xref: /openbmc/linux/arch/x86/boot/compressed/Makefile (revision 4f6cce39) 
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
19KASAN_SANITIZE			:= n
20OBJECT_FILES_NON_STANDARD	:= y
21
22# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
23KCOV_INSTRUMENT		:= n
24
25targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
26	vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4
27
28KBUILD_CFLAGS := -m$(BITS) -D__KERNEL__ -O2
29KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC)
30KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
31cflags-$(CONFIG_X86_32) := -march=i386
32cflags-$(CONFIG_X86_64) := -mcmodel=small
33KBUILD_CFLAGS += $(cflags-y)
34KBUILD_CFLAGS += -mno-mmx -mno-sse
35KBUILD_CFLAGS += $(call cc-option,-ffreestanding)
36KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector)
37
38KBUILD_AFLAGS  := $(KBUILD_CFLAGS) -D__ASSEMBLY__
39GCOV_PROFILE := n
40UBSAN_SANITIZE :=n
41
42LDFLAGS := -m elf_$(UTS_MACHINE)
43# Compressed kernel should be built as PIE since it may be loaded at any
44# address by the bootloader.
45ifeq ($(CONFIG_X86_32),y)
46LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker)
47else
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.
51LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \
52	&& echo "-z noreloc-overflow -pie --no-dynamic-linker")
53endif
54LDFLAGS_vmlinux := -T
55
56hostprogs-y	:= mkpiggy
57HOST_EXTRACFLAGS += -I$(srctree)/tools/include
58
59sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p'
60
61quiet_cmd_voffset = VOFFSET $@
62      cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@
63
64targets += ../voffset.h
65
66$(obj)/../voffset.h: vmlinux FORCE
67	$(call if_changed,voffset)
68
69$(obj)/misc.o: $(obj)/../voffset.h
70
71vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \
72	$(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \
73	$(obj)/piggy.o $(obj)/cpuflags.o
74
75vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
76vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
77ifdef CONFIG_X86_64
78	vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/pagetable.o
79endif
80
81$(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
82
83vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
84	$(objtree)/drivers/firmware/efi/libstub/lib.a
85vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
86
87# The compressed kernel is built with -fPIC/-fPIE so that a boot loader
88# can place it anywhere in memory and it will still run. However, since
89# it is executed as-is without any ELF relocation processing performed
90# (and has already had all relocation sections stripped from the binary),
91# none of the code can use data relocations (e.g. static assignments of
92# pointer values), since they will be meaningless at runtime. This check
93# will refuse to link the vmlinux if any of these relocations are found.
94quiet_cmd_check_data_rel = DATAREL $@
95define cmd_check_data_rel
96	for obj in $(filter %.o,$^); do \
97		readelf -S $$obj | grep -qF .rel.local && { \
98			echo "error: $$obj has data relocations!" >&2; \
99			exit 1; \
100		} || true; \
101	done
102endef
103
104$(obj)/vmlinux: $(vmlinux-objs-y) FORCE
105	$(call if_changed,check_data_rel)
106	$(call if_changed,ld)
107
108OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
109$(obj)/vmlinux.bin: vmlinux FORCE
110	$(call if_changed,objcopy)
111
112targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs
113
114CMD_RELOCS = arch/x86/tools/relocs
115quiet_cmd_relocs = RELOCS  $@
116      cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<
117$(obj)/vmlinux.relocs: vmlinux FORCE
118	$(call if_changed,relocs)
119
120vmlinux.bin.all-y := $(obj)/vmlinux.bin
121vmlinux.bin.all-$(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	$(call if_changed,lz4)
135
136suffix-$(CONFIG_KERNEL_GZIP)	:= gz
137suffix-$(CONFIG_KERNEL_BZIP2)	:= bz2
138suffix-$(CONFIG_KERNEL_LZMA)	:= lzma
139suffix-$(CONFIG_KERNEL_XZ)	:= xz
140suffix-$(CONFIG_KERNEL_LZO) 	:= lzo
141suffix-$(CONFIG_KERNEL_LZ4) 	:= lz4
142
143quiet_cmd_mkpiggy = MKPIGGY $@
144      cmd_mkpiggy = $(obj)/mkpiggy $< > $@ || ( rm -f $@ ; false )
145
146targets += piggy.S
147$(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE
148	$(call if_changed,mkpiggy)
149