xref: /openbmc/linux/arch/x86/boot/compressed/Makefile (revision 29c37341) 
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# Sanitizer runtimes are unavailable and cannot be linked for early boot code.
21KASAN_SANITIZE			:= n
22KCSAN_SANITIZE			:= n
23OBJECT_FILES_NON_STANDARD	:= y
24
25# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
26KCOV_INSTRUMENT		:= n
27
28targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
29	vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 vmlinux.bin.zst
30
31KBUILD_CFLAGS := -m$(BITS) -O2
32KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC)
33KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
34cflags-$(CONFIG_X86_32) := -march=i386
35cflags-$(CONFIG_X86_64) := -mcmodel=small
36KBUILD_CFLAGS += $(cflags-y)
37KBUILD_CFLAGS += -mno-mmx -mno-sse
38KBUILD_CFLAGS += -ffreestanding
39KBUILD_CFLAGS += -fno-stack-protector
40KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
41KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
42KBUILD_CFLAGS += -Wno-pointer-sign
43KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
44KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
45KBUILD_CFLAGS += -D__DISABLE_EXPORTS
46
47KBUILD_AFLAGS  := $(KBUILD_CFLAGS) -D__ASSEMBLY__
48GCOV_PROFILE := n
49UBSAN_SANITIZE :=n
50
51KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE)
52# Compressed kernel should be built as PIE since it may be loaded at any
53# address by the bootloader.
54ifeq ($(CONFIG_X86_32),y)
55KBUILD_LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker)
56else
57# To build 64-bit compressed kernel as PIE, we disable relocation
58# overflow check to avoid relocation overflow error with a new linker
59# command-line option, -z noreloc-overflow.
60KBUILD_LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \
61	&& echo "-z noreloc-overflow -pie --no-dynamic-linker")
62endif
63LDFLAGS_vmlinux := -T
64
65hostprogs	:= mkpiggy
66HOST_EXTRACFLAGS += -I$(srctree)/tools/include
67
68sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p'
69
70quiet_cmd_voffset = VOFFSET $@
71      cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@
72
73targets += ../voffset.h
74
75$(obj)/../voffset.h: vmlinux FORCE
76	$(call if_changed,voffset)
77
78$(obj)/misc.o: $(obj)/../voffset.h
79
80vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/kernel_info.o $(obj)/head_$(BITS).o \
81	$(obj)/misc.o $(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \
82	$(obj)/piggy.o $(obj)/cpuflags.o
83
84vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
85vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
86ifdef CONFIG_X86_64
87	vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr_64.o
88	vmlinux-objs-y += $(obj)/mem_encrypt.o
89	vmlinux-objs-y += $(obj)/pgtable_64.o
90endif
91
92vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
93
94vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
95efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a
96
97# The compressed kernel is built with -fPIC/-fPIE so that a boot loader
98# can place it anywhere in memory and it will still run. However, since
99# it is executed as-is without any ELF relocation processing performed
100# (and has already had all relocation sections stripped from the binary),
101# none of the code can use data relocations (e.g. static assignments of
102# pointer values), since they will be meaningless at runtime. This check
103# will refuse to link the vmlinux if any of these relocations are found.
104quiet_cmd_check_data_rel = DATAREL $@
105define cmd_check_data_rel
106	for obj in $(filter %.o,$^); do \
107		$(READELF) -S $$obj | grep -qF .rel.local && { \
108			echo "error: $$obj has data relocations!" >&2; \
109			exit 1; \
110		} || true; \
111	done
112endef
113
114# We need to run two commands under "if_changed", so merge them into a
115# single invocation.
116quiet_cmd_check-and-link-vmlinux = LD      $@
117      cmd_check-and-link-vmlinux = $(cmd_check_data_rel); $(cmd_ld)
118
119$(obj)/vmlinux: $(vmlinux-objs-y) $(efi-obj-y) FORCE
120	$(call if_changed,check-and-link-vmlinux)
121
122OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
123$(obj)/vmlinux.bin: vmlinux FORCE
124	$(call if_changed,objcopy)
125
126targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs
127
128CMD_RELOCS = arch/x86/tools/relocs
129quiet_cmd_relocs = RELOCS  $@
130      cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<
131$(obj)/vmlinux.relocs: vmlinux FORCE
132	$(call if_changed,relocs)
133
134vmlinux.bin.all-y := $(obj)/vmlinux.bin
135vmlinux.bin.all-$(CONFIG_X86_NEED_RELOCS) += $(obj)/vmlinux.relocs
136
137$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE
138	$(call if_changed,gzip)
139$(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE
140	$(call if_changed,bzip2)
141$(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE
142	$(call if_changed,lzma)
143$(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE
144	$(call if_changed,xzkern)
145$(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE
146	$(call if_changed,lzo)
147$(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE
148	$(call if_changed,lz4)
149$(obj)/vmlinux.bin.zst: $(vmlinux.bin.all-y) FORCE
150	$(call if_changed,zstd22)
151
152suffix-$(CONFIG_KERNEL_GZIP)	:= gz
153suffix-$(CONFIG_KERNEL_BZIP2)	:= bz2
154suffix-$(CONFIG_KERNEL_LZMA)	:= lzma
155suffix-$(CONFIG_KERNEL_XZ)	:= xz
156suffix-$(CONFIG_KERNEL_LZO) 	:= lzo
157suffix-$(CONFIG_KERNEL_LZ4) 	:= lz4
158suffix-$(CONFIG_KERNEL_ZSTD)	:= zst
159
160quiet_cmd_mkpiggy = MKPIGGY $@
161      cmd_mkpiggy = $(obj)/mkpiggy $< > $@
162
163targets += piggy.S
164$(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE
165	$(call if_changed,mkpiggy)
166