Re: [PATCH] hw/ppc/ppc405_boards: Change kernel load address

[Peter Maydell]

On Fri, 3 Dec 2021 at 10:32, Thomas Huth <thuth@redhat.com> wrote:
> I guess it's an accidential NULL pointer dereference somewhere in the u-boot
> code ... which will be quite hard to track down when the first page of
> memory is marked as writable... :-/

Attach a target-arch gdb to the QEMU gdbstub and put a watchpoint on
address zero ? (Or if you suspect something inside QEMU is doing it
then run QEMU under gdb and watchpoint the host memory location
corresponding to guest address 0, but that's more painful.) Nothing
in the pre-kernel part of the boot process will have set up paging,
so the watchpointing should be pretty reliable.

-- PMM