GDB protocol

Fernando Nasser fnasser@cygnus.com
Fri Jul 28 10:30:00 GMT 2000


What is the address of _start?  I believe is 20000, isn't it?
Your program stopped at 20008 and it executed something that 
caused a trace interrupt but as gdb has inserted the two breakpoints
elsewhere you get the SIGTRAP message.

Problems like this can be better debugged using the command line interface.
Use "gdb -nw" to get into command mode.

Before you enter "cont", disassemble a bunch of instructions from 20000 on.

F.


Gerwyn Davies wrote:
> 
> Does anyone know the GDB protocol?
> 
> I'm using Insight and gdb ver GNU gdb 4.17-gnupro-98r2, runing the Mips-elf
> toolset.
> I dont seem to be able execute any code on the target. I'm able to acess the
> targets memory and registers, without any problem.
> 
> Here's what I am doing:-
> 
> File->Open,
> Run->Download
> Run->Run
> 
> Insight then returns and locates to my __start lable. I then click on
> Continue, and get this trace:-
> 
> Continuing.
> Sending packet: $ma002015c,4#b9...Ack
> Packet received: 0005000d
> Sending packet: $Ma002015c,4:0005000d#8c...Ack
> Packet received: OK
> Sending packet: $ma0020df8,4#f2...Ack
> Packet received: 0005000d
> Sending packet: $Ma0020df8,4:0005000d#c5...Ack
> Packet received: OK
> Sending packet: $c#63...Ack
> Packet received: T0525:a0020008;1d:80007fe8;
> 
> Program received signal SIGTRAP, Trace/breakpoint trap.
> Sending packet: $g#67...Ack
> Packet received:
> 00000000b4020000bfc040d8bfc040a0fffffeff80000100800005008<snip>
> Sending packet: $ma0020004,4#84...Ack
> Packet received: 00000000
> Sending packet: $Ma002015c,4:0005000d#8c...Ack
> Packet received: OK
> Sending packet: $Ma0020df8,4:0005000d#c5...Ack
> Packet received: OK
> 0xa0020008 in _start () at crt0.S:59
> 
> What happens is that Insight returns to the same point in the code, which
> looks as if the Continue was ignored.
> If I could understand the trace I may get some clue to what is going wrong.
> 
> Can anyone help me?
> 
> Thanks
> 
> Gerwyn

-- 
Fernando Nasser
Red Hat - Toronto                       E-Mail:  fnasser@cygnus.com
2323 Yonge Street, Suite #300           Tel:  416-482-2661 ext. 311
Toronto, Ontario   M4P 2C9              Fax:  416-482-6299


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