xref: /openbmc/linux/arch/riscv/kernel/vdso/Makefile (revision b60a5b8d) 
1# Copied from arch/tile/kernel/vdso/Makefile
2
3# Symbols present in the vdso
4vdso-syms  = rt_sigreturn
5ifdef CONFIG_64BIT
6vdso-syms += gettimeofday
7vdso-syms += clock_gettime
8vdso-syms += clock_getres
9endif
10vdso-syms += getcpu
11vdso-syms += flush_icache
12
13# Files to link into the vdso
14obj-vdso = $(patsubst %, %.o, $(vdso-syms))
15
16# Build rules
17targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
18obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
19
20obj-y += vdso.o vdso-syms.o
21CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
22
23# Disable gcov profiling for VDSO code
24GCOV_PROFILE := n
25
26# Force dependency
27$(obj)/vdso.o: $(obj)/vdso.so
28
29# link rule for the .so file, .lds has to be first
30SYSCFLAGS_vdso.so.dbg = $(c_flags)
31$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
32	$(call if_changed,vdsold)
33
34# We also create a special relocatable object that should mirror the symbol
35# table and layout of the linked DSO.  With ld -R we can then refer to
36# these symbols in the kernel code rather than hand-coded addresses.
37
38SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
39                            $(call cc-ldoption, -Wl$(comma)--hash-style=both)
40$(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
41	$(call if_changed,vdsold)
42
43LDFLAGS_vdso-syms.o := -r -R
44$(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
45	$(call if_changed,ld)
46
47# strip rule for the .so file
48$(obj)/%.so: OBJCOPYFLAGS := -S
49$(obj)/%.so: $(obj)/%.so.dbg FORCE
50	$(call if_changed,objcopy)
51
52# actual build commands
53# The DSO images are built using a special linker script
54# Add -lgcc so rv32 gets static muldi3 and lshrdi3 definitions.
55# Make sure only to export the intended __vdso_xxx symbol offsets.
56quiet_cmd_vdsold = VDSOLD  $@
57      cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \
58                           -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \
59                   $(CROSS_COMPILE)objcopy \
60                           $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@
61
62# install commands for the unstripped file
63quiet_cmd_vdso_install = INSTALL $@
64      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
65
66vdso.so: $(obj)/vdso.so.dbg
67	@mkdir -p $(MODLIB)/vdso
68	$(call cmd,vdso_install)
69
70vdso_install: vdso.so
71