linux-yocto/arch/x86/boot/compressed/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

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 includes 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__

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|__start_rodata|__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)