2018-01-23 6:46 GMT+09:00 Jakub Kicinski <kubakici@xxxxx>: > Hi! > > in drivers/net/ethernet/netronome/nfp there is a module which is built > from C sources in 4 directories. What is the best way to handle that? > > Currently we just add all the objects in one Makefile: > > nfp-objs := \ > nfpcore/nfp6000_pcie.o \ > nfpcore/nfp_cppcore.o \ > etc. I recommend you to refactor the Makefile, adding Makefiles into nfpcore, nic, flower, bpf sub-directories. Also, ifeq is ugly, can you rewrite like follows? nfp-$(CONFIG_NFP_APP_FLOWER) += flower/ nfp-$(CONFIG_BPF_SYSCALL) += bpf/ nfp-$(CONFIG_NFP_DEBUG) += nfp_net_debugfs.o > However, this makes it impossible to build a single object in subdirs: > > $ make drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.o > scripts/Makefile.build:45: drivers/net/ethernet/netronome/nfp/nfpcore/Makefile: No such file or directory > make[2]: *** No rule to make target 'drivers/net/ethernet/netronome/nfp/nfpcore/Makefile'. Stop. > > Documentation/kbuild/modules.txt also contains an unclear remark that > this is not recommended (or is it about the use of $(src)?): > > --- 4.3 Several Subdirectories > ... > To build the module complex.ko, we then need the following > kbuild file: > > --> filename: Kbuild > obj-m := complex.o > complex-y := src/complex_main.o > complex-y += src/hal/hardwareif.o > > ccflags-y := -I$(src)/include > ccflags-y += -I$(src)/src/hal/include > > As you can see, kbuild knows how to handle object files located > in other directories. The trick is to specify the directory > relative to the kbuild file's location. **That being said, this > is NOT recommended practice.** > > Making the include optional would work: > > diff --git a/scripts/Makefile.build b/scripts/Makefile.build > @@ -42,7 +42,7 @@ save-cflags := $(CFLAGS) > # The filename Kbuild has precedence over Makefile > kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src)) > kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile) > -include $(kbuild-file) > +-include $(kbuild-file) > > # If the save-* variables changed error out > ifeq ($(KBUILD_NOPEDANTIC),) > > Or we could create empty Makefiles in subdirectories... Is there a > better way of handling this? Which is preferred? -- Best Regards Masahiro Yamada -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
