xref: /openbmc/linux/arch/x86/boot/compressed/Makefile (revision 8a5aaf97) 
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
20KASAN_SANITIZE			:= n
21OBJECT_FILES_NON_STANDARD	:= y
22
23# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
24KCOV_INSTRUMENT		:= n
25
26targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
27	vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4
28
29KBUILD_CFLAGS := -m$(BITS) -O2
30KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC)
31KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
32cflags-$(CONFIG_X86_32) := -march=i386
33cflags-$(CONFIG_X86_64) := -mcmodel=small
34KBUILD_CFLAGS += $(cflags-y)
35KBUILD_CFLAGS += -mno-mmx -mno-sse
36KBUILD_CFLAGS += $(call cc-option,-ffreestanding)
37KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector)
38KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
39KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
40KBUILD_CFLAGS += -Wno-pointer-sign
41
42KBUILD_AFLAGS  := $(KBUILD_CFLAGS) -D__ASSEMBLY__
43GCOV_PROFILE := n
44UBSAN_SANITIZE :=n
45
46KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE)
47# Compressed kernel should be built as PIE since it may be loaded at any
48# address by the bootloader.
49ifeq ($(CONFIG_X86_32),y)
50KBUILD_LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker)
51else
52# To build 64-bit compressed kernel as PIE, we disable relocation
53# overflow check to avoid relocation overflow error with a new linker
54# command-line option, -z noreloc-overflow.
55KBUILD_LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \
56	&& echo "-z noreloc-overflow -pie --no-dynamic-linker")
57endif
58LDFLAGS_vmlinux := -T
59
60hostprogs-y	:= mkpiggy
61HOST_EXTRACFLAGS += -I$(srctree)/tools/include
62
63sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p'
64
65quiet_cmd_voffset = VOFFSET $@
66      cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@
67
68targets += ../voffset.h
69
70$(obj)/../voffset.h: vmlinux FORCE
71	$(call if_changed,voffset)
72
73$(obj)/misc.o: $(obj)/../voffset.h
74
75vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \
76	$(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \
77	$(obj)/piggy.o $(obj)/cpuflags.o
78
79vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
80vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
81ifdef CONFIG_X86_64
82	vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr_64.o
83	vmlinux-objs-y += $(obj)/mem_encrypt.o
84	vmlinux-objs-y += $(obj)/pgtable_64.o
85endif
86
87$(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
88
89vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
90	$(objtree)/drivers/firmware/efi/libstub/lib.a
91vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
92
93# The compressed kernel is built with -fPIC/-fPIE so that a boot loader
94# can place it anywhere in memory and it will still run. However, since
95# it is executed as-is without any ELF relocation processing performed
96# (and has already had all relocation sections stripped from the binary),
97# none of the code can use data relocations (e.g. static assignments of
98# pointer values), since they will be meaningless at runtime. This check
99# will refuse to link the vmlinux if any of these relocations are found.
100quiet_cmd_check_data_rel = DATAREL $@
101define cmd_check_data_rel
102	for obj in $(filter %.o,$^); do \
103		${CROSS_COMPILE}readelf -S $$obj | grep -qF .rel.local && { \
104			echo "error: $$obj has data relocations!" >&2; \
105			exit 1; \
106		} || true; \
107	done
108endef
109
110# We need to run two commands under "if_changed", so merge them into a
111# single invocation.
112quiet_cmd_check-and-link-vmlinux = LD      $@
113      cmd_check-and-link-vmlinux = $(cmd_check_data_rel); $(cmd_ld)
114
115$(obj)/vmlinux: $(vmlinux-objs-y) FORCE
116	$(call if_changed,check-and-link-vmlinux)
117
118OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
119$(obj)/vmlinux.bin: vmlinux FORCE
120	$(call if_changed,objcopy)
121
122targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs
123
124CMD_RELOCS = arch/x86/tools/relocs
125quiet_cmd_relocs = RELOCS  $@
126      cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<
127$(obj)/vmlinux.relocs: vmlinux FORCE
128	$(call if_changed,relocs)
129
130vmlinux.bin.all-y := $(obj)/vmlinux.bin
131vmlinux.bin.all-$(CONFIG_X86_NEED_RELOCS) += $(obj)/vmlinux.relocs
132
133$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE
134	$(call if_changed,gzip)
135$(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE
136	$(call if_changed,bzip2)
137$(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE
138	$(call if_changed,lzma)
139$(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE
140	$(call if_changed,xzkern)
141$(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE
142	$(call if_changed,lzo)
143$(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE
144	$(call if_changed,lz4)
145
146suffix-$(CONFIG_KERNEL_GZIP)	:= gz
147suffix-$(CONFIG_KERNEL_BZIP2)	:= bz2
148suffix-$(CONFIG_KERNEL_LZMA)	:= lzma
149suffix-$(CONFIG_KERNEL_XZ)	:= xz
150suffix-$(CONFIG_KERNEL_LZO) 	:= lzo
151suffix-$(CONFIG_KERNEL_LZ4) 	:= lz4
152
153quiet_cmd_mkpiggy = MKPIGGY $@
154      cmd_mkpiggy = $(obj)/mkpiggy $< > $@
155
156targets += piggy.S
157$(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE
158	$(call if_changed,mkpiggy)
159