1 # SPDX-License-Identifier: GPL-2.0-only
3 # Makefile for compat_vdso
6 # Symbols present in the compat_vdso
7 compat_vdso-syms = rt_sigreturn
8 compat_vdso-syms += getcpu
9 compat_vdso-syms += flush_icache
14 # binutils 2.35 does not support the zifencei extension, but in the ISA
15 # spec 20191213, G stands for IMAFD_ZICSR_ZIFENCEI.
16 ifdef CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
17 COMPAT_CC_FLAGS := -march=rv32g -mabi=ilp32
19 COMPAT_CC_FLAGS := -march=rv32imafd -mabi=ilp32
21 COMPAT_LD_FLAGS := -melf32lriscv
23 # Disable attributes, as they're useless and break the build.
24 COMPAT_CC_FLAGS += $(call cc-option,-mno-riscv-attribute)
25 COMPAT_CC_FLAGS += $(call as-option,-Wa$(comma)-mno-arch-attr)
27 # Files to link into the compat_vdso
28 obj-compat_vdso = $(patsubst %, %.o, $(compat_vdso-syms)) note.o
31 targets := $(obj-compat_vdso) compat_vdso.so compat_vdso.so.dbg compat_vdso.lds
32 obj-compat_vdso := $(addprefix $(obj)/, $(obj-compat_vdso))
34 obj-y += compat_vdso.o
35 CPPFLAGS_compat_vdso.lds += -P -C -DCOMPAT_VDSO -U$(ARCH)
37 # Disable profiling and instrumentation for VDSO code
44 $(obj)/compat_vdso.o: $(obj)/compat_vdso.so
46 # link rule for the .so file, .lds has to be first
47 $(obj)/compat_vdso.so.dbg: $(obj)/compat_vdso.lds $(obj-compat_vdso) FORCE
48 $(call if_changed,compat_vdsold)
49 LDFLAGS_compat_vdso.so.dbg = -shared -S -soname=linux-compat_vdso.so.1 \
50 --build-id=sha1 --hash-style=both --eh-frame-hdr
52 $(obj-compat_vdso): %.o: %.S FORCE
53 $(call if_changed_dep,compat_vdsoas)
55 # strip rule for the .so file
56 $(obj)/%.so: OBJCOPYFLAGS := -S
57 $(obj)/%.so: $(obj)/%.so.dbg FORCE
58 $(call if_changed,objcopy)
60 # Generate VDSO offsets using helper script
61 gen-compat_vdsosym := $(srctree)/$(src)/gen_compat_vdso_offsets.sh
62 quiet_cmd_compat_vdsosym = VDSOSYM $@
63 cmd_compat_vdsosym = $(NM) $< | $(gen-compat_vdsosym) | LC_ALL=C sort > $@
65 include/generated/compat_vdso-offsets.h: $(obj)/compat_vdso.so.dbg FORCE
66 $(call if_changed,compat_vdsosym)
68 # actual build commands
69 # The DSO images are built using a special linker script
70 # Make sure only to export the intended __compat_vdso_xxx symbol offsets.
71 quiet_cmd_compat_vdsold = VDSOLD $@
72 cmd_compat_vdsold = $(COMPAT_LD) $(ld_flags) $(COMPAT_LD_FLAGS) -T $(filter-out FORCE,$^) -o $@.tmp && \
73 $(OBJCOPY) $(patsubst %, -G __compat_vdso_%, $(compat_vdso-syms)) $@.tmp $@ && \
76 # actual build commands
77 quiet_cmd_compat_vdsoas = VDSOAS $@
78 cmd_compat_vdsoas = $(COMPAT_CC) $(a_flags) $(COMPAT_CC_FLAGS) -c -o $@ $<