Re: port-evbarm/60214: panic: kernel diagnostic assertion "(armreg_ttbcr_read() & TTBCR_S_PD0) != 0" failed

[Nick Hudson <nick.hudson%gmx.co.uk@localhost>]

> On 27 Apr 2026, at 17:20, Andreas Gustafsson via gnats <gnats-admin%NetBSD.org@localhost> wrote:
> 
>> Number:         60214
>> Category:       port-evbarm
>> Synopsis:       panic: kernel diagnostic assertion "(armreg_ttbcr_read() & TTBCR_S_PD0) != 0" failed
>> Confidential:   no
>> Severity:       serious
>> Priority:       high
>> Responsible:    port-evbarm-maintainer
>> State:          open
>> Class:          sw-bug
>> Submitter-Id:   net
>> Arrival-Date:   Mon Apr 27 16:20:00 +0000 2026
>> Originator:     Andreas Gustafsson
>> Release:        NetBSD-current, source date >= 2026.04.19.15.09.50
>> Organization:
> 
>> Environment:
> System: NetBSD
> Architecture: arm
> Machine: evbarm
>> Description:
> 
> Booting NetBSD/evbarm-earmv7hf under "qemu-system-arm -M virt" fails with
> a message like
> 
>  panic: kernel diagnostic assertion "(armreg_ttbcr_read() & TTBCR_S_PD0) != 0" failed: file "/dev/shm/build/2026.04.19.15.09.50-evbarm-earmv7hf-virt/src/sys/arch/arm/arm32/pmap.c", line 5151
> 

This is because qemu default cpu for -M virt is missing the Security Extensions required for TTBCR.PD0.

Perhaps my KASSERT expecting security extensions is over zealous and should be relaxed to be dependent on security extensions being available.