diff options
| author | Stafford Horne <shorne@gmail.com> | 2017-02-05 18:55:40 +0900 |
|---|---|---|
| committer | Stafford Horne <shorne@gmail.com> | 2017-02-25 05:08:47 +0900 |
| commit | a4d4426635804379d618dd28e29f574a2bc11184 (patch) | |
| tree | 38ef4394a132b84ebac0db16ca86d1792311c9da /arch/openrisc/kernel | |
| parent | a0eba4f7ebcdf81da0a4480d8fc514af4f76579e (diff) | |
openrisc: head: Init r0 to 0 on start
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.
Reported-by: Jakob Viketoft <jakob.viketoft@aacmicrotec.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Diffstat (limited to 'arch/openrisc/kernel')
| -rw-r--r-- | arch/openrisc/kernel/head.S | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S index fe55156983e0..d01b82eace3e 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 */ |