| # SPDX-License-Identifier: GPL-2.0 |
| # Unified Makefile for i386 and x86_64 |
| |
| # select defconfig based on actual architecture |
| ifeq ($(ARCH),x86) |
| ifeq ($(shell uname -m),x86_64) |
| KBUILD_DEFCONFIG := x86_64_defconfig |
| else |
| KBUILD_DEFCONFIG := i386_defconfig |
| endif |
| else |
| KBUILD_DEFCONFIG := $(ARCH)_defconfig |
| endif |
| |
| # For gcc stack alignment is specified with -mpreferred-stack-boundary, |
| # clang has the option -mstack-alignment for that purpose. |
| ifneq ($(call cc-option, -mpreferred-stack-boundary=4),) |
| cc_stack_align4 := -mpreferred-stack-boundary=2 |
| cc_stack_align8 := -mpreferred-stack-boundary=3 |
| else ifneq ($(call cc-option, -mstack-alignment=16),) |
| cc_stack_align4 := -mstack-alignment=4 |
| cc_stack_align8 := -mstack-alignment=8 |
| endif |
| |
| # How to compile the 16-bit code. Note we always compile for -march=i386; |
| # that way we can complain to the user if the CPU is insufficient. |
| # |
| # The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For |
| # older versions of GCC, include an *assembly* header to make sure that |
| # gcc doesn't play any games behind our back. |
| CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h |
| M16_CFLAGS := $(call cc-option, -m16, $(CODE16GCC_CFLAGS)) |
| |
| REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING \ |
| -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ |
| -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ |
| -mno-mmx -mno-sse |
| |
| REALMODE_CFLAGS += -ffreestanding |
| REALMODE_CFLAGS += -fno-stack-protector |
| REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member) |
| REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4)) |
| export REALMODE_CFLAGS |
| |
| # BITS is used as extension for files which are available in a 32 bit |
| # and a 64 bit version to simplify shared Makefiles. |
| # e.g.: obj-y += foo_$(BITS).o |
| export BITS |
| |
| # |
| # Prevent GCC from generating any FP code by mistake. |
| # |
| # This must happen before we try the -mpreferred-stack-boundary, see: |
| # |
| # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383 |
| # |
| KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow |
| KBUILD_CFLAGS += $(call cc-option,-mno-avx,) |
| |
| ifeq ($(CONFIG_X86_32),y) |
| BITS := 32 |
| UTS_MACHINE := i386 |
| CHECKFLAGS += -D__i386__ |
| |
| biarch := $(call cc-option,-m32) |
| KBUILD_AFLAGS += $(biarch) |
| KBUILD_CFLAGS += $(biarch) |
| |
| KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return |
| |
| # Never want PIC in a 32-bit kernel, prevent breakage with GCC built |
| # with nonstandard options |
| KBUILD_CFLAGS += -fno-pic |
| |
| # Align the stack to the register width instead of using the default |
| # alignment of 16 bytes. This reduces stack usage and the number of |
| # alignment instructions. |
| KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align4)) |
| |
| # CPU-specific tuning. Anything which can be shared with UML should go here. |
| include arch/x86/Makefile_32.cpu |
| KBUILD_CFLAGS += $(cflags-y) |
| |
| # temporary until string.h is fixed |
| KBUILD_CFLAGS += -ffreestanding |
| else |
| BITS := 64 |
| UTS_MACHINE := x86_64 |
| CHECKFLAGS += -D__x86_64__ |
| |
| biarch := -m64 |
| KBUILD_AFLAGS += -m64 |
| KBUILD_CFLAGS += -m64 |
| |
| # Align jump targets to 1 byte, not the default 16 bytes: |
| KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1) |
| |
| # Pack loops tightly as well: |
| KBUILD_CFLAGS += $(call cc-option,-falign-loops=1) |
| |
| # Don't autogenerate traditional x87 instructions |
| KBUILD_CFLAGS += $(call cc-option,-mno-80387) |
| KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387) |
| |
| # By default gcc and clang use a stack alignment of 16 bytes for x86. |
| # However the standard kernel entry on x86-64 leaves the stack on an |
| # 8-byte boundary. If the compiler isn't informed about the actual |
| # alignment it will generate extra alignment instructions for the |
| # default alignment which keep the stack *mis*aligned. |
| # Furthermore an alignment to the register width reduces stack usage |
| # and the number of alignment instructions. |
| KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align8)) |
| |
| # Use -mskip-rax-setup if supported. |
| KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup) |
| |
| # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu) |
| cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8) |
| cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona) |
| |
| cflags-$(CONFIG_MCORE2) += \ |
| $(call cc-option,-march=core2,$(call cc-option,-mtune=generic)) |
| cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \ |
| $(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic)) |
| cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic) |
| KBUILD_CFLAGS += $(cflags-y) |
| |
| KBUILD_CFLAGS += -mno-red-zone |
| KBUILD_CFLAGS += -mcmodel=kernel |
| endif |
| |
| ifdef CONFIG_X86_X32 |
| x32_ld_ok := $(call try-run,\ |
| /bin/echo -e '1: .quad 1b' | \ |
| $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" - && \ |
| $(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMPO" && \ |
| $(LD) -m elf32_x86_64 "$$TMPO" -o "$$TMP",y,n) |
| ifeq ($(x32_ld_ok),y) |
| CONFIG_X86_X32_ABI := y |
| KBUILD_AFLAGS += -DCONFIG_X86_X32_ABI |
| KBUILD_CFLAGS += -DCONFIG_X86_X32_ABI |
| else |
| $(warning CONFIG_X86_X32 enabled but no binutils support) |
| endif |
| endif |
| export CONFIG_X86_X32_ABI |
| |
| # |
| # If the function graph tracer is used with mcount instead of fentry, |
| # '-maccumulate-outgoing-args' is needed to prevent a GCC bug |
| # (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109) |
| # |
| ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| ifndef CONFIG_HAVE_FENTRY |
| ACCUMULATE_OUTGOING_ARGS := 1 |
| else |
| ifeq ($(call cc-option-yn, -mfentry), n) |
| ACCUMULATE_OUTGOING_ARGS := 1 |
| |
| # GCC ignores '-maccumulate-outgoing-args' when used with '-Os'. |
| # If '-Os' is enabled, disable it and print a warning. |
| ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE |
| undefine CONFIG_CC_OPTIMIZE_FOR_SIZE |
| $(warning Disabling CONFIG_CC_OPTIMIZE_FOR_SIZE. Your compiler does not have -mfentry so you cannot optimize for size with CONFIG_FUNCTION_GRAPH_TRACER.) |
| endif |
| |
| endif |
| endif |
| endif |
| |
| ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1) |
| # This compiler flag is not supported by Clang: |
| KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,) |
| endif |
| |
| # Workaround for a gcc prelease that unfortunately was shipped in a suse release |
| KBUILD_CFLAGS += -Wno-sign-compare |
| # |
| KBUILD_CFLAGS += -fno-asynchronous-unwind-tables |
| |
| # Avoid indirect branches in kernel to deal with Spectre |
| ifdef CONFIG_RETPOLINE |
| KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) |
| # Additionally, avoid generating expensive indirect jumps which |
| # are subject to retpolines for small number of switch cases. |
| # clang turns off jump table generation by default when under |
| # retpoline builds, however, gcc does not for x86. This has |
| # only been fixed starting from gcc stable version 8.4.0 and |
| # onwards, but not for older ones. See gcc bug #86952. |
| ifndef CONFIG_CC_IS_CLANG |
| KBUILD_CFLAGS += $(call cc-option,-fno-jump-tables) |
| endif |
| endif |
| |
| KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE) |
| |
| ifdef CONFIG_X86_NEED_RELOCS |
| LDFLAGS_vmlinux := --emit-relocs --discard-none |
| else |
| LDFLAGS_vmlinux := |
| endif |
| |
| # |
| # The 64-bit kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to |
| # the linker to force 2MB page size regardless of the default page size used |
| # by the linker. |
| # |
| ifdef CONFIG_X86_64 |
| LDFLAGS_vmlinux += -z max-page-size=0x200000 |
| endif |
| |
| |
| archscripts: scripts_basic |
| $(Q)$(MAKE) $(build)=arch/x86/tools relocs |
| |
| ### |
| # Syscall table generation |
| |
| archheaders: |
| $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all |
| |
| ### |
| # Kernel objects |
| |
| head-y := arch/x86/kernel/head_$(BITS).o |
| head-y += arch/x86/kernel/head$(BITS).o |
| head-y += arch/x86/kernel/ebda.o |
| head-y += arch/x86/kernel/platform-quirks.o |
| |
| libs-y += arch/x86/lib/ |
| |
| # See arch/x86/Kbuild for content of core part of the kernel |
| core-y += arch/x86/ |
| |
| # drivers-y are linked after core-y |
| drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/ |
| drivers-$(CONFIG_PCI) += arch/x86/pci/ |
| |
| # must be linked after kernel/ |
| drivers-$(CONFIG_OPROFILE) += arch/x86/oprofile/ |
| |
| # suspend and hibernation support |
| drivers-$(CONFIG_PM) += arch/x86/power/ |
| |
| drivers-$(CONFIG_FB) += arch/x86/video/ |
| |
| #### |
| # boot loader support. Several targets are kept for legacy purposes |
| |
| boot := arch/x86/boot |
| |
| BOOT_TARGETS = bzdisk fdimage fdimage144 fdimage288 isoimage |
| |
| PHONY += bzImage $(BOOT_TARGETS) |
| |
| # Default kernel to build |
| all: bzImage |
| |
| # KBUILD_IMAGE specify target image being built |
| KBUILD_IMAGE := $(boot)/bzImage |
| |
| bzImage: vmlinux |
| ifeq ($(CONFIG_X86_DECODER_SELFTEST),y) |
| $(Q)$(MAKE) $(build)=arch/x86/tools posttest |
| endif |
| $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE) |
| $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot |
| $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@ |
| |
| $(BOOT_TARGETS): vmlinux |
| $(Q)$(MAKE) $(build)=$(boot) $@ |
| |
| PHONY += install bzlilo |
| install bzlilo: |
| $(Q)$(MAKE) $(build)=$(boot) $@ |
| |
| PHONY += vdso_install |
| vdso_install: |
| $(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@ |
| |
| archprepare: checkbin |
| checkbin: |
| ifndef CONFIG_CC_HAS_ASM_GOTO |
| @echo Compiler lacks asm-goto support. |
| @exit 1 |
| endif |
| ifdef CONFIG_RETPOLINE |
| ifeq ($(RETPOLINE_CFLAGS),) |
| @echo "You are building kernel with non-retpoline compiler." >&2 |
| @echo "Please update your compiler." >&2 |
| @false |
| endif |
| endif |
| |
| archclean: |
| $(Q)rm -rf $(objtree)/arch/i386 |
| $(Q)rm -rf $(objtree)/arch/x86_64 |
| $(Q)$(MAKE) $(clean)=$(boot) |
| $(Q)$(MAKE) $(clean)=arch/x86/tools |
| |
| define archhelp |
| echo '* bzImage - Compressed kernel image (arch/x86/boot/bzImage)' |
| echo ' install - Install kernel using' |
| echo ' (your) ~/bin/$(INSTALLKERNEL) or' |
| echo ' (distribution) /sbin/$(INSTALLKERNEL) or' |
| echo ' install to $$(INSTALL_PATH) and run lilo' |
| echo ' fdimage - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)' |
| echo ' fdimage144 - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)' |
| echo ' fdimage288 - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)' |
| echo ' isoimage - Create a boot CD-ROM image (arch/x86/boot/image.iso)' |
| echo ' bzdisk/fdimage*/isoimage also accept:' |
| echo ' FDARGS="..." arguments for the booted kernel' |
| echo ' FDINITRD=file initrd for the booted kernel' |
| endef |