Solved (was: Brain storm: how do I debug this?)

[Shachar Shemesh]

On 19/03/11 14:42, Shachar Shemesh wrote:
>
> Now I'm stuck for idea as to what to try next. Anyone?
>
The problem turned out to be that the inittab was running everything it 
had to do, and was done. It closed the serial line (had several "getty" 
running on /dev/tty1 through /dev/tty6, for some reason), and that's it. 
It wasn't doing anything because it ran out of things to do. I removed 
the terminals from the non-existing virtual consoles, and added one for 
/dev/ttyS0, and the problem was resolved.

More importantly is how I figured it out. Once I realized that the 
kernel was running fine, I ran "strace -o log -p 1 -f" from single user 
mode, before letting it continue with the boot. This gave me a log of 
everything init and its derivatives was doing, which allowed me to debug 
what the system was doing. As usual, strace to the rescue.

The only mystery now left is why magic sysreq wasn't working merely 
because /dev/ttyS0 was closed. After all, console messages were still 
going there. Still, that's a mystery for another time. I'm off to play 
with my embedian system now....

Shachar

-- 
Shachar Shemesh
Lingnu Open Source Consulting Ltd.
http://www.lingnu.com

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