Re: [PATCH] powerpc: enable 64-bit mode

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 15.03.16 19:43, Thomas Huth wrote:
> On 15.03.2016 14:15, Laurent Vivier wrote:
>> When they are started, processors are in 32-bit mode,
>> as we are testing ppc64 processors, enable the 64bit mode
>> on starting.
>>
>> Signed-off-by: Laurent Vivier <lvivier@xxxxxxxxxx>
>> ---
>>  powerpc/cstart64.S | 9 +++++++++
>>  1 file changed, 9 insertions(+)
>>
>> diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S
>> index c87e3d6..634b854 100644
>> --- a/powerpc/cstart64.S
>> +++ b/powerpc/cstart64.S
>> @@ -18,6 +18,15 @@
>>  .globl start
>>  start:
>>  	FIXUP_ENDIAN
>> +
>> +	/* enable 64-bit mode */
>> +	mfmsr	r11
>> +	li	r12,-1
>> +	rldicr	r12,r12,0,0
> 
> Nice idea to set the highest bit, I didn't know that one yet :-)
> 
>> +	or	r11,r11,r12
>> +	mtmsrd	r11
>> +	isync
> 
> Looks good!
> 
> Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx>
> 
> 
> PS: As far as I can see, the C code has already been compiled for 64
> bits ... how did that work if it has been run in 32-bit mode so far??

And why would we enter a 64bit CPU without MSR_SF set?


Alex
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux