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1# SPDX-License-Identifier: GPL-2.0
2# Unified Makefile for i386 and x86_64
3
4# select defconfig based on actual architecture
5ifeq ($(ARCH),x86)
6  ifeq ($(shell uname -m),x86_64)
7        KBUILD_DEFCONFIG := x86_64_defconfig
8  else
9        KBUILD_DEFCONFIG := i386_defconfig
10  endif
11else
12        KBUILD_DEFCONFIG := $(ARCH)_defconfig
13endif
14
15# For gcc stack alignment is specified with -mpreferred-stack-boundary,
16# clang has the option -mstack-alignment for that purpose.
17ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
18      cc_stack_align4 := -mpreferred-stack-boundary=2
19      cc_stack_align8 := -mpreferred-stack-boundary=3
20else ifneq ($(call cc-option, -mstack-alignment=16),)
21      cc_stack_align4 := -mstack-alignment=4
22      cc_stack_align8 := -mstack-alignment=8
23endif
24
25# How to compile the 16-bit code.  Note we always compile for -march=i386;
26# that way we can complain to the user if the CPU is insufficient.
27#
28# The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For
29# older versions of GCC, include an *assembly* header to make sure that
30# gcc doesn't play any games behind our back.
31CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h
32M16_CFLAGS	 := $(call cc-option, -m16, $(CODE16GCC_CFLAGS))
33
34REALMODE_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 $(call cc-option,-fcf-protection=none)
38
39REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding)
40REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector)
41REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member)
42REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4))
43REALMODE_CFLAGS += $(CLANG_FLAGS)
44export REALMODE_CFLAGS
45
46# BITS is used as extension for files which are available in a 32 bit
47# and a 64 bit version to simplify shared Makefiles.
48# e.g.: obj-y += foo_$(BITS).o
49export BITS
50
51ifdef CONFIG_X86_NEED_RELOCS
52        LDFLAGS_vmlinux := --emit-relocs --discard-none
53endif
54
55#
56# Prevent GCC from generating any FP code by mistake.
57#
58# This must happen before we try the -mpreferred-stack-boundary, see:
59#
60#    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
61#
62KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow
63KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
64
65# Intel CET isn't enabled in the kernel
66KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
67
68ifeq ($(CONFIG_X86_32),y)
69        BITS := 32
70        UTS_MACHINE := i386
71        CHECKFLAGS += -D__i386__
72
73        biarch := $(call cc-option,-m32)
74        KBUILD_AFLAGS += $(biarch)
75        KBUILD_CFLAGS += $(biarch)
76
77        KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
78
79        # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
80        # with nonstandard options
81        KBUILD_CFLAGS += -fno-pic
82
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))
87
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)
91
92        # temporary until string.h is fixed
93        KBUILD_CFLAGS += -ffreestanding
94else
95        BITS := 64
96        UTS_MACHINE := x86_64
97        CHECKFLAGS += -D__x86_64__
98
99        biarch := -m64
100        KBUILD_AFLAGS += -m64
101        KBUILD_CFLAGS += -m64
102
103        # Align jump targets to 1 byte, not the default 16 bytes:
104        KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1)
105
106        # Pack loops tightly as well:
107        KBUILD_CFLAGS += $(call cc-option,-falign-loops=1)
108
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)
112
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))
121
122	# Use -mskip-rax-setup if supported.
123	KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
124
125        # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
126        cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
127        cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
128
129        cflags-$(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)
135
136        KBUILD_CFLAGS += -mno-red-zone
137        KBUILD_CFLAGS += -mcmodel=kernel
138endif
139
140ifdef CONFIG_X86_X32
141	x32_ld_ok := $(call try-run,\
142			/bin/echo -e '1: .quad 1b' | \
143			$(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" - && \
144			$(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMPO" && \
145			$(LD) -m elf32_x86_64 "$$TMPO" -o "$$TMP",y,n)
146        ifeq ($(x32_ld_ok),y)
147                CONFIG_X86_X32_ABI := y
148                KBUILD_AFLAGS += -DCONFIG_X86_X32_ABI
149                KBUILD_CFLAGS += -DCONFIG_X86_X32_ABI
150        else
151                $(warning CONFIG_X86_X32 enabled but no binutils support)
152        endif
153endif
154export CONFIG_X86_X32_ABI
155
156#
157# If the function graph tracer is used with mcount instead of fentry,
158# '-maccumulate-outgoing-args' is needed to prevent a GCC bug
159# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109)
160#
161ifdef CONFIG_FUNCTION_GRAPH_TRACER
162  ifndef CONFIG_HAVE_FENTRY
163	ACCUMULATE_OUTGOING_ARGS := 1
164  else
165    ifeq ($(call cc-option-yn, -mfentry), n)
166	ACCUMULATE_OUTGOING_ARGS := 1
167
168	# GCC ignores '-maccumulate-outgoing-args' when used with '-Os'.
169	# If '-Os' is enabled, disable it and print a warning.
170        ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
171          undefine CONFIG_CC_OPTIMIZE_FOR_SIZE
172          $(warning Disabling CONFIG_CC_OPTIMIZE_FOR_SIZE.  Your compiler does not have -mfentry so you cannot optimize for size with CONFIG_FUNCTION_GRAPH_TRACER.)
173        endif
174
175    endif
176  endif
177endif
178
179ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1)
180	# This compiler flag is not supported by Clang:
181	KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,)
182endif
183
184# Stackpointer is addressed different for 32 bit and 64 bit x86
185sp-$(CONFIG_X86_32) := esp
186sp-$(CONFIG_X86_64) := rsp
187
188# do binutils support CFI?
189cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1)
190# is .cfi_signal_frame supported too?
191cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1)
192cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1)
193
194# does binutils support specific instructions?
195asinstr += $(call as-instr,pshufb %xmm0$(comma)%xmm0,-DCONFIG_AS_SSSE3=1)
196avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1)
197avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1)
198avx512_instr :=$(call as-instr,vpmovm2b %k1$(comma)%zmm5,-DCONFIG_AS_AVX512=1)
199sha1_ni_instr :=$(call as-instr,sha1msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA1_NI=1)
200sha256_ni_instr :=$(call as-instr,sha256msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA256_NI=1)
201
202KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
203KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
204
205KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE)
206
207#
208# The 64-bit kernel must be aligned to 2MB.  Pass -z max-page-size=0x200000 to
209# the linker to force 2MB page size regardless of the default page size used
210# by the linker.
211#
212ifdef CONFIG_X86_64
213KBUILD_LDFLAGS += $(call ld-option, -z max-page-size=0x200000)
214endif
215
216ifdef CONFIG_LTO_CLANG
217KBUILD_LDFLAGS	+= -plugin-opt=-code-model=kernel \
218		   -plugin-opt=-stack-alignment=$(if $(CONFIG_X86_32),4,8)
219endif
220
221# Workaround for a gcc prelease that unfortunately was shipped in a suse release
222KBUILD_CFLAGS += -Wno-sign-compare
223#
224KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
225
226# Avoid indirect branches in kernel to deal with Spectre
227ifdef CONFIG_RETPOLINE
228  KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
229  # Additionally, avoid generating expensive indirect jumps which
230  # are subject to retpolines for small number of switch cases.
231  # clang turns off jump table generation by default when under
232  # retpoline builds, however, gcc does not for x86. This has
233  # only been fixed starting from gcc stable version 8.4.0 and
234  # onwards, but not for older ones. See gcc bug #86952.
235  ifndef CONFIG_CC_IS_CLANG
236    KBUILD_CFLAGS += $(call cc-option,-fno-jump-tables)
237  endif
238endif
239
240archscripts: scripts_basic
241	$(Q)$(MAKE) $(build)=arch/x86/tools relocs
242
243###
244# Syscall table generation
245
246archheaders:
247	$(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all
248
249###
250# Kernel objects
251
252head-y := arch/x86/kernel/head_$(BITS).o
253head-y += arch/x86/kernel/head$(BITS).o
254head-y += arch/x86/kernel/ebda.o
255head-y += arch/x86/kernel/platform-quirks.o
256
257libs-y  += arch/x86/lib/
258
259# See arch/x86/Kbuild for content of core part of the kernel
260core-y += arch/x86/
261
262# drivers-y are linked after core-y
263drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
264drivers-$(CONFIG_PCI)            += arch/x86/pci/
265
266# must be linked after kernel/
267drivers-$(CONFIG_OPROFILE) += arch/x86/oprofile/
268
269# suspend and hibernation support
270drivers-$(CONFIG_PM) += arch/x86/power/
271
272drivers-$(CONFIG_FB) += arch/x86/video/
273
274####
275# boot loader support. Several targets are kept for legacy purposes
276
277boot := arch/x86/boot
278
279BOOT_TARGETS = bzlilo bzdisk fdimage fdimage144 fdimage288 isoimage
280
281PHONY += bzImage $(BOOT_TARGETS)
282
283# Default kernel to build
284all: bzImage
285
286# KBUILD_IMAGE specify target image being built
287KBUILD_IMAGE := $(boot)/bzImage
288
289bzImage: vmlinux
290ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
291	$(Q)$(MAKE) $(build)=arch/x86/tools posttest
292endif
293	$(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
294	$(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
295	$(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@
296
297$(BOOT_TARGETS): vmlinux
298	$(Q)$(MAKE) $(build)=$(boot) $@
299
300PHONY += install
301install:
302	$(Q)$(MAKE) $(build)=$(boot) $@
303
304PHONY += vdso_install
305vdso_install:
306	$(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@
307
308archprepare: checkbin
309checkbin:
310ifndef CONFIG_CC_HAS_ASM_GOTO
311	@echo Compiler lacks asm-goto support.
312	@exit 1
313endif
314ifdef CONFIG_RETPOLINE
315ifeq ($(RETPOLINE_CFLAGS),)
316	@echo "You are building kernel with non-retpoline compiler." >&2
317	@echo "Please update your compiler." >&2
318	@false
319endif
320endif
321
322archclean:
323	$(Q)rm -rf $(objtree)/arch/i386
324	$(Q)rm -rf $(objtree)/arch/x86_64
325	$(Q)$(MAKE) $(clean)=$(boot)
326	$(Q)$(MAKE) $(clean)=arch/x86/tools
327
328define archhelp
329  echo  '* bzImage      - Compressed kernel image (arch/x86/boot/bzImage)'
330  echo  '  install      - Install kernel using'
331  echo  '                  (your) ~/bin/$(INSTALLKERNEL) or'
332  echo  '                  (distribution) /sbin/$(INSTALLKERNEL) or'
333  echo  '                  install to $$(INSTALL_PATH) and run lilo'
334  echo  '  fdimage      - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
335  echo  '  fdimage144   - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
336  echo  '  fdimage288   - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
337  echo  '  isoimage     - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
338  echo  '                  bzdisk/fdimage*/isoimage also accept:'
339  echo  '                  FDARGS="..."  arguments for the booted kernel'
340  echo  '                  FDINITRD=file initrd for the booted kernel'
341endef
342