Commit d72b0801 authored by Ian Munsie's avatar Ian Munsie Committed by Benjamin Herrenschmidt

powerpc: Add ability to build little endian kernels

This patch allows the kbuild system to successfully compile a kernel
for the little endian PowerPC64 architecture. A subsequent patch
will add the CONFIG_CPU_LITTLE_ENDIAN kernel config option which
must be set to build such a kernel.

If cross compiling, CROSS_COMPILE must point to a suitable toolchain
(compiled for the powerpc64le-linux and powerpcle-linux targets).
Signed-off-by: default avatarIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 7df697c8
...@@ -65,11 +65,29 @@ endif ...@@ -65,11 +65,29 @@ endif
UTS_MACHINE := $(OLDARCH) 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 ($(HAS_BIARCH),y) ifeq ($(HAS_BIARCH),y)
override AS += -a$(CONFIG_WORD_SIZE) override AS += -a$(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 CC += -m$(CONFIG_WORD_SIZE)
override AR := GNUTARGET=elf$(CONFIG_WORD_SIZE)-powerpc $(AR) override AR := GNUTARGET=elf$(CONFIG_WORD_SIZE)-$(GNUTARGET) $(AR)
endif endif
LDFLAGS_vmlinux-y := -Bstatic LDFLAGS_vmlinux-y := -Bstatic
...@@ -95,7 +113,7 @@ endif ...@@ -95,7 +113,7 @@ endif
CFLAGS-$(CONFIG_PPC64) := -mtraceback=no -mcall-aixdesc CFLAGS-$(CONFIG_PPC64) := -mtraceback=no -mcall-aixdesc
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcmodel=medium,-mminimal-toc) CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcmodel=medium,-mminimal-toc)
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mno-pointers-to-nested-functions) CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mno-pointers-to-nested-functions)
CFLAGS-$(CONFIG_PPC32) := -ffixed-r2 -mmultiple CFLAGS-$(CONFIG_PPC32) := -ffixed-r2 $(MULTIPLEWORD)
ifeq ($(CONFIG_PPC_BOOK3S_64),y) ifeq ($(CONFIG_PPC_BOOK3S_64),y)
CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power7,-mtune=power4) CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power7,-mtune=power4)
......
...@@ -22,7 +22,8 @@ all: $(obj)/zImage ...@@ -22,7 +22,8 @@ all: $(obj)/zImage
BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -Os -msoft-float -pipe \ -fno-strict-aliasing -Os -msoft-float -pipe \
-fomit-frame-pointer -fno-builtin -fPIC -nostdinc \ -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 BOOTAFLAGS := -D__ASSEMBLY__ $(BOOTCFLAGS) -traditional -nostdinc
ifdef CONFIG_DEBUG_INFO ifdef CONFIG_DEBUG_INFO
......
...@@ -4,7 +4,11 @@ ...@@ -4,7 +4,11 @@
*/ */
#include <asm/vdso.h> #include <asm/vdso.h>
#ifdef __LITTLE_ENDIAN__
OUTPUT_FORMAT("elf32-powerpcle", "elf32-powerpcle", "elf32-powerpcle")
#else
OUTPUT_FORMAT("elf32-powerpc", "elf32-powerpc", "elf32-powerpc") OUTPUT_FORMAT("elf32-powerpc", "elf32-powerpc", "elf32-powerpc")
#endif
OUTPUT_ARCH(powerpc:common) OUTPUT_ARCH(powerpc:common)
ENTRY(_start) ENTRY(_start)
......
...@@ -4,7 +4,11 @@ ...@@ -4,7 +4,11 @@
*/ */
#include <asm/vdso.h> #include <asm/vdso.h>
#ifdef __LITTLE_ENDIAN__
OUTPUT_FORMAT("elf64-powerpcle", "elf64-powerpcle", "elf64-powerpcle")
#else
OUTPUT_FORMAT("elf64-powerpc", "elf64-powerpc", "elf64-powerpc") OUTPUT_FORMAT("elf64-powerpc", "elf64-powerpc", "elf64-powerpc")
#endif
OUTPUT_ARCH(powerpc:common64) OUTPUT_ARCH(powerpc:common64)
ENTRY(_start) ENTRY(_start)
......
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