Makefile
# SPDX-License-Identifier: GPL-2.0
#
# linux/arch/x86/boot/compressed/Makefile
#
# create a compressed vmlinux image from the original vmlinux
#
# vmlinuz is:
# decompression code (*.o)
# asm globals (piggy.S), including:
# vmlinux.bin.(gz|bz2|lzma|...)
#
# vmlinux.bin is:
# vmlinux stripped of debugging and comments
# vmlinux.bin.all is:
# vmlinux.bin + vmlinux.relocs
# vmlinux.bin.(gz|bz2|lzma|...) is:
# (see scripts/Makefile.lib size_append)
# compressed vmlinux.bin.all + u32 size of vmlinux.bin.all
# Sanitizer runtimes are unavailable and cannot be linked for early boot code.
KASAN_SANITIZE := n
KCSAN_SANITIZE := n
KMSAN_SANITIZE := n
OBJECT_FILES_NON_STANDARD := y
# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
KCOV_INSTRUMENT := n
targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 vmlinux.bin.zst
# CLANG_FLAGS must come before any cc-disable-warning or cc-option calls in
# case of cross compiling, as it has the '--target=' flag, which is needed to
# avoid errors with '-march=i386', and future flags may depend on the target to
# be valid.
KBUILD_CFLAGS := -m$(BITS) -O2 $(CLANG_FLAGS)
KBUILD_CFLAGS += -fno-strict-aliasing -fPIE
KBUILD_CFLAGS += -Wundef
KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
cflags-$(CONFIG_X86_32) := -march=i386
cflags-$(CONFIG_X86_64) := -mcmodel=small -mno-red-zone
KBUILD_CFLAGS += $(cflags-y)
KBUILD_CFLAGS += -mno-mmx -mno-sse
KBUILD_CFLAGS += -ffreestanding -fshort-wchar
KBUILD_CFLAGS += -fno-stack-protector
KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
KBUILD_CFLAGS += -Wno-pointer-sign
KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
KBUILD_CFLAGS += -D__DISABLE_EXPORTS
# Disable relocation relaxation in case the link is not PIE.
KBUILD_CFLAGS += $(call cc-option,-Wa$(comma)-mrelax-relocations=no)
KBUILD_CFLAGS += -include $(srctree)/include/linux/hidden.h
# sev.c indirectly inludes inat-table.h which is generated during
# compilation and stored in $(objtree). Add the directory to the includes so
# that the compiler finds it even with out-of-tree builds (make O=/some/path).
CFLAGS_sev.o += -I$(objtree)/arch/x86/lib/
KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
GCOV_PROFILE := n
UBSAN_SANITIZE :=n
KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE)
KBUILD_LDFLAGS += $(call ld-option,--no-ld-generated-unwind-info)
# Compressed kernel should be built as PIE since it may be loaded at any
# address by the bootloader.
LDFLAGS_vmlinux := -pie $(call ld-option, --no-dynamic-linker)
ifdef CONFIG_LD_ORPHAN_WARN
LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
endif
LDFLAGS_vmlinux += -z noexecstack
ifeq ($(CONFIG_LD_IS_BFD),y)
LDFLAGS_vmlinux += $(call ld-option,--no-warn-rwx-segments)
endif
ifeq ($(CONFIG_EFI_STUB),y)
# ensure that the static EFI stub library will be pulled in, even if it is
# never referenced explicitly from the startup code
LDFLAGS_vmlinux += -u efi_pe_entry
endif
LDFLAGS_vmlinux += -T
hostprogs := mkpiggy
HOST_EXTRACFLAGS += -I$(srctree)/tools/include
sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p'
quiet_cmd_voffset = VOFFSET $@
cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@
targets += ../voffset.h
$(obj)/../voffset.h: vmlinux FORCE
$(call if_changed,voffset)
$(obj)/misc.o: $(obj)/../voffset.h
vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/kernel_info.o $(obj)/head_$(BITS).o \
$(obj)/misc.o $(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \
$(obj)/piggy.o $(obj)/cpuflags.o
vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
ifdef CONFIG_X86_64
vmlinux-objs-y += $(obj)/ident_map_64.o
vmlinux-objs-y += $(obj)/idt_64.o $(obj)/idt_handlers_64.o
vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/mem_encrypt.o
vmlinux-objs-y += $(obj)/pgtable_64.o
vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/sev.o
endif
vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdx.o $(obj)/tdcall.o $(obj)/tdx-shared.o
vmlinux-objs-$(CONFIG_UNACCEPTED_MEMORY) += $(obj)/mem.o
vmlinux-objs-$(CONFIG_EFI) += $(obj)/efi.o
vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_mixed.o
vmlinux-objs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
$(obj)/vmlinux: $(vmlinux-objs-y) FORCE
$(call if_changed,ld)
OBJCOPYFLAGS_vmlinux.bin := -R .comment -S
$(obj)/vmlinux.bin: vmlinux FORCE
$(call if_changed,objcopy)
targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs
# vmlinux.relocs is created by the vmlinux postlink step.
$(obj)/vmlinux.relocs: vmlinux
@true
vmlinux.bin.all-y := $(obj)/vmlinux.bin
vmlinux.bin.all-$(CONFIG_X86_NEED_RELOCS) += $(obj)/vmlinux.relocs
$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE
$(call if_changed,gzip)
$(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE
$(call if_changed,bzip2_with_size)
$(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE
$(call if_changed,lzma_with_size)
$(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE
$(call if_changed,xzkern_with_size)
$(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE
$(call if_changed,lzo_with_size)
$(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE
$(call if_changed,lz4_with_size)
$(obj)/vmlinux.bin.zst: $(vmlinux.bin.all-y) FORCE
$(call if_changed,zstd22_with_size)
suffix-$(CONFIG_KERNEL_GZIP) := gz
suffix-$(CONFIG_KERNEL_BZIP2) := bz2
suffix-$(CONFIG_KERNEL_LZMA) := lzma
suffix-$(CONFIG_KERNEL_XZ) := xz
suffix-$(CONFIG_KERNEL_LZO) := lzo
suffix-$(CONFIG_KERNEL_LZ4) := lz4
suffix-$(CONFIG_KERNEL_ZSTD) := zst
quiet_cmd_mkpiggy = MKPIGGY $@
cmd_mkpiggy = $(obj)/mkpiggy $< > $@
targets += piggy.S
$(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE
$(call if_changed,mkpiggy)