powerpc: Add option to use thin archives

Add an option to use thin archives to build the kernel.
Thin archives are explained in commit a5967db9af ("kbuild: allow
architectures to use thin archives instead of ld -r").

This is a gradual way to introduce the option to testers.

Some change to the way we invoke ar is required so it can be used
by scripts/link-vmlinux.sh.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Make it an explicit option not dependant on COMPILE_TEST]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Nicholas Piggin 2016-10-19 14:15:59 +11:00 committed by Michael Ellerman
parent 5e9d0e3d9e
commit 43c9127d94
2 changed files with 10 additions and 2 deletions

View file

@ -396,6 +396,14 @@ config MPROFILE_KERNEL
depends on PPC64 && CPU_LITTLE_ENDIAN
def_bool !DISABLE_MPROFILE_KERNEL
config USE_THIN_ARCHIVES
bool "Build the kernel using thin archives"
default n
select THIN_ARCHIVES
help
Build the kernel using thin archives.
If you're unsure say N.
config IOMMU_HELPER
def_bool PPC64

View file

@ -23,7 +23,7 @@ CROSS32AR := $(CROSS32_COMPILE)ar
ifeq ($(HAS_BIARCH),y)
ifeq ($(CROSS32_COMPILE),)
CROSS32CC := $(CC) -m32
CROSS32AR := GNUTARGET=elf32-powerpc $(AR)
KBUILD_ARFLAGS += --target=elf32-powerpc
endif
endif
@ -85,7 +85,7 @@ ifeq ($(HAS_BIARCH),y)
override AS += -a$(BITS)
override LD += -m elf$(BITS)$(LDEMULATION)
override CC += -m$(BITS)
override AR := GNUTARGET=elf$(BITS)-$(GNUTARGET) $(AR)
KBUILD_ARFLAGS += --target=elf$(BITS)-$(GNUTARGET)
endif
LDFLAGS_vmlinux-y := -Bstatic