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) 17ccflags-y += $(DISABLE_LTO) 18 19# Disable gcov profiling for VDSO code 20GCOV_PROFILE := n 21 22# Workaround for bare-metal (ELF) toolchains that neglect to pass -shared 23# down to collect2, resulting in silent corruption of the vDSO image. 24ccflags-y += -Wl,-shared 25 26obj-y += vdso.o 27extra-y += vdso.lds 28CPPFLAGS_vdso.lds += -P -C -U$(ARCH) 29 30# Force dependency (incbin is bad) 31$(obj)/vdso.o : $(obj)/vdso.so 32 33# Link rule for the .so file, .lds has to be first 34$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) 35 $(call if_changed,vdsold) 36 37# Strip rule for the .so file 38$(obj)/%.so: OBJCOPYFLAGS := -S 39$(obj)/%.so: $(obj)/%.so.dbg FORCE 40 $(call if_changed,objcopy) 41 42# Generate VDSO offsets using helper script 43gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh 44quiet_cmd_vdsosym = VDSOSYM $@ 45define cmd_vdsosym 46 $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ 47endef 48 49include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE 50 $(call if_changed,vdsosym) 51 52# Assembly rules for the .S files 53$(obj-vdso): %.o: %.S FORCE 54 $(call if_changed_dep,vdsoas) 55 56# Actual build commands 57quiet_cmd_vdsold = VDSOL $@ 58 cmd_vdsold = $(CC) $(c_flags) -Wl,-n -Wl,-T $^ -o $@ 59quiet_cmd_vdsoas = VDSOA $@ 60 cmd_vdsoas = $(CC) $(a_flags) -c -o $@ $< 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