From owner-freebsd-hackers Mon Aug 30 12: 0:43 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from bingnet2.cc.binghamton.edu (bingnet2.cc.binghamton.edu [128.226.1.18]) by hub.freebsd.org (Postfix) with ESMTP id 39865152A6 for ; Mon, 30 Aug 1999 12:00:40 -0700 (PDT) (envelope-from zzhang@cs.binghamton.edu) Received: from sol.cs.binghamton.edu (cs1-gw.cs.binghamton.edu [128.226.171.72]) by bingnet2.cc.binghamton.edu (8.9.3/8.9.3) with SMTP id PAA21384 for ; Mon, 30 Aug 1999 15:00:39 -0400 (EDT) Date: Mon, 30 Aug 1999 14:47:03 -0400 (EDT) From: Zhihui Zhang To: freebsd-hackers@FreeBSD.ORG Subject: Re: Help with remote debugging (gdb -k) In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Mon, 30 Aug 1999, Zhihui Zhang wrote: > > After reading the handbook and some postings in the mailing list archive. > I still can not make remote debugging work. I basically did the following > on FreeBSD-current 4.0 (A is debugging machine, B is the target): > > (1) Build a debug kernel (options DDB and BREAK_TO_DEBUGGER) on box A. > The sio flag I used is 0x90 (I also tried 0x80). Ftp the file /kernel to > box B and renamed as /kernel.A > > (2) Boot the kernel /kernel.A on box B with -d option: > > >>FreeBSD/i386 boot > Default: 0:wd(0,a)/boot/loader > boot: /kernel.A -d > Debugger("Boot flags requested debugger") > Stopped at 0xc0252c27: movl $0, 0xc031ed98 > db> gdb > Next trap will enter GDB remote protocol mode > db> s > > (3) On machine A, go to the compile directory: > > #gdb -g kernel.debug > > (kgdb) target remote /dev/cuaa0 > > Remote debugging using /dev/cuaa0 > Ignoring packet error, continuing... > Ignoring packet error, continuing... > Couldn't establish connection to remote target > Malformed response to offset query, timeout > > The serial cable is null-modem and has been tested with kermit. It is > connected to /dev/ttyd0 (com 1) of machine B and com 2 of machine A. > > I did not do "strip -x" because I assume this is done by FreeBSD 4.0 > automatically and the file debug.kernel is the one with symbols. > > Any help is appreciated. > I have just found the reason. I should specify the local serial port of the debugging machine. So I should use: (kgdb) target remote /dev/cuaa1 <-- do not use /dev/cuaa0 Now everything works fine. -Zhihui To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message