1 # Unified Makefile for i386 and x86_64
3 # select defconfig based on actual architecture
5 ifeq ($(shell uname -m),x86_64)
6 KBUILD_DEFCONFIG := x86_64_defconfig
8 KBUILD_DEFCONFIG := i386_defconfig
11 KBUILD_DEFCONFIG := $(ARCH)_defconfig
14 # For gcc stack alignment is specified with -mpreferred-stack-boundary,
15 # clang has the option -mstack-alignment for that purpose.
16 ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
17 cc_stack_align4 := -mpreferred-stack-boundary=2
18 cc_stack_align8 := -mpreferred-stack-boundary=3
19 else ifneq ($(call cc-option, -mstack-alignment=16),)
20 cc_stack_align4 := -mstack-alignment=4
21 cc_stack_align8 := -mstack-alignment=8
24 # How to compile the 16-bit code. Note we always compile for -march=i386;
25 # that way we can complain to the user if the CPU is insufficient.
27 # The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For
28 # older versions of GCC, include an *assembly* header to make sure that
29 # gcc doesn't play any games behind our back.
30 CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h
31 M16_CFLAGS := $(call cc-option, -m16, $(CODE16GCC_CFLAGS))
33 REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -D__KERNEL__ \
34 -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 $(call cc-option,-fcf-protection=none)
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 REALMODE_CFLAGS += $(CLANG_FLAGS)
44 export REALMODE_CFLAGS
46 # BITS is used as extension for files which are available in a 32 bit
47 # and a 64 bit version to simplify shared Makefiles.
48 # e.g.: obj-y += foo_$(BITS).o
51 ifdef CONFIG_X86_NEED_RELOCS
52 LDFLAGS_vmlinux := --emit-relocs --discard-none
56 # Prevent GCC from generating any FP code by mistake.
58 # This must happen before we try the -mpreferred-stack-boundary, see:
60 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
62 KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow
63 KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
65 # Intel CET isn't enabled in the kernel
66 KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
68 ifeq ($(CONFIG_X86_32),y)
71 CHECKFLAGS += -D__i386__
73 biarch := $(call cc-option,-m32)
74 KBUILD_AFLAGS += $(biarch)
75 KBUILD_CFLAGS += $(biarch)
77 KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
79 # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
80 # with nonstandard options
81 KBUILD_CFLAGS += -fno-pic
83 # Align the stack to the register width instead of using the default
84 # alignment of 16 bytes. This reduces stack usage and the number of
85 # alignment instructions.
86 KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align4))
88 # Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
89 # a lot more stack due to the lack of sharing of stacklots:
90 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0400, \
91 $(call cc-option,-fno-unit-at-a-time))
93 # CPU-specific tuning. Anything which can be shared with UML should go here.
94 include arch/x86/Makefile_32.cpu
95 KBUILD_CFLAGS += $(cflags-y)
97 # temporary until string.h is fixed
98 KBUILD_CFLAGS += -ffreestanding
101 UTS_MACHINE := x86_64
102 CHECKFLAGS += -D__x86_64__ -m64
105 KBUILD_AFLAGS += -m64
106 KBUILD_CFLAGS += -m64
108 # Align jump targets to 1 byte, not the default 16 bytes:
109 KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1)
111 # Pack loops tightly as well:
112 KBUILD_CFLAGS += $(call cc-option,-falign-loops=1)
114 # Don't autogenerate traditional x87 instructions
115 KBUILD_CFLAGS += $(call cc-option,-mno-80387)
116 KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)
118 # By default gcc and clang use a stack alignment of 16 bytes for x86.
119 # However the standard kernel entry on x86-64 leaves the stack on an
120 # 8-byte boundary. If the compiler isn't informed about the actual
121 # alignment it will generate extra alignment instructions for the
122 # default alignment which keep the stack *mis*aligned.
123 # Furthermore an alignment to the register width reduces stack usage
124 # and the number of alignment instructions.
125 KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align8))
127 # Use -mskip-rax-setup if supported.
128 KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
130 # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
131 cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
132 cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
134 cflags-$(CONFIG_MCORE2) += \
135 $(call cc-option,-march=core2,$(call cc-option,-mtune=generic))
136 cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \
137 $(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
138 cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)
139 KBUILD_CFLAGS += $(cflags-y)
141 KBUILD_CFLAGS += -mno-red-zone
142 KBUILD_CFLAGS += -mcmodel=kernel
144 # -funit-at-a-time shrinks the kernel .text considerably
145 # unfortunately it makes reading oopses harder.
146 KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
148 # this works around some issues with generating unwind tables in older gccs
149 # newer gccs do it by default
150 KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args)
154 x32_ld_ok := $(call try-run,\
155 /bin/echo -e '1: .quad 1b' | \
156 $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" - && \
157 $(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMPO" && \
158 $(LD) -m elf32_x86_64 "$$TMPO" -o "$$TMP",y,n)
159 ifeq ($(x32_ld_ok),y)
160 CONFIG_X86_X32_ABI := y
161 KBUILD_AFLAGS += -DCONFIG_X86_X32_ABI
162 KBUILD_CFLAGS += -DCONFIG_X86_X32_ABI
164 $(warning CONFIG_X86_X32 enabled but no binutils support)
167 export CONFIG_X86_X32_ABI
169 # Don't unroll struct assignments with kmemcheck enabled
170 ifeq ($(CONFIG_KMEMCHECK),y)
171 KBUILD_CFLAGS += $(call cc-option,-fno-builtin-memcpy)
174 # Stackpointer is addressed different for 32 bit and 64 bit x86
175 sp-$(CONFIG_X86_32) := esp
176 sp-$(CONFIG_X86_64) := rsp
178 # do binutils support CFI?
179 cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1)
180 # is .cfi_signal_frame supported too?
181 cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1)
182 cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1)
184 # does binutils support specific instructions?
185 asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1)
186 asinstr += $(call as-instr,pshufb %xmm0$(comma)%xmm0,-DCONFIG_AS_SSSE3=1)
187 asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1)
188 avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1)
189 avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1)
190 avx512_instr :=$(call as-instr,vpmovm2b %k1$(comma)%zmm5,-DCONFIG_AS_AVX512=1)
191 sha1_ni_instr :=$(call as-instr,sha1msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA1_NI=1)
192 sha256_ni_instr :=$(call as-instr,sha256msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA256_NI=1)
194 KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
195 KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
197 LDFLAGS := -m elf_$(UTS_MACHINE)
200 # The 64-bit kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to
201 # the linker to force 2MB page size regardless of the default page size used
205 LDFLAGS += $(call ld-option, -z max-page-size=0x200000)
209 KBUILD_CFLAGS += -pipe
210 # Workaround for a gcc prelease that unfortunately was shipped in a suse release
211 KBUILD_CFLAGS += -Wno-sign-compare
213 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
215 KBUILD_CFLAGS += $(mflags-y)
216 KBUILD_AFLAGS += $(mflags-y)
218 # Avoid indirect branches in kernel to deal with Spectre
219 ifdef CONFIG_RETPOLINE
220 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
221 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
223 RETPOLINE_CFLAGS += $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
224 KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
227 archscripts: scripts_basic
228 $(Q)$(MAKE) $(build)=arch/x86/tools relocs
231 # Syscall table generation
234 $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all
237 ifeq ($(CONFIG_KEXEC_FILE),y)
238 $(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c
240 ifdef CONFIG_RETPOLINE
241 ifeq ($(RETPOLINE_CFLAGS),)
242 @echo "You are building kernel with non-retpoline compiler." >&2
243 @echo "Please update your compiler." >&2
251 head-y := arch/x86/kernel/head_$(BITS).o
252 head-y += arch/x86/kernel/head$(BITS).o
253 head-y += arch/x86/kernel/ebda.o
254 head-y += arch/x86/kernel/platform-quirks.o
256 libs-y += arch/x86/lib/
258 # See arch/x86/Kbuild for content of core part of the kernel
261 # drivers-y are linked after core-y
262 drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
263 drivers-$(CONFIG_PCI) += arch/x86/pci/
265 # must be linked after kernel/
266 drivers-$(CONFIG_OPROFILE) += arch/x86/oprofile/
268 # suspend and hibernation support
269 drivers-$(CONFIG_PM) += arch/x86/power/
271 drivers-$(CONFIG_FB) += arch/x86/video/
273 drivers-$(CONFIG_RAS) += arch/x86/ras/
276 # boot loader support. Several targets are kept for legacy purposes
278 boot := arch/x86/boot
280 BOOT_TARGETS = bzlilo bzdisk fdimage fdimage144 fdimage288 isoimage
282 PHONY += bzImage $(BOOT_TARGETS)
284 # Default kernel to build
287 # KBUILD_IMAGE specify target image being built
288 KBUILD_IMAGE := $(boot)/bzImage
291 ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
292 $(Q)$(MAKE) $(build)=arch/x86/tools posttest
294 $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
295 $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
296 $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@
298 $(BOOT_TARGETS): vmlinux
299 $(Q)$(MAKE) $(build)=$(boot) $@
303 $(Q)$(MAKE) $(build)=$(boot) $@
305 PHONY += vdso_install
307 $(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@
310 $(Q)rm -rf $(objtree)/arch/i386
311 $(Q)rm -rf $(objtree)/arch/x86_64
312 $(Q)$(MAKE) $(clean)=$(boot)
313 $(Q)$(MAKE) $(clean)=arch/x86/tools
314 $(Q)$(MAKE) $(clean)=arch/x86/purgatory
317 echo '* bzImage - Compressed kernel image (arch/x86/boot/bzImage)'
318 echo ' install - Install kernel using'
319 echo ' (your) ~/bin/$(INSTALLKERNEL) or'
320 echo ' (distribution) /sbin/$(INSTALLKERNEL) or'
321 echo ' install to $$(INSTALL_PATH) and run lilo'
322 echo ' fdimage - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
323 echo ' fdimage144 - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
324 echo ' fdimage288 - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
325 echo ' isoimage - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
326 echo ' bzdisk/fdimage*/isoimage also accept:'
327 echo ' FDARGS="..." arguments for the booted kernel'
328 echo ' FDINITRD=file initrd for the booted kernel'