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 -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
  39 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding)
  40 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector)
  41 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member)
  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 --discard-none
  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         # 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
  90 else
  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
 134 endif
 135
 136 ifdef 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
 149 endif
 150 export 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 #
 157 ifdef 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
 173 endif
 174
 175 ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1)
 176         # This compiler flag is not supported by Clang:
 177         KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,)
 178 endif
 179
 180 KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE)
 181
 182 #
 183 # The 64-bit kernel must be aligned to 2MB.  Pass -z max-page-size=0x200000 to
 184 # the linker to force 2MB page size regardless of the default page size used
 185 # by the linker.
 186 #
 187 ifdef CONFIG_X86_64
 188 KBUILD_LDFLAGS += $(call ld-option, -z max-page-size=0x200000)
 189 endif
 190
 191 # Workaround for a gcc prelease that unfortunately was shipped in a suse release
 192 KBUILD_CFLAGS += -Wno-sign-compare
 193 #
 194 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
 195
 196 # Avoid indirect branches in kernel to deal with Spectre
 197 ifdef CONFIG_RETPOLINE
 198   KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
 199   # Additionally, avoid generating expensive indirect jumps which
 200   # are subject to retpolines for small number of switch cases.
 201   # clang turns off jump table generation by default when under
 202   # retpoline builds, however, gcc does not for x86. This has
 203   # only been fixed starting from gcc stable version 8.4.0 and
 204   # onwards, but not for older ones. See gcc bug #86952.
 205   ifndef CONFIG_CC_IS_CLANG
 206     KBUILD_CFLAGS += $(call cc-option,-fno-jump-tables)
 207   endif
 208 endif
 209
 210 archscripts: scripts_basic
 211         $(Q)$(MAKE) $(build)=arch/x86/tools relocs
 212
 213 ###
 214 # Syscall table generation
 215
 216 archheaders:
 217         $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all
 218
 219 ###
 220 # Kernel objects
 221
 222 head-y := arch/x86/kernel/head_$(BITS).o
 223 head-y += arch/x86/kernel/head$(BITS).o
 224 head-y += arch/x86/kernel/ebda.o
 225 head-y += arch/x86/kernel/platform-quirks.o
 226
 227 libs-y  += arch/x86/lib/
 228
 229 # See arch/x86/Kbuild for content of core part of the kernel
 230 core-y += arch/x86/
 231
 232 # drivers-y are linked after core-y
 233 drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
 234 drivers-$(CONFIG_PCI)            += arch/x86/pci/
 235
 236 # must be linked after kernel/
 237 drivers-$(CONFIG_OPROFILE) += arch/x86/oprofile/
 238
 239 # suspend and hibernation support
 240 drivers-$(CONFIG_PM) += arch/x86/power/
 241
 242 drivers-$(CONFIG_FB) += arch/x86/video/
 243
 244 ####
 245 # boot loader support. Several targets are kept for legacy purposes
 246
 247 boot := arch/x86/boot
 248
 249 BOOT_TARGETS = bzdisk fdimage fdimage144 fdimage288 isoimage
 250
 251 PHONY += bzImage $(BOOT_TARGETS)
 252
 253 # Default kernel to build
 254 all: bzImage
 255
 256 # KBUILD_IMAGE specify target image being built
 257 KBUILD_IMAGE := $(boot)/bzImage
 258
 259 bzImage: vmlinux
 260 ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
 261         $(Q)$(MAKE) $(build)=arch/x86/tools posttest
 262 endif
 263         $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
 264         $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
 265         $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@
 266
 267 $(BOOT_TARGETS): vmlinux
 268         $(Q)$(MAKE) $(build)=$(boot) $@
 269
 270 PHONY += install bzlilo
 271 install bzlilo:
 272         $(Q)$(MAKE) $(build)=$(boot) $@
 273
 274 PHONY += vdso_install
 275 vdso_install:
 276         $(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@
 277
 278 archprepare: checkbin
 279 checkbin:
 280 ifndef CONFIG_CC_HAS_ASM_GOTO
 281         @echo Compiler lacks asm-goto support.
 282         @exit 1
 283 endif
 284 ifdef CONFIG_RETPOLINE
 285 ifeq ($(RETPOLINE_CFLAGS),)
 286         @echo "You are building kernel with non-retpoline compiler." >&2
 287         @echo "Please update your compiler." >&2
 288         @false
 289 endif
 290 endif
 291
 292 archclean:
 293         $(Q)rm -rf $(objtree)/arch/i386
 294         $(Q)rm -rf $(objtree)/arch/x86_64
 295         $(Q)$(MAKE) $(clean)=$(boot)
 296         $(Q)$(MAKE) $(clean)=arch/x86/tools
 297
 298 define archhelp
 299   echo  '* bzImage      - Compressed kernel image (arch/x86/boot/bzImage)'
 300   echo  '  install      - Install kernel using'
 301   echo  '                  (your) ~/bin/$(INSTALLKERNEL) or'
 302   echo  '                  (distribution) /sbin/$(INSTALLKERNEL) or'
 303   echo  '                  install to $$(INSTALL_PATH) and run lilo'
 304   echo  '  fdimage      - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
 305   echo  '  fdimage144   - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
 306   echo  '  fdimage288   - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
 307   echo  '  isoimage     - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
 308   echo  '                  bzdisk/fdimage*/isoimage also accept:'
 309   echo  '                  FDARGS="..."  arguments for the booted kernel'
 310   echo  '                  FDINITRD=file initrd for the booted kernel'
 311 endef