psci: fix use of clobbered registers in asm
The functions `psci_get_context_id` and `psci_get_target_pc`
are written in C, so the C compiler may clobber registers r0-r3.
Do not use these registers to save data across calls.
Signed-off-by: Sam Edwards <CFSworks@gmail.com>
diff --git a/arch/arm/cpu/armv7/psci.S b/arch/arm/cpu/armv7/psci.S
index 6c066e5..4142872 100644
--- a/arch/arm/cpu/armv7/psci.S
+++ b/arch/arm/cpu/armv7/psci.S
@@ -311,11 +311,11 @@
bl psci_arch_cpu_entry
bl psci_get_cpu_id @ CPU ID => r0
- mov r2, r0 @ CPU ID => r2
bl psci_get_context_id @ context id => r0
- mov r1, r0 @ context id => r1
- mov r0, r2 @ CPU ID => r0
+ push {r0} @ save context id
+ bl psci_get_cpu_id @ CPU ID => r0
bl psci_get_target_pc @ target PC => r0
+ pop {r1} @ context id => r1
b _do_nonsec_entry
ENDPROC(psci_cpu_entry)