2 # linux/arch/x86/boot/compressed/Makefile
4 # create a compressed vmlinux image from the original vmlinux
7 # decompression code (*.o)
8 # asm globals (piggy.S), including:
9 # vmlinux.bin.(gz|bz2|lzma|...)
12 # vmlinux stripped of debugging and comments
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
20 OBJECT_FILES_NON_STANDARD := y
22 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
25 targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
26 vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4
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 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
39 KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
43 LDFLAGS := -m elf_$(UTS_MACHINE)
44 # Compressed kernel should be built as PIE since it may be loaded at any
45 # address by the bootloader.
46 ifeq ($(CONFIG_X86_32),y)
47 LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker)
49 # To build 64-bit compressed kernel as PIE, we disable relocation
50 # overflow check to avoid relocation overflow error with a new linker
51 # command-line option, -z noreloc-overflow.
52 LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \
53 && echo "-z noreloc-overflow -pie --no-dynamic-linker")
57 hostprogs-y := mkpiggy
58 HOST_EXTRACFLAGS += -I$(srctree)/tools/include
60 sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p'
62 quiet_cmd_voffset = VOFFSET $@
63 cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@
65 targets += ../voffset.h
67 $(obj)/../voffset.h: vmlinux FORCE
68 $(call if_changed,voffset)
70 $(obj)/misc.o: $(obj)/../voffset.h
72 vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \
73 $(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \
74 $(obj)/piggy.o $(obj)/cpuflags.o
76 vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
77 vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
79 vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/pagetable.o
82 $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
84 vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
85 $(objtree)/drivers/firmware/efi/libstub/lib.a
86 vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
88 # The compressed kernel is built with -fPIC/-fPIE so that a boot loader
89 # can place it anywhere in memory and it will still run. However, since
90 # it is executed as-is without any ELF relocation processing performed
91 # (and has already had all relocation sections stripped from the binary),
92 # none of the code can use data relocations (e.g. static assignments of
93 # pointer values), since they will be meaningless at runtime. This check
94 # will refuse to link the vmlinux if any of these relocations are found.
95 quiet_cmd_check_data_rel = DATAREL $@
96 define cmd_check_data_rel
97 for obj in $(filter %.o,$^); do \
98 ${CROSS_COMPILE}readelf -S $$obj | grep -qF .rel.local && { \
99 echo "error: $$obj has data relocations!" >&2; \
105 $(obj)/vmlinux: $(vmlinux-objs-y) FORCE
106 $(call if_changed,check_data_rel)
107 $(call if_changed,ld)
109 OBJCOPYFLAGS_vmlinux.bin := -R .comment -S
110 $(obj)/vmlinux.bin: vmlinux FORCE
111 $(call if_changed,objcopy)
113 targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs
115 CMD_RELOCS = arch/x86/tools/relocs
116 quiet_cmd_relocs = RELOCS $@
117 cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<
118 $(obj)/vmlinux.relocs: vmlinux FORCE
119 $(call if_changed,relocs)
121 vmlinux.bin.all-y := $(obj)/vmlinux.bin
122 vmlinux.bin.all-$(CONFIG_X86_NEED_RELOCS) += $(obj)/vmlinux.relocs
124 $(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE
125 $(call if_changed,gzip)
126 $(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE
127 $(call if_changed,bzip2)
128 $(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE
129 $(call if_changed,lzma)
130 $(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE
131 $(call if_changed,xzkern)
132 $(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE
133 $(call if_changed,lzo)
134 $(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE
135 $(call if_changed,lz4)
137 suffix-$(CONFIG_KERNEL_GZIP) := gz
138 suffix-$(CONFIG_KERNEL_BZIP2) := bz2
139 suffix-$(CONFIG_KERNEL_LZMA) := lzma
140 suffix-$(CONFIG_KERNEL_XZ) := xz
141 suffix-$(CONFIG_KERNEL_LZO) := lzo
142 suffix-$(CONFIG_KERNEL_LZ4) := lz4
144 quiet_cmd_mkpiggy = MKPIGGY $@
145 cmd_mkpiggy = $(obj)/mkpiggy $< > $@ || ( rm -f $@ ; false )
148 $(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE
149 $(call if_changed,mkpiggy)