arch/x86/boot/compressed/Makefile

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