Re: What pokes the ISA IO port of 0x211 ?

Bart Van Assche
2008-04-21T15:51:16Z

On Mon, Apr 21, 2008 at 1:12 PM, Frantisek Rysanek
<Frantisek.Rysanek@post.cz> wrote:
> I'm dealing with an embedded PC motherboard that contains some custom
> circuitry (GPIO), accessible via an ISA IO range between 0x200 and
> 0x218.
>
> There's an interesting issue with this in recent Linux (tried
> 2.6.22.6 and 2.6.24.2): something probes IO port 0x211 on boot, which
> happens to be an add-on buzzer control port - effectively the kernel
> boot launches an accoustic alarm :-)
>
> Any ideas what this could be?

Did you already have a look at /proc/ioports ? This file should
contain every range of ISA bus address in use by any kernel component.

Bart.