底层驱动开发

								# List of files in the vdso, has to be asm only for now								obj-vdso32 = sigtramp.o gettimeofday.o datapage.o cacheflush.o note.o								# Build rules								targets := $(obj-vdso32) vdso32.so				obj-vdso32 := $(addprefix $(obj)/, $(obj-vdso32))												EXTRA_CFLAGS := -shared -s -fno-common -fno-builtin				EXTRA_CFLAGS += -nostdlib -Wl,-soname=linux-vdso32.so.1				EXTRA_AFLAGS := -D__VDSO32__ -s								obj-y += vdso32_wrapper.o				extra-y += vdso32.lds				CPPFLAGS_vdso32.lds += -P -C -U$(ARCH)								# Force dependency (incbin is bad)				$(obj)/vdso32_wrapper.o : $(obj)/vdso32.so								# link rule for the .so file, .lds has to be first				$(obj)/vdso32.so: $(src)/vdso32.lds $(obj-vdso32)					$(call if_changed,vdso32ld)								# assembly rules for the .S files				$(obj-vdso32): %.o: %.S					$(call if_changed_dep,vdso32as)								# actual build commands				quiet_cmd_vdso32ld = VDSO32L $@				      cmd_vdso32ld = $(CROSS32CC) $(c_flags) -Wl,-T $^ -o $@				quiet_cmd_vdso32as = VDSO32A $@				      cmd_vdso32as = $(CROSS32CC) $(a_flags) -c -o $@ $