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