diff options
Diffstat (limited to 'arch/x86/Makefile')
| -rw-r--r-- | arch/x86/Makefile | 56 |
1 files changed, 43 insertions, 13 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 07639c656fc..33f71b01fd2 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -11,11 +11,37 @@ else KBUILD_DEFCONFIG := $(ARCH)_defconfig 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. +# +# The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For +# older versions of GCC, we need to play evil and unreliable tricks to +# attempt to ensure that our asm(".code16gcc") is first in the asm +# output. +CODE16GCC_CFLAGS := -m32 -include $(srctree)/arch/x86/boot/code16gcc.h \ + $(call cc-option, -fno-toplevel-reorder,\ + $(call cc-option, -fno-unit-at-a-time)) +M16_CFLAGS := $(call cc-option, -m16, $(CODE16GCC_CFLAGS)) + +REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -D__KERNEL__ \ + -DDISABLE_BRANCH_PROFILING \ + -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ + -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ + -mno-mmx -mno-sse \ + $(call cc-option, -ffreestanding) \ + $(call cc-option, -fno-stack-protector) \ + $(call cc-option, -mpreferred-stack-boundary=2) +export REALMODE_CFLAGS + # BITS is used as extension for files which are available in a 32 bit # and a 64 bit version to simplify shared Makefiles. # e.g.: obj-y += foo_$(BITS).o export BITS +ifdef CONFIG_X86_NEED_RELOCS + LDFLAGS_vmlinux := --emit-relocs +endif + ifeq ($(CONFIG_X86_32),y) BITS := 32 UTS_MACHINE := i386 @@ -25,12 +51,11 @@ ifeq ($(CONFIG_X86_32),y) KBUILD_AFLAGS += $(biarch) KBUILD_CFLAGS += $(biarch) - ifdef CONFIG_RELOCATABLE - LDFLAGS_vmlinux := --emit-relocs - endif - KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return + # Don't autogenerate MMX or SSE instructions + KBUILD_CFLAGS += -mno-mmx -mno-sse + # Never want PIC in a 32-bit kernel, prevent breakage with GCC built # with nonstandard options KBUILD_CFLAGS += -fno-pic @@ -54,11 +79,17 @@ else UTS_MACHINE := x86_64 CHECKFLAGS += -D__x86_64__ -m64 + biarch := -m64 KBUILD_AFLAGS += -m64 KBUILD_CFLAGS += -m64 + # Don't autogenerate traditional x87, MMX or SSE instructions + KBUILD_CFLAGS += -mno-mmx -mno-sse + KBUILD_CFLAGS += $(call cc-option,-mno-80387) + KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387) + # Use -mpreferred-stack-boundary=3 if supported. - KBUILD_CFLAGS += $(call cc-option,-mno-sse -mpreferred-stack-boundary=3) + KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=3) # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu) cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8) @@ -80,16 +111,14 @@ else # this works around some issues with generating unwind tables in older gccs # newer gccs do it by default - KBUILD_CFLAGS += -maccumulate-outgoing-args + KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args) endif +# Make sure compiler does not have buggy stack-protector support. ifdef CONFIG_CC_STACKPROTECTOR cc_has_sp := $(srctree)/scripts/gcc-x86_$(BITS)-has-stack-protector.sh - ifeq ($(shell $(CONFIG_SHELL) $(cc_has_sp) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y) - stackp-y := -fstack-protector - KBUILD_CFLAGS += $(stackp-y) - else - $(warning stack protector enabled but no compiler support) + ifneq ($(shell $(CONFIG_SHELL) $(cc_has_sp) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y) + $(warning stack-protector enabled but compiler support broken) endif endif @@ -126,6 +155,7 @@ cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTI # does binutils support specific instructions? asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1) +asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1) avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1) avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1) @@ -223,8 +253,8 @@ archclean: PHONY += kvmconfig kvmconfig: $(if $(wildcard $(objtree)/.config),, $(error You need an existing .config for this target)) - $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh -m -O $(objtree) $(objtree)/.config arch/x86/configs/kvm_guest.config - $(Q)yes "" | $(MAKE) oldconfig + $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh -m -O $(objtree) $(objtree)/.config $(srctree)/arch/x86/configs/kvm_guest.config + $(Q)yes "" | $(MAKE) -f $(srctree)/Makefile oldconfig define archhelp echo '* bzImage - Compressed kernel image (arch/x86/boot/bzImage)' |