1 # SPDX-License-Identifier: GPL-2.0
2 # Unified Makefile for i386 and x86_64
4 # select defconfig based on actual architecture
6 ifeq ($(shell uname
-m
),x86_64
)
7 KBUILD_DEFCONFIG
:= x86_64_defconfig
9 KBUILD_DEFCONFIG
:= i386_defconfig
12 KBUILD_DEFCONFIG
:= $(ARCH
)_defconfig
15 # For gcc stack alignment is specified with -mpreferred-stack-boundary,
16 # clang has the option -mstack-alignment for that purpose.
17 ifneq ($(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 ($(call cc-option
, -mstack-alignment
=16),)
21 cc_stack_align4
:= -mstack-alignment
=4
22 cc_stack_align8
:= -mstack-alignment
=8
25 # How to compile the 16-bit code. Note we always compile for -march=i386;
26 # that way we can complain to the user if the CPU is insufficient.
28 # The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For
29 # older versions of GCC, include an *assembly* header to make sure that
30 # gcc doesn't play any games behind our back.
31 CODE16GCC_CFLAGS
:= -m32
-Wa
,$(srctree
)/arch
/x86
/boot
/code16gcc.h
32 M16_CFLAGS
:= $(call cc-option
, -m16
, $(CODE16GCC_CFLAGS
))
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 \
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
), $(cc_stack_align4
))
42 export REALMODE_CFLAGS
44 # BITS is used as extension for files which are available in a 32 bit
45 # and a 64 bit version to simplify shared Makefiles.
46 # e.g.: obj-y += foo_$(BITS).o
49 ifdef CONFIG_X86_NEED_RELOCS
50 LDFLAGS_vmlinux
:= --emit-relocs
54 # Prevent GCC from generating any FP code by mistake.
56 # This must happen before we try the -mpreferred-stack-boundary, see:
58 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
60 KBUILD_CFLAGS
+= -mno-sse
-mno-mmx
-mno-sse2
-mno-3dnow
61 KBUILD_CFLAGS
+= $(call cc-option
,-mno-avx
,)
63 ifeq ($(CONFIG_X86_32
),y
)
66 CHECKFLAGS
+= -D__i386__
68 biarch
:= $(call cc-option
,-m32
)
69 KBUILD_AFLAGS
+= $(biarch
)
70 KBUILD_CFLAGS
+= $(biarch
)
72 KBUILD_CFLAGS
+= -msoft-float
-mregparm
=3 -freg-struct-return
74 # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
75 # with nonstandard options
76 KBUILD_CFLAGS
+= -fno-pic
78 # Align the stack to the register width instead of using the default
79 # alignment of 16 bytes. This reduces stack usage and the number of
80 # alignment instructions.
81 KBUILD_CFLAGS
+= $(call cc-option
,$(cc_stack_align4
))
83 # Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
84 # a lot more stack due to the lack of sharing of stacklots:
85 KBUILD_CFLAGS
+= $(call cc-ifversion
, -lt
, 0400, \
86 $(call cc-option
,-fno-unit-at-a-time
))
88 # CPU-specific tuning. Anything which can be shared with UML should go here.
89 include arch
/x86
/Makefile_32.cpu
90 KBUILD_CFLAGS
+= $(cflags-y
)
92 # temporary until string.h is fixed
93 KBUILD_CFLAGS
+= -ffreestanding
97 CHECKFLAGS
+= -D__x86_64__
-m64
100 KBUILD_AFLAGS
+= -m64
101 KBUILD_CFLAGS
+= -m64
103 # Align jump targets to 1 byte, not the default 16 bytes:
104 KBUILD_CFLAGS
+= $(call cc-option
,-falign-jumps
=1)
106 # Pack loops tightly as well:
107 KBUILD_CFLAGS
+= $(call cc-option
,-falign-loops
=1)
109 # Don't autogenerate traditional x87 instructions
110 KBUILD_CFLAGS
+= $(call cc-option
,-mno-80387
)
111 KBUILD_CFLAGS
+= $(call cc-option
,-mno-fp-ret-in-387
)
113 # By default gcc and clang use a stack alignment of 16 bytes for x86.
114 # However the standard kernel entry on x86-64 leaves the stack on an
115 # 8-byte boundary. If the compiler isn't informed about the actual
116 # alignment it will generate extra alignment instructions for the
117 # default alignment which keep the stack *mis*aligned.
118 # Furthermore an alignment to the register width reduces stack usage
119 # and the number of alignment instructions.
120 KBUILD_CFLAGS
+= $(call cc-option
,$(cc_stack_align8
))
122 # Use -mskip-rax-setup if supported.
123 KBUILD_CFLAGS
+= $(call cc-option
,-mskip-rax-setup
)
125 # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
126 cflags-
$(CONFIG_MK8
) += $(call cc-option
,-march
=k8
)
127 cflags-
$(CONFIG_MPSC
) += $(call cc-option
,-march
=nocona
)
129 cflags-
$(CONFIG_MCORE2
) += \
130 $(call cc-option
,-march
=core2
,$(call cc-option
,-mtune
=generic
))
131 cflags-
$(CONFIG_MATOM
) += $(call cc-option
,-march
=atom
) \
132 $(call cc-option
,-mtune
=atom
,$(call cc-option
,-mtune
=generic
))
133 cflags-
$(CONFIG_GENERIC_CPU
) += $(call cc-option
,-mtune
=generic
)
134 KBUILD_CFLAGS
+= $(cflags-y
)
136 KBUILD_CFLAGS
+= -mno-red-zone
137 KBUILD_CFLAGS
+= -mcmodel
=kernel
139 # -funit-at-a-time shrinks the kernel .text considerably
140 # unfortunately it makes reading oopses harder.
141 KBUILD_CFLAGS
+= $(call cc-option
,-funit-at-a-time
)
145 x32_ld_ok
:= $(call try-run
,\
146 /bin
/echo
-e
'1: .quad 1b' | \
147 $(CC
) $(KBUILD_AFLAGS
) -c
-x assembler
-o
"$$TMP" - && \
148 $(OBJCOPY
) -O elf32-x86-64
"$$TMP" "$$TMPO" && \
149 $(LD
) -m elf32_x86_64
"$$TMPO" -o
"$$TMP",y
,n
)
150 ifeq ($(x32_ld_ok
),y
)
151 CONFIG_X86_X32_ABI
:= y
152 KBUILD_AFLAGS
+= -DCONFIG_X86_X32_ABI
153 KBUILD_CFLAGS
+= -DCONFIG_X86_X32_ABI
155 $(warning CONFIG_X86_X32 enabled but no binutils support
)
158 export CONFIG_X86_X32_ABI
161 # If the function graph tracer is used with mcount instead of fentry,
162 # '-maccumulate-outgoing-args' is needed to prevent a GCC bug
163 # (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109)
165 ifdef CONFIG_FUNCTION_GRAPH_TRACER
166 ifndef CONFIG_HAVE_FENTRY
167 ACCUMULATE_OUTGOING_ARGS
:= 1
169 ifeq ($(call cc-option-yn
, -mfentry
), n
)
170 ACCUMULATE_OUTGOING_ARGS
:= 1
172 # GCC ignores '-maccumulate-outgoing-args' when used with '-Os'.
173 # If '-Os' is enabled, disable it and print a warning.
174 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
175 undefine CONFIG_CC_OPTIMIZE_FOR_SIZE
176 $(warning Disabling CONFIG_CC_OPTIMIZE_FOR_SIZE. Your compiler does not have
-mfentry so you cannot optimize for size with CONFIG_FUNCTION_GRAPH_TRACER.
)
183 ifndef CC_HAVE_ASM_GOTO
184 $(error Compiler lacks asm-goto support.
)
188 # Jump labels need '-maccumulate-outgoing-args' for gcc < 4.5.2 to prevent a
189 # GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46226). There's no way
190 # to test for this bug at compile-time because the test case needs to execute,
191 # which is a no-go for cross compilers. So check the GCC version instead.
193 ifdef CONFIG_JUMP_LABEL
194 ifneq ($(ACCUMULATE_OUTGOING_ARGS
), 1)
195 ACCUMULATE_OUTGOING_ARGS
= $(call cc-if-fullversion
, -lt
, 040502, 1)
199 ifeq ($(ACCUMULATE_OUTGOING_ARGS
), 1)
200 # This compiler flag is not supported by Clang:
201 KBUILD_CFLAGS
+= $(call cc-option
,-maccumulate-outgoing-args
,)
204 # Stackpointer is addressed different for 32 bit and 64 bit x86
205 sp-
$(CONFIG_X86_32
) := esp
206 sp-
$(CONFIG_X86_64
) := rsp
208 # do binutils support CFI?
209 cfi
:= $(call as-instr
,.cfi_startproc
\n.cfi_rel_offset
$(sp-y
)$(comma
)0\n.cfi_endproc
,-DCONFIG_AS_CFI
=1)
210 # is .cfi_signal_frame supported too?
211 cfi-sigframe
:= $(call as-instr
,.cfi_startproc
\n.cfi_signal_frame
\n.cfi_endproc
,-DCONFIG_AS_CFI_SIGNAL_FRAME
=1)
212 cfi-sections
:= $(call as-instr
,.cfi_sections .debug_frame
,-DCONFIG_AS_CFI_SECTIONS
=1)
214 # does binutils support specific instructions?
215 asinstr
:= $(call as-instr
,fxsaveq
(%rax
),-DCONFIG_AS_FXSAVEQ
=1)
216 asinstr
+= $(call as-instr
,pshufb
%xmm0
$(comma
)%xmm0
,-DCONFIG_AS_SSSE3
=1)
217 asinstr
+= $(call as-instr
,crc32l
%eax
$(comma
)%eax
,-DCONFIG_AS_CRC32
=1)
218 avx_instr
:= $(call as-instr
,vxorps
%ymm0
$(comma
)%ymm1
$(comma
)%ymm2
,-DCONFIG_AS_AVX
=1)
219 avx2_instr
:=$(call as-instr
,vpbroadcastb
%xmm0
$(comma
)%ymm1
,-DCONFIG_AS_AVX2
=1)
220 avx512_instr
:=$(call as-instr
,vpmovm2b
%k1
$(comma
)%zmm5
,-DCONFIG_AS_AVX512
=1)
221 sha1_ni_instr
:=$(call as-instr
,sha1msg1
%xmm0
$(comma
)%xmm1
,-DCONFIG_AS_SHA1_NI
=1)
222 sha256_ni_instr
:=$(call as-instr
,sha256msg1
%xmm0
$(comma
)%xmm1
,-DCONFIG_AS_SHA256_NI
=1)
224 KBUILD_AFLAGS
+= $(cfi
) $(cfi-sigframe
) $(cfi-sections
) $(asinstr
) $(avx_instr
) $(avx2_instr
) $(avx512_instr
) $(sha1_ni_instr
) $(sha256_ni_instr
)
225 KBUILD_CFLAGS
+= $(cfi
) $(cfi-sigframe
) $(cfi-sections
) $(asinstr
) $(avx_instr
) $(avx2_instr
) $(avx512_instr
) $(sha1_ni_instr
) $(sha256_ni_instr
)
227 LDFLAGS
:= -m elf_
$(UTS_MACHINE
)
230 # The 64-bit kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to
231 # the linker to force 2MB page size regardless of the default page size used
235 LDFLAGS
+= $(call ld-option
, -z max-page-size
=0x200000)
239 KBUILD_CFLAGS
+= -pipe
240 # Workaround for a gcc prelease that unfortunately was shipped in a suse release
241 KBUILD_CFLAGS
+= -Wno-sign-compare
243 KBUILD_CFLAGS
+= -fno-asynchronous-unwind-tables
245 # Avoid indirect branches in kernel to deal with Spectre
246 ifdef CONFIG_RETPOLINE
247 ifneq ($(RETPOLINE_CFLAGS
),)
248 KBUILD_CFLAGS
+= $(RETPOLINE_CFLAGS
) -DRETPOLINE
252 archscripts
: scripts_basic
253 $(Q
)$(MAKE
) $(build
)=arch
/x86
/tools relocs
256 # Syscall table generation
259 $(Q
)$(MAKE
) $(build
)=arch
/x86
/entry
/syscalls
all
262 ifeq ($(CONFIG_KEXEC_FILE
),y
)
263 $(Q
)$(MAKE
) $(build
)=arch
/x86
/purgatory arch
/x86
/purgatory
/kexec-purgatory.c
269 head-y
:= arch
/x86
/kernel
/head_
$(BITS
).o
270 head-y
+= arch
/x86
/kernel
/head
$(BITS
).o
271 head-y
+= arch
/x86
/kernel
/ebda.o
272 head-y
+= arch
/x86
/kernel
/platform-quirks.o
274 libs-y
+= arch
/x86
/lib
/
276 # See arch/x86/Kbuild for content of core part of the kernel
279 # drivers-y are linked after core-y
280 drivers-
$(CONFIG_MATH_EMULATION
) += arch
/x86
/math-emu
/
281 drivers-
$(CONFIG_PCI
) += arch
/x86
/pci
/
283 # must be linked after kernel/
284 drivers-
$(CONFIG_OPROFILE
) += arch
/x86
/oprofile
/
286 # suspend and hibernation support
287 drivers-
$(CONFIG_PM
) += arch
/x86
/power
/
289 drivers-
$(CONFIG_FB
) += arch
/x86
/video
/
292 # boot loader support. Several targets are kept for legacy purposes
294 boot
:= arch
/x86
/boot
296 BOOT_TARGETS
= bzlilo bzdisk fdimage fdimage144 fdimage288 isoimage
298 PHONY
+= bzImage
$(BOOT_TARGETS
)
300 # Default kernel to build
303 # KBUILD_IMAGE specify target image being built
304 KBUILD_IMAGE
:= $(boot
)/bzImage
307 ifeq ($(CONFIG_X86_DECODER_SELFTEST
),y
)
308 $(Q
)$(MAKE
) $(build
)=arch
/x86
/tools posttest
310 $(Q
)$(MAKE
) $(build
)=$(boot
) $(KBUILD_IMAGE
)
311 $(Q
)mkdir
-p
$(objtree
)/arch
/$(UTS_MACHINE
)/boot
312 $(Q
)ln
-fsn ..
/..
/x86
/boot
/bzImage
$(objtree
)/arch
/$(UTS_MACHINE
)/boot
/$@
314 $(BOOT_TARGETS
): vmlinux
315 $(Q
)$(MAKE
) $(build
)=$(boot
) $@
319 $(Q
)$(MAKE
) $(build
)=$(boot
) $@
321 PHONY
+= vdso_install
323 $(Q
)$(MAKE
) $(build
)=arch
/x86
/entry
/vdso
$@
326 $(Q
)rm -rf
$(objtree
)/arch
/i386
327 $(Q
)rm -rf
$(objtree
)/arch
/x86_64
328 $(Q
)$(MAKE
) $(clean)=$(boot
)
329 $(Q
)$(MAKE
) $(clean)=arch
/x86
/tools
330 $(Q
)$(MAKE
) $(clean)=arch
/x86
/purgatory
333 echo
'* bzImage - Compressed kernel image (arch/x86/boot/bzImage)'
334 echo
' install - Install kernel using'
335 echo
' (your) ~/bin/$(INSTALLKERNEL) or'
336 echo
' (distribution) /sbin/$(INSTALLKERNEL) or'
337 echo
' install to $$(INSTALL_PATH) and run lilo'
338 echo
' fdimage - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
339 echo
' fdimage144 - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
340 echo
' fdimage288 - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
341 echo
' isoimage - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
342 echo
' bzdisk/fdimage*/isoimage also accept:'
343 echo
' FDARGS="..." arguments for the booted kernel'
344 echo
' FDINITRD=file initrd for the booted kernel'