Re: [PATCH v3] target/hppa: Add CPU reset method

[Helge Deller]

On 12/29/24 02:58, Richard Henderson wrote:
> On 12/27/24 15:17, Helge Deller wrote:
> > Add the CPU reset method, which resets all CPU registers and the TLB to
> > zero. Then the CPU will switch to 32-bit mode (PSW_W bit is not set) and
> > start execution at address 0xf0000004.
> > Although we currently want to zero out all values in the CPUHPPAState
> > struct, add the end_reset_fields marker in case the state structs gets
> > extended with other variables later on which should not be reset.
> >
> > Signed-off-by: Helge Deller <deller@gmx.de>
> >
> > V3:
> > - Call reset function from hppa_machine_reset() instead
> >
> > V2:
> > - Add end_reset_fields marker
> > - call reset function in hppa_cpu_initfn()
> ...
> > diff --git a/target/hppa/cpu.c b/target/hppa/cpu.c
> > index c38439c180..b908cf65c6 100644
> > --- a/target/hppa/cpu.c
> > +++ b/target/hppa/cpu.c
> > @@ -235,15 +235,39 @@ static const TCGCPUOps hppa_tcg_ops = {
> >   #endif /* !CONFIG_USER_ONLY */
> >   };
> > +static void hppa_cpu_reset_hold(Object *obj, ResetType type)
> > +{
> > +    HPPACPU *cpu = HPPA_CPU(obj);
> > +    HPPACPUClass *scc = HPPA_CPU_GET_CLASS(cpu);
> > +    CPUHPPAState *env = &cpu->env;
> > +    CPUState *cs = CPU(cpu);
> > +
> > +    if (scc->parent_phases.hold) {
> > +        scc->parent_phases.hold(obj, type);
> > +    }
> > +
> > +    memset(env, 0, offsetof(CPUHPPAState, end_reset_fields));
> > +    cpu_set_pc(cs, 0xf0000004);
> > +    cpu_hppa_put_psw(env, hppa_is_pa20(env) ? PSW_W : 0);
> > +    cpu_hppa_loaded_fr0(env);
> > +
> > +    cs->exception_index = -1;
> > +    cs->halted = 0;
> > +}
>
> There's also a set of exception_index in hppa_cpu_initfn.

I don't quite understand...
Do you suggest I should remove the initialization of exception_index here,
or drop the one in hppa_cpu_initfn() ?

> Otherwise,
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

Thanks!
Helge