Date: Wed, 8 Oct 2008 21:43:38 -0700 From: "alan yang" <alancyang@gmail.com> To: "Julian Elischer" <julian@elischer.org> Cc: freebsd-questions@freebsd.org Subject: Re: kgdb debugging Message-ID: <290865fd0810082143l46796079mfe2c6adeed4656b0@mail.gmail.com> In-Reply-To: <48EBA6F2.2090606@elischer.org> References: <290865fd0810061544ubbe92fdsf75501bb729da3f0@mail.gmail.com> <48EA9E95.80105@FreeBSD.org> <290865fd0810061712sfdf5a0p4d3954773ee27a3d@mail.gmail.com> <290865fd0810071053k6da13d96j391ade1a30599fa1@mail.gmail.com> <48EBA6F2.2090606@elischer.org>
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thank you all, device.hints solved it! On Tue, Oct 7, 2008 at 11:14 AM, Julian Elischer <julian@elischer.org> wrote: > alan yang wrote: >> >> Could people shed some light how to get remote debugging going, must >> be something that i overlooked, really appreciate. >> >> Two FreeBSD7 systems, target and development, connected with null >> modem cable on each's COM1. >> >> step 1) >> - rebuild kernel with following options: >> options DDB >> options KDB >> options GDB >> >> makeoptions DEBUG=-g > > add hints.dev.uart.0.flags=0xc0 > (or whatever it is) (see man uart or man sio) > to /boot/device.hints > >> >> step 2) >> - from development system >> cd to /usr/src/sys/i386/comiple/MYKERNEL >> kgdb -r /dev/cuad0 kernel.debug >> >> it displays the following: >> Switching to remote protocol >> Ignoring packet error, continuing >> ......... >> Couldn't establish connection to remote target >> Malformed response to offset query, timeout >> >> step 3) >> - from targetsystem: >> 1. Ctrl + Alt + Esc to go into db >> 2. from db> type gdb >> 3. it displays: "The remote GDB backend could not be >> selected" >> >> >> >> On Mon, Oct 6, 2008 at 5:12 PM, alan yang <alancyang@gmail.com> wrote: >>> >>> the problem is, when entering gdb from db as described in the following: >>> -- >>> Enter ing gdb from ddb >>> In FreeBSD you can build a kernel with support for both ddb and gdb. >>> You can then >>> change backwards and forwards between them. For example, if you're in >>> ddb, you can >>> go to gdb like this: >>> db> gdb >>> Next trap will enter GDB remote protocol mode >>> db> si step a single instruction to reenter ddb >>> -- >>> after typing gdb command, it says: "The remote GDB backend could not >>> be selected" >>> that i am not sure what this indicates; looking at subr_kdb.c, wonder >>> maybe kdb_dbbe_set is not set? seems kdb_dbbe_set is not referenced >>> anywhere, not sure how to get it right. >>> >>> thanks for shed some light ... >>> >>> On Mon, Oct 6, 2008 at 4:26 PM, Pietro Cerutti <gahr@freebsd.org> wrote: >>>> >>>> -----BEGIN PGP SIGNED MESSAGE----- >>>> Hash: SHA512 >>>> >>>> alan yang wrote: >>>> | hi, there, >>>> | >>>> | wonder people can shed some lights on remote debugging. i have >>>> | freebsd7 configured with option DDB / KDB / GDB but after entering the >>>> | db on the target system the command gdb gives "the remote GDB backend >>>> | could not be selected". >>>> | >>>> | i browsed through the mailing list, and do find 1 similar post but >>>> | without answer. >>>> | >>>> | thanks in advance & apology if i overlooked things ... >>>> >>>> I suggest the following tutorial: >>>> http://www.lemis.com/grog/Papers/Debug-tutorial/tutorial.pdf >>>> >>>> Have fun :) >>>> >>>> | >>>> | cheers, >>>> | alan >>>> | _______________________________________________ >>>> | freebsd-hackers@freebsd.org mailing list >>>> | http://lists.freebsd.org/mailman/listinfo/freebsd-hackers >>>> | To unsubscribe, send any mail to >>>> "freebsd-hackers-unsubscribe@freebsd.org" >>>> >>>> >>>> - -- >>>> Pietro Cerutti >>>> gahr@FreeBSD.org >>>> >>>> PGP Public Key: >>>> http://gahr.ch/pgp >>>> >>>> -----BEGIN PGP SIGNATURE----- >>>> Version: GnuPG v2.0.9 (FreeBSD) >>>> >>>> iEYEAREKAAYFAkjqnpQACgkQwMJqmJVx945RSwCgoDb0JTr8LSFDB1vpAbGUjb76 >>>> ZH0An19HpFVJJTUB5/XnyZc0pIDzgxc3 >>>> =6Pdm >>>> -----END PGP SIGNATURE----- >>>> >> _______________________________________________ >> freebsd-hackers@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-hackers >> To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org" > >
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