Hello Masahiro,
On 10/10/24 5:07 pm, Masahiro Yamada wrote:
On Thu, Oct 10, 2024 at 6:57 PM Hari Bathini <hbathini@xxxxxxxxxxxxx> wrote:
On 09/10/24 8:53 pm, Masahiro Yamada wrote:
On Mon, Sep 16, 2024 at 5:58 AM Hari Bathini <hbathini@xxxxxxxxxxxxx> wrote:
From: Naveen N Rao <naveen@xxxxxxxxxx>
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 <naveen@xxxxxxxxxx>
Signed-off-by: Hari Bathini <hbathini@xxxxxxxxxxxxx>
---
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..
It is because you did not add vmlinux.arch.S to 'targets'
See my comment in 12/17.
targets += vmlinux.arch.S
Just curious if the changes you suggested makes FORCE necessary
or FORCE was expected even without the other changes you suggested?
FORCE is necessary.
arch/powerpc/tools/Makefile must be checked every time.
When arch/powerpc/tools/ftrace-gen-ool-stubs.sh is changed,
vmlinux must be relinked.
Thanks for the review and clarifications!
Posted v6 with the changes. Please review:
https://lore.kernel.org/all/20241018173632.277333-1-hbathini@xxxxxxxxxxxxx/
- Hari
