On Nov 18, 2005, at 6:10 AM, Yogesh P wrote:
Firstly, I have set the open firmware flag to 0x4 and tried pressing
command and power button, but the machine gets into the
open firmware command displaying "Welcome to Open firmware" message.
Pressing control and power button has the same effect. I have a USB
keyboard with G4.
The Q&A doesn't say to use the command or control keys unless you're running a PowerBook or iBook. That's because those systems have different keyboard hardware.
If you shut the machine down and then power it up normally, do you still stop at the Open Firmware prompt? Have you intentionally set the Open Firmware auto-boot? configuration variable to FALSE so the machine will stop at Open Firmware each time it is powered on?
Here are the various functions of the power button depending on the state of the machine:
- If the system is powered off:
1. Pressing the power button will start the system.
- If the system is already running:
1. Holding the power button for five seconds will power off the system immediately (without saving anything to disk).
2. Pressing the power button briefly (shorter than five seconds!) will either put the system to sleep (if the debug=0x4 flag is not set) or generate a NMI (if the debug=0x4 flag is set).
Depending on the version of the OS and the other bits you set in the debug flags, you might not see any visible indication that the machine is stopped as a result of an NMI. I usually set the Date & Time system preference to show the seconds in the menu bar clock. That way it's easy to see if the machine is stopped because the time shown by the menu bar clock will stop updating.
So the idea is to get the target machine running with the debug flags set, then press the power button briefly, then attach from the development machine.
I hope this is clearer.
--gc