From 26584853a44c58f3d6ac7360d697a2ddcd1a3efa Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Sat, 30 May 2009 14:00:18 +0100 Subject: Add core support for ARMv6/v7 big-endian Starting with ARMv6, the CPUs support the BE-8 variant of big-endian (byte-invariant). This patch adds the core support: - setting of the BE-8 mode via the CPSR.E register for both kernel and user threads - big-endian page table walking - REV used to rotate instructions read from memory during fault processing as they are still little-endian format - Kconfig and Makefile support for BE-8. The --be8 option must be passed to the final linking stage to convert the instructions to little-endian Signed-off-by: Catalin Marinas --- arch/arm/kernel/entry-armv.S | 3 +++ arch/arm/kernel/entry-common.S | 3 +++ arch/arm/kernel/process.c | 2 +- 3 files changed, 7 insertions(+), 1 deletion(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index d662a2f1fd8..9d7ce4377c5 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -482,6 +482,9 @@ __und_usr: subeq r4, r2, #4 @ ARM instr at LR - 4 subne r4, r2, #2 @ Thumb instr at LR - 2 1: ldreqt r0, [r4] +#ifdef CONFIG_CPU_ENDIAN_BE8 + reveq r0, r0 @ little endian instruction +#endif beq call_fpe @ Thumb instruction #if __LINUX_ARM_ARCH__ >= 7 diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index b55cb033180..366e5097a41 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -210,6 +210,9 @@ ENTRY(vector_swi) A710( teq ip, #0x0f000000 ) A710( bne .Larm710bug ) #endif +#ifdef CONFIG_CPU_ENDIAN_BE8 + rev r10, r10 @ little endian instruction +#endif #elif defined(CONFIG_AEABI) diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index c3265a2e7cd..1585423699e 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -365,7 +365,7 @@ pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) regs.ARM_r2 = (unsigned long)fn; regs.ARM_r3 = (unsigned long)do_exit; regs.ARM_pc = (unsigned long)kernel_thread_helper; - regs.ARM_cpsr = SVC_MODE; + regs.ARM_cpsr = SVC_MODE | PSR_ENDSTATE; return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); } -- cgit v1.2.3