xref: /openbmc/linux/arch/x86/Makefile (revision ddc141e5) 
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 -D__KERNEL__ \
35		   -DDISABLE_BRANCH_PROFILING \
36		   -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
37		   -fno-strict-aliasing -fomit-frame-pointer -fno-pic \
38		   -mno-mmx -mno-sse
39
40REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding)
41REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector)
42REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4))
43export REALMODE_CFLAGS
44
45# BITS is used as extension for files which are available in a 32 bit
46# and a 64 bit version to simplify shared Makefiles.
47# e.g.: obj-y += foo_$(BITS).o
48export BITS
49
50ifdef CONFIG_X86_NEED_RELOCS
51        LDFLAGS_vmlinux := --emit-relocs
52endif
53
54#
55# Prevent GCC from generating any FP code by mistake.
56#
57# This must happen before we try the -mpreferred-stack-boundary, see:
58#
59#    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
60#
61KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow
62KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
63
64ifeq ($(CONFIG_X86_32),y)
65        BITS := 32
66        UTS_MACHINE := i386
67        CHECKFLAGS += -D__i386__
68
69        biarch := $(call cc-option,-m32)
70        KBUILD_AFLAGS += $(biarch)
71        KBUILD_CFLAGS += $(biarch)
72
73        KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
74
75        # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
76        # with nonstandard options
77        KBUILD_CFLAGS += -fno-pic
78
79        # Align the stack to the register width instead of using the default
80        # alignment of 16 bytes. This reduces stack usage and the number of
81        # alignment instructions.
82        KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align4))
83
84        # Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
85        # a lot more stack due to the lack of sharing of stacklots:
86        KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0400, \
87				$(call cc-option,-fno-unit-at-a-time))
88
89        # CPU-specific tuning. Anything which can be shared with UML should go here.
90        include arch/x86/Makefile_32.cpu
91        KBUILD_CFLAGS += $(cflags-y)
92
93        # temporary until string.h is fixed
94        KBUILD_CFLAGS += -ffreestanding
95else
96        BITS := 64
97        UTS_MACHINE := x86_64
98        CHECKFLAGS += -D__x86_64__ -m64
99
100        biarch := -m64
101        KBUILD_AFLAGS += -m64
102        KBUILD_CFLAGS += -m64
103
104        # Align jump targets to 1 byte, not the default 16 bytes:
105        KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1)
106
107        # Pack loops tightly as well:
108        KBUILD_CFLAGS += $(call cc-option,-falign-loops=1)
109
110        # Don't autogenerate traditional x87 instructions
111        KBUILD_CFLAGS += $(call cc-option,-mno-80387)
112        KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)
113
114        # By default gcc and clang use a stack alignment of 16 bytes for x86.
115        # However the standard kernel entry on x86-64 leaves the stack on an
116        # 8-byte boundary. If the compiler isn't informed about the actual
117        # alignment it will generate extra alignment instructions for the
118        # default alignment which keep the stack *mis*aligned.
119        # Furthermore an alignment to the register width reduces stack usage
120        # and the number of alignment instructions.
121        KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align8))
122
123	# Use -mskip-rax-setup if supported.
124	KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
125
126        # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
127        cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
128        cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
129
130        cflags-$(CONFIG_MCORE2) += \
131                $(call cc-option,-march=core2,$(call cc-option,-mtune=generic))
132	cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \
133		$(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
134        cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)
135        KBUILD_CFLAGS += $(cflags-y)
136
137        KBUILD_CFLAGS += -mno-red-zone
138        KBUILD_CFLAGS += -mcmodel=kernel
139
140        # -funit-at-a-time shrinks the kernel .text considerably
141        # unfortunately it makes reading oopses harder.
142        KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
143endif
144
145ifdef CONFIG_X86_X32
146	x32_ld_ok := $(call try-run,\
147			/bin/echo -e '1: .quad 1b' | \
148			$(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" - && \
149			$(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMPO" && \
150			$(LD) -m elf32_x86_64 "$$TMPO" -o "$$TMP",y,n)
151        ifeq ($(x32_ld_ok),y)
152                CONFIG_X86_X32_ABI := y
153                KBUILD_AFLAGS += -DCONFIG_X86_X32_ABI
154                KBUILD_CFLAGS += -DCONFIG_X86_X32_ABI
155        else
156                $(warning CONFIG_X86_X32 enabled but no binutils support)
157        endif
158endif
159export CONFIG_X86_X32_ABI
160
161#
162# If the function graph tracer is used with mcount instead of fentry,
163# '-maccumulate-outgoing-args' is needed to prevent a GCC bug
164# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109)
165#
166ifdef CONFIG_FUNCTION_GRAPH_TRACER
167  ifndef CONFIG_HAVE_FENTRY
168	ACCUMULATE_OUTGOING_ARGS := 1
169  else
170    ifeq ($(call cc-option-yn, -mfentry), n)
171	ACCUMULATE_OUTGOING_ARGS := 1
172
173	# GCC ignores '-maccumulate-outgoing-args' when used with '-Os'.
174	# If '-Os' is enabled, disable it and print a warning.
175        ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
176          undefine CONFIG_CC_OPTIMIZE_FOR_SIZE
177          $(warning Disabling CONFIG_CC_OPTIMIZE_FOR_SIZE.  Your compiler does not have -mfentry so you cannot optimize for size with CONFIG_FUNCTION_GRAPH_TRACER.)
178        endif
179
180    endif
181  endif
182endif
183
184#
185# Jump labels need '-maccumulate-outgoing-args' for gcc < 4.5.2 to prevent a
186# GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46226).  There's no way
187# to test for this bug at compile-time because the test case needs to execute,
188# which is a no-go for cross compilers.  So check the GCC version instead.
189#
190ifdef CONFIG_JUMP_LABEL
191  ifneq ($(ACCUMULATE_OUTGOING_ARGS), 1)
192	ACCUMULATE_OUTGOING_ARGS = $(call cc-if-fullversion, -lt, 040502, 1)
193  endif
194endif
195
196ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1)
197	# This compiler flag is not supported by Clang:
198	KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,)
199endif
200
201# Stackpointer is addressed different for 32 bit and 64 bit x86
202sp-$(CONFIG_X86_32) := esp
203sp-$(CONFIG_X86_64) := rsp
204
205# do binutils support CFI?
206cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1)
207# is .cfi_signal_frame supported too?
208cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1)
209cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1)
210
211# does binutils support specific instructions?
212asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1)
213asinstr += $(call as-instr,pshufb %xmm0$(comma)%xmm0,-DCONFIG_AS_SSSE3=1)
214asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1)
215avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1)
216avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1)
217avx512_instr :=$(call as-instr,vpmovm2b %k1$(comma)%zmm5,-DCONFIG_AS_AVX512=1)
218sha1_ni_instr :=$(call as-instr,sha1msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA1_NI=1)
219sha256_ni_instr :=$(call as-instr,sha256msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA256_NI=1)
220
221KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
222KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
223
224LDFLAGS := -m elf_$(UTS_MACHINE)
225
226# Speed up the build
227KBUILD_CFLAGS += -pipe
228# Workaround for a gcc prelease that unfortunately was shipped in a suse release
229KBUILD_CFLAGS += -Wno-sign-compare
230#
231KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
232
233# Avoid indirect branches in kernel to deal with Spectre
234ifdef CONFIG_RETPOLINE
235ifneq ($(RETPOLINE_CFLAGS),)
236  KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) -DRETPOLINE
237endif
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
249archprepare:
250ifeq ($(CONFIG_KEXEC_FILE),y)
251	$(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c
252endif
253
254###
255# Kernel objects
256
257head-y := arch/x86/kernel/head_$(BITS).o
258head-y += arch/x86/kernel/head$(BITS).o
259head-y += arch/x86/kernel/ebda.o
260head-y += arch/x86/kernel/platform-quirks.o
261
262libs-y  += arch/x86/lib/
263
264# See arch/x86/Kbuild for content of core part of the kernel
265core-y += arch/x86/
266
267# drivers-y are linked after core-y
268drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
269drivers-$(CONFIG_PCI)            += arch/x86/pci/
270
271# must be linked after kernel/
272drivers-$(CONFIG_OPROFILE) += arch/x86/oprofile/
273
274# suspend and hibernation support
275drivers-$(CONFIG_PM) += arch/x86/power/
276
277drivers-$(CONFIG_FB) += arch/x86/video/
278
279####
280# boot loader support. Several targets are kept for legacy purposes
281
282boot := arch/x86/boot
283
284BOOT_TARGETS = bzlilo bzdisk fdimage fdimage144 fdimage288 isoimage
285
286PHONY += bzImage $(BOOT_TARGETS)
287
288# Default kernel to build
289all: bzImage
290
291# KBUILD_IMAGE specify target image being built
292KBUILD_IMAGE := $(boot)/bzImage
293
294bzImage: vmlinux
295ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
296	$(Q)$(MAKE) $(build)=arch/x86/tools posttest
297endif
298	$(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
299	$(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
300	$(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@
301
302$(BOOT_TARGETS): vmlinux
303	$(Q)$(MAKE) $(build)=$(boot) $@
304
305PHONY += install
306install:
307	$(Q)$(MAKE) $(build)=$(boot) $@
308
309PHONY += vdso_install
310vdso_install:
311	$(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@
312
313archclean:
314	$(Q)rm -rf $(objtree)/arch/i386
315	$(Q)rm -rf $(objtree)/arch/x86_64
316	$(Q)$(MAKE) $(clean)=$(boot)
317	$(Q)$(MAKE) $(clean)=arch/x86/tools
318	$(Q)$(MAKE) $(clean)=arch/x86/purgatory
319
320define archhelp
321  echo  '* bzImage      - Compressed kernel image (arch/x86/boot/bzImage)'
322  echo  '  install      - Install kernel using'
323  echo  '                  (your) ~/bin/$(INSTALLKERNEL) or'
324  echo  '                  (distribution) /sbin/$(INSTALLKERNEL) or'
325  echo  '                  install to $$(INSTALL_PATH) and run lilo'
326  echo  '  fdimage      - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
327  echo  '  fdimage144   - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
328  echo  '  fdimage288   - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
329  echo  '  isoimage     - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
330  echo  '                  bzdisk/fdimage*/isoimage also accept:'
331  echo  '                  FDARGS="..."  arguments for the booted kernel'
332  echo  '                  FDINITRD=file initrd for the booted kernel'
333endef
334