xref: /openbmc/linux/arch/x86/Makefile (revision e6dec923) 
1# Unified Makefile for i386 and x86_64
2
3# select defconfig based on actual architecture
4ifeq ($(ARCH),x86)
5  ifeq ($(shell uname -m),x86_64)
6        KBUILD_DEFCONFIG := x86_64_defconfig
7  else
8        KBUILD_DEFCONFIG := i386_defconfig
9  endif
10else
11        KBUILD_DEFCONFIG := $(ARCH)_defconfig
12endif
13
14# For gcc stack alignment is specified with -mpreferred-stack-boundary,
15# clang has the option -mstack-alignment for that purpose.
16ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
17        cc_stack_align_opt := -mpreferred-stack-boundary
18else ifneq ($(call cc-option, -mstack-alignment=4),)
19        cc_stack_align_opt := -mstack-alignment
20endif
21
22# How to compile the 16-bit code.  Note we always compile for -march=i386;
23# that way we can complain to the user if the CPU is insufficient.
24#
25# The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For
26# older versions of GCC, include an *assembly* header to make sure that
27# gcc doesn't play any games behind our back.
28CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h
29M16_CFLAGS	 := $(call cc-option, -m16, $(CODE16GCC_CFLAGS))
30
31REALMODE_CFLAGS	:= $(M16_CFLAGS) -g -Os -D__KERNEL__ \
32		   -DDISABLE_BRANCH_PROFILING \
33		   -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
34		   -fno-strict-aliasing -fomit-frame-pointer -fno-pic \
35		   -mno-mmx -mno-sse
36
37REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding)
38REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector)
39REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align_opt)=2)
40export REALMODE_CFLAGS
41
42# BITS is used as extension for files which are available in a 32 bit
43# and a 64 bit version to simplify shared Makefiles.
44# e.g.: obj-y += foo_$(BITS).o
45export BITS
46
47ifdef CONFIG_X86_NEED_RELOCS
48        LDFLAGS_vmlinux := --emit-relocs
49endif
50
51#
52# Prevent GCC from generating any FP code by mistake.
53#
54# This must happen before we try the -mpreferred-stack-boundary, see:
55#
56#    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
57#
58KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow
59KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
60
61ifeq ($(CONFIG_X86_32),y)
62        BITS := 32
63        UTS_MACHINE := i386
64        CHECKFLAGS += -D__i386__
65
66        biarch := $(call cc-option,-m32)
67        KBUILD_AFLAGS += $(biarch)
68        KBUILD_CFLAGS += $(biarch)
69
70        KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
71
72        # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
73        # with nonstandard options
74        KBUILD_CFLAGS += -fno-pic
75
76        # Align the stack to the register width instead of using the default
77        # alignment of 16 bytes. This reduces stack usage and the number of
78        # alignment instructions.
79        KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align_opt)=2)
80
81        # Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
82        # a lot more stack due to the lack of sharing of stacklots:
83        KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0400, \
84				$(call cc-option,-fno-unit-at-a-time))
85
86        # CPU-specific tuning. Anything which can be shared with UML should go here.
87        include arch/x86/Makefile_32.cpu
88        KBUILD_CFLAGS += $(cflags-y)
89
90        # temporary until string.h is fixed
91        KBUILD_CFLAGS += -ffreestanding
92else
93        BITS := 64
94        UTS_MACHINE := x86_64
95        CHECKFLAGS += -D__x86_64__ -m64
96
97        biarch := -m64
98        KBUILD_AFLAGS += -m64
99        KBUILD_CFLAGS += -m64
100
101        # Align jump targets to 1 byte, not the default 16 bytes:
102        KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1)
103
104        # Pack loops tightly as well:
105        KBUILD_CFLAGS += $(call cc-option,-falign-loops=1)
106
107        # Don't autogenerate traditional x87 instructions
108        KBUILD_CFLAGS += $(call cc-option,-mno-80387)
109        KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)
110
111        # By default gcc and clang use a stack alignment of 16 bytes for x86.
112        # However the standard kernel entry on x86-64 leaves the stack on an
113        # 8-byte boundary. If the compiler isn't informed about the actual
114        # alignment it will generate extra alignment instructions for the
115        # default alignment which keep the stack *mis*aligned.
116        # Furthermore an alignment to the register width reduces stack usage
117        # and the number of alignment instructions.
118        KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align_opt)=3)
119
120	# Use -mskip-rax-setup if supported.
121	KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
122
123        # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
124        cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
125        cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
126
127        cflags-$(CONFIG_MCORE2) += \
128                $(call cc-option,-march=core2,$(call cc-option,-mtune=generic))
129	cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \
130		$(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
131        cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)
132        KBUILD_CFLAGS += $(cflags-y)
133
134        KBUILD_CFLAGS += -mno-red-zone
135        KBUILD_CFLAGS += -mcmodel=kernel
136
137        # -funit-at-a-time shrinks the kernel .text considerably
138        # unfortunately it makes reading oopses harder.
139        KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
140endif
141
142ifdef CONFIG_X86_X32
143	x32_ld_ok := $(call try-run,\
144			/bin/echo -e '1: .quad 1b' | \
145			$(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" - && \
146			$(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMPO" && \
147			$(LD) -m elf32_x86_64 "$$TMPO" -o "$$TMP",y,n)
148        ifeq ($(x32_ld_ok),y)
149                CONFIG_X86_X32_ABI := y
150                KBUILD_AFLAGS += -DCONFIG_X86_X32_ABI
151                KBUILD_CFLAGS += -DCONFIG_X86_X32_ABI
152        else
153                $(warning CONFIG_X86_X32 enabled but no binutils support)
154        endif
155endif
156export CONFIG_X86_X32_ABI
157
158# Don't unroll struct assignments with kmemcheck enabled
159ifeq ($(CONFIG_KMEMCHECK),y)
160	KBUILD_CFLAGS += $(call cc-option,-fno-builtin-memcpy)
161endif
162
163#
164# If the function graph tracer is used with mcount instead of fentry,
165# '-maccumulate-outgoing-args' is needed to prevent a GCC bug
166# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109)
167#
168ifdef CONFIG_FUNCTION_GRAPH_TRACER
169  ifndef CONFIG_HAVE_FENTRY
170	ACCUMULATE_OUTGOING_ARGS := 1
171  else
172    ifeq ($(call cc-option-yn, -mfentry), n)
173	ACCUMULATE_OUTGOING_ARGS := 1
174
175	# GCC ignores '-maccumulate-outgoing-args' when used with '-Os'.
176	# If '-Os' is enabled, disable it and print a warning.
177        ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
178          undefine CONFIG_CC_OPTIMIZE_FOR_SIZE
179          $(warning Disabling CONFIG_CC_OPTIMIZE_FOR_SIZE.  Your compiler does not have -mfentry so you cannot optimize for size with CONFIG_FUNCTION_GRAPH_TRACER.)
180        endif
181
182    endif
183  endif
184endif
185
186#
187# Jump labels need '-maccumulate-outgoing-args' for gcc < 4.5.2 to prevent a
188# GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46226).  There's no way
189# to test for this bug at compile-time because the test case needs to execute,
190# which is a no-go for cross compilers.  So check the GCC version instead.
191#
192ifdef CONFIG_JUMP_LABEL
193  ifneq ($(ACCUMULATE_OUTGOING_ARGS), 1)
194	ACCUMULATE_OUTGOING_ARGS = $(call cc-if-fullversion, -lt, 040502, 1)
195  endif
196endif
197
198ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1)
199	# This compiler flag is not supported by Clang:
200	KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,)
201endif
202
203# Stackpointer is addressed different for 32 bit and 64 bit x86
204sp-$(CONFIG_X86_32) := esp
205sp-$(CONFIG_X86_64) := rsp
206
207# do binutils support CFI?
208cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1)
209# is .cfi_signal_frame supported too?
210cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1)
211cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1)
212
213# does binutils support specific instructions?
214asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1)
215asinstr += $(call as-instr,pshufb %xmm0$(comma)%xmm0,-DCONFIG_AS_SSSE3=1)
216asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1)
217avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1)
218avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1)
219avx512_instr :=$(call as-instr,vpmovm2b %k1$(comma)%zmm5,-DCONFIG_AS_AVX512=1)
220sha1_ni_instr :=$(call as-instr,sha1msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA1_NI=1)
221sha256_ni_instr :=$(call as-instr,sha256msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA256_NI=1)
222
223KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
224KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
225
226LDFLAGS := -m elf_$(UTS_MACHINE)
227
228# Speed up the build
229KBUILD_CFLAGS += -pipe
230# Workaround for a gcc prelease that unfortunately was shipped in a suse release
231KBUILD_CFLAGS += -Wno-sign-compare
232#
233KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
234
235KBUILD_CFLAGS += $(mflags-y)
236KBUILD_AFLAGS += $(mflags-y)
237
238archscripts: scripts_basic
239	$(Q)$(MAKE) $(build)=arch/x86/tools relocs
240
241###
242# Syscall table generation
243
244archheaders:
245	$(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all
246
247archprepare:
248ifeq ($(CONFIG_KEXEC_FILE),y)
249	$(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c
250endif
251
252###
253# Kernel objects
254
255head-y := arch/x86/kernel/head_$(BITS).o
256head-y += arch/x86/kernel/head$(BITS).o
257head-y += arch/x86/kernel/ebda.o
258head-y += arch/x86/kernel/platform-quirks.o
259
260libs-y  += arch/x86/lib/
261
262# See arch/x86/Kbuild for content of core part of the kernel
263core-y += arch/x86/
264
265# drivers-y are linked after core-y
266drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
267drivers-$(CONFIG_PCI)            += arch/x86/pci/
268
269# must be linked after kernel/
270drivers-$(CONFIG_OPROFILE) += arch/x86/oprofile/
271
272# suspend and hibernation support
273drivers-$(CONFIG_PM) += arch/x86/power/
274
275drivers-$(CONFIG_FB) += arch/x86/video/
276
277####
278# boot loader support. Several targets are kept for legacy purposes
279
280boot := arch/x86/boot
281
282BOOT_TARGETS = bzlilo bzdisk fdimage fdimage144 fdimage288 isoimage
283
284PHONY += bzImage $(BOOT_TARGETS)
285
286# Default kernel to build
287all: bzImage
288
289# KBUILD_IMAGE specify target image being built
290KBUILD_IMAGE := $(boot)/bzImage
291
292bzImage: vmlinux
293ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
294	$(Q)$(MAKE) $(build)=arch/x86/tools posttest
295endif
296	$(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
297	$(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
298	$(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@
299
300$(BOOT_TARGETS): vmlinux
301	$(Q)$(MAKE) $(build)=$(boot) $@
302
303PHONY += install
304install:
305	$(Q)$(MAKE) $(build)=$(boot) $@
306
307PHONY += vdso_install
308vdso_install:
309	$(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@
310
311archclean:
312	$(Q)rm -rf $(objtree)/arch/i386
313	$(Q)rm -rf $(objtree)/arch/x86_64
314	$(Q)$(MAKE) $(clean)=$(boot)
315	$(Q)$(MAKE) $(clean)=arch/x86/tools
316	$(Q)$(MAKE) $(clean)=arch/x86/purgatory
317
318define archhelp
319  echo  '* bzImage      - Compressed kernel image (arch/x86/boot/bzImage)'
320  echo  '  install      - Install kernel using'
321  echo  '                  (your) ~/bin/$(INSTALLKERNEL) or'
322  echo  '                  (distribution) /sbin/$(INSTALLKERNEL) or'
323  echo  '                  install to $$(INSTALL_PATH) and run lilo'
324  echo  '  fdimage      - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
325  echo  '  fdimage144   - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
326  echo  '  fdimage288   - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
327  echo  '  isoimage     - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
328  echo  '                  bzdisk/fdimage*/isoimage also accept:'
329  echo  '                  FDARGS="..."  arguments for the booted kernel'
330  echo  '                  FDINITRD=file initrd for the booted kernel'
331endef
332