Re: [PATCH 4/4] hw/arm/xlnx-zynqmp: adapt cluster-id based on the boot cpu

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

On Tue, 13 May 2025 at 15:15, Clément Chigot <chigot@adacore.com> wrote:
>
> When gdb is being connected to QEmu, it will be attached to the first

(QEMU is all-caps, by the way)

> CPU cluster. However, the ZynqMP board has two clusters, those being of
> two different architectures.
> Therefore, when gdb is connecting to the ZynqMP, it receives the target
> descriptor of the first CPU cluster. Up to now, it was always the APU
> cluster, which is AARCH64.
>
> When booting on a RPU, gdb will still connect to the APU. If gdb is
> supporting only ARM32, it will receive the APU target descriptor,
> resulting in:
>   | (gdb) target remote :1234
>   | warning: while parsing target description (at line 1): Target
>   | description specified unknown architecture "aarch64"
>
> Adjust the cluster-id based on the boot cpu will resolve the above
> issue; allowing a pure ARM32 toolchain to debug programs running on
> RPUs.

I'm not really enthusiastic about renumbering the clusters
like this. I think you should be able to get gdb to connect
to the second cluster via the multiple-inferior support:

https://www.qemu.org/docs/master/system/gdb.html#debugging-multicore-machines

thanks
-- PMM