Hi,
Thank you very much! I have got the answer, we can use MSR/MRS instructions to load/save these regs.
Thanks and regards,
Harry
At 2015-08-29 00:25:17, "Julien Grall" <julien.grall@xxxxxxxxxx> wrote:
>On 25/08/15 05:43, harry wrote:
>> Hi,
>
>Hi,
>
>> Now I want to implement some functions in other hypervisor, so I need to
>> read SP_usr and SP_svc in HYP mode. I know Xen has implemented this
>> function. But I use it with regs->sp_usr/svc to achieve this. But I
>> don't know how to achieve it. I have read the entry.S file and get the
>> process to save the regs, but some definition is not clear. I want to
>> know if there is some asm command to achieve this? Or do I need to
>> switch the mode manually to read it?
>
>Please reach out the mailing list related to the hypervisor you want to
>modify to know whether they have handy helpers to access SP_usr/SP_svc.
>
>If not, I would advice you to read the ARM ARM in order to know how to
>access banked registers, particularly the section "Encoding and use of
>Banked register transfer instructions".
>
>Regards,
>
>--
>Julien Grall
