summaryrefslogtreecommitdiffstats
path: root/arch/x86/Makefile
blob: bafbd905e6e7c4857064156d0d70a8275b9dd19d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
# SPDX-License-Identifier: GPL-2.0
# Unified Makefile for i386 and x86_64

# select defconfig based on actual architecture
ifeq ($(ARCH),x86)
  ifeq ($(shell uname -m),x86_64)
        KBUILD_DEFCONFIG := x86_64_defconfig
  else
        KBUILD_DEFCONFIG := i386_defconfig
  endif
else
        KBUILD_DEFCONFIG := $(ARCH)_defconfig
endif

ifdef CONFIG_CC_IS_GCC
RETPOLINE_CFLAGS	:= $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
RETPOLINE_CFLAGS	+= $(call cc-option,-mindirect-branch-cs-prefix)
RETPOLINE_VDSO_CFLAGS	:= $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register)
endif
ifdef CONFIG_CC_IS_CLANG
RETPOLINE_CFLAGS	:= -mretpoline-external-thunk
RETPOLINE_VDSO_CFLAGS	:= -mretpoline
endif

ifdef CONFIG_RETHUNK
RETHUNK_CFLAGS		:= -mfunction-return=thunk-extern
RETPOLINE_CFLAGS	+= $(RETHUNK_CFLAGS)
endif

export RETHUNK_CFLAGS
export RETPOLINE_CFLAGS
export RETPOLINE_VDSO_CFLAGS

# For gcc stack alignment is specified with -mpreferred-stack-boundary,
# clang has the option -mstack-alignment for that purpose.
ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
      cc_stack_align4 := -mpreferred-stack-boundary=2
      cc_stack_align8 := -mpreferred-stack-boundary=3
else ifneq ($(call cc-option, -mstack-alignment=16),)
      cc_stack_align4 := -mstack-alignment=4
      cc_stack_align8 := -mstack-alignment=8
endif

# How to compile the 16-bit code.  Note we always compile for -march=i386;
# that way we can complain to the user if the CPU is insufficient.
REALMODE_CFLAGS	:= -m16 -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \
		   -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
		   -fno-strict-aliasing -fomit-frame-pointer -fno-pic \
		   -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none)

REALMODE_CFLAGS += -ffreestanding
REALMODE_CFLAGS += -fno-stack-protector
REALMODE_CFLAGS += -Wno-address-of-packed-member
REALMODE_CFLAGS += $(cc_stack_align4)
REALMODE_CFLAGS += $(CLANG_FLAGS)
export REALMODE_CFLAGS

# BITS is used as extension for files which are available in a 32 bit
# and a 64 bit version to simplify shared Makefiles.
# e.g.: obj-y += foo_$(BITS).o
export BITS

#
# Prevent GCC from generating any FP code by mistake.
#
# This must happen before we try the -mpreferred-stack-boundary, see:
#
#    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
#
KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx

ifeq ($(CONFIG_X86_KERNEL_IBT),y)
#
# Kernel IBT has S_CET.NOTRACK_EN=0, as such the compilers must not generate
# NOTRACK prefixes. Current generation compilers unconditionally employ NOTRACK
# for jump-tables, as such, disable jump-tables for now.
#
# (jump-tables are implicitly disabled by RETPOLINE)
#
#   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104816
#
KBUILD_CFLAGS += $(call cc-option,-fcf-protection=branch -fno-jump-tables)
else
KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
endif

ifeq ($(CONFIG_X86_32),y)
        BITS := 32
        UTS_MACHINE := i386
        CHECKFLAGS += -D__i386__

        KBUILD_AFLAGS += -m32
        KBUILD_CFLAGS += -m32

        KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return

        # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
        # with nonstandard options
        KBUILD_CFLAGS += -fno-pic

        # Align the stack to the register width instead of using the default
        # alignment of 16 bytes. This reduces stack usage and the number of
        # alignment instructions.
        KBUILD_CFLAGS += $(cc_stack_align4)

        # CPU-specific tuning. Anything which can be shared with UML should go here.
        include $(srctree)/arch/x86/Makefile_32.cpu
        KBUILD_CFLAGS += $(cflags-y)

        # temporary until string.h is fixed
        KBUILD_CFLAGS += -ffreestanding

	ifeq ($(CONFIG_STACKPROTECTOR),y)
		ifeq ($(CONFIG_SMP),y)
			KBUILD_CFLAGS += -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard
		else
			KBUILD_CFLAGS += -mstack-protector-guard=global
		endif
	endif
else
        BITS := 64
        UTS_MACHINE := x86_64
        CHECKFLAGS += -D__x86_64__

        KBUILD_AFLAGS += -m64
        KBUILD_CFLAGS += -m64

        # Align jump targets to 1 byte, not the default 16 bytes:
        KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1)

        # Pack loops tightly as well:
        KBUILD_CFLAGS += $(call cc-option,-falign-loops=1)

        # Don't autogenerate traditional x87 instructions
        KBUILD_CFLAGS += -mno-80387
        KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)

        # By default gcc and clang use a stack alignment of 16 bytes for x86.
        # However the standard kernel entry on x86-64 leaves the stack on an
        # 8-byte boundary. If the compiler isn't informed about the actual
        # alignment it will generate extra alignment instructions for the
        # default alignment which keep the stack *mis*aligned.
        # Furthermore an alignment to the register width reduces stack usage
        # and the number of alignment instructions.
        KBUILD_CFLAGS += $(cc_stack_align8)

	# Use -mskip-rax-setup if supported.
	KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)

        # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
        cflags-$(CONFIG_MK8)		+= -march=k8
        cflags-$(CONFIG_MPSC)		+= -march=nocona
        cflags-$(CONFIG_MCORE2)		+= -march=core2
        cflags-$(CONFIG_MATOM)		+= -march=atom
        cflags-$(CONFIG_GENERIC_CPU)	+= -mtune=generic
        KBUILD_CFLAGS += $(cflags-y)

        KBUILD_CFLAGS += -mno-red-zone
        KBUILD_CFLAGS += -mcmodel=kernel
endif

#
# If the function graph tracer is used with mcount instead of fentry,
# '-maccumulate-outgoing-args' is needed to prevent a GCC bug
# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109)
#
ifdef CONFIG_FUNCTION_GRAPH_TRACER
  ifndef CONFIG_HAVE_FENTRY
	ACCUMULATE_OUTGOING_ARGS := 1
  endif
endif

ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1)
	# This compiler flag is not supported by Clang:
	KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,)
endif

# Workaround for a gcc prelease that unfortunately was shipped in a suse release
KBUILD_CFLAGS += -Wno-sign-compare
#
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables

# Avoid indirect branches in kernel to deal with Spectre
ifdef CONFIG_RETPOLINE
  KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
  # Additionally, avoid generating expensive indirect jumps which
  # are subject to retpolines for small number of switch cases.
  # clang turns off jump table generation by default when under
  # retpoline builds, however, gcc does not for x86. This has
  # only been fixed starting from gcc stable version 8.4.0 and
  # onwards, but not for older ones. See gcc bug #86952.
  ifndef CONFIG_CC_IS_CLANG
    KBUILD_CFLAGS += -fno-jump-tables
  endif
endif

ifdef CONFIG_SLS
  KBUILD_CFLAGS += -mharden-sls=all
endif

KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE)

ifdef CONFIG_LTO_CLANG
ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
KBUILD_LDFLAGS	+= -plugin-opt=-stack-alignment=$(if $(CONFIG_X86_32),4,8)
endif
endif

ifdef CONFIG_X86_NEED_RELOCS
LDFLAGS_vmlinux := --emit-relocs --discard-none
else
LDFLAGS_vmlinux :=
endif

#
# The 64-bit kernel must be aligned to 2MB.  Pass -z max-page-size=0x200000 to
# the linker to force 2MB page size regardless of the default page size used
# by the linker.
#
ifdef CONFIG_X86_64
LDFLAGS_vmlinux += -z max-page-size=0x200000
endif


archscripts: scripts_basic
	$(Q)$(MAKE) $(build)=arch/x86/tools relocs

###
# Syscall table generation

archheaders:
	$(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all

###
# Kernel objects

head-y := arch/x86/kernel/head_$(BITS).o
head-y += arch/x86/kernel/head$(BITS).o
head-y += arch/x86/kernel/ebda.o
head-y += arch/x86/kernel/platform-quirks.o

libs-y  += arch/x86/lib/

# drivers-y are linked after core-y
drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
drivers-$(CONFIG_PCI)            += arch/x86/pci/

# suspend and hibernation support
drivers-$(CONFIG_PM) += arch/x86/power/

drivers-$(CONFIG_FB) += arch/x86/video/

####
# boot loader support. Several targets are kept for legacy purposes

boot := arch/x86/boot

BOOT_TARGETS = bzdisk fdimage fdimage144 fdimage288 hdimage isoimage

PHONY += bzImage $(BOOT_TARGETS)

# Default kernel to build
all: bzImage

# KBUILD_IMAGE specify target image being built
KBUILD_IMAGE := $(boot)/bzImage

bzImage: vmlinux
ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
	$(Q)$(MAKE) $(build)=arch/x86/tools posttest
endif
	$(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
	$(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
	$(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@

$(BOOT_TARGETS): vmlinux
	$(Q)$(MAKE) $(build)=$(boot) $@

PHONY += install
install:
	$(call cmd,install)

PHONY += vdso_install
vdso_install:
	$(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@

archprepare: checkbin
checkbin:
ifdef CONFIG_RETPOLINE
ifeq ($(RETPOLINE_CFLAGS),)
	@echo "You are building kernel with non-retpoline compiler." >&2
	@echo "Please update your compiler." >&2
	@false
endif
endif

archclean:
	$(Q)rm -rf $(objtree)/arch/i386
	$(Q)rm -rf $(objtree)/arch/x86_64

define archhelp
  echo  '* bzImage		- Compressed kernel image (arch/x86/boot/bzImage)'
  echo  '  install		- Install kernel using (your) ~/bin/$(INSTALLKERNEL) or'
  echo  '			  (distribution) /sbin/$(INSTALLKERNEL) or install to '
  echo  '			  $$(INSTALL_PATH) and run lilo'
  echo  ''
  echo  '  fdimage		- Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
  echo  '  fdimage144		- Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
  echo  '  fdimage288		- Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
  echo  '  hdimage		- Create a BIOS/EFI hard disk image (arch/x86/boot/hdimage)'
  echo  '  isoimage		- Create a boot CD-ROM image (arch/x86/boot/image.iso)'
  echo  '			  bzdisk/fdimage*/hdimage/isoimage also accept:'
  echo  '			  FDARGS="..."  arguments for the booted kernel'
  echo  '			  FDINITRD=file initrd for the booted kernel'
  echo  ''
  echo  '  kvm_guest.config	- Enable Kconfig items for running this kernel as a KVM guest'
  echo  '  xen.config		- Enable Kconfig items for running this kernel as a Xen guest'
  echo  '  x86_debug.config	- Enable tip tree debugging options for testing'

endef