Re: qemu-system-aarch64 hangs in a cortex-a72 test

[Peter Maydell <peter.maydell@linaro.org>]

On Mon, 6 Oct 2025 at 11:05, Liviu Ionescu <ilg@livius.net> wrote:
>
>
>
> > On 6 Oct 2025, at 12:55, Peter Maydell <peter.maydell@linaro.org> wrote:
> >
> > Notably 9.0 is the first release which included
> > commit 59754f85ed, which enforces the architectural
> > requirement that when the MMU is disabled unaligned
> > loads and stores must fault.
>
> Ok, this is a good hint, a loop in an exception handler is a very likely cause of the program hanging.
>
> > ... (You should be able
> > to see that in the -d debug logs if it's happening,
> > or via gdbstub if you put a breakpoint on the exception
> > entry point.)
>
> I'll try to run a debug session and see if this is the case, and fix it.

Note that depending on your compiler's config it might assume
unaligned accesses are OK by default (because they are when
the MMU is on for v7 and later CPUs). If that's the case, it's
possible the fix might be as simple as "recompile with the
-mno-unaligned-access option in CFLAGS".

-- PMM