Re: [Qemu-devel] KVM call agenda for Tuesday 3

[Anthony Liguori <anthony@codemonkey.ws>]

On 01/02/2012 09:54 AM, Peter Maydell wrote:
> On 2 January 2012 13:46, Andreas Färber<afaerber@suse.de>  wrote:
>> * when can we expect to be able to model SoCs rather than CPUs? Will
>> this affect command line usage - are we going to have '-device
>> ti-tms570' rather than '-cpu cortex-r4' then, or -cpu overriding the
>> container's default?
>
> My initial inclination is to say that specifying the CPU on the
> command line is almost always the wrong thing for ARM platforms
> (now or in a future QOM world). For instance, if you start the
> vexpress-a9 board with something other than -cpu cortex-a9 it won't
> complain but it won't do the right thing either (you'll get the
> private peripherals for the A9 with whatever CPU core you asked for).
>
> I don't think you want to have the user specifying -device my-soc
> on the command line either -- the user should be selecting a board
> (machine) model, which will generally nail down which soc and cpu
> are used.

Let's separate out what a user *should* do from what a user *can* do.

A user *should* have a command line syntax that reflects something that makes 
sense to them.  For instance, qemu-system-arm --machine beaglebone

I don't really care what the SoC or CPU in my beaglebone is.  I just want to 
emulate one.

But I do believe we want to make it possible for -device to create a CPU even 
when it doesn't make sense.

Regards,

Anthony Liguori