reliable debug output

reliable debug output

[Christian Widmer]

when debugging drivers using printk i've the problem that most often 
the msg passed to printk don't show up on the console since the machine 
crashed before. i also what to use my own ASSERT macros which halt the 
machine immediatly on an error. i could write some functions that write 
the debug string to the serial port but this is impractical since if've 
a cluster of pc and i can't connect them all to some serial lines for 
debugging. are there some functions which write directly into the graphic 
cards ram assuming that thy operate in console mode, no x-server running?
or is ther any other way to for reliable debug prints.

Re: reliable debug output

[Alan Cox]

> when debugging drivers using printk i've the problem that most often 
> the msg passed to printk don't show up on the console since the machine 
> crashed before. i also what to use my own ASSERT macros which halt the 

printk writes to the console synchronously unless you have configured
syslogk to process the messages and log them itself. You may want to boot
with syslogk disabled and see if that is your problem.

2.4 also supports serial console which can be useful when the box insists on
crashing in X11

Re: reliable debug output

[Christian Widmer]

do i need klogd?

On Wednesday 05 September 2001 13:50, Alan Cox wrote:
> > when debugging drivers using printk i've the problem that most often
> > the msg passed to printk don't show up on the console since the machine
> > crashed before. i also what to use my own ASSERT macros which halt the
>
> printk writes to the console synchronously unless you have configured
> syslogk to process the messages and log them itself. You may want to boot
> with syslogk disabled and see if that is your problem.
>
> 2.4 also supports serial console which can be useful when the box insists
> on crashing in X11