Re: [XEN PATCH v7 12/51] build: avoid building arm/arm/*/head.o twice

[Julien Grall <julien@xxxxxxx>]

Hi Anthony,

On 24/08/2021 16:12, Anthony PERARD wrote:
> On Tue, Aug 24, 2021 at 01:53:11PM +0100, Julien Grall wrote:
> > Hi Anthony,
> >
> > On 24/08/2021 11:49, Anthony PERARD wrote:
> > > head.o is been built twice, once because it is in $(ALL_OBJS) and a
> > > second time because it is in $(extra-y) and thus it is rebuilt when
> > > building "arch/arm/built_in.o".
> > >
> > > Fix this by adding a dependency of "head.o" on the directory
> > > "arch/arm/".
> > >
> > > Also, we should avoid building object that are in subdirectories, so
> > > move the declaration in there. This doesn't change anything as
> > > "arch/arm/built_in.o" depends on "arch/arm/$subarch/built_in.o" which
> > > depends on $(extra-y), so we still need to depend on
> > > "arch/arm/built_in.o".
> > head.o as to be right at the beginning of the binary. Will this still be
> > guaranteed with this change?
> I guess what you want to know is: no change to the final binary.
>
> The layout of the final binary is defined by $(ALL_OBJS), which this
> patch doesn't change.
>
> This patch only ask make that when it want to build "head.o", it need
> first to build "arm/built_in.o", then "head.o" exist so we ask make to
> not do anything in this Makefile.
Cool. Thanks for the confirmation! You can add:

Acked-by: Julien Grall <jgrall@xxxxxxxxxx>

Cheers,

--
Julien Grall