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