Re: Facing a malformed packet error using Insight debugger

[Keith Seitz <keiths@redhat.com>]

Insightuser wrote:
> Hi,
> I am using insight to debug my target mips2.
> If I use the command line debugger provided by montavista, after connecting
> to my target , the resposne is 
> 
> (gdb) set solib-absolute-prefix .
> (gdb) target remote 192.168.12.162:1000
> Remote debugging using 192.168.12.162:1000
> 0x2aaa8830 in __start () from ./lib/ld.so.1
> (gdb) c
> 
> and this works fine.

You left off the version information -- what does "show version" say?


> GNU gdb 6.6
> Copyright (C) 2006 Free Software Foundation, Inc.

Wow, that is one old debugger!! I really suggest you try at least 6.8. 
Even better: use a snapshot. Insight and gdb are always kept in a usable 
state. I only ever use CVS HEAD for my daily work.

> [New Thread 240]
> warning: Invalid remote reply: nf1
> Malformed packet(b) (missing colon): 25:bcc9d62a;1d:f8aa9c7f;thread:f0;
> Packet: 'TR242;25:bcc9d62a;1d:f8aa9c7f;thread:f0;'

I'm long out of practice with the remote protocol, but this packet does 
look malformed. According to GDB's remote.c and the documentation, the 
proper reply packet starting with 'T' should be 
"TssN1:R1;N2:R2;...;Nn:Rn". ss = Signal number; N1..Nn = register 
numbers; R1..Rn = register values. I have no idea what "nf1" could 
possibly be.

According to remote_parse_stop_reply in remote.c, the code skips the 
first three bytes of the packet, parsers the next two bytes as a 
register number and looks for the colon that separates this number from 
the value. It doesn't find the colon, and the error above is emitted.

As far as I can tell, gdb/insight are working as designed. [But again, 
let me warn you that I am no pro at the remote protocol.] Are you 
perhaps using some sort of custom Monta Vista extension to the remote 
protocol?

You might have better luck with this question if you email the gdb 
mailing list; that is where the experts hang out, many of them from 
Monta Vista.

Keith