Computer hangs on reboot

[Andrey Shuvikov]

On 5/29/07, Andrey Shuvikov <mr.hyro at gmail.com> wrote:
> On 5/29/07, John Baldwin <jhb at freebsd.org> wrote:
> > On Saturday 26 May 2007 01:14:52 pm Andrey Shuvikov wrote:
> > > I tried to add some debug output to cpu_reset_real() code:
> > >
> > >   printf("cpu_reset_real(): before keyboard reset\n");
> > >   outb(IO_KBD + 4, 0xFE);
> > >   printf("cpu_reset_real(): after keyboard reset\n");
> > >
> > > The last two lines I see on the screen when I try to reboot are:
> > >
> > > cpu_reset_real(): before keyboard reset
> > > c
> > >
> > > So the computer is halted but doesn't go to reboot.
> >
> > So what if you disable the keyboard reset and let the other methods happen?
> >
> > --
> > John Baldwin
> >
>
> I tried to set BROKEN_KEYBOARD_RESET option but nothing changed
> (except that I didn't see these debugging messages, obviously). Is it
> possible that keyboard controller issues the reset signal but the CPU
> waits for something? Or reset pin is disabled somehow?
>

Tried to investigate further... Added code to print keyboard
controller output port to make sure A20 is open. Got 0x0B. Does it
mean that A20 is really open? If A20 is controlled by some kind of
"Fast A20" option, will keyboard controller still show the right
status? And what else can I check?

Thanks,
Andrey