Re: [Qemu-devel] [Qemu-arm] [PATCH 2/6] armv7m: Replace armv7m.hack with unassigned_access handler

[Peter Maydell]

On 24 January 2017 at 16:31, Alex Bennée <address@hidden> wrote:
>
> Peter Maydell <address@hidden> writes:
>> -    /* Hack to map an additional page of ram at the top of the address
>> -       space.  This stops qemu complaining about executing code outside RAM
>> -       when returning from an exception.  */
>> -    memory_region_init_ram(hack, NULL, "armv7m.hack", 0x1000, &error_fatal);
>> -    vmstate_register_ram_global(hack);
>> -    memory_region_add_subregion(system_memory, 0xfffff000, hack);
>> -
>
> What stops a model inadvertently registering a block of memory on-top?
> Should we check the memory region really is unassigned?

It would just be a board code bug, and a pretty implausible one
I think (at least no less plausible than any other typoing of
a device or memory address, 99% of which are uncheckable).

thanks
-- PMM