Re: Issues using KGDB on a Linux machine to debug NetBSD

[<Paul_Koning%Dell.com@localhost>]

On Jun 8, 2012, at 4:53 PM, Israel Jacquez wrote:

> On Fri, Jun 8, 2012 at 1:46 PM,  <Paul_Koning%dell.com@localhost> wrote:
>> 
>> On Jun 8, 2012, at 4:35 PM, Israel Jacquez wrote:
>> 
>>> Hello,
>>> 
>>> I'll make this short. I can't seem to get debugging support working
>>> even when following the guide:
>>> <http://www.netbsd.org/docs/kernel/kgdb.html>.
>>> ...
>>> Immediately, I get dropped into DDB. I can only see this through the
>>> serial console as the target machine is running headless. After, I
>>> invoke i486--netbsd-gdb that (should) read .gdbinit:
>>> file sys/arch/i386/compile/obj/GENERIC-DEBUG/netbsd.gdb
>>> set remote interrupt-sequence Ctrl-C
>>> set remotebaud 115200
>>> target remote /dev/ttyUSB0
>>> 
>>> After in GDB, all I see is:
>>> warning: unrecognized item "qSupported:xm" in "qSupported" response
>>> Ignoring packet error, continuing...
>>> Ignoring packet error, continuing...
>>> ...
>>> 
>>> Any help? Tips?
>> 
>> To see exactly what's going on, use the gdb command "set debug remote 1" 
>> before the "target remote" command.  That will show the dialog between gdb 
>> and the system being debugged.
>> 
>> It looks like the system is sendng something that your gdb doesn't 
>> understand.  Perhaps it's too old; what version are you using?
> 
> The version that was built (i486--netbsd-gdb) is GNU gdb (GDB) 7.3.1.
> 
> I'll try again. Here is the output. (/boot.cfg is set to automatically
> "boot netbsd -d"):
> 
> GNU gdb (GDB) 7.3.1
> Copyright (C) 2011 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "--host=x86_64-unknown-linux-gnu
> --target=i486--netbsdelf".
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>.
> Sending packet: :xmlRegisters=i386;qRelocInsn+#25...Sending packet:
> :xmlRegisters=i386;qRelocInsn+#25...putpkt: Junk:
>>> NetBSD/x86 BIOS Boot, Revision 5.2 (from NetBSD 5.1.2)
>>> Memory: 638/1037184 k ...

It looks like you connected while the boot output was still coming out.  Gdb 
doesn't seem to like that very much at all.  I have a modified gdb that treats 
anything unrecognized as "console output" but without that change, you're going 
to have problems if your target mixes program output with gdb protocol data.

        paul