From: Ian Munsie <imun...@au1.ibm.com>
This patch allows the kbuild system to successfully compile a kernel for
the little endian PowerPC64 architecture.
To build such a kernel a supported platform must be used and
CONFIG_CPU_LITTLE_ENDIAN must be set. If cross compiling, CROSS_COMPILE
must point to a suitable toolchain (compiled for the powerpc64le-linux
and powerpcle-linux targets).
Signed-off-by: Ian Munsie <imun...@au1.ibm.com>
Signed-off-by: Anton Blanchard <an...@samba.org>
---
arch/powerpc/Makefile | 24 +++++++++++++++++++++---
arch/powerpc/boot/Makefile | 3 ++-
arch/powerpc/kernel/vdso32/vdso32.lds.S | 4 ++++
arch/powerpc/kernel/vdso64/vdso64.lds.S | 4 ++++
arch/powerpc/platforms/Kconfig.cputype | 11 +++++++++++
5 files changed, 42 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index c574a69..0ebad9c 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -65,11 +65,29 @@ endif
UTS_MACHINE := $(OLDARCH)
+ifeq ($(CONFIG_CPU_LITTLE_ENDIAN),y)
+override CC += -mlittle-endian
+override AS += -mlittle-endian
+override LD += -EL
+override CROSS32CC += -mlittle-endian
+override CROSS32AS += -mlittle-endian
+LDEMULATION := lppc
+GNUTARGET := powerpcle
+MULTIPLEWORD := -mno-multiple
+else
+override CC += -mbig-endian
+override AS += -mbig-endian
+override LD += -EB
+LDEMULATION := ppc
+GNUTARGET := powerpc
+MULTIPLEWORD := -mmultiple
+endif
+
ifeq ($(HAS_BIARCH),y)
override AS += -a$(CONFIG_WORD_SIZE)
-override LD += -m elf$(CONFIG_WORD_SIZE)ppc
+override LD += -m elf$(CONFIG_WORD_SIZE)$(LDEMULATION)
override CC += -m$(CONFIG_WORD_SIZE)
-override AR := GNUTARGET=elf$(CONFIG_WORD_SIZE)-powerpc $(AR)
+override AR := GNUTARGET=elf$(CONFIG_WORD_SIZE)-$(GNUTARGET) $(AR)
endif
LDFLAGS_vmlinux-y := -Bstatic
@@ -95,7 +113,7 @@ endif
CFLAGS-$(CONFIG_PPC64) := -mtraceback=no -mcall-aixdesc
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcmodel=medium,-mminimal-toc)
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mno-pointers-to-nested-functions)
-CFLAGS-$(CONFIG_PPC32) := -ffixed-r2 -mmultiple
+CFLAGS-$(CONFIG_PPC32) := -ffixed-r2 $(MULTIPLEWORD)
CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power7,-mtune=power4)
CFLAGS-$(CONFIG_CELL_CPU) += $(call cc-option,-mcpu=cell)
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 6a15c96..1e6baf0 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -22,7 +22,8 @@ all: $(obj)/zImage
BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -Os -msoft-float -pipe \
-fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
- -isystem $(shell $(CROSS32CC) -print-file-name=include)
+ -isystem $(shell $(CROSS32CC) -print-file-name=include) \
+ -mbig-endian
BOOTAFLAGS := -D__ASSEMBLY__ $(BOOTCFLAGS) -traditional -nostdinc
ifdef CONFIG_DEBUG_INFO
diff --git a/arch/powerpc/kernel/vdso32/vdso32.lds.S
b/arch/powerpc/kernel/vdso32/vdso32.lds.S
index f223409..e58ee10 100644
--- a/arch/powerpc/kernel/vdso32/vdso32.lds.S
+++ b/arch/powerpc/kernel/vdso32/vdso32.lds.S
@@ -4,7 +4,11 @@
*/
#include <asm/vdso.h>
+#ifdef __LITTLE_ENDIAN__
+OUTPUT_FORMAT("elf32-powerpcle", "elf32-powerpcle", "elf32-powerpcle")
+#else
OUTPUT_FORMAT("elf32-powerpc", "elf32-powerpc", "elf32-powerpc")
+#endif
OUTPUT_ARCH(powerpc:common)
ENTRY(_start)
diff --git a/arch/powerpc/kernel/vdso64/vdso64.lds.S
b/arch/powerpc/kernel/vdso64/vdso64.lds.S
index e486381..64fb183 100644
--- a/arch/powerpc/kernel/vdso64/vdso64.lds.S
+++ b/arch/powerpc/kernel/vdso64/vdso64.lds.S
@@ -4,7 +4,11 @@
*/
#include <asm/vdso.h>
+#ifdef __LITTLE_ENDIAN__
+OUTPUT_FORMAT("elf64-powerpcle", "elf64-powerpcle", "elf64-powerpcle")
+#else
OUTPUT_FORMAT("elf64-powerpc", "elf64-powerpc", "elf64-powerpc")
+#endif
OUTPUT_ARCH(powerpc:common64)
ENTRY(_start)
diff --git a/arch/powerpc/platforms/Kconfig.cputype
b/arch/powerpc/platforms/Kconfig.cputype
index 47d9a03..89f91ed 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -389,3 +389,14 @@ config PPC_DOORBELL
default n
endmenu
+
+config CPU_LITTLE_ENDIAN
+ bool "Build little endian kernel"
+ default n
+ help
+ This option selects whether a big endian or little endian kernel will
+ be built.
+
+ Note that if cross compiling a little endian kernel,
+ CROSS_COMPILE must point to a toolchain capable of targeting
+ little endian powerpc.
--
1.8.1.2
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