1 # SPDX-License-Identifier: GPL-2.0
3 # linux/arch/x86/boot/compressed/Makefile
5 # create a compressed vmlinux image from the original vmlinux
8 # decompression code (*.o)
9 # asm globals (piggy.S), including:
10 # vmlinux.bin.(gz|bz2|lzma|...)
13 # vmlinux stripped of debugging and comments
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
21 OBJECT_FILES_NON_STANDARD := y
23 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
26 targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
27 vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4
29 KBUILD_CFLAGS := -m$(BITS) -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 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
40 KBUILD_CFLAGS += -Wno-pointer-sign
41 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
42 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
44 KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
48 KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE)
49 # Compressed kernel should be built as PIE since it may be loaded at any
50 # address by the bootloader.
51 ifeq ($(CONFIG_X86_32),y)
52 KBUILD_LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker)
54 # To build 64-bit compressed kernel as PIE, we disable relocation
55 # overflow check to avoid relocation overflow error with a new linker
56 # command-line option, -z noreloc-overflow.
57 KBUILD_LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \
58 && echo "-z noreloc-overflow -pie --no-dynamic-linker")
63 HOST_EXTRACFLAGS += -I$(srctree)/tools/include
65 sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p'
67 quiet_cmd_voffset = VOFFSET $@
68 cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@
70 targets += ../voffset.h
72 $(obj)/../voffset.h: vmlinux FORCE
73 $(call if_changed,voffset)
75 $(obj)/misc.o: $(obj)/../voffset.h
77 vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/kernel_info.o $(obj)/head_$(BITS).o \
78 $(obj)/misc.o $(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \
79 $(obj)/piggy.o $(obj)/cpuflags.o
81 vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
82 vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
84 vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr_64.o
85 vmlinux-objs-y += $(obj)/mem_encrypt.o
86 vmlinux-objs-y += $(obj)/pgtable_64.o
89 vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
91 vmlinux-objs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
92 vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
94 # The compressed kernel is built with -fPIC/-fPIE so that a boot loader
95 # can place it anywhere in memory and it will still run. However, since
96 # it is executed as-is without any ELF relocation processing performed
97 # (and has already had all relocation sections stripped from the binary),
98 # none of the code can use data relocations (e.g. static assignments of
99 # pointer values), since they will be meaningless at runtime. This check
100 # will refuse to link the vmlinux if any of these relocations are found.
101 quiet_cmd_check_data_rel = DATAREL $@
102 define cmd_check_data_rel
103 for obj in $(filter %.o,$^); do \
104 $(READELF) -S $$obj | grep -qF .rel.local && { \
105 echo "error: $$obj has data relocations!" >&2; \
111 # We need to run two commands under "if_changed", so merge them into a
113 quiet_cmd_check-and-link-vmlinux = LD $@
114 cmd_check-and-link-vmlinux = $(cmd_check_data_rel); $(cmd_ld)
116 $(obj)/vmlinux: $(vmlinux-objs-y) FORCE
117 $(call if_changed,check-and-link-vmlinux)
119 OBJCOPYFLAGS_vmlinux.bin := -R .comment -S
120 $(obj)/vmlinux.bin: vmlinux FORCE
121 $(call if_changed,objcopy)
123 targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs
125 CMD_RELOCS = arch/x86/tools/relocs
126 quiet_cmd_relocs = RELOCS $@
127 cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<
128 $(obj)/vmlinux.relocs: vmlinux FORCE
129 $(call if_changed,relocs)
131 vmlinux.bin.all-y := $(obj)/vmlinux.bin
132 vmlinux.bin.all-$(CONFIG_X86_NEED_RELOCS) += $(obj)/vmlinux.relocs
134 $(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE
135 $(call if_changed,gzip)
136 $(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE
137 $(call if_changed,bzip2)
138 $(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE
139 $(call if_changed,lzma)
140 $(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE
141 $(call if_changed,xzkern)
142 $(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE
143 $(call if_changed,lzo)
144 $(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE
145 $(call if_changed,lz4)
147 suffix-$(CONFIG_KERNEL_GZIP) := gz
148 suffix-$(CONFIG_KERNEL_BZIP2) := bz2
149 suffix-$(CONFIG_KERNEL_LZMA) := lzma
150 suffix-$(CONFIG_KERNEL_XZ) := xz
151 suffix-$(CONFIG_KERNEL_LZO) := lzo
152 suffix-$(CONFIG_KERNEL_LZ4) := lz4
154 quiet_cmd_mkpiggy = MKPIGGY $@
155 cmd_mkpiggy = $(obj)/mkpiggy $< > $@
158 $(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE
159 $(call if_changed,mkpiggy)