Last week I send this patch, but no reply. Now I try to explain it clearly: When I try to add a file(which in a subdir) to my board's obj-y, the build progress crashed. for example, I use at91rm9200ek board, and in kernel dir run: mkdir objtree make O=objtree at91rm9200-defconfig mkdir arch/arm/mach-at91/dir touch arch/arm/mach-at91/dir/file.c and edit arch/arm/mach-at91/dir/file.c to add some code. then edit arch/arm/mach-at91/Makefile, change the flowwing line: obj-$(CONFIG_MACH_AT91RM9200EK) += board-rm9200ek.o to: obj-$(CONFIG_MACH_AT91RM9200EK) += board-rm9200ek.o dir/file.o Now build it: make O=objtree Then the error appears: ... CC arch/arm/mach-at91/board-rm9200dk.o CC arch/arm/mach-at91/board-rm9200ek.o CC arch/arm/mach-at91/dir/file.o linux-2.6/arch/arm/mach-at91/dir/file.c:5: fatal error: opening dependency file arch/arm/mach-at91/dir/.file.o.d: No such file or directory Check the objtree: LANG=en ls objtree/arch/arm/mach-at91/dir ls: cannot access objtree/arch/arm/mach-at91/dir: No such file or directory It's appearantly that the target dir not created for file.o I check kbuild source code. It seems that kbuild create dirs for that in $(obj-dirs). But if the dir need not to create a built-in.o, It should never in $(obj-dirs). So I make this patch to make sure It in $(obj-dirs) Anybody Anyidea? 张忠山 (1): let kbuild mkdir for dir/file.o scripts/Makefile.lib | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) -- 1.7.9.5 -- 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