Re: [PATCH 6/8] kbuild: move more module installation code to scripts/Makefile.modinst

[Masahiro Yamada]

On Tue, Aug 29, 2023 at 11:15 AM Nicolas Schier <nicolas@xxxxxxxxx> wrote:
>
> On Wed 23 Aug 2023 20:50:46 GMT, Masahiro Yamada wrote:
> > Move more relevant code to scripts/Makefile.modinst.
> >
> > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> > ---
> >
> >  Makefile                 | 34 +++++++--------------------------
> >  scripts/Makefile.modinst | 41 +++++++++++++++++++++++++++++++++++++---
> >  2 files changed, 45 insertions(+), 30 deletions(-)
> >
> > diff --git a/Makefile b/Makefile
> > index 7d9cab3d2186..82d22debf6c9 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -1477,24 +1477,6 @@ endif
> >
> >  endif # CONFIG_MODULES
> >
> > -modinst_pre :=
> > -ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
> > -modinst_pre := __modinst_pre
> > -endif
> > -
> > -modules_install: $(modinst_pre)
> > -PHONY += __modinst_pre
> > -__modinst_pre:
> > -     @rm -rf $(MODLIB)/kernel
> > -     @rm -f $(MODLIB)/build
> > -     @mkdir -p $(MODLIB)
> > -ifdef CONFIG_MODULES
> > -     @ln -s $(CURDIR) $(MODLIB)/build
> > -     @sed 's:^\(.*\)\.o$$:kernel/\1.ko:' modules.order > $(MODLIB)/modules.order
> > -endif
> > -     @cp -f modules.builtin $(MODLIB)/
> > -     @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
> > -
> >  ###
> >  # Cleaning is done on three levels.
> >  # make clean     Delete most generated files
> > @@ -1836,12 +1818,15 @@ help:
> >       @echo  '  clean           - remove generated files in module directory only'
> >       @echo  ''
> >
> > +ifndef CONFIG_MODULES
> > +modules modules_install: __external_modules_error
> >  __external_modules_error:
> >       @echo >&2 '***'
> >       @echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
> >       @echo >&2 '*** You cannot build or install external modules.'
> >       @echo >&2 '***'
> >       @false
> > +endif
> >
> >  endif # KBUILD_EXTMOD
> >
> > @@ -1850,6 +1835,9 @@ endif # KBUILD_EXTMOD
> >
> >  PHONY += modules modules_install modules_prepare
> >
> > +modules_install:
> > +     $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
>
> I was a bit surprised to see 'modules_install' being allowed
> unconditionally for in-tree usage (thus, even if CONFIG_MODULES=n), but
> then realised that this is the same behaviour as we had before.  Out of
> curiosity:  _why_ do we need to install
> $(MODLIB)/modules.builtin{,.modinfo} also for configs w/
> CONFIG_MODULES=n?


I see your tags in commit
8ae071fc216a25f4f797f33c56857f4dd6b4408e    :)


Some drivers need to load firmware.

To make such drivers working in initrd,
mkinitramfs needs to copy necessary firmware files
into the initrd.
So, the tool needs to know which drivers are enabled.

That is my understanding why modules.builtin(.modinfo)
is needed even with CONFIG_MODULES=n.





-- 
Best Regards
Masahiro Yamada