On 16/03/2016 11:06, Alexander Graf wrote:
>
>
> On 16.03.16 11:05, Laurent Vivier wrote:
>> On 16/03/2016 10:48, Alexander Graf wrote:
>>>
>>>
>>> On 16.03.16 10:43, Laurent Vivier wrote:
>>>> When a qemu-system-ppc64 is started, the 64-bit mode bit
>>>> is not set in MSR.
>>>>
>>>> Signed-off-by: Laurent Vivier <lviv...@redhat.com>
>>>
>>> I guess commit 2cf3eb6df552cee74b52de9989e270b74e42847e broke this. I'm
>>> surprised it didn't cause us more problems :).
>>
>> Linux kernel is ready to manage that: see enable_64b_mode in
>> arch/powerpc/kernel/head_64.S
>
> We don't boot Linux directly though, only openBIOS and SLOF :).
Same thing in SLOF:
./board-qemu/llfw/startup.S
_start:
...
mfmsr r11 /* grab the current MSR */
li r12,(MSR_SF | MSR_ISF)@highest
sldi r12,r12,48
or r11,r11,r12
mtmsrd r11
isync
And openbios seems to disable it explicitly:
./arch/ppc/qemu/start.S
_entry:
...
/* clear MSR, disable MMU, SF */
[BTW, I've never been able to compile a 64bit version of openbios...]
Laurent
