Date: Fri, 14 Mar 1997 15:08:47 -0700 (MST) From: Nate Williams <nate@mt.sri.com> To: Bakul Shah <bakul@torrentnet.com> Cc: hackers@freebsd.org Subject: Re: kernel remote debugging using gdb Message-ID: <199703142208.PAA07831@rocky.mt.sri.com> In-Reply-To: <199703142053.PAA00554@chai.plexuscom.com> References: <199703142053.PAA00554@chai.plexuscom.com>
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> What I did: > > - recompiled the boot program to always use COM1 as console and > installed it on the primary disk on the test machine (called TEST). > > - used the following options in the TEST config file: > options COMCONSOLE You don't need COMCONSOLE for this to work, as a matter of fact you really don't want it due to the problems you've outlined below. > There are two problems: > > - Sendind a break in multiuser mode (before or after attaching gdb) > does not seem to drop the kernel in the debugger. This seems to > work occasionally but I haven't as yet figured out under what > conditions. I suspect the break is lost. If you aren't using the COMCONSOLE, do it on the real console. > - In single user mode when gdb is attached, you can not type anything > on the console nor can you see any printf() output[1]. That's because trying to MUX the gdb connection and the console is not a good idea. Serial debugging should not be attempted for remote connections simply because you can hang yourself. Nate
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