arch/x86/Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2 # Unified Makefile for i386 and x86_64
   3
   4 # select defconfig based on actual architecture
   5 ifeq ($(ARCH),x86)
   6   ifeq ($(shell uname -m),x86_64)
   7         KBUILD_DEFCONFIG := x86_64_defconfig
   8   else
   9         KBUILD_DEFCONFIG := i386_defconfig
  10   endif
  11 else
  12         KBUILD_DEFCONFIG := $(ARCH)_defconfig
  13 endif
  14
  15 # For gcc stack alignment is specified with -mpreferred-stack-boundary,
  16 # clang has the option -mstack-alignment for that purpose.
  17 ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
  18       cc_stack_align4 := -mpreferred-stack-boundary=2
  19       cc_stack_align8 := -mpreferred-stack-boundary=3
  20 else ifneq ($(call cc-option, -mstack-alignment=16),)
  21       cc_stack_align4 := -mstack-alignment=4
  22       cc_stack_align8 := -mstack-alignment=8
  23 endif
  24
  25 # How to compile the 16-bit code.  Note we always compile for -march=i386;
  26 # that way we can complain to the user if the CPU is insufficient.
  27 #
  28 # The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For
  29 # older versions of GCC, include an *assembly* header to make sure that
  30 # gcc doesn't play any games behind our back.
  31 CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h
  32 M16_CFLAGS       := $(call cc-option, -m16, $(CODE16GCC_CFLAGS))
  33
  34 REALMODE_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
  40 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding)
  41 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector)
  42 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member)
  43 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4))
  44 export REALMODE_CFLAGS
  45
  46 # BITS is used as extension for files which are available in a 32 bit
  47 # and a 64 bit version to simplify shared Makefiles.
  48 # e.g.: obj-y += foo_$(BITS).o
  49 export BITS
  50
  51 ifdef CONFIG_X86_NEED_RELOCS
  52         LDFLAGS_vmlinux := --emit-relocs --discard-none
  53 endif
  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 #
  62 KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow
  63 KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
  64
  65 ifeq ($(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
  96 else
  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         # By default gcc and clang use a stack alignment of 16 bytes for x86.
 116         # However the standard kernel entry on x86-64 leaves the stack on an
 117         # 8-byte boundary. If the compiler isn't informed about the actual
 118         # alignment it will generate extra alignment instructions for the
 119         # default alignment which keep the stack *mis*aligned.
 120         # Furthermore an alignment to the register width reduces stack usage
 121         # and the number of alignment instructions.
 122         KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align8))
 123
 124         # Use -mskip-rax-setup if supported.
 125         KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
 126
 127         # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
 128         cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
 129         cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
 130
 131         cflags-$(CONFIG_MCORE2) += \
 132                 $(call cc-option,-march=core2,$(call cc-option,-mtune=generic))
 133         cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \
 134                 $(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
 135         cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)
 136         KBUILD_CFLAGS += $(cflags-y)
 137
 138         KBUILD_CFLAGS += -mno-red-zone
 139         KBUILD_CFLAGS += -mcmodel=kernel
 140
 141         # -funit-at-a-time shrinks the kernel .text considerably
 142         # unfortunately it makes reading oopses harder.
 143         KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
 144 endif
 145
 146 ifdef CONFIG_X86_X32
 147         x32_ld_ok := $(call try-run,\
 148                         /bin/echo -e '1: .quad 1b' | \
 149                         $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" - && \
 150                         $(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMPO" && \
 151                         $(LD) -m elf32_x86_64 "$$TMPO" -o "$$TMP",y,n)
 152         ifeq ($(x32_ld_ok),y)
 153                 CONFIG_X86_X32_ABI := y
 154                 KBUILD_AFLAGS += -DCONFIG_X86_X32_ABI
 155                 KBUILD_CFLAGS += -DCONFIG_X86_X32_ABI
 156         else
 157                 $(warning CONFIG_X86_X32 enabled but no binutils support)
 158         endif
 159 endif
 160 export CONFIG_X86_X32_ABI
 161
 162 #
 163 # If the function graph tracer is used with mcount instead of fentry,
 164 # '-maccumulate-outgoing-args' is needed to prevent a GCC bug
 165 # (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109)
 166 #
 167 ifdef CONFIG_FUNCTION_GRAPH_TRACER
 168   ifndef CONFIG_HAVE_FENTRY
 169         ACCUMULATE_OUTGOING_ARGS := 1
 170   else
 171     ifeq ($(call cc-option-yn, -mfentry), n)
 172         ACCUMULATE_OUTGOING_ARGS := 1
 173
 174         # GCC ignores '-maccumulate-outgoing-args' when used with '-Os'.
 175         # If '-Os' is enabled, disable it and print a warning.
 176         ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 177           undefine CONFIG_CC_OPTIMIZE_FOR_SIZE
 178           $(warning Disabling CONFIG_CC_OPTIMIZE_FOR_SIZE.  Your compiler does not have -mfentry so you cannot optimize for size with CONFIG_FUNCTION_GRAPH_TRACER.)
 179         endif
 180
 181     endif
 182   endif
 183 endif
 184
 185 #
 186 # Jump labels need '-maccumulate-outgoing-args' for gcc < 4.5.2 to prevent a
 187 # GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46226).  There's no way
 188 # to test for this bug at compile-time because the test case needs to execute,
 189 # which is a no-go for cross compilers.  So check the GCC version instead.
 190 #
 191 ifdef CONFIG_JUMP_LABEL
 192   ifneq ($(ACCUMULATE_OUTGOING_ARGS), 1)
 193         ACCUMULATE_OUTGOING_ARGS = $(call cc-if-fullversion, -lt, 040502, 1)
 194   endif
 195 endif
 196
 197 ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1)
 198         # This compiler flag is not supported by Clang:
 199         KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,)
 200 endif
 201
 202 # Stackpointer is addressed different for 32 bit and 64 bit x86
 203 sp-$(CONFIG_X86_32) := esp
 204 sp-$(CONFIG_X86_64) := rsp
 205
 206 # do binutils support CFI?
 207 cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1)
 208 # is .cfi_signal_frame supported too?
 209 cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1)
 210 cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1)
 211
 212 # does binutils support specific instructions?
 213 asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1)
 214 asinstr += $(call as-instr,pshufb %xmm0$(comma)%xmm0,-DCONFIG_AS_SSSE3=1)
 215 asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1)
 216 avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1)
 217 avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1)
 218 avx512_instr :=$(call as-instr,vpmovm2b %k1$(comma)%zmm5,-DCONFIG_AS_AVX512=1)
 219 sha1_ni_instr :=$(call as-instr,sha1msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA1_NI=1)
 220 sha256_ni_instr :=$(call as-instr,sha256msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA256_NI=1)
 221
 222 KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
 223 KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
 224
 225 LDFLAGS := -m elf_$(UTS_MACHINE)
 226
 227 #
 228 # The 64-bit kernel must be aligned to 2MB.  Pass -z max-page-size=0x200000 to
 229 # the linker to force 2MB page size regardless of the default page size used
 230 # by the linker.
 231 #
 232 ifdef CONFIG_X86_64
 233 LDFLAGS += $(call ld-option, -z max-page-size=0x200000)
 234 endif
 235
 236 # Speed up the build
 237 KBUILD_CFLAGS += -pipe
 238 # Workaround for a gcc prelease that unfortunately was shipped in a suse release
 239 KBUILD_CFLAGS += -Wno-sign-compare
 240 #
 241 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
 242
 243 # Avoid indirect branches in kernel to deal with Spectre
 244 ifdef CONFIG_RETPOLINE
 245   KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
 246   # Additionally, avoid generating expensive indirect jumps which
 247   # are subject to retpolines for small number of switch cases.
 248   # clang turns off jump table generation by default when under
 249   # retpoline builds, however, gcc does not for x86. This has
 250   # only been fixed starting from gcc stable version 8.4.0 and
 251   # onwards, but not for older ones. See gcc bug #86952.
 252   ifndef CONFIG_CC_IS_CLANG
 253     KBUILD_CFLAGS += $(call cc-option,-fno-jump-tables)
 254   endif
 255 endif
 256
 257 archscripts: scripts_basic
 258         $(Q)$(MAKE) $(build)=arch/x86/tools relocs
 259
 260 ###
 261 # Syscall table generation
 262
 263 archheaders:
 264         $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all
 265
 266 archprepare:
 267 ifeq ($(CONFIG_KEXEC_FILE),y)
 268         $(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c
 269 endif
 270 ifdef CONFIG_RETPOLINE
 271 ifeq ($(RETPOLINE_CFLAGS),)
 272         @echo "You are building kernel with non-retpoline compiler." >&2
 273         @echo "Please update your compiler." >&2
 274         @false
 275 endif
 276 endif
 277
 278 ###
 279 # Kernel objects
 280
 281 head-y := arch/x86/kernel/head_$(BITS).o
 282 head-y += arch/x86/kernel/head$(BITS).o
 283 head-y += arch/x86/kernel/ebda.o
 284 head-y += arch/x86/kernel/platform-quirks.o
 285
 286 libs-y  += arch/x86/lib/
 287
 288 # See arch/x86/Kbuild for content of core part of the kernel
 289 core-y += arch/x86/
 290
 291 # drivers-y are linked after core-y
 292 drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
 293 drivers-$(CONFIG_PCI)            += arch/x86/pci/
 294
 295 # must be linked after kernel/
 296 drivers-$(CONFIG_OPROFILE) += arch/x86/oprofile/
 297
 298 # suspend and hibernation support
 299 drivers-$(CONFIG_PM) += arch/x86/power/
 300
 301 drivers-$(CONFIG_FB) += arch/x86/video/
 302
 303 ####
 304 # boot loader support. Several targets are kept for legacy purposes
 305
 306 boot := arch/x86/boot
 307
 308 BOOT_TARGETS = bzlilo bzdisk fdimage fdimage144 fdimage288 isoimage
 309
 310 PHONY += bzImage $(BOOT_TARGETS)
 311
 312 # Default kernel to build
 313 all: bzImage
 314
 315 # KBUILD_IMAGE specify target image being built
 316 KBUILD_IMAGE := $(boot)/bzImage
 317
 318 bzImage: vmlinux
 319 ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
 320         $(Q)$(MAKE) $(build)=arch/x86/tools posttest
 321 endif
 322         $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
 323         $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
 324         $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@
 325
 326 $(BOOT_TARGETS): vmlinux
 327         $(Q)$(MAKE) $(build)=$(boot) $@
 328
 329 PHONY += install
 330 install:
 331         $(Q)$(MAKE) $(build)=$(boot) $@
 332
 333 PHONY += vdso_install
 334 vdso_install:
 335         $(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@
 336
 337 archclean:
 338         $(Q)rm -rf $(objtree)/arch/i386
 339         $(Q)rm -rf $(objtree)/arch/x86_64
 340         $(Q)$(MAKE) $(clean)=$(boot)
 341         $(Q)$(MAKE) $(clean)=arch/x86/tools
 342         $(Q)$(MAKE) $(clean)=arch/x86/purgatory
 343
 344 define archhelp
 345   echo  '* bzImage      - Compressed kernel image (arch/x86/boot/bzImage)'
 346   echo  '  install      - Install kernel using'
 347   echo  '                  (your) ~/bin/$(INSTALLKERNEL) or'
 348   echo  '                  (distribution) /sbin/$(INSTALLKERNEL) or'
 349   echo  '                  install to $$(INSTALL_PATH) and run lilo'
 350   echo  '  fdimage      - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
 351   echo  '  fdimage144   - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
 352   echo  '  fdimage288   - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
 353   echo  '  isoimage     - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
 354   echo  '                  bzdisk/fdimage*/isoimage also accept:'
 355   echo  '                  FDARGS="..."  arguments for the booted kernel'
 356   echo  '                  FDINITRD=file initrd for the booted kernel'
 357 endef