[LinuxBIOS] VIA Auto Power ON

[Marcel Graber]

Hi,

Is there a solution to get the via epia-m2 board to auto Power on (like
the MAINBOARD_POWER_ON in other southbridges)?  
I've seen that the fastboot Bios from VIA (which is also linuxbios) can
do it

Tnx for help,
marcel

[Peter Stuge]

On Wed, May 02, 2007 at 08:01:14AM +0200, Marcel Graber wrote:
> Is there a solution to get the via epia-m2 board to auto Power

There's a simple way to do it in hardware at least, put a capacitor
over the PWRSW pins.

I've gotten the most reliable results with a 1uF electrolytic
capacitor, higher capacitances have been unreliable.

(Note the polarity if you're using an electrolytic capacitor.)

//Peter

[Corey Osgood]

Peter Stuge wrote:
> On Wed, May 02, 2007 at 08:01:14AM +0200, Marcel Graber wrote:
> > Is there a solution to get the via epia-m2 board to auto Power
>
> There's a simple way to do it in hardware at least, put a capacitor
> over the PWRSW pins.
>
> I've gotten the most reliable results with a 1uF electrolytic
> capacitor, higher capacitances have been unreliable.
>
> (Note the polarity if you're using an electrolytic capacitor.)
>
> //Peter

Looking at the vt8237r datasheet, for offset 82 of device 17, bus
control/power management device:

4  SUSC# AC-Power-On Default Value .................RO
   This bit is written at RTC Index 0D bit-7. If this bit
   is 0, the system is configured to “default on” when
   power is connected.

So a good place to start would be the vt8235 datahseets.

-Corey

[Jonathan McDowell]

On Wed, May 02, 2007 at 08:01:14AM +0200, Marcel Graber wrote:
> Is there a solution to get the via epia-m2 board to auto Power on
> (like the MAINBOARD_POWER_ON in other southbridges)?  I've seen that
> the fastboot Bios from VIA (which is also linuxbios) can do it

At one point I had this working, but I managed to lose the patch and
was unable to figure out how to do it again - the register Corey
mentions is read only and I believe I tried writing to it without any
luck.

Currently I've kludged round the issue by setting the state to always
power on in the original Via BIOS before I reflash with LinuxBIOS. It
would of course be nicer to do it properly with just LinuxBIOS.

J.