On 29 May 2015 at 13:55, aurelio remonda <aurelioremo...@gmail.com> wrote > Perhaps we could commit this now and add the VFP in the future?
That's how we've generally worked, yes -- if you just ask for a "Cortex-A9" or whatever you get the maximum set of features that CPU can support (so always Neon & VFP even if some A9 hardware is configured without VFP), and if we add support for a feature that the hardware has after the CPU model was first added then we add the feature to that CPU. (So we didn't have TrustZone support when the A9 was initially put into QEMU, but when we put in the TZ support we turned on the ARM_FEATURE_EL3 bit for the A9 by default.) If we need to also support CPUs of that model that don't have a particular optional feature we can do that via a CPU property (as we do with 'has_el3' for disabling TZ support). Then a board that wants an M4 without FPU can set the property to false, or a user who wants to control it from the command line can do so via -cpu cortex-m4,has-fpu=false or similar. -- PMM
