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 <catalin.marinas@arm.com>
diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h
index 1845892..6a89567 100644
--- a/arch/arm/include/asm/processor.h
+++ b/arch/arm/include/asm/processor.h
@@ -71,6 +71,7 @@
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) */ \
diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
index 4a4290f..67b833c 100644
--- a/arch/arm/include/asm/ptrace.h
+++ b/arch/arm/include/asm/ptrace.h
@@ -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__
/*