Re: [PATCH v2 2/3] linux-module: honor modules Makefile

[Henning Schild <henning.schild@siemens.com>]

Am Thu, 1 Sep 2022 18:08:08 +0200
schrieb Jan Kiszka <jan.kiszka@siemens.com>:

> On 27.08.22 10:59, Henning Schild wrote:
> > External modules might have their own appends and target
> > definitions in their Makefile. All we need to give them is the
> > target name and KDIR, not dive into KDIR right away.  
> 
> My observation with external modules makefile having their own rules
> is that they generally also have their own KDIR variables. There is no
> standard way of telling those pick up the kernel from a standard place
> and install it at the standard location.
> 
> > 
> > Signed-off-by: Henning Schild <henning.schild@siemens.com>
> > ---
> >  meta/recipes-kernel/linux-module/files/debian/rules.tmpl | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git
> > a/meta/recipes-kernel/linux-module/files/debian/rules.tmpl
> > b/meta/recipes-kernel/linux-module/files/debian/rules.tmpl index
> > d3bd7dc30f21..0d16186b5ff3 100755 ---
> > a/meta/recipes-kernel/linux-module/files/debian/rules.tmpl +++
> > b/meta/recipes-kernel/linux-module/files/debian/rules.tmpl @@
> > -48,13 +48,13 @@ KDIR := $(shell dpkg -L $(KERNEL_DEP) | grep
> > "/lib/modules/.*/build") endif override_dh_auto_clean:
> > -	$(MAKE) -C $(KDIR) M=$(PWD) clean
> > +	$(MAKE) KDIR=$(KDIR) clean
> >  
> >  override_dh_auto_build:
> > -	$(MAKE) -C $(KDIR) M=$(PWD) modules
> > +	$(MAKE) KDIR=$(KDIR) modules
> >  
> >  override_dh_auto_install:
> > -	$(MAKE) -C $(KDIR) M=$(PWD)
> > INSTALL_MOD_PATH=$(PWD)/debian/${PN} modules_install
> > +	$(MAKE) KDIR=$(KDIR) INSTALL_MOD_PATH=$(PWD)/debian/${PN}
> > modules_install 
> >  %:
> >  	CFLAGS= LDFLAGS= dh $@ --parallel  
> 
> This breaks existing users with makefile that are unusable or do not
> have own rules. I would refrain from that breakage.
> 
> If you have a more complex case than what we support, you can simply
> provide your own rules and can then even account for the other
> specialties that usually come with such module makefiles.
> 
> Same arguing applies to patch 3.

I am not sure i would agree that the example Makefile is indeed valid,
since it does not allow self sustained building with a simple "make
modules_install". But yes for modules with such Makefiles this would be
a breaking change.

Will go and carry the special rules entries downstream, while i still
think Isar should take that and rather make those weirdos carry their
own rules ... accepting a breakage.

But i have no clue how "weird" vs "common" it would be to have such a
super-minimal Makefile. And my case is probably also not "common"
enough to ague for too long.

Henning

> Jan
>