Re: NetBSD 7.0 i386 panic during boot

[Mayuresh <mayuresh%acm.org@localhost>]

On Tue, Oct 13, 2015 at 05:24:31PM +0530, Mayuresh wrote:
> On Sun, Oct 11, 2015 at 01:13:42PM -0400, Christos Zoulas wrote:
> > | > This looks like a NULL pointer dereference. Do you have a backtrace?
> > | 
> > | Unfortunately the keyboard stops working when db prompt appears. So cannot
> > | gather complete trace.
> > 
> > Compile a kernel with
> > options DDB_ONPANIC 2
> > (man 4 options)
> 
> Did just that, make depend and make. Copied the kernel to bootable USB and
> tried to boot from it. Get the panic error but not stack trace.

On a healthy system I tried triggering ddb with above kernel (with
DDB_ONPANIC set), with Ctrl-Alt-Esc. It did not print trace.

To cross check that the option is effective I did this:

$sysctl ddb.onpanic
ddb.onpanic = 2

Also commented out the following line in /etc/sysctl.conf as below to
ensure that it is not overriding the compiled option.
#ddb.onpanic?=1

So looks like my procedure was alright. Is there anything else needed to
make kernel print trace on entering ddb, when keyboard can't be used?

Mayuresh.