Re: [PATCH v3] Add MO(mod objs) variable to process ext modules with subdirs

[Randy Dunlap]

Hi Valerii,

On 4/5/24 9:56 AM, Valerii Chernous wrote:
> The change allow to build external modules with nested makefiles.
> With current unofficial way(using "src" variable) it is possible to build
> external(out of tree) kernel module with separate source and build
> artifacts dirs but with nested makefiles it doesn't work properly.
> Build system trap to recursion inside makefiles, artifacts output dir
> path grow with each iteration until exceed max path len and build failed.
> Providing "MO" variable and using "override" directive with declaring
> "src" variable solves the problem
> Usage example:
> make -C KERNEL_SOURCE_TREE MO=BUILD_OUT_DIR M=EXT_MOD_SRC_DIR modules
> 
> Cc: xe-linux-external@xxxxxxxxx
> Cc: Valerii Chernous <vchernou@xxxxxxxxx>
> Signed-off-by: Valerii Chernous <vchernou@xxxxxxxxx>
> ---
>  Documentation/kbuild/kbuild.rst  | 14 +++++++++++++-
>  Documentation/kbuild/modules.rst | 16 +++++++++++++++-
>  Makefile                         | 17 +++++++++++++++++
>  scripts/Makefile.build           |  7 +++++++
>  4 files changed, 52 insertions(+), 2 deletions(-)
> 

I can read it now. There are still a few small things that I would
change, but they aren't a big deal.

I'll leave it for Masahiro or others to comment on.

Thanks.
-- 
#Randy