From d72b08017161ab385d4ae080ea415c9eb7ceef83 Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Mon, 23 Sep 2013 12:05:11 +1000 Subject: [PATCH] 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: Ian Munsie Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt --- 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 ++++ 4 files changed, 31 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index debfa2b1c1de..d3c91bf923b7 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 $(MULTIPLEWORD) ifeq ($(CONFIG_PPC_BOOK3S_64),y) CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power7,-mtune=power4) diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile index 15ca2255f438..ca7f08cc4afd 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 f223409629b9..e58ee10fa5c0 100644 --- a/arch/powerpc/kernel/vdso32/vdso32.lds.S +++ b/arch/powerpc/kernel/vdso32/vdso32.lds.S @@ -4,7 +4,11 @@ */ #include +#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 e4863819663b..64fb183a47c2 100644 --- a/arch/powerpc/kernel/vdso64/vdso64.lds.S +++ b/arch/powerpc/kernel/vdso64/vdso64.lds.S @@ -4,7 +4,11 @@ */ #include +#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) -- 2.20.1