On 09/10/24 8:53 pm, Masahiro Yamada wrote:
On Mon, Sep 16, 2024 at 5:58 AM Hari Bathini <hbath...@linux.ibm.com> wrote:
From: Naveen N Rao <nav...@kernel.org>
On powerpc, we would like to be able to make a pass on vmlinux.o and
generate a new object file to be linked into vmlinux. Add a generic pass
in Makefile.vmlinux that architectures can use for this purpose.
Architectures need to select CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX and must
provide arch/<arch>/tools/Makefile with .arch.vmlinux.o target, which
will be invoked prior to the final vmlinux link step.
Signed-off-by: Naveen N Rao <nav...@kernel.org>
Signed-off-by: Hari Bathini <hbath...@linux.ibm.com>
---
Changes in v5:
* Intermediate files named .vmlinux.arch.* instead of .arch.vmlinux.*
arch/Kconfig | 6 ++++++
scripts/Makefile.vmlinux | 7 +++++++
scripts/link-vmlinux.sh | 7 ++++++-
3 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index 975dd22a2dbd..ef868ff8156a 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -1643,4 +1643,10 @@ config CC_HAS_SANE_FUNCTION_ALIGNMENT
config ARCH_NEED_CMPXCHG_1_EMU
bool
+config ARCH_WANTS_PRE_LINK_VMLINUX
+ def_bool n
Redundant default. This line should be "bool".
+ help
+ An architecture can select this if it provides
arch/<arch>/tools/Makefile
+ with .arch.vmlinux.o target to be linked into vmlinux.
+
endmenu
diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux
index 49946cb96844..edf6fae8d960 100644
--- a/scripts/Makefile.vmlinux
+++ b/scripts/Makefile.vmlinux
@@ -22,6 +22,13 @@ targets += .vmlinux.export.o
vmlinux: .vmlinux.export.o
endif
+ifdef CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX
+vmlinux: arch/$(SRCARCH)/tools/.vmlinux.arch.o
If you move this to arch/*/tools/, there is no reason
to make it a hidden file.
Thanks for reviewing and the detailed comments, Masahiro.
vmlinux: arch/$(SRCARCH)/tools/vmlinux.arch.o
+arch/$(SRCARCH)/tools/.vmlinux.arch.o: vmlinux.o
FORCE is missing.
I dropped FORCE as it was rebuilding vmlinux on every invocation
of `make` irrespective of whether vmlinux.o changed or not..
Just curious if the changes you suggested makes FORCE necessary
or FORCE was expected even without the other changes you suggested?
Thanks
Hari
