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