[Ti] powerbook crashing [panic.log]

[Dr Trevor J. Hutley]

On 23 Mar 2006, at 03:03, Kynan Shook wrote:

> Well, in theory, they should all get logged, but I have seen them  
> get missed myself, and I'm not always sure why.
>
> In 10.2, when they changed from the behavior of dumping ugly text  
> all over your screen to putting up a multi-lingual message, they  
> redirected the text to the PRAM.  Then, the next time you reboot,  
> the OS sees that there is a panic log in the PRAM, and writes it to  
> disk.  It's done this way because writing to the PRAM is a more  
> basic access; once the kernel has panicked, there is no guarantee  
> that the OS is in a state where it would be possible to write to  
> the disk.

THANK YOU for this very clear explanation - unknown to me - about the  
mechanism of saving a panic log.
>
> There are two reasons why a panic won't be logged.  The first is if  
> you have turned on remote debugging in Open Firmware - this is used  
> by people who write kernel code.  Once the kernel panics, they can  
> use a second computer to tap into memory and the kernel and see  
> what went wrong.  You would almost certainly know if you had turned  
> this on.  If you think you might've turned it on, type "nvram boot- 
> args" on the command line; if it prints out just "boot-args", it's  
> off.

Just did that, and it is off.....
>
> The other time it won't save the panic log is if you reset PRAM.

almost never do that

> One could do this inadvertently by using the button on the back of  
> certain TiBooks, under the keyboard of others, or by pressing a  
> certain key combo.  To properly reboot a panicked Mac, you should  
> either press Command-Control-Power or hold down the power button  
> for several seconds.

that is what I do

> Also, I believe the information is only saved for 1 reboot, so if  
> you boot into Single User Mode

I think that is the explanation.  After a kernel panic, I typically  
boot in to single user mode and run fsck or applejack, in case the  
panic has damaged something.

Your very careful thinking and systematic analysis has explained why  
I have few panics logged, and I have understood quite a few new  
things about MacOS.
Thank you very much.

regards,  Trevor