FreeBSD cannot power down
Bruce Cran
bruce at cran.org.uk
Sat Dec 6 18:01:27 PST 2008
On Thu, Dec 04, 2008 at 03:42:51AM -0800, Unga wrote:
> --- On Tue, 12/2/08, Unga <unga888 at yahoo.com> wrote:
>
> > From: Unga <unga888 at yahoo.com>
> > Subject: FreeBSD cannot power down
> > To: freebsd-questions at freebsd.org
> > Date: Tuesday, December 2, 2008, 11:22 PM
> > Hi all
> >
> > After a kernel recompilation on i386 RELENG_7 (not the
> > latest), I cannot power down the machine.
> >
> > kldstat shows acpi.ko is loaded.
> >
> > It used to switch off but now the "shutdown -p
> > now" halts the system with following messages:
> > The operating system has halted.
> > Please press any key to reboot.
> >
> > What else could I check to identify the cause?
> >
> > Appreciate your ideas on this.
> >
>
> I had a look at source code. The program flow seems to be is as follows:
>
> shutdown => (signals) init => reboot() => boot() => shutdown_final => shutdown_halt() => cpu_halt()
>
> I did not see which function is called to request a power down.
>
> The __asm__ ("hlt") doesn't power down, isn't it?
>
> Could you guys help me to identify how shutdown request a power down.
>
HLT is just an old power-saving instruction that was traditionally run
in the idle loop. From reading the code it looks like the system
should be powered off during poweroff_wait but I can't see where ACPI is
told to remove power. You might get more help by asking on the
freebsd-acpi list.
--
Bruce Cran
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