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  #   Aˆl–Ü4ý( ©³( 	Å€fàD¦-ÿÊ„Dû_ÁÈ ,    A# 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 | sed -e 's/i.86/i386/'),i386)
        KBUILD_DEFCONFIG := i386_defconfig
  else
        KBUILD_DEFCONFIG := x86_64_defconfig
  endif
else
        KBUILD_DEFCONFIG := $(ARCH)_defconfig
endif

ifdef CONFIG_CC_IS_GCC
RETPOLINE_CFLAGS	:= $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
RETPOLINE_VDSO_CFLAGS	:= $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register)
endif
ifdef CONFIG_CC_IS_CLANG
RETPOLINE_CFLAGS	:= -mretpoline-external-thunk
RETPOLINE_VDSO_CFLAGS	:= -mretpoline
endif
RETPOLINE_CFLAGS	+= $(call cc-option,-mindirect-branch-cs-prefix)

ifdef CONFIG_MITIGATION_RETHUNK
RETHUNK_CFLAGS		:= -mfunction-return=thunk-extern
RETPOLINE_CFLAGS	+= $(RETHUNK_CFLAGS)
endif

export RETHUNK_CFLAGS
export RETPOLINE_CFLAGS
export RETPOLINE_VDSO_CFLAGS

# 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.
REALMODE_CFLAGS	:= -std=gnu11 -m16 -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \
		   -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
		   -fno-strict-aliasing -fomit-frame-pointer -fno-pic \
		   -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none)

REALMODE_CFLAGS += -ffreestanding
REALMODE_CFLAGS += -fno-stack-protector
REALMODE_CFLAGS += -Wno-address-of-packed-member
REALMODE_CFLAGS += $(cc_stack_align4)
REALMODE_CFLAGS += $(CLANG_FLAGS)
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 -mno-avx
KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2

ifeq ($(CONFIG_X86_KERNEL_IBT),y)
#
# Kernel IBT has S_CET.NOTRACK_EN=0, as such the compilers must not generate
# NOTRACK prefixes. Current generation compilers unconditionally employ NOTRACK
# for jump-tables, as such, disable jump-tables for now.
#
# (jump-tables are implicitly disabled by RETPOLINE)
#
#   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104816
#
KBUILD_CFLAGS += $(call cc-option,-fcf-protection=branch -fno-jump-tables)
KBUILD_RUSTFLAGS += -Zcf-protection=branch -Zno-jump-tables
else
KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
endif

ifeq ($(CONFIG_X86_32),y)
        BITS := 32
        UTS_MACHINE := i386
        CHECKFLAGS += -D__i386__

        KBUILD_AFLAGS += -m32
        KBUILD_CFLAGS += -m32

        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 += $(cc_stack_align4)

        # CPU-specific tuning. Anything which can be shared with UML should go here.
        include $(srctree)/arch/x86/Makefile_32.cpu
        KBUILD_CFLAGS += $(cflags-y)

        # temporary until string.h is fixed
        KBUILD_CFLAGS += -ffreestanding

	ifeq ($(CONFIG_STACKPROTECTOR),y)
		i