xref: /openbmc/linux/arch/riscv/kernel/vdso/Makefile (revision ba61bb17)
1# Copied from arch/tile/kernel/vdso/Makefile
2
3# Symbols present in the vdso
4vdso-syms  = rt_sigreturn
5vdso-syms += gettimeofday
6vdso-syms += clock_gettime
7vdso-syms += clock_getres
8vdso-syms += getcpu
9vdso-syms += flush_icache
10
11# Files to link into the vdso
12obj-vdso = $(patsubst %, %.o, $(vdso-syms))
13
14# Build rules
15targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
16obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
17
18obj-y += vdso.o vdso-syms.o
19CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
20
21# Disable gcov profiling for VDSO code
22GCOV_PROFILE := n
23
24# Force dependency
25$(obj)/vdso.o: $(obj)/vdso.so
26
27# link rule for the .so file, .lds has to be first
28SYSCFLAGS_vdso.so.dbg = $(c_flags)
29$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
30	$(call if_changed,vdsold)
31
32# We also create a special relocatable object that should mirror the symbol
33# table and layout of the linked DSO.  With ld -R we can then refer to
34# these symbols in the kernel code rather than hand-coded addresses.
35
36SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
37                            $(call cc-ldoption, -Wl$(comma)--hash-style=both)
38$(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
39	$(call if_changed,vdsold)
40
41LDFLAGS_vdso-syms.o := -r -R
42$(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
43	$(call if_changed,ld)
44
45# strip rule for the .so file
46$(obj)/%.so: OBJCOPYFLAGS := -S
47$(obj)/%.so: $(obj)/%.so.dbg FORCE
48	$(call if_changed,objcopy)
49
50# actual build commands
51# The DSO images are built using a special linker script
52# Add -lgcc so rv32 gets static muldi3 and lshrdi3 definitions.
53# Make sure only to export the intended __vdso_xxx symbol offsets.
54quiet_cmd_vdsold = VDSOLD  $@
55      cmd_vdsold = $(CC) $(KCFLAGS) $(call cc-option, -no-pie) -nostdlib $(SYSCFLAGS_$(@F)) \
56                           -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp -lgcc && \
57                   $(CROSS_COMPILE)objcopy \
58                           $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@
59
60# install commands for the unstripped file
61quiet_cmd_vdso_install = INSTALL $@
62      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
63
64vdso.so: $(obj)/vdso.so.dbg
65	@mkdir -p $(MODLIB)/vdso
66	$(call cmd,vdso_install)
67
68vdso_install: vdso.so
69