1#
2# Building a vDSO image for AArch64.
3#
4# Author: Will Deacon <will.deacon@arm.com>
5# Heavily based on the vDSO Makefiles for other archs.
6#
7
8obj-vdso := gettimeofday.o note.o sigreturn.o
9
10# Build rules
11targets := $(obj-vdso) vdso.so vdso.so.dbg
12obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
13
14ccflags-y := -shared -fno-common -fno-builtin
15ccflags-y += -nostdlib -Wl,-soname=linux-vdso.so.1 \
16		$(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
17
18# Workaround for bare-metal (ELF) toolchains that neglect to pass -shared
19# down to collect2, resulting in silent corruption of the vDSO image.
20ccflags-y += -Wl,-shared
21
22obj-y += vdso.o
23extra-y += vdso.lds vdso-offsets.h
24CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
25
26# Force dependency (incbin is bad)
27$(obj)/vdso.o : $(obj)/vdso.so
28
29# Link rule for the .so file, .lds has to be first
30$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso)
31	$(call if_changed,vdsold)
32
33# Strip rule for the .so file
34$(obj)/%.so: OBJCOPYFLAGS := -S
35$(obj)/%.so: $(obj)/%.so.dbg FORCE
36	$(call if_changed,objcopy)
37
38# Generate VDSO offsets using helper script
39gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
40quiet_cmd_vdsosym = VDSOSYM $@
41define cmd_vdsosym
42	$(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ && \
43	cp $@ include/generated/
44endef
45
46$(obj)/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
47	$(call if_changed,vdsosym)
48
49# Assembly rules for the .S files
50$(obj-vdso): %.o: %.S FORCE
51	$(call if_changed_dep,vdsoas)
52
53# Actual build commands
54quiet_cmd_vdsold = VDSOL   $@
55      cmd_vdsold = $(CC) $(c_flags) -Wl,-n -Wl,-T $^ -o $@
56quiet_cmd_vdsoas = VDSOA   $@
57      cmd_vdsoas = $(CC) $(a_flags) -c -o $@ $<
58
59# Install commands for the unstripped file
60quiet_cmd_vdso_install = INSTALL $@
61      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
62
63vdso.so: $(obj)/vdso.so.dbg
64	@mkdir -p $(MODLIB)/vdso
65	$(call cmd,vdso_install)
66
67vdso_install: vdso.so
68