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Date: Fri, 5 May 1995 23:48:50 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199505051348.XAA23370@godzilla.zeta.org.au>
To: freebsd-bugs@FreeBSD.org, sung!imdave@iwcs.att.com
Subject: Re: sio bug in april snap
Sender: bugs-owner@FreeBSD.org
Precedence: bulk

>I am attempting to get remote login over a modem working and
>although the modem connects and I do get the login prompt,
>tons of garbage start spewing out which is echoed back to the
>freebsd machine which sees it and of course says "illegal
>login" (although its real difficult to see this amongst the
>spewing garbage.)  I don't know if this is a problem

Probably the line speed is wrong.

>Running April SNAP, compiled kernel with "-O -m486" flags,
>using gettytab "std.38400".  /etc/ttys is unchanged except
>for enabling the getty on /dev/ttyd0 and using std.38400.

This should give 38400.  Is that what you want?

>ie.  stty </dev/ttyid1 clocal -hupcl 1200

>causes:

>fatal trap 12: page fault in kernel mode

This was broken the day before the SNAP and fixed the day after.

>BYW, how the *@# can I get a disassembly to see where the
>failing instruction is?  I tried gdb /kernel, but gdb couldn't
>find "debugging symbols".  I couldn't find any disassembler

`gdb -k /kernel /dev/mem' is the best available if you don't have ddb
compiled into the kernel.  gdb has been able to disassemble files with
only non-debugging symbols for some time.  However, symbol lookup for
disassembly seems to be broken.  `disass mi_switch' gives "No function
contains specified address".  `disass 0xf0115c20 0xf0115cff' works.  It
even finds mi_switch!?

I normally use the kernel debugger.

>program -- is there none?  Also, no crash program.  Finally,

`gdb -k /var/crash/kernelname /var/crash/corename' sort of works, as
above, on crash dumps even when the kernel isn't compiled with -g.

See also kernel-debug.FAQ.

Bruce