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) -D__KERNEL__ -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) 39 40KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ 41GCOV_PROFILE := n 42UBSAN_SANITIZE :=n 43 44LDFLAGS := -m elf_$(UTS_MACHINE) 45# Compressed kernel should be built as PIE since it may be loaded at any 46# address by the bootloader. 47ifeq ($(CONFIG_X86_32),y) 48LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker) 49else 50# To build 64-bit compressed kernel as PIE, we disable relocation 51# overflow check to avoid relocation overflow error with a new linker 52# command-line option, -z noreloc-overflow. 53LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \ 54 && echo "-z noreloc-overflow -pie --no-dynamic-linker") 55endif 56LDFLAGS_vmlinux := -T 57 58hostprogs-y := mkpiggy 59HOST_EXTRACFLAGS += -I$(srctree)/tools/include 60 61sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p' 62 63quiet_cmd_voffset = VOFFSET $@ 64 cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@ 65 66targets += ../voffset.h 67 68$(obj)/../voffset.h: vmlinux FORCE 69 $(call if_changed,voffset) 70 71$(obj)/misc.o: $(obj)/../voffset.h 72 73vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \ 74 $(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \ 75 $(obj)/piggy.o $(obj)/cpuflags.o 76 77vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o 78vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o 79ifdef CONFIG_X86_64 80 vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/pagetable.o 81 vmlinux-objs-y += $(obj)/pgtable_64.o 82endif 83 84$(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone 85 86vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \ 87 $(objtree)/drivers/firmware/efi/libstub/lib.a 88vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o 89 90# The compressed kernel is built with -fPIC/-fPIE so that a boot loader 91# can place it anywhere in memory and it will still run. However, since 92# it is executed as-is without any ELF relocation processing performed 93# (and has already had all relocation sections stripped from the binary), 94# none of the code can use data relocations (e.g. static assignments of 95# pointer values), since they will be meaningless at runtime. This check 96# will refuse to link the vmlinux if any of these relocations are found. 97quiet_cmd_check_data_rel = DATAREL $@ 98define cmd_check_data_rel 99 for obj in $(filter %.o,$^); do \ 100 ${CROSS_COMPILE}readelf -S $$obj | grep -qF .rel.local && { \ 101 echo "error: $$obj has data relocations!" >&2; \ 102 exit 1; \ 103 } || true; \ 104 done 105endef 106 107# We need to run two commands under "if_changed", so merge them into a 108# single invocation. 109quiet_cmd_check-and-link-vmlinux = LD $@ 110 cmd_check-and-link-vmlinux = $(cmd_check_data_rel); $(cmd_ld) 111 112$(obj)/vmlinux: $(vmlinux-objs-y) FORCE 113 $(call if_changed,check-and-link-vmlinux) 114 115OBJCOPYFLAGS_vmlinux.bin := -R .comment -S 116$(obj)/vmlinux.bin: vmlinux FORCE 117 $(call if_changed,objcopy) 118 119targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs 120 121CMD_RELOCS = arch/x86/tools/relocs 122quiet_cmd_relocs = RELOCS $@ 123 cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $< 124$(obj)/vmlinux.relocs: vmlinux FORCE 125 $(call if_changed,relocs) 126 127vmlinux.bin.all-y := $(obj)/vmlinux.bin 128vmlinux.bin.all-$(CONFIG_X86_NEED_RELOCS) += $(obj)/vmlinux.relocs 129 130$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE 131 $(call if_changed,gzip) 132$(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE 133 $(call if_changed,bzip2) 134$(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE 135 $(call if_changed,lzma) 136$(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE 137 $(call if_changed,xzkern) 138$(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE 139 $(call if_changed,lzo) 140$(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE 141 $(call if_changed,lz4) 142 143suffix-$(CONFIG_KERNEL_GZIP) := gz 144suffix-$(CONFIG_KERNEL_BZIP2) := bz2 145suffix-$(CONFIG_KERNEL_LZMA) := lzma 146suffix-$(CONFIG_KERNEL_XZ) := xz 147suffix-$(CONFIG_KERNEL_LZO) := lzo 148suffix-$(CONFIG_KERNEL_LZ4) := lz4 149 150quiet_cmd_mkpiggy = MKPIGGY $@ 151 cmd_mkpiggy = $(obj)/mkpiggy $< > $@ || ( rm -f $@ ; false ) 152 153targets += piggy.S 154$(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE 155 $(call if_changed,mkpiggy) 156