openrisc: head: Init r0 to 0 on start
authorStafford Horne <shorne@gmail.com>
Sun, 5 Feb 2017 09:55:40 +0000 (18:55 +0900)
committerStafford Horne <shorne@gmail.com>
Fri, 24 Feb 2017 20:08:47 +0000 (05:08 +0900)
commita4d4426635804379d618dd28e29f574a2bc11184
tree38ef4394a132b84ebac0db16ca86d1792311c9da
parenta0eba4f7ebcdf81da0a4480d8fc514af4f76579e
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>
arch/openrisc/kernel/head.S