FreeBSD cannot power down

[Unga]

--- 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.

Many thanks in advance.

Unga