Re: [Qemu-arm] [Qemu-devel] [PATCH v1 1/1] arm_gic: Include the GIC ArchRev in the ICPIDR2 register

[Peter Maydell]

On 18 January 2016 at 21:41, Alistair Francis
<address@hidden> wrote:
> On Mon, Jan 11, 2016 at 5:58 AM, Peter Maydell <address@hidden> wrote:
>> The current implementation of the ID registers seems to be
>> simply "like the 11MPCore interrupt controller". I think we
>> should get them right more generally if we're going to fix them:
>>
>>                        fd0 .. fdc     fe0 .. fec      ff0 ... ffc
>> 11MPCore               reserved       90 13 04 00     0d f0 05 b1
>> ARM GICv1 (eg A9)      04 00 00 00    90 b3 1b 00     0d f0 05 b1
>> ARM GICv2 (eg A15)     04 00 00 00    90 b4 2b 00     0d f0 05 b1
>>
>> Your patch doesn't account for ICPIDR1 also having a field that
>> changes between GICv1 and GICv2 (for ARM implementations), and
>> we're missing the fd0..fdc bytes.
>>
>> I think this is probably simplest modelled with several
>> gic_id arrays and using the appropriate one for 11MPCore/GICv1/GICv2,
>> rather than trying to OR extra values into the 11MPCore ID values.
>
> Ok, just to make sure I am reading this right. You think I should just
> create three arrays and then if() the revision to determine which one
> to use?

Yes, something like that. The fd0..fdc being reserved for 11MPCore
is documented to mean RAZ/WI, so you can just make those array elements
zeroes.

thanks
-- PMM