On 22-Apr-99 Jim DiFronzo wrote:
>> I'm looking to trap the signal from the power button on many modern
> ATX/NLX
>> motherboards (I think they might call it 'soft power' or something), and
> use it
>> to do something useful.
*snip*
> The power button is an APM function of the BIOS and chipset. When the user
> presses the power button the chipset senses that trigger, enters SMM. In SMM
> the processor jumps to a memory location in BIOS and start executing the
> Interrupt handler for that function. Some BIOS's use an interrupt rather
> than SMM, but the results are the same. On most BIOS's the function sends an
> APM_USER_SUSPEND or APM_SYSTEM_SUSPEND signal to the OS.
I had guessed it was something like that, but wasn't sure. I'm not clear on
one thing though - if you press power to get an APM_USER_SUSPEND or
APM_SYSTEM_SUSPEND, what happens when you press the suspend button that comes
with some machines (not this one, but some).
*snip some very useful kernel stuff*
> Hope this helps.
A great help, thank you.
Richard Waid.
Network Engineer - [EMAIL PROTECTED] - 021 636 661
iOpen Technologies Ltd.
