linux/arch/x86/Makefile
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   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 := -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 += $(CLANG_FLAGS)
  56export REALMODE_CFLAGS
  57
  58# BITS is used as extension for files which are available in a 32 bit
  59# and a 64 bit version to simplify shared Makefiles.
  60# e.g.: obj-y += foo_$(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)
  84KBUILD_RUSTFLAGS += -Zcf-protection=branch -Zno-jump-tables
  85else
  86KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
  87endif
  88
  89ifeq ($(CONFIG_X86_32),y)
  90        BITS := 32
  91        UTS_MACHINE := i386
  92        CHECKFLAGS += -D__i386__
  93
  94        KBUILD_AFLAGS += -m32
  95        KBUILD_CFLAGS += -m32
  96
  97        KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
  98
  99        # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
 100        # with nonstandard options
 101        KBUILD_CFLAGS += -fno-pic
 102
 103        # Align the stack to the register width instead of using the default
 104        # alignment of 16 bytes. This reduces stack usage and the number of
 105        # alignment instructions.
 106        KBUILD_CFLAGS += $(cc_stack_align4)
 107
 108        # CPU-specific tuning. Anything which can be shared with UML should go here.
 109        include $(srctree)/arch/x86/Makefile_32.cpu
 110        KBUILD_CFLAGS += $(cflags-y)
 111
 112        # temporary until string.h is fixed
 113        KBUILD_CFLAGS += -ffreestanding
 114
 115        ifeq ($(CONFIG_STACKPROTECTOR),y)
 116                ifeq ($(CONFIG_SMP),y)
 117                        KBUILD_CFLAGS += -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__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) $(build)=arch/x86/entry/syscalls all
 250
 251###
 252# Kernel objects
 253
 254libs-y  += arch/x86/lib/
 255
 256core-y += arch/x86/virt/
 257
 258# drivers-y are linked after core-y
 259drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
 260drivers-$(CONFIG_PCI)            += arch/x86/pci/
 261
 262# suspend and hibernation support
 263drivers-$(CONFIG_PM) += arch/x86/power/
 264
 265drivers-$(CONFIG_FB_CORE) += arch/x86/video/
 266
 267####
 268# boot loader support. Several targets are kept for legacy purposes
 269
 270boot := arch/x86/boot
 271
 272BOOT_TARGETS = bzdisk fdimage fdimage144 fdimage288 hdimage isoimage
 273
 274PHONY += bzImage $(BOOT_TARGETS)
 275
 276# Default kernel to build
 277all: bzImage
 278
 279# KBUILD_IMAGE specify target image being built
 280KBUILD_IMAGE := $(boot)/bzImage
 281
 282bzImage: vmlinux
 283ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
 284        $(Q)$(MAKE) $(build)=arch/x86/tools posttest
 285endif
 286        $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
 287        $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
 288        $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@
 289
 290$(BOOT_TARGETS): vmlinux
 291        $(Q)$(MAKE) $(build)=$(boot) $@
 292
 293PHONY += install
 294install:
 295        $(call cmd,install)
 296
 297vdso-install-$(CONFIG_X86_64)           += arch/x86/entry/vdso/vdso64.so.dbg
 298vdso-install-$(CONFIG_X86_X32_ABI)      += arch/x86/entry/vdso/vdsox32.so.dbg
 299vdso-install-$(CONFIG_X86_32)           += arch/x86/entry/vdso/vdso32.so.dbg
 300vdso-install-$(CONFIG_IA32_EMULATION)   += arch/x86/entry/vdso/vdso32.so.dbg
 301
 302archprepare: checkbin
 303checkbin:
 304ifdef CONFIG_RETPOLINE
 305ifeq ($(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
 312ifdef CONFIG_UNWINDER_ORC
 313orc_hash_h := arch/$(SRCARCH)/include/generated/asm/orc_hash.h
 314orc_hash_sh := $(srctree)/scripts/orc_hash.sh
 315targets += $(orc_hash_h)
 316quiet_cmd_orc_hash = GEN     $@
 317      cmd_orc_hash = mkdir -p $(dir $@); \
 318                     $(CONFIG_SHELL) $(orc_hash_sh) < $< > $@
 319$(orc_hash_h): $(srctree)/arch/x86/include/asm/orc_types.h $(orc_hash_sh) FORCE
 320        $(call if_changed,orc_hash)
 321archprepare: $(orc_hash_h)
 322endif
 323
 324archclean:
 325        $(Q)rm -rf $(objtree)/arch/i386
 326        $(Q)rm -rf $(objtree)/arch/x86_64
 327
 328define archhelp
 329  echo  '* bzImage              - Compressed kernel image (arch/x86/boot/bzImage)'
 330  echo  '  install              - Install kernel using (your) ~/bin/$(INSTALLKERNEL) or'
 331  echo  '                         (distribution) /sbin/$(INSTALLKERNEL) or install to '
 332  echo  '                         $$(INSTALL_PATH) and run lilo'
 333  echo  ''
 334  echo  '  fdimage              - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
 335  echo  '  fdimage144           - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
 336  echo  '  fdimage288           - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
 337  echo  '  hdimage              - Create a BIOS/EFI hard disk image (arch/x86/boot/hdimage)'
 338  echo  '  isoimage             - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
 339  echo  '                         bzdisk/fdimage*/hdimage/isoimage also accept:'
 340  echo  '                         FDARGS="..."  arguments for the booted kernel'
 341  echo  '                         FDINITRD=file initrd for the booted kernel'
 342
 343endef
 344