arch/x86/boot/compressed/Makefile

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