Re: [RFC 15/15] target/riscv: rvb: support and turn on B-extension from command line

[Alistair Francis]

On 19/11/2020 7:02 pm, Kito Cheng wrote:
> > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> > index 0bbfd7f4574..bc29e118c6d 100644
> > --- a/target/riscv/cpu.c
> > +++ b/target/riscv/cpu.c
> > @@ -438,6 +438,9 @@ static void riscv_cpu_realize(DeviceState *dev, Error 
> > **errp)
> >           if (cpu->cfg.ext_h) {
> >               target_misa |= RVH;
> >           }
> > +        if (cpu->cfg.ext_b) {
> > +            target_misa |= RVB;
> > +        }
> >           if (cpu->cfg.ext_v) {
> >               target_misa |= RVV;
> >               if (!is_power_of_2(cpu->cfg.vlen)) {
> > @@ -515,6 +518,7 @@ static Property riscv_cpu_properties[] = {
> >       DEFINE_PROP_BOOL("s", RISCVCPU, cfg.ext_s, true),
> >       DEFINE_PROP_BOOL("u", RISCVCPU, cfg.ext_u, true),
> >       /* This is experimental so mark with 'x-' */
> > +    DEFINE_PROP_BOOL("x-b", RISCVCPU, cfg.ext_b, true),
>
> I think the default value should be false?

Good catch, I missed that.

Yes it should be false.

Alistair

> >       DEFINE_PROP_BOOL("x-h", RISCVCPU, cfg.ext_h, false),
> >       DEFINE_PROP_BOOL("x-v", RISCVCPU, cfg.ext_v, false),
> >       DEFINE_PROP_BOOL("Counters", RISCVCPU, cfg.ext_counters, true),