Re: early buf termination

Re: early buf termination

[Wenbo Yang]

s88 wrote:

>       I'm implementing a gdb stub for my ARM simulator with TCP connection.
> As I query the registers information from gdb, I got
> "fetch_register_using_p: early buf termination" msg.
> 
> (gdb) info registers
> r0             fetch_register_using_p: early buf termination
> (gdb)
> 
> the gdb client send the packet which contains "$p0#a0" to my gdb server.
> The gdb server reply 0 (should be $0#something) to the gdb client.

You can read remote.c:3419 for more information. I think the meaning is:
unexpected message end. It should be more characters but your message
terminated. You should give GDB the standard RSP response.

Regards,
Wenbo
-- 
Wenbo Yang

The State Key Lab. of Information Security
Graduate School of CAS, 19A Yuquan Road, Beijing, China
Homepage: http://solrex.cn

SimpLight Nanoelectronics Ltd. 6 Zhichun Road, 10th Floor, Beijing, China
Phone: +86-10-5126-6989   ---  Email: wenbo.yang@simplnano.com

Re: RSP handling

[Wenbo Yang]

> s88 wrote:
> 
 > but something is strange after the connection created. I set a
 > breakpoint in the main function (br main), but after the connection
 > created the gdb stop at the first instruction of crt0.S.
Is there anything wrong? Your stub gave GDB where the PC pointed to, and GDB 
printed it out with source code accordingly. You didn't start debugging, you 
were just attaching to the target. The PC you got should be the saved PC value 
while enter exception handler(stub). It has little meaning, you can go ahead by 
"continue".

Wenbo
-- 
Wenbo Yang

The State Key Lab. of Information Security
Graduate School of CAS, 19A Yuquan Road, Beijing, China
Homepage: http://solrex.cn

SimpLight Nanoelectronics Ltd. 6 Zhichun Road, 10th Floor, Beijing, China
Phone: +86-10-5126-6989   ---  Email: wenbo.yang@simplnano.com

Re: RSP handling

[Jim Blandy]

Wenbo Yang <wenbo.yang@simplnano.com> writes:
>> but something is strange after the connection created. I set a
>> breakpoint in the main function (br main), but after the connection
>> created the gdb stop at the first instruction of crt0.S.
> Is there anything wrong? Your stub gave GDB where the PC pointed to,
> and GDB printed it out with source code accordingly. You didn't start
> debugging, you were just attaching to the target. The PC you got
> should be the saved PC value while enter exception handler(stub). It
> has little meaning, you can go ahead by "continue".

Right.  When you connect to a target via the remote protocol, GDB
treats that as connecting to a program that's already running; it's
showing you the location where it's currently stopped.

early buf termination

[s88]

Hi all:
       I'm implementing a gdb stub for my ARM simulator with TCP connection.
As I query the registers information from gdb, I got
"fetch_register_using_p: early buf termination" msg.

(gdb) info registers
r0             fetch_register_using_p: early buf termination
(gdb)

the gdb client send the packet which contains "$p0#a0" to my gdb server.
The gdb server reply 0 (should be $0#something) to the gdb client.

Does anyone know the meaning of the "early buf termination"?

thanx!!

Dave.
-- 
System  on Chip Design  Lab.
Dept. of Computer Science and Information Engineering,
National Chung Cheng University
E-mail : s88.tw@acm.org

Re: early buf termination

[Daniel Jacobowitz]

On Mon, Jul 09, 2007 at 10:56:21AM +0800, s88 wrote:
> the gdb client send the packet which contains "$p0#a0" to my gdb server.
> The gdb server reply 0 (should be $0#something) to the gdb client.

"Each byte of data is described by two hex digits."  It's bytes of
data, not a number; you need the full width of the register.

-- 
Daniel Jacobowitz
CodeSourcery