string.h is fixed 95 KBUILD_CFLAGS += -ffreestanding 96else 97 BITS := 64 98 UTS_MACHINE := x86_64 99 CHECKFLAGS += -D__x86_64__ -m64 100 101 biarch := -m64 102 KBUILD_AFLAGS += -m64 103 KBUILD_CFLAGS += -m64 104 105 # Align jump targets to 1 byte, not the default 16 bytes: 106 KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1) 107 108 # Pack loops tightly as well: 109 KBUILD_CFLAGS += $(call cc-option,-falign-loops=1) 110 111 # Don't autogenerate traditional x87 instructions 112 KBUILD_CFLAGS += $(call cc-option,-mno-80387) 113 KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387) 114 115 KBUILD_CFLAGS += -fno-pic 116 117 # By default gcc and clang use a stack alignment of 16 bytes for x86. 118 # However the standard kernel entry on x86-64 leaves the stack on an 119 # 8-byte boundary. If the compiler isn't informed about the actual 120 # alignment it will generate extra alignment instructions for the 121 # default alignment which keep the stack *mis*aligned. 122 # Furthermore an alignment to the register width reduces stack usage 123 # and the number of alignment instructions. 124 KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align8)) 125 126 # Use -mskip-rax-setup if supported. 127 KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup) 128 129 # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu) 130 cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8) 131 cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona) 132 133 cflags-$(CONFIG_MCORE2) += \ 134 $(call cc-option,-march=core2,$(call cc-option,-mtune=generic)) 135 cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \ 136 $(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic)) 137 cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic) 138 KBUILD_CFLAGS += $(cflags-y) 139 140 KBUILD_CFLAGS += -mno-red-zone 141 KBUILD_CFLAGS += -mcmodel=kernel 142 143 # -funit-at-a-time shrinks the kernel .text considerably 144 # unfortunately it makes reading oopses harder. 145 KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time) 146endif 147 148ifdef CONFIG_X86_X32 149 x32_ld_ok := $(call try-run,\ 150 /bin/echo -e '1: .quad 1b' | \ 151 $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" - && \ 152 $(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMPO" && \ 153 $(LD) -m elf32_x86_64 "$$TMPO" -o "$$TMP",y,n) 154 ifeq ($(x32_ld_ok),y) 155 CONFIG_X86_X32_ABI := y 156 KBUILD_AFLAGS += -DCONFIG_X86_X32_ABI 157 KBUILD_CFLAGS += -DCONFIG_X86_X32_ABI 158 else 159 $(warning CONFIG_X86_X32 enabled but no binutils support) 160 endif 161endif 162export CONFIG_X86_X32_ABI 163 164# 165# If the function graph tracer is used with mcount instead of fentry, 166# '-maccumulate-outgoing-args' is needed to prevent a GCC bug 167# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109) 168# 169ifdef CONFIG_FUNCTION_GRAPH_TRACER 170 ifndef CONFIG_HAVE_FENTRY 171 ACCUMULATE_OUTGOING_ARGS := 1 172 else 173 ifeq ($(call cc-option-yn, -mfentry), n) 174 ACCUMULATE_OUTGOING_ARGS := 1 175 176 # GCC ignores '-maccumulate-outgoing-args' when used with '-Os'. 177 # If '-Os' is enabled, disable it and print a warning. 178 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE 179 undefine CONFIG_CC_OPTIMIZE_FOR_SIZE 180 $(warning Disabling CONFIG_CC_OPTIMIZE_FOR_SIZE. Your compiler does not have -mfentry so you cannot optimize for size with CONFIG_FUNCTION_GRAPH_TRACER.) 181 endif 182 183 endif 184 endif 185endif 186 187# 188# Jump labels need '-maccumulate-outgoing-args' for gcc < 4.5.2 to prevent a 189# GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46226). There's no way 190# to test for this bug at compile-time because the test case needs to execute, 191# which is a no-go for cross compilers. So check the GCC version instead. 192# 193ifdef CONFIG_JUMP_LABEL 194 ifneq ($(ACCUMULATE_OUTGOING_ARGS), 1) 195 ACCUMULATE_OUTGOING_ARGS = $(call cc-if-fullversion, -lt, 040502, 1) 196 endif 197endif 198 199ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1) 200 # This compiler flag is not supported by Clang: 201 KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,) 202endif 203 204# Stackpointer is addressed different for 32 bit and 64 bit x86 205sp-$(CONFIG_X86_32) := esp 206sp-$(CONFIG_X86_64) := rsp 207 208# do binutils support CFI? 209cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1) 210# is .cfi_signal_frame supported too? 211cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1) 212cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1) 213 214# does binutils support specific instructions? 215asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1) 216asinstr += $(call as-instr,pshufb %xmm0$(comma)%xmm0,-DCONFIG_AS_SSSE3=1) 217asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1) 218avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1) 219avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1) 220avx512_instr :=$(call as-instr,vpmovm2b %k1$(comma)%zmm5,-DCONFIG_AS_AVX512=1) 221sha1_ni_instr :=$(call as-instr,sha1msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA1_NI=1) 222sha256_ni_instr :=$(call as-instr,sha256msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA256_NI=1) 223 224KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr) 225KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr) 226 227LDFLAGS := -m elf_$(UTS_MACHINE) 228 229# 230# The 64-bit kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to 231# the linker to force 2MB page size regardless of the default page size used 232# by the linker. 233# 234ifdef CONFIG_X86_64 235LDFLAGS += $(call ld-option, -z max-page-size=0x200000) 236endif 237 238# Speed up the build 239KBUILD_CFLAGS += -pipe 240# Workaround for a gcc prelease that unfortunately was shipped in a suse release 241KBUILD_CFLAGS += -Wno-sign-compare 242# 243KBUILD_CFLAGS += -fno-asynchronous-unwind-tables 244 245# Avoid indirect branches in kernel to deal with Spectre 246ifdef CONFIG_RETPOLINE 247 KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) 248 # Additionally, avoid generating expensive indirect jumps which 249 # are subject to retpolines for small number of switch cases. 250 # clang turns off jump table generation by default when under 251 # retpoline builds, however, gcc does not for x86. This has 252 # only been fixed starting from gcc stable version 8.4.0 and 253 # onwards, but not for older ones. See gcc bug #86952. 254 ifneq ($(cc-name), clang) 255 KBUILD_CFLAGS += $(call cc-option,-fno-jump-tables) 256 endif 257endif 258 259archscripts: scripts_basic 260 $(Q)$(MAKE) $(build)=arch/x86/tools relocs 261 262### 263# Syscall table generation 264 265archheaders: 266 $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all 267 268archprepare: 269ifeq ($(CONFIG_KEXEC_FILE),y) 270 $(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c 271endif 272ifdef CONFIG_RETPOLINE 273ifeq ($(RETPOLINE_CFLAGS),) 274 @echo "You are building kernel with non-retpoline compiler." >&2 275 @echo "Please update your compiler." >&2 276 @false 277endif 278endif 279 280### 281# Kernel objects 282 283head-y := arch/x86/kernel/head_$(BITS).o 284head-y += arch/x86/kernel/head$(BITS).o 285head-y += arch/x86/kernel/ebda.o 286head-y += arch/x86/kernel/platform-quirks.o 287 288libs-y += arch/x86/lib/ 289 290# See arch/x86/Kbuild for content of core part of the kernel 291core-y += arch/x86/ 292 293# drivers-y are linked after core-y 294drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/ 295drivers-$(CONFIG_PCI) += arch/x86/pci/ 296 297# must be linked after kernel/ 298drivers-$(CONFIG_OPROFILE) += arch/x86/oprofile/ 299 300# suspend and hibernation support 301drivers-$(CONFIG_PM) += arch/x86/power/ 302 303drivers-$(CONFIG_FB) += arch/x86/video/ 304 305#### 306# boot loader support. Several targets are kept for legacy purposes 307 308boot := arch/x86/boot 309 310BOOT_TARGETS = bzlilo bzdisk fdimage fdimage144 fdimage288 isoimage 311 312PHONY += bzImage $(BOOT_TARGETS) 313 314# Default kernel to build 315all: bzImage 316 317# KBUILD_IMAGE specify target image being built 318KBUILD_IMAGE := $(boot)/bzImage 319 320bzImage: vmlinux 321ifeq ($(CONFIG_X86_DECODER_SELFTEST),y) 322 $(Q)$(MAKE) $(build)=arch/x86/tools posttest 323endif 324 $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE) 325 $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot 326 $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@ 327 328$(BOOT_TARGETS): vmlinux 329 $(Q)$(MAKE) $(build)=$(boot) $@ 330 331PHONY += install 332install: 333 $(Q)$(MAKE) $(build)=$(boot) $@ 334 335PHONY += vdso_install 336vdso_install: 337 $(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@ 338 339archclean: 340 $(Q)rm -rf $(objtree)/arch/i386 341 $(Q)rm -rf $(objtree)/arch/x86_64 342 $(Q)$(MAKE) $(clean)=$(boot) 343 $(Q)$(MAKE) $(clean)=arch/x86/tools 344 $(Q)$(MAKE) $(clean)=arch/x86/purgatory 345 346define archhelp 347 echo '* bzImage - Compressed kernel image (arch/x86/boot/bzImage)' 348 echo ' install - Install kernel using' 349 echo ' (your) ~/bin/$(INSTALLKERNEL) or' 350 echo ' (distribution) /sbin/$(INSTALLKERNEL) or' 351 echo ' install to $$(INSTALL_PATH) and run lilo' 352 echo ' fdimage - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)' 353 echo ' fdimage144 - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)' 354 echo ' fdimage288 - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)' 355 echo ' isoimage - Create a boot CD-ROM image (arch/x86/boot/image.iso)' 356 echo ' bzdisk/fdimage*/isoimage also accept:' 357 echo ' FDARGS="..." arguments for the booted kernel' 358 echo ' FDINITRD=file initrd for the booted kernel' 359endef 360