Hello, Does the build system support building built-in components of vmlinux out-of-tree? That is, I know that these two are possible: (1) build out-of-tree code as a loadable kernel module (.ko) (use the M=/path/to/out-of-tree/dir) (2) build an in-tree module as a statically built-in component of vmlinux instead of as a LKM (use the CONFIG_<module>=y, or otherwise add the object files to obj-y instead of obj-m) The question is can you build an an _out-of-tree_ module as a statically built-in component of vmlinux? It seems you can't do it without modifying the root Makefile. That is, the reason (2) works is because the directory that will have built-in.o in it is in-tree and explicitly referenced by the root Makefile. I would hope that the M=dir parameter would effectively add the dir to the list, but it seems that it does not, spoiling the whole party: the built-in.o is correctly created, but it is not picked up by the vmlinux link-line. The only workaround I have working is to add an ugly out-of-tree path into the list of directories in the root Makefile. I could not find this use-case in the neither in the Kbuild documentation nor online. Thank you in advance. -alexei