Re: [PATCH 1/1] kbuild: install the modules.order for external modules

[Masahiro Yamada <masahiroy@kernel.org>]

(Cc: Lucas De Marchi)

On Thu, Dec 16, 2021 at 2:23 AM Will McVicker <willmcvicker@google.com> wrote:
>
> Add support to install the modules.order file for external modules
> during module_install in order to retain the Makefile ordering
> of external modules. This helps reduce the extra steps necessary to
> properly order loading of external modules when there are multiple
> kernel modules compiled within a given KBUILD_EXTMOD directory.
>
> To handle compiling multiple external modules within the same
> INSTALL_MOD_DIR, kbuild will append a suffix to the installed
> modules.order file defined like so:
>
>   echo ${KBUILD_EXTMOD} | sed 's:[./_]:_:g'
>
> Ex:
>   KBUILD_EXTMOD=/mnt/a.b/c-d/my_driver results in:
>   modules.order._mnt_a_b_c_d_my_driver
>
> The installed module.order.$(extmod_suffix) files can then be cat'd
> together to create a single modules.order file which would define the
> order to load all of the modules during boot.


So, the user must do this manually?

cat extra/modules.order._mnt_a_b_c_d_my_driver  \
   extra/modules.order._mnt_e_f_g_h_my_driver \
   >> modules.order

This is so ugly, and incomplete.

I cc'ed the kmod maintainer, who may have
comments or better approach.






> Signed-off-by: Will McVicker <willmcvicker@google.com>
> ---
>  scripts/Makefile.modinst | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst
> index ff9b09e4cfca..2e2e31696fd6 100644
> --- a/scripts/Makefile.modinst
> +++ b/scripts/Makefile.modinst
> @@ -24,6 +24,10 @@ suffix-$(CONFIG_MODULE_COMPRESS_XZ)  := .xz
>  suffix-$(CONFIG_MODULE_COMPRESS_ZSTD)  := .zst
>
>  modules := $(patsubst $(extmod_prefix)%, $(dst)/%$(suffix-y), $(modules))
> +ifneq ($(KBUILD_EXTMOD),)
> +extmod_suffix := $(subst /,_,$(subst .,_,$(subst -,_,$(KBUILD_EXTMOD))))
> +modules += $(dst)/modules.order.$(extmod_suffix)
> +endif
>
>  __modinst: $(modules)
>         @:
> @@ -82,6 +86,12 @@ $(dst)/%.ko: $(extmod_prefix)%.ko FORCE
>         $(call cmd,strip)
>         $(call cmd,sign)
>
> +ifneq ($(KBUILD_EXTMOD),)
> +$(dst)/modules.order.$(extmod_suffix): $(MODORDER) FORCE
> +       $(call cmd,install)
> +       @sed -i "s:^$(KBUILD_EXTMOD):$(INSTALL_MOD_DIR):g" $@
> +endif
> +
>  else
>
>  $(dst)/%.ko: FORCE
> --
> 2.34.1.173.g76aa8bc2d0-goog
>


-- 
Best Regards
Masahiro Yamada