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author | Nicholas Piggin <npiggin@gmail.com> | 2018-05-30 22:19:19 +1000 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-06-01 23:08:03 +1000 |
commit | 4bf4f42a2febb449a5cc5d79e7c58e5b168942d7 (patch) | |
tree | b90f527c27de466297efb79951b5922b1e9799fc /arch/powerpc/Makefile | |
parent | 6da6c0db5316275015e8cc2959f12a17584aeb64 (diff) | |
download | linux-stable-4bf4f42a2febb449a5cc5d79e7c58e5b168942d7.tar.gz linux-stable-4bf4f42a2febb449a5cc5d79e7c58e5b168942d7.tar.bz2 linux-stable-4bf4f42a2febb449a5cc5d79e7c58e5b168942d7.zip |
powerpc/kbuild: Set default generic machine type for 32-bit compile
Some 64-bit toolchains uses the wrong ISA variant for compiling 32-bit
kernels, even with -m32. Debian's powerpc64le is one such case, and
that is because it is built with --with-cpu=power8.
So when cross compiling a 32-bit kernel with a 64-bit toolchain, set
-mcpu=powerpc initially, which is the generic 32-bit powerpc machine
type and scheduling model. CPU and platform code can override this
with subsequent -mcpu flags if necessary.
This is not done for 32-bit toolchains otherwise it would override
their defaults, which are presumably set appropriately for the
environment (moreso than a 64-bit cross compiler).
This fixes a lot of build failures due to incompatible assembly when
compiling 32-bit kernel with the Debian powerpc64le 64-bit toolchain.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/Makefile')
-rw-r--r-- | arch/powerpc/Makefile | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 95813df90801..d628724087c6 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -24,6 +24,14 @@ ifeq ($(HAS_BIARCH),y) ifeq ($(CROSS32_COMPILE),) CROSS32CC := $(CC) -m32 KBUILD_ARFLAGS += --target=elf32-powerpc +ifdef CONFIG_PPC32 +# These options will be overridden by any -mcpu option that the CPU +# or platform code sets later on the command line, but they are needed +# to set a sane 32-bit cpu target for the 64-bit cross compiler which +# may default to the wrong ISA. +KBUILD_CFLAGS += -mcpu=powerpc +KBUILD_AFLAGS += -mcpu=powerpc +endif endif endif |