redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

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>
hifive-unleashed-5.1
Nicholas Piggin 2018-05-30 22:19:19 +10:00 committed by Michael Ellerman
parent 6da6c0db53
commit 4bf4f42a2f
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/powerpc/Makefile
View File

@ -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