On Wed, Jul 25, 2018 at 03:46:01PM +0200, Ard Biesheuvel wrote: > On 25 July 2018 at 15:38, Andrew Jones <drjo...@redhat.com> wrote: > > On Wed, Jul 25, 2018 at 03:03:40PM +0200, Ard Biesheuvel wrote: > >> On 25 July 2018 at 14:59, Andrew Jones <drjo...@redhat.com> wrote: > >> > On Wed, Jul 25, 2018 at 01:47:00PM +0100, Daniel P. Berrangé wrote: > >> >> 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. > >> >> > >> > > >> > That would indeed stop me from whining about a machine model with an > >> > 'sbsa' name not strictly implementing a minimal SBSA machine :-) > >> > > >> > >> I still don't get why only a minimal machine is worth considering, > >> given that a real-world minimal SBSA machine is not capable of doing > >> anything useful. > > > > One definition of an SBSA machine can be quite different than another. > > If we only hard code the required [useless] base, but also provide a > > readconfig for the rest, then we get a useful machine without loss of > > flexibility. > > > > That flexibility comes at the cost of platform-bus code (since we need > > to add devices to the system bus) and a less concise command line. The > > platform-bus code may indeed be too expensive for this purpose, but > > we may need to see patches to be sure. I understand the desire to have > > a shorter command line, but this is QEMU :) > > > > My concern is not the QEMU side. It is the code that we will need to > add to UEFI and ARM-TF to deal with the dynamic nature of the > underlying platform. That code has no counterpart in real world > hardware, but will surely turn up in production firmware nonetheless > if we end up having to add that to our SBSA reference codebase.
It sounds like there's already some sort of informal SBSA reference instance specification that UEFI and ARM-TF intend to support. If that instance specification were slightly more formal, i.e. documented somewhere and given a more descriptive name (not just 'sbsa'), then I think it would be a lot more palatable to hard code those specifications directly into a QEMU machine model of the same name. Thanks, drew
