Re: [PATCH 10/11] target/arm: Make SPSR_hyp accessible for Cortex-R52

[Peter Maydell]

On Thu, 14 Jul 2022 at 15:54, Tobias Roehmel <quic_trohmel@quicinc.com> wrote:
>
> From: Tobias Röhmel <quic_trohmel@quicinc.com>
>
> The Cortex-R52 can access SPSR_hyp from hypervisor mode
> as discussed here: https://github.com/zephyrproject-rtos/zephyr/issues/47330

The v8R Supplement pseudocode aarch32/functions/system/SPSRaccessValid
says this is UNPREDICTABLE:

when '11110' // SPSR_hyp
    if !HaveEL(EL2) || mode != M32_Monitor then UNPREDICTABLE;

so unless that's incorrect then I think QEMU is within its rights
to UNDEF this (and real hardware may choose to UNDEF or not).

I will enquire about whether there is a bug in the sample R52
startup code.

thanks
-- PMM