On 02/24/2017 05:32 AM, Stafford Horne wrote:
Originally openrisc spec 0 specified that r0 would be wired to ground.
This is no longer the case. r0 is not guaranteed to be 0 at init, so we
need to initialize it to 0 before using it.
Also, if we are clearing r0 we cant use r0 to clear itself. Change the
the CLEAR_GPR macro to use movhi for clearing.
Use the Reported-by: tag here since you are taking the time to mention
him in the summary mail.
Reported-by: Jakob...
Signed-off-by: Stafford Horne <sho...@gmail.com>
---
arch/openrisc/kernel/head.S | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S
index 573e131..e8a1784 100644
--- a/arch/openrisc/kernel/head.S
+++ b/arch/openrisc/kernel/head.S
@@ -35,7 +35,7 @@
l.add rd,rd,rs
#define CLEAR_GPR(gpr) \
- l.or gpr,r0,r0
+ l.movhi gpr,0x0
#define LOAD_SYMBOL_2_GPR(gpr,symbol) \
l.movhi gpr,hi(symbol) ;\
@@ -443,6 +443,9 @@ _dispatch_do_ipage_fault:
__HEAD
.global _start
_start:
+ /* Init r0 to zero as per spec */
+ CLEAR_GPR(r0)
+
/* save kernel parameters */
l.or r25,r0,r3 /* pointer to fdt */
