| Message ID | alpine.LFD.2.00.1109071554480.20358@xanadu.home (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On Wed, Sep 7, 2011 at 3:59 PM, Nicolas Pitre <nico@fluxnic.net> wrote: > On Wed, 7 Sep 2011, Arnaud Lacombe wrote: > >> Hi, >> >> On Wed, Sep 7, 2011 at 3:07 PM, Nicolas Pitre <nico@fluxnic.net> wrote: >> > On Fri, 19 Aug 2011, Arnaud Lacombe wrote: >> > >> >> Hi folks, >> >> >> >> The attached patch modify Kbuild to allow to directly re-use code in multiple >> >> directory without having to go through a copy. Technically, it changes Kbuild to >> >> use by default the VPATH feature of GNU make and provides accessors for Makefile >> >> to change it indirectly. >> >> >> >> Considering: >> >> >> >> arch/foo/lib: >> >> fancy.c >> >> >> >> We want to be able to build it with -DPANTS=32 in the kernel, but the >> >> bootloader requires -DPANTS_SIZE=30. >> >> >> >> Currently we would do, either: >> >> >> >> arch/foo/lib/Makefile >> >> LDFLAGS_fancy.o := -DPANTS=32 >> >> obj-y += fancy.o >> >> >> >> and, either: >> >> >> >> arch/foo/boot/Makefile: >> >> LDFLAGS_fancy.o := -DPANTS=30 >> >> obj-y += fancy.o >> >> $(obj)/fancy.c: $(srctree)/arch/foo/lib/fancy.c >> >> $(call cmd,shipped) >> >> >> >> or >> >> >> >> arch/foo/boot/Makefile: >> >> LDFLAGS_fancy.o := -DPANTS=30 >> >> obj-y += fancy.o >> >> $(obj)/fancy.o: $(srctree)/arch/foo/lib/fancy.c >> >> $(call cmd,cc_c_o) >> >> >> >> The former implies an extra copy of the source file, the latter expose Kbuild >> >> internal function. >> >> >> >> With the attached patch, we would do: >> >> >> >> arch/foo/boot/Makefile: >> >> LDFLAGS_fancy.o := -DPANTS=30 >> >> obj-y += fancy.o >> >> vpath-y += $(srctree)/arch/foo/lib >> >> >> >> and let GNU make do the job. >> >> >> >> Comments welcome, >> > >> > It doesn't work. Whatever I do to arch/arm/boot/compressed/Makefile >> > (which admittedly looks a bit hairy and could benefit from a shave) in >> > order to remove the $(call cmd,shipped) used with lib1funcs.S, I always >> > end up with: >> > >> > make[2]: *** No rule to make target `arch/arm/boot/compressed/lib1funcs.S', needed by `arch/arm/boot/compressed/lib1funcs.o'. Stop. >> > >> What was the exact change you made which triggered this ? > > In its simplest expression (not caring about the now undefined lib1funcs > variable): > > diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile > index 0c74a6fab9..b34ed80977 100644 > --- a/arch/arm/boot/compressed/Makefile > +++ b/arch/arm/boot/compressed/Makefile > @@ -70,6 +70,10 @@ ifeq ($(CONFIG_ARCH_SHMOBILE),y) > OBJS += head-shmobile.o > endif > > +# For __aeabi_uidivmod > +OBJS += lib1funcs.o > +vpath-y += $(srctree)/arch/arm/lib > + > # > # We now have a PIC decompressor implementation. Decompressors running > # from RAM should not define ZTEXTADDR. Decompressors running directly > @@ -120,12 +124,6 @@ LDFLAGS_vmlinux += -X > # Next argument is a linker script > LDFLAGS_vmlinux += -T > > -# For __aeabi_uidivmod > -lib1funcs = $(obj)/lib1funcs.o > - > -$(obj)/lib1funcs.S: $(srctree)/arch/$(SRCARCH)/lib/lib1funcs.S FORCE > - $(call cmd,shipped) > - > # We need to prevent any GOTOFF relocs being used with references > # to symbols in the .bss section since we cannot relocate them > # independently from the rest at run time. This can be achieved by > you missed: # Make sure files are removed during clean -extra-y += piggy.gzip piggy.lzo piggy.lzma lib1funcs.S +extra-y += piggy.gzip piggy.lzo piggy.lzma This confused make. before: % rm -rf /linux/obj/vpath-arm/arch/arm/boot/compressed/ % make ARCH=arm V=2 \ CROSS_COMPILE=arm-none-linux-gnueabi- \ O=/linux/obj/vpath-arm [...] CC arch/arm/boot/compressed/decompress.o - due to target missing make[3]: *** No rule to make target `arch/arm/boot/compressed/lib1funcs.S', needed by `arch/arm/boot/compressed/lib1funcs.o'. Stop. make[2]: *** [arch/arm/boot/compressed/vmlinux] Error 2 make[1]: *** [zImage] Error 2 make: *** [sub-make] Error 2 after: % rm -rf /linux/obj/vpath-arm/arch/arm/boot/compressed/ % make ARCH=arm V=2 \ CROSS_COMPILE=arm-none-linux-gnueabi- \ O=/linux/obj/vpath-arm [...] CC arch/arm/boot/compressed/decompress.o - due to target missing AS arch/arm/boot/compressed/lib1funcs.o - due to target missing LD arch/arm/boot/compressed/vmlinux - due to target missing OBJCOPY arch/arm/boot/zImage - due to: arch/arm/boot/compressed/vmlinux Kernel: arch/arm/boot/zImage is ready Building modules, stage 2. MODPOST 33 modules - due to target is PHONY - Arnaud > > Nicolas >
diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index 0c74a6fab9..b34ed80977 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -70,6 +70,10 @@ ifeq ($(CONFIG_ARCH_SHMOBILE),y) OBJS += head-shmobile.o endif +# For __aeabi_uidivmod +OBJS += lib1funcs.o +vpath-y += $(srctree)/arch/arm/lib + # # We now have a PIC decompressor implementation. Decompressors running # from RAM should not define ZTEXTADDR. Decompressors running directly @@ -120,12 +124,6 @@ LDFLAGS_vmlinux += -X # Next argument is a linker script LDFLAGS_vmlinux += -T -# For __aeabi_uidivmod -lib1funcs = $(obj)/lib1funcs.o - -$(obj)/lib1funcs.S: $(srctree)/arch/$(SRCARCH)/lib/lib1funcs.S FORCE - $(call cmd,shipped) - # We need to prevent any GOTOFF relocs being used with references # to symbols in the .bss section since we cannot relocate them # independently from the rest at run time. This can be achieved by