| Message ID | 20210824105038.1257926-13-anthony.perard@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xen: Build system improvements, now with out-of-tree build! | expand |
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 $(extra-y), so we still need to depend on > "arch/arm/built_in.o". head.o as to be right at the beginning of the binary. Will this still be guaranteed with this change? Cheers, > > Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> > --- > xen/arch/arm/Makefile | 7 ++++++- > xen/arch/arm/arm32/Makefile | 1 + > xen/arch/arm/arm64/Makefile | 2 ++ > 3 files changed, 9 insertions(+), 1 deletion(-) > > diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile > index 3d0af8ebc93c..cc90d9796e6e 100644 > --- a/xen/arch/arm/Makefile > +++ b/xen/arch/arm/Makefile > @@ -64,7 +64,6 @@ obj-$(CONFIG_SBSA_VUART_CONSOLE) += vpl011.o > obj-y += vsmc.o > obj-y += vpsci.o > obj-y += vuart.o > -extra-y += $(TARGET_SUBARCH)/head.o > > extra-y += xen.lds > > @@ -76,6 +75,12 @@ endif > > ALL_OBJS := $(TARGET_SUBARCH)/head.o $(ALL_OBJS) > > +# head.o is built by descending into the sub-directory, depends on the part of > +# $(ALL_OBJS) that will eventually recurse into $(TARGET_SUBARCH)/ and build > +# head.o > +$(TARGET_SUBARCH)/head.o: $(BASEDIR)/arch/arm/built_in.o > +$(TARGET_SUBARCH)/head.o: ; > + > ifdef CONFIG_LIVEPATCH > all_symbols = --all-symbols > ifdef CONFIG_FAST_SYMBOL_LOOKUP > diff --git a/xen/arch/arm/arm32/Makefile b/xen/arch/arm/arm32/Makefile > index 96105d238307..3040eabce3ad 100644 > --- a/xen/arch/arm/arm32/Makefile > +++ b/xen/arch/arm/arm32/Makefile > @@ -11,3 +11,4 @@ obj-y += smpboot.o > obj-y += traps.o > obj-y += vfp.o > > +extra-y += head.o > diff --git a/xen/arch/arm/arm64/Makefile b/xen/arch/arm/arm64/Makefile > index 40642ff57494..0bb284dedab2 100644 > --- a/xen/arch/arm/arm64/Makefile > +++ b/xen/arch/arm/arm64/Makefile > @@ -13,3 +13,5 @@ obj-y += smpboot.o > obj-y += traps.o > obj-y += vfp.o > obj-y += vsysreg.o > + > +extra-y += head.o >
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. Thanks,
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 $(ALL_OBJS), which this > patch doesn't change. > > This patch only ask make that when it want to build "head.o", it need > first to build "arm/built_in.o", then "head.o" exist so we ask make to > not do anything in this Makefile. Cool. Thanks for the confirmation! You can add: Acked-by: Julien Grall <jgrall@amazon.com> Cheers,
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile index 3d0af8ebc93c..cc90d9796e6e 100644 --- a/xen/arch/arm/Makefile +++ b/xen/arch/arm/Makefile @@ -64,7 +64,6 @@ obj-$(CONFIG_SBSA_VUART_CONSOLE) += vpl011.o obj-y += vsmc.o obj-y += vpsci.o obj-y += vuart.o -extra-y += $(TARGET_SUBARCH)/head.o extra-y += xen.lds @@ -76,6 +75,12 @@ endif ALL_OBJS := $(TARGET_SUBARCH)/head.o $(ALL_OBJS) +# head.o is built by descending into the sub-directory, depends on the part of +# $(ALL_OBJS) that will eventually recurse into $(TARGET_SUBARCH)/ and build +# head.o +$(TARGET_SUBARCH)/head.o: $(BASEDIR)/arch/arm/built_in.o +$(TARGET_SUBARCH)/head.o: ; + ifdef CONFIG_LIVEPATCH all_symbols = --all-symbols ifdef CONFIG_FAST_SYMBOL_LOOKUP diff --git a/xen/arch/arm/arm32/Makefile b/xen/arch/arm/arm32/Makefile index 96105d238307..3040eabce3ad 100644 --- a/xen/arch/arm/arm32/Makefile +++ b/xen/arch/arm/arm32/Makefile @@ -11,3 +11,4 @@ obj-y += smpboot.o obj-y += traps.o obj-y += vfp.o +extra-y += head.o diff --git a/xen/arch/arm/arm64/Makefile b/xen/arch/arm/arm64/Makefile index 40642ff57494..0bb284dedab2 100644 --- a/xen/arch/arm/arm64/Makefile +++ b/xen/arch/arm/arm64/Makefile @@ -13,3 +13,5 @@ obj-y += smpboot.o obj-y += traps.o obj-y += vfp.o obj-y += vsysreg.o + +extra-y += head.o
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". Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> --- xen/arch/arm/Makefile | 7 ++++++- xen/arch/arm/arm32/Makefile | 1 + xen/arch/arm/arm64/Makefile | 2 ++ 3 files changed, 9 insertions(+), 1 deletion(-)