[PATCH 04/14] ARM: set BE8 if LE in head code

Ben Dooks
2013-07-24T10:27:52Z

If we are booting in LE and compiled for BE8, then add code to
set the state to bE8. Since the instruction stream is always LE,
we do not need to do anything special to the instruction.

Also ensure that the secondary processors are started in the same mode.

Note, we do add about 20 bytes to the kernel image, but it seems easier
to do this than adding another configuration to change.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
---
arch/arm/boot/compressed/head.S | 1 +
arch/arm/kernel/head.S | 4 ++++
arch/arm/kernel/sleep.S | 1 +
3 files changed, 6 insertions(+)

diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 4eb8364..4d83bfd 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -135,6 +135,7 @@ start:
.word _edata @ zImage end address
THUMB( .thumb )
1:
+ ARM_BE8( setend be ) @ go BE8 if LE, no-op if BE8
mrs r9, cpsr
#ifdef CONFIG_ARM_VIRT_EXT
bl __hyp_stub_install @ get into SVC mode, reversibly
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index e40c0b3b..706c441 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -77,6 +77,7 @@

__HEAD
ENTRY(stext)
+ ARM_BE8(setend be ) @ ensure we are in BE8 mode

THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM.
THUMB( bx r9 ) @ If this is a Thumb-2 kernel,
@@ -351,6 +352,9 @@ ENTRY(secondary_startup)
* the processor type - there is no need to check the machine type
* as it has already been validated by the primary processor.
*/
+
+ ARM_BE8(setend be) @ if system starts LE, go BE8
+
#ifdef CONFIG_ARM_VIRT_EXT
bl __hyp_stub_install_secondary
#endif
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S
index 987dcf3..954c28a 100644
--- a/arch/arm/kernel/sleep.S
+++ b/arch/arm/kernel/sleep.S
@@ -81,6 +81,7 @@ ENDPROC(cpu_resume_after_mmu)
.data
.align
ENTRY(cpu_resume)
+ARM_BE8(setend be) @ ensure we are in BE mode
#ifdef CONFIG_SMP
adr r0, sleep_save_sp
ALT_SMP(mrc p15, 0, r1, c0, c0, 5)
--
1.7.10.4