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/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index fbe5eef..ce39dc5 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -40,7 +40,7 @@
OBJS += head-sharpsl.o
endif
-ifeq ($(CONFIG_CPU_BIG_ENDIAN),y)
+ifeq ($(CONFIG_CPU_ENDIAN_BE32),y)
ifeq ($(CONFIG_CPU_CP15),y)
OBJS += big-endian.o
else
@@ -78,6 +78,9 @@
# linker symbols. We only define initrd_phys and params_phys if the
# machine class defined the corresponding makefile variable.
LDFLAGS_vmlinux := --defsym zreladdr=$(ZRELADDR)
+ifeq ($(CONFIG_CPU_ENDIAN_BE8),y)
+LDFLAGS_vmlinux += --be8
+endif
ifneq ($(INITRD_PHYS),)
LDFLAGS_vmlinux += --defsym initrd_phys=$(INITRD_PHYS)
endif
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index b371fba..01d49be 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -438,6 +438,9 @@
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 @@
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