On Wed, Jul 25, 2018 at 01:19:09PM +0100, Peter Maydell wrote: > On 25 July 2018 at 12:44, Andrew Jones <drjo...@redhat.com> wrote: > > On Wed, Jul 25, 2018 at 06:46:59PM +0800, Hongbo Zhang wrote: > >> For Armv7, there is one typical platform 'vexpress', but for Armv8, no > > > > Wasn't the vexpress model designed for a specific machine? > > Yes. > > > Namely for > > Arm's simulator? > > No. > > > Is the vexpress model really something typical among > > all the Armv7 platforms? > > No. > > "Vexpress" is a model specifically of a development board > produced by Arm (the versatile express). It's useful if you > want to run code that runs on that devboard, but (as with > most of the devboards we model), it's not necessarily ideal, > because it has all the limitations of the real hardware it's > modelling (in this case the big ones are limited memory, no PCI). > The hardware it models is also quite old now (maybe 7 or 8 years) > and it's not really "typical" of anything. (In the primarily > embedded space where most v7 CPUs are there's not really anything > that could be described as "typical" anyway: everything is > different.) > > For most people who just want to run Linux on an emulated v7 CPU, > I would recommend the "virt" board, for the same reasons I > recommend it for v8 cores. > > >> such typical one, the 'virt' is typically for running workloads, one > >> example is using it under OpenStack. > >> So a 'typical' one for Armv8 is needed for firmware and OS > >> development, similar like 'vexpress' for Armv7. > > > > What is a "typical" Armv8 machine? What will a typical Armv8 machine be in > > two years? > > > > Note, I'm not actually opposed to the current definition (because I don't > > really have one myself). I'm just opposed to hard coding one. > > AIUI the aim here is to provide an emulated platform that is > set up in the way that server-style armv8 machines are > recommended to be set up, so it can be used as a testbed and > demonstration for the firmware/OS software stack. The hope > is that following "best practices" results in a "typical" > machine :-) But the word "typical" is probably not really > very helpful here... > > I would expect that in the future we'd want this machine type > to evolve with the recommendations for how to build server > platform hardware, which might indeed be different in two years, > since it would be the development platform for writing/testing > the firmware/OS stack for that two-years-time hardware.
Would iut make any sense to call the machine "refplatform" or "refboard" to indicate it is a generic reference platform, not specifically following any particular real impl, albeit influence by the sbsa spec. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
