1# SPDX-License-Identifier: GPL-2.0 2# 3# linux/arch/x86/boot/compressed/Makefile 4# 5# create a compressed vmlinux image from the original vmlinux 6# 7# vmlinuz is: 8# decompression code (*.o) 9# asm globals (piggy.S), including: 10# vmlinux.bin.(gz|bz2|lzma|...) 11# 12# vmlinux.bin is: 13# vmlinux stripped of debugging and comments 14# vmlinux.bin.all is: 15# vmlinux.bin + vmlinux.relocs 16# vmlinux.bin.(gz|bz2|lzma|...) is: 17# (see scripts/Makefile.lib size_append) 18# compressed vmlinux.bin.all + u32 size of vmlinux.bin.all 19 20KASAN_SANITIZE := n 21OBJECT_FILES_NON_STANDARD := y 22 23# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. 24KCOV_INSTRUMENT := n 25 26targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \ 27 vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 28 29KBUILD_CFLAGS := -m$(BITS) -O2 30KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC) 31KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING 32cflags-$(CONFIG_X86_32) := -march=i386 33cflags-$(CONFIG_X86_64) := -mcmodel=small 34KBUILD_CFLAGS += $(cflags-y) 35KBUILD_CFLAGS += -mno-mmx -mno-sse 36KBUILD_CFLAGS += $(call cc-option,-ffreestanding) 37KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector) 38KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) 39KBUILD_CFLAGS += $(call cc-disable-warning, gnu) 40 41KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ 42GCOV_PROFILE := n 43UBSAN_SANITIZE :=n 44 45LDFLAGS := -m elf_$(UTS_MACHINE) 46# Compressed kernel should be built as PIE since it may be loaded at any 47# address by the bootloader. 48ifeq ($(CONFIG_X86_32),y) 49LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker) 50else 51# To build 64-bit compressed kernel as PIE, we disable relocation 52# overflow check to avoid relocation overflow error with a new linker 53# command-line option, -z noreloc-overflow. 54LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \ 55 && echo "-z noreloc-overflow -pie --no-dynamic-linker") 56endif 57LDFLAGS_vmlinux := -T 58 59hostprogs-y := mkpiggy 60HOST_EXTRACFLAGS += -I$(srctree)/tools/include 61 62sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p' 63 64quiet_cmd_voffset = VOFFSET $@ 65 cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@ 66 67targets += ../voffset.h 68 69$(obj)/../voffset.h: vmlinux FORCE 70 $(call if_changed,voffset) 71 72$(obj)/misc.o: $(obj)/../voffset.h 73 74vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \ 75 $(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \ 76 $(obj)/piggy.o $(obj)/cpuflags.o 77 78vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o 79vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o 80ifdef CONFIG_X86_64 81 vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr_64.o 82 vmlinux-objs-y += $(obj)/mem_encrypt.o 83 vmlinux-objs-y += $(obj)/pgtable_64.o 84endif 85 86$(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone 87 88vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \ 89 $(objtree)/drivers/firmware/efi/libstub/lib.a 90vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o 91 92# The compressed kernel is built with -fPIC/-fPIE so that a boot loader 93# can place it anywhere in memory and it will still run. However, since 94# it is executed as-is without any ELF relocation processing performed 95# (and has already had all relocation sections stripped from the binary), 96# none of the code can use data relocations (e.g. static assignments of 97# pointer values), since they will be meaningless at runtime. This check 98# will refuse to link the vmlinux if any of these relocations are found. 99quiet_cmd_check_data_rel = DATAREL $@ 100define cmd_check_data_rel 101 for obj in $(filter %.o,$^); do \ 102 ${CROSS_COMPILE}readelf -S $$obj | grep -qF .rel.local && { \ 103 echo "error: $$obj has data relocations!" >&2; \ 104 exit 1; \ 105 } || true; \ 106 done 107endef 108 109$(obj)/vmlinux: $(vmlinux-objs-y) FORCE 110 $(call if_changed,check_data_rel) 111 $(call if_changed,ld) 112 113OBJCOPYFLAGS_vmlinux.bin := -R .comment -S 114$(obj)/vmlinux.bin: vmlinux FORCE 115 $(call if_changed,objcopy) 116 117targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs 118 119CMD_RELOCS = arch/x86/tools/relocs 120quiet_cmd_relocs = RELOCS $@ 121 cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $< 122$(obj)/vmlinux.relocs: vmlinux FORCE 123 $(call if_changed,relocs) 124 125vmlinux.bin.all-y := $(obj)/vmlinux.bin 126vmlinux.bin.all-$(CONFIG_X86_NEED_RELOCS) += $(obj)/vmlinux.relocs 127 128$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE 129 $(call if_changed,gzip) 130$(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE 131 $(call if_changed,bzip2) 132$(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE 133 $(call if_changed,lzma) 134$(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE 135 $(call if_changed,xzkern) 136$(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE 137 $(call if_changed,lzo) 138$(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE 139 $(call if_changed,lz4) 140 141suffix-$(CONFIG_KERNEL_GZIP) := gz 142suffix-$(CONFIG_KERNEL_BZIP2) := bz2 143suffix-$(CONFIG_KERNEL_LZMA) := lzma 144suffix-$(CONFIG_KERNEL_XZ) := xz 145suffix-$(CONFIG_KERNEL_LZO) := lzo 146suffix-$(CONFIG_KERNEL_LZ4) := lz4 147 148quiet_cmd_mkpiggy = MKPIGGY $@ 149 cmd_mkpiggy = $(obj)/mkpiggy $< > $@ || ( rm -f $@ ; false ) 150 151targets += piggy.S 152$(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE 153 $(call if_changed,mkpiggy) 154