Re: git: 58de79153622 - main - arm64: mte: configure initial state for system registers

From: Mark Johnston <markj_at_freebsd.org>
Date: Wed, 29 Apr 2026 03:05:29 UTC
On Mon, Apr 13, 2026 at 02:24:09PM +0000, Andrew Turner wrote:
> The branch main has been updated by andrew:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=58de79153622145cb6fc57bc92c4de678876992f
> 
> commit 58de79153622145cb6fc57bc92c4de678876992f
> Author:     Harry Moulton <harry.moulton@arm.com>
> AuthorDate: 2026-04-13 11:54:38 +0000
> Commit:     Andrew Turner <andrew@FreeBSD.org>
> CommitDate: 2026-04-13 14:23:05 +0000
> 
>     arm64: mte: configure initial state for system registers
>     
>     The fields in SCTLR_EL1 and HCR_EL2 for enabling MTE are set, and if the
>     ID_AA64PFR1_EL1 register shows MTE is present, the GCR_EL1 register is
>     also configured, and the two TFSR registers which hold pending tag check
>     faults are cleared.
>     
>     Reviewed by:    andrew
>     Sponsored by:   Arm Ltd
>     Signed-off-by:  Harry Moulton <harry.moulton@arm.com>
>     Differential Revision:  https://reviews.freebsd.org/D55946

After this commit I can't boot a FreeBSD aarch64 VM in qemu using "-cpu
max": boot hangs shortly after the loader handoff.  If I revert just
this commit on the latest main, I'm able to boot.