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) 40KBUILD_CFLAGS += -Wno-pointer-sign 41 42KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ 43GCOV_PROFILE := n 44UBSAN_SANITIZE :=n 45 46KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE) 47# Compressed kernel should be built as PIE since it may be loaded at any 48# address by the bootloader. 49ifeq ($(CONFIG_X86_32),y) 50KBUILD_LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker) 51else 52# To build 64-bit compressed kernel as PIE, we disable relocation 53# overflow check to avoid relocation overflow error with a new linker 54# command-line option, -z noreloc-overflow. 55KBUILD_LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \ 56 && echo "-z noreloc-overflow -pie --no-dynamic-linker") 57endif 58LDFLAGS_vmlinux := -T 59 60hostprogs-y := mkpiggy 61HOST_EXTRACFLAGS += -I$(srctree)/tools/include 62 63sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p' 64 65quiet_cmd_voffset = VOFFSET $@ 66 cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@ 67 68targets += ../voffset.h 69 70$(obj)/../voffset.h: vmlinux FORCE 71 $(call if_changed,voffset) 72 73$(obj)/misc.o: $(obj)/../voffset.h 74 75vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \ 76 $(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \ 77 $(obj)/piggy.o $(obj)/cpuflags.o 78 79vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o 80vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o 81ifdef CONFIG_X86_64 82 vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr_64.o 83 vmlinux-objs-y += $(obj)/mem_encrypt.o 84 vmlinux-objs-y += $(obj)/pgtable_64.o 85endif 86 87$(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone 88 89vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \ 90 $(objtree)/drivers/firmware/efi/libstub/lib.a 91vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o 92 93# The compressed kernel is built with -fPIC/-fPIE so that a boot loader 94# can place it anywhere in memory and it will still run. However, since 95# it is executed as-is without any ELF relocation processing performed 96# (and has already had all relocation sections stripped from the binary), 97# none of the code can use data relocations (e.g. static assignments of 98# pointer values), since they will be meaningless at runtime. This check 99# will refuse to link the vmlinux if any of these relocations are found. 100quiet_cmd_check_data_rel = DATAREL $@ 101define cmd_check_data_rel 102 for obj in $(filter %.o,$^); do \ 103 ${CROSS_COMPILE}readelf -S $$obj | grep -qF .rel.local && { \ 104 echo "error: $$obj has data relocations!" >&2; \ 105 exit 1; \ 106 } || true; \ 107 done 108endef 109 110# We need to run two commands under "if_changed", so merge them into a 111# single invocation. 112quiet_cmd_check-and-link-vmlinux = LD $@ 113 cmd_check-and-link-vmlinux = $(cmd_check_data_rel); $(cmd_ld) 114 115$(obj)/vmlinux: $(vmlinux-objs-y) FORCE 116 $(call if_changed,check-and-link-vmlinux) 117 118OBJCOPYFLAGS_vmlinux.bin := -R .comment -S 119$(obj)/vmlinux.bin: vmlinux FORCE 120 $(call if_changed,objcopy) 121 122targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs 123 124CMD_RELOCS = arch/x86/tools/relocs 125quiet_cmd_relocs = RELOCS $@ 126 cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $< 127$(obj)/vmlinux.relocs: vmlinux FORCE 128 $(call if_changed,relocs) 129 130vmlinux.bin.all-y := $(obj)/vmlinux.bin 131vmlinux.bin.all-$(CONFIG_X86_NEED_RELOCS) += $(obj)/vmlinux.relocs 132 133$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE 134 $(call if_changed,gzip) 135$(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE 136 $(call if_changed,bzip2) 137$(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE 138 $(call if_changed,lzma) 139$(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE 140 $(call if_changed,xzkern) 141$(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE 142 $(call if_changed,lzo) 143$(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE 144 $(call if_changed,lz4) 145 146suffix-$(CONFIG_KERNEL_GZIP) := gz 147suffix-$(CONFIG_KERNEL_BZIP2) := bz2 148suffix-$(CONFIG_KERNEL_LZMA) := lzma 149suffix-$(CONFIG_KERNEL_XZ) := xz 150suffix-$(CONFIG_KERNEL_LZO) := lzo 151suffix-$(CONFIG_KERNEL_LZ4) := lz4 152 153quiet_cmd_mkpiggy = MKPIGGY $@ 154 cmd_mkpiggy = $(obj)/mkpiggy $< > $@ || ( rm -f $@ ; false ) 155 156targets += piggy.S 157$(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE 158 $(call if_changed,mkpiggy) 159