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Commit 26584853 authored by Catalin Marinas's avatar Catalin Marinas
Browse files

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: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent ee8c9571

arch/arm/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -11,6 +11,9 @@ 
# Copyright (C) 1995-2001 by Russell King



LDFLAGS_vmlinux	:=-p --no-undefined -X

ifeq ($(CONFIG_CPU_ENDIAN_BE8),y)

LDFLAGS_vmlinux	+= --be8

endif

CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET)

OBJCOPYFLAGS	:=-O binary -R .note -R .note.gnu.build-id -R .comment -S

GZFLAGS		:=-9

arch/arm/boot/compressed/Makefile

+4 −1
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ ifeq ($(CONFIG_PXA_SHARPSL),y) 
OBJS		+= head-sharpsl.o

endif



ifeq ($(CONFIG_CPU_BIG_ENDIAN),y)

ifeq ($(CONFIG_CPU_ENDIAN_BE32),y)

ifeq ($(CONFIG_CPU_CP15),y)

OBJS		+= big-endian.o

else
@@ -78,6 +78,9 @@ EXTRA_AFLAGS := -Wa,-march=all 
# linker symbols.  We only define initrd_phys and params_phys if the

# machine class defined the corresponding makefile variable.

LDFLAGS_vmlinux := --defsym zreladdr=$(ZRELADDR)

ifeq ($(CONFIG_CPU_ENDIAN_BE8),y)

LDFLAGS_vmlinux += --be8

endif

ifneq ($(INITRD_PHYS),)

LDFLAGS_vmlinux += --defsym initrd_phys=$(INITRD_PHYS)

endif

arch/arm/boot/compressed/head.S

+6 −0
Original line number Diff line number Diff line
@@ -438,6 +438,9 @@ __armv4_mmu_cache_on: 
		mrc	p15, 0, r0, c1, c0, 0	@ read control reg

		orr	r0, r0, #0x5000		@ I-cache enable, RR cache replacement

		orr	r0, r0, #0x0030

#ifdef CONFIG_CPU_ENDIAN_BE8

		orr	r0, r0, #1 << 25	@ big-endian page tables

#endif

		bl	__common_mmu_cache_on

		mov	r0, #0

		mcr	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
@@ -455,6 +458,9 @@ __armv7_mmu_cache_on: 
		mrc	p15, 0, r0, c1, c0, 0	@ read control reg

		orr	r0, r0, #0x5000		@ I-cache enable, RR cache replacement

		orr	r0, r0, #0x003c		@ write buffer

#ifdef CONFIG_CPU_ENDIAN_BE8

		orr	r0, r0, #1 << 25	@ big-endian page tables

#endif

		orrne	r0, r0, #1		@ MMU enabled

		movne	r1, #-1

		mcrne	p15, 0, r3, c2, c0, 0	@ load page table pointer

arch/arm/include/asm/processor.h

+1 −0
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ struct thread_struct { 
		regs->ARM_cpsr = USR26_MODE;				\

	if (elf_hwcap & HWCAP_THUMB && pc & 1)				\

		regs->ARM_cpsr |= PSR_T_BIT;				\

	regs->ARM_cpsr |= PSR_ENDSTATE;					\

	regs->ARM_pc = pc & ~1;		/* pc */			\

	regs->ARM_sp = sp;		/* sp */			\

	regs->ARM_r2 = stack[2];	/* r2 (envp) */			\

arch/arm/include/asm/ptrace.h

+10 −0
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ 
#define PSR_F_BIT	0x00000040

#define PSR_I_BIT	0x00000080

#define PSR_A_BIT	0x00000100

#define PSR_E_BIT	0x00000200

#define PSR_J_BIT	0x01000000

#define PSR_Q_BIT	0x08000000

#define PSR_V_BIT	0x10000000
@@ -72,6 +73,15 @@ 
#define PSR_IT_MASK	0x0600fc00	/* If-Then execution state mask */

#define PSR_ENDIAN_MASK	0x00000200	/* Endianness state mask */



/*

 * Default endianness state

 */

#ifdef CONFIG_CPU_ENDIAN_BE8

#define PSR_ENDSTATE	PSR_E_BIT

#else

#define PSR_ENDSTATE	0

#endif



#ifndef __ASSEMBLY__



/*