Alternate Restart method needed

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G

Guest

Although ACPI has a standard method to specify how to restart a system,
Windows XP always ignores it. There are also two standard hardware methods to
restart a computer. The first method is to send a command (0xFE) to the
keyboard controller (output port 0x64) (this is a legacy from the PC/AT) and
the second is to set a bit in I/O port 0x92. Windows XP always sends the
reset command to the keyboard controller and no other method.

My device is truely headless. No keyboard controller, no video controller.
So, when I try to do "shutdown -r -t 0" the OS shutsdown, but the system does
not restart.

Does anyone know how I can get this to work?

Somewhere in one of the Windows system files there are instructions like
"mov al, 0feh / out 64h, al". If these were changed to "mov al, 02 / out 92h,
al" it would reset the system correctly. I am surprised that Microsoft hasn't
patched this file to do both types of reset for Windows XPe, because keyboard
controllers are obviously not needed for headless embedded systems. This
would be a very safe change (no security implications for example), and
wouldn't take significant time for MS to implement or test... but it's
probably wishful thinking.
 
XPe comes with a Power Management command line tool called XPEPM.EXE that
can perform shutdwon, restart, hibernate, and standby. Would this help?

Regards,

Sean Liming
www.sjjmicro.com / www.seanliming.com
XP Embedded Book Author - XP Embedded Advanced, XP Embedded Supplemental
Toolkit
 
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