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 | sed -e 's/i.86/i386/'),i386) 7 KBUILD_DEFCONFIG := i386_defconfig 8 else 9 KBUILD_DEFCONFIG := x86_64_defconfig 10 endif 11else 12 KBUILD_DEFCONFIG := $(ARCH)_defconfig 13endif 14 15ifdef CONFIG_CC_IS_GCC 16RETPOLINE_CFLAGS := $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register) 17RETPOLINE_VDSO_CFLAGS := $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register) 18endif 19ifdef CONFIG_CC_IS_CLANG 20RETPOLINE_CFLAGS := -mretpoline-external-thunk 21RETPOLINE_VDSO_CFLAGS := -mretpoline 22endif 23RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch-cs-prefix) 24 25ifdef CONFIG_RETHUNK 26RETHUNK_CFLAGS := -mfunction-return=thunk-extern 27RETPOLINE_CFLAGS += $(RETHUNK_CFLAGS) 28endif 29 30export RETHUNK_CFLAGS 31export RETPOLINE_CFLAGS 32export RETPOLINE_VDSO_CFLAGS 33 34# For gcc stack alignment is specified with -mpreferred-stack-boundary, 35# clang has the option -mstack-alignment for that purpose. 36ifneq ($(call cc-option, -mpreferred-stack-boundary=4),) 37 cc_stack_align4 := -mpreferred-stack-boundary=2 38 cc_stack_align8 := -mpreferred-stack-boundary=3 39else ifneq ($(call cc-option, -mstack-alignment=16),) 40 cc_stack_align4 := -mstack-alignment=4 41 cc_stack_align8 := -mstack-alignment=8 42endif 43 44# How to compile the 16-bit code. Note we always compile for -march=i386; 45# that way we can complain to the user if the CPU is insufficient. 46REALMODE_CFLAGS := -std=gnu11 -m16 -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \ 47 -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ 48 -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ 49 -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none) 50 51REALMODE_CFLAGS += -ffreestanding 52REALMODE_CFLAGS += -fno-stack-protector 53REALMODE_CFLAGS += -Wno-address-of-packed-member 54REALMODE_CFLAGS += $(cc_stack_align4) 55REALMODE_CFLAGS += $(CLANG_FLAGS) 56export REALMODE_CFLAGS 57 58# BITS is used as extension for files which are available in a 32 bit 59# and a 64 bit version to simplify shared Makefiles. 60# e.g.: obj-y += foo_$(BITS).o 61export BITS 62 63# 64# Prevent GCC from generating any FP code by mistake. 65# 66# This must happen before we try the -mpreferred-stack-boundary, see: 67# 68# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383 69# 70KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx 71KBUILD_RUSTFLAGS += --target=$(objtree)/scripts/target.json 72KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2 73 74ifeq ($(CONFIG_X86_KERNEL_IBT),y) 75# 76# Kernel IBT has S_CET.NOTRACK_EN=0, as such the compilers must not generate 77# NOTRACK prefixes. Current generation compilers unconditionally employ NOTRACK 78# for jump-tables, as such, disable jump-tables for now. 79# 80# (jump-tables are implicitly disabled by RETPOLINE) 81# 82# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104816 83# 84KBUILD_CFLAGS += $(call cc-option,-fcf-protection=branch -fno-jump-tables) 85KBUILD_RUSTFLAGS += -Zcf-protection=branch -Zno-jump-tables 86else 87KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none) 88endif 89 90ifeq ($(CONFIG_X86_32),y) 91 BITS := 32 92 UTS_MACHINE := i386 93 CHECKFLAGS += -D__i386__ 94 95 KBUILD_AFLAGS += -m32 96 KBUILD_CFLAGS += -m32 97 98 KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return 99 100 # Never want PIC in a 32-bit kernel, prevent breakage with GCC built 101 # with nonstandard options 102 KBUILD_CFLAGS += -fno-pic 103 104 # Align the stack to the register width instead of using the default 105 # alignment of 16 bytes. This reduces stack usage and the number of 106 # alignment instructions. 107 KBUILD_CFLAGS += $(cc_stack_align4) 108 109 # CPU-specific tuning. Anything which can be shared with UML should go here. 110 include $(srctree)/arch/x86/Makefile_32.cpu 111 KBUILD_CFLAGS += $(cflags-y) 112 113 # temporary until string.h is fixed 114 KBUILD_CFLAGS += -ffreestanding 115 116 ifeq ($(CONFIG_STACKPROTECTOR),y) 117 ifeq ($(CONFIG_SMP),y) 118 KBUILD_CFLAGS += -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard 119 else 120 KBUILD_CFLAGS += -mstack-protector-guard=global 121 endif 122 endif 123else 124 BITS := 64 125 UTS_MACHINE := x86_64 126 CHECKFLAGS += -D__x86_64__ 127 128 KBUILD_AFLAGS += -m64 129 KBUILD_CFLAGS += -m64 130 131 # Align jump targets to 1 byte, not the default 16 bytes: 132 KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1) 133 134 # Pack loops tightly as well: 135 KBUILD_CFLAGS += $(call cc-option,-falign-loops=1) 136 137 # Don't autogenerate traditional x87 instructions 138 KBUILD_CFLAGS += -mno-80387 139 KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387) 140 141 # By default gcc and clang use a stack alignment of 16 bytes for x86. 142 # However the standard kernel entry on x86-64 leaves the stack on an 143 # 8-byte boundary. If the compiler isn't informed about the actual 144 # alignment it will generate extra alignment instructions for the 145 # default alignment which keep the stack *mis*aligned. 146 # Furthermore an alignment to the register width reduces stack usage 147 # and the number of alignment instructions. 148 KBUILD_CFLAGS += $(cc_stack_align8) 149 150 # Use -mskip-rax-setup if supported. 151 KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup) 152 153 # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu) 154 cflags-$(CONFIG_MK8) += -march=k8 155 cflags-$(CONFIG_MPSC) += -march=nocona 156 cflags-$(CONFIG_MCORE2) += -march=core2 157 cflags-$(CONFIG_MATOM) += -march=atom 158 cflags-$(CONFIG_GENERIC_CPU) += -mtune=generic 159 KBUILD_CFLAGS += $(cflags-y) 160 161 rustflags-$(CONFIG_MK8) += -Ctarget-cpu=k8 162 rustflags-$(CONFIG_MPSC) += -Ctarget-cpu=nocona 163 rustflags-$(CONFIG_MCORE2) += -Ctarget-cpu=core2 164 rustflags-$(CONFIG_MATOM) += -Ctarget-cpu=atom 165 rustflags-$(CONFIG_GENERIC_CPU) += -Ztune-cpu=generic 166 KBUILD_RUSTFLAGS += $(rustflags-y) 167 168 KBUILD_CFLAGS += -mno-red-zone 169 KBUILD_CFLAGS += -mcmodel=kernel 170 KBUILD_RUSTFLAGS += -Cno-redzone=y 171 KBUILD_RUSTFLAGS += -Ccode-model=kernel 172endif 173 174# 175# If the function graph tracer is used with mcount instead of fentry, 176# '-maccumulate-outgoing-args' is needed to prevent a GCC bug 177# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109) 178# 179ifdef CONFIG_FUNCTION_GRAPH_TRACER 180 ifndef CONFIG_HAVE_FENTRY 181 ACCUMULATE_OUTGOING_ARGS := 1 182 endif 183endif 184 185ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1) 186 # This compiler flag is not supported by Clang: 187 KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,) 188endif 189 190# Workaround for a gcc prelease that unfortunately was shipped in a suse release 191KBUILD_CFLAGS += -Wno-sign-compare 192# 193KBUILD_CFLAGS += -fno-asynchronous-unwind-tables 194 195# Avoid indirect branches in kernel to deal with Spectre 196ifdef CONFIG_RETPOLINE 197 KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) 198 # Additionally, avoid generating expensive indirect jumps which 199 # are subject to retpolines for small number of switch cases. 200 # clang turns off jump table generation by default when under 201 # retpoline builds, however, gcc does not for x86. This has 202 # only been fixed starting from gcc stable version 8.4.0 and 203 # onwards, but not for older ones. See gcc bug #86952. 204 ifndef CONFIG_CC_IS_CLANG 205 KBUILD_CFLAGS += -fno-jump-tables 206 endif 207endif 208 209ifdef CONFIG_SLS 210 KBUILD_CFLAGS += -mharden-sls=all 211endif 212 213ifdef CONFIG_CALL_PADDING 214PADDING_CFLAGS := -fpatchable-function-entry=$(CONFIG_FUNCTION_PADDING_BYTES),$(CONFIG_FUNCTION_PADDING_BYTES) 215KBUILD_CFLAGS += $(PADDING_CFLAGS) 216export PADDING_CFLAGS 217endif 218 219KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE) 220 221ifdef CONFIG_LTO_CLANG 222ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y) 223KBUILD_LDFLAGS += -plugin-opt=-stack-alignment=$(if $(CONFIG_X86_32),4,8) 224endif 225endif 226 227ifdef CONFIG_X86_NEED_RELOCS 228LDFLAGS_vmlinux := --emit-relocs --discard-none 229else 230LDFLAGS_vmlinux := 231endif 232 233# 234# The 64-bit kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to 235# the linker to force 2MB page size regardless of the default page size used 236# by the linker. 237# 238ifdef CONFIG_X86_64 239LDFLAGS_vmlinux += -z max-page-size=0x200000 240endif 241 242 243archscripts: scripts_basic 244 $(Q)$(MAKE) $(build)=arch/x86/tools relocs 245 246### 247# Syscall table generation 248 249archheaders: 250 $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all 251 252### 253# Kernel objects 254 255libs-y += arch/x86/lib/ 256 257core-y += arch/x86/virt/ 258 259# drivers-y are linked after core-y 260drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/ 261drivers-$(CONFIG_PCI) += arch/x86/pci/ 262 263# suspend and hibernation support 264drivers-$(CONFIG_PM) += arch/x86/power/ 265 266drivers-$(CONFIG_FB_CORE) += arch/x86/video/ 267 268#### 269# boot loader support. Several targets are kept for legacy purposes 270 271boot := arch/x86/boot 272 273BOOT_TARGETS = bzdisk fdimage fdimage144 fdimage288 hdimage isoimage 274 275PHONY += bzImage $(BOOT_TARGETS) 276 277# Default kernel to build 278all: bzImage 279 280# KBUILD_IMAGE specify target image being built 281KBUILD_IMAGE := $(boot)/bzImage 282 283bzImage: vmlinux 284ifeq ($(CONFIG_X86_DECODER_SELFTEST),y) 285 $(Q)$(MAKE) $(build)=arch/x86/tools posttest 286endif 287 $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE) 288 $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot 289 $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@ 290 291$(BOOT_TARGETS): vmlinux 292 $(Q)$(MAKE) $(build)=$(boot) $@ 293 294PHONY += install 295install: 296 $(call cmd,install) 297 298vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg 299vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg 300vdso-install-$(CONFIG_X86_32) += arch/x86/entry/vdso/vdso32.so.dbg 301vdso-install-$(CONFIG_IA32_EMULATION) += arch/x86/entry/vdso/vdso32.so.dbg 302 303archprepare: checkbin 304checkbin: 305ifdef CONFIG_RETPOLINE 306ifeq ($(RETPOLINE_CFLAGS),) 307 @echo "You are building kernel with non-retpoline compiler." >&2 308 @echo "Please update your compiler." >&2 309 @false 310endif 311endif 312 313ifdef CONFIG_UNWINDER_ORC 314orc_hash_h := arch/$(SRCARCH)/include/generated/asm/orc_hash.h 315orc_hash_sh := $(srctree)/scripts/orc_hash.sh 316targets += $(orc_hash_h) 317quiet_cmd_orc_hash = GEN $@ 318 cmd_orc_hash = mkdir -p $(dir $@); \ 319 $(CONFIG_SHELL) $(orc_hash_sh) < $< > $@ 320$(orc_hash_h): $(srctree)/arch/x86/include/asm/orc_types.h $(orc_hash_sh) FORCE 321 $(call if_changed,orc_hash) 322archprepare: $(orc_hash_h) 323endif 324 325archclean: 326 $(Q)rm -rf $(objtree)/arch/i386 327 $(Q)rm -rf $(objtree)/arch/x86_64 328 329define archhelp 330 echo '* bzImage - Compressed kernel image (arch/x86/boot/bzImage)' 331 echo ' install - Install kernel using (your) ~/bin/$(INSTALLKERNEL) or' 332 echo ' (distribution) /sbin/$(INSTALLKERNEL) or install to ' 333 echo ' $$(INSTALL_PATH) and run lilo' 334 echo '' 335 echo ' fdimage - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)' 336 echo ' fdimage144 - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)' 337 echo ' fdimage288 - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)' 338 echo ' hdimage - Create a BIOS/EFI hard disk image (arch/x86/boot/hdimage)' 339 echo ' isoimage - Create a boot CD-ROM image (arch/x86/boot/image.iso)' 340 echo ' bzdisk/fdimage*/hdimage/isoimage also accept:' 341 echo ' FDARGS="..." arguments for the booted kernel' 342 echo ' FDINITRD=file initrd for the booted kernel' 343 344endef 345