1 # SPDX-License-Identifier: GPL-2.0-only
2 
3 PHONY := __default
4 __default: vmlinux.o modules.builtin.modinfo modules.builtin
5 
6 include include/config/auto.conf
7 include $(srctree)/scripts/Kbuild.include
8 
9 # for objtool
10 include $(srctree)/scripts/Makefile.lib
11 
12 # Generate a linker script to ensure correct ordering of initcalls for Clang LTO
13 # ---------------------------------------------------------------------------
14 
15 quiet_cmd_gen_initcalls_lds = GEN     $@
16       cmd_gen_initcalls_lds = \
17 	$(PYTHON3) $(srctree)/scripts/jobserver-exec \
18 	$(PERL) $(real-prereqs) > $@
19 
20 .tmp_initcalls.lds: $(srctree)/scripts/generate_initcall_order.pl \
21 		vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
22 	$(call if_changed,gen_initcalls_lds)
23 
24 targets := .tmp_initcalls.lds
25 
26 ifdef CONFIG_LTO_CLANG
27 initcalls-lds := .tmp_initcalls.lds
28 endif
29 
30 # objtool for vmlinux.o
31 # ---------------------------------------------------------------------------
32 #
33 # For LTO and IBT, objtool doesn't run on individual translation units.
34 # Run everything on vmlinux instead.
35 
36 objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION))
37 
38 vmlinux-objtool-args-$(delay-objtool)			+= $(objtool-args-y)
39 vmlinux-objtool-args-$(CONFIG_GCOV_KERNEL)		+= --no-unreachable
40 vmlinux-objtool-args-$(CONFIG_NOINSTR_VALIDATION)	+= --noinstr \
41 							   $(if $(or $(CONFIG_MITIGATION_UNRET_ENTRY),$(CONFIG_MITIGATION_SRSO)), --unret)
42 
43 objtool-args = $(vmlinux-objtool-args-y) --link
44 
45 # Link of vmlinux.o used for section mismatch analysis
46 # ---------------------------------------------------------------------------
47 
48 vmlinux-o-ld-args-$(CONFIG_BUILTIN_MODULE_RANGES)	+= -Map=$@.map
49 
50 quiet_cmd_ld_vmlinux.o = LD      $@
51       cmd_ld_vmlinux.o = \
52 	$(LD) ${KBUILD_LDFLAGS} -r -o $@ \
53 	$(vmlinux-o-ld-args-y) \
54 	$(addprefix -T , $(initcalls-lds)) \
55 	--whole-archive vmlinux.a --no-whole-archive \
56 	--start-group $(KBUILD_VMLINUX_LIBS) --end-group \
57 	$(cmd_objtool)
58 
59 define rule_ld_vmlinux.o
60 	$(call cmd_and_savecmd,ld_vmlinux.o)
61 	$(call cmd,gen_objtooldep)
62 endef
63 
64 vmlinux.o: $(initcalls-lds) vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
65 	$(call if_changed_rule,ld_vmlinux.o)
66 
67 targets += vmlinux.o
68 
69 # module.builtin.modinfo
70 # ---------------------------------------------------------------------------
71 
72 OBJCOPYFLAGS_modules.builtin.modinfo := -j .modinfo -O binary
73 
74 targets += modules.builtin.modinfo
75 modules.builtin.modinfo: vmlinux.o FORCE
76 	$(call if_changed,objcopy)
77 
78 # module.builtin
79 # ---------------------------------------------------------------------------
80 
81 # The second line aids cases where multiple modules share the same object.
82 
83 quiet_cmd_modules_builtin = GEN     $@
84       cmd_modules_builtin = \
85 	tr '\0' '\n' < $< | \
86 	sed -n 's/^[[:alnum:]:_]*\.file=//p' | \
87 	tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$$/.ko/' > $@
88 
89 targets += modules.builtin
90 modules.builtin: modules.builtin.modinfo FORCE
91 	$(call if_changed,modules_builtin)
92 
93 # Add FORCE to the prerequisites of a target to force it to be always rebuilt.
94 # ---------------------------------------------------------------------------
95 
96 PHONY += FORCE
97 FORCE:
98 
99 # Read all saved command lines and dependencies for the $(targets) we
100 # may be building above, using $(if_changed{,_dep}). As an
101 # optimization, we don't need to read them if the target does not
102 # exist, we will rebuild anyway in that case.
103 
104 existing-targets := $(wildcard $(sort $(targets)))
105 
106 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
107 
108 .PHONY: $(PHONY)
109