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>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 76bbcde049b0..a25f34bd99da 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -639,6 +639,20 @@ config CPU_BIG_ENDIAN
           port must properly enable any big-endian related features
           of your chipset/board/processor.
 
+config CPU_ENDIAN_BE8
+        bool
+        depends on CPU_BIG_ENDIAN
+        default CPU_V6 || CPU_V7
+        help
+          Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors.
+
+config CPU_ENDIAN_BE32
+        bool
+        depends on CPU_BIG_ENDIAN
+        default !CPU_ENDIAN_BE8
+        help
+          Support for the BE-32 (big-endian) mode on pre-ARMv6 processors.
+
 config CPU_HIGH_VECTOR
         depends on !MMU && CPU_CP15 && !CPU_ARM740T
         bool "Select the High exception vector"