On Thu, 14 Jul 2022 at 16:46, Peter Maydell <peter.mayd...@linaro.org> wrote: > > On Thu, 14 Jul 2022 at 15:54, Tobias Roehmel <quic_troh...@quicinc.com> wrote: > > > > From: Tobias Röhmel <quic_troh...@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.
The author of the startup code example agrees it's a bug that went unnoticed because the FVP happens to permit this UNPREDICTABLE case, so we don't need this QEMU patch. -- PMM
