TRACE implementation

TRACE implementation

[sumanth]

Hi,
       I am trying to implement trace in my port. Can anyone point me 
where in
       gdb source I can refer to? Any helpful documents.

       Once my trace is implemented , I have data in trace buffer. How 
can I convert the data
       from trace buffer and display it to user. Heard there are 3rd 
party tools which comes in handy .
       If any , please mail me. (preferably some gdb gui).

PS: I am novice in gdb implementation .

Thanks,
Sumanth G

Re: TRACE implementation

[Michael Snyder]

sumanth wrote:
> Hi,
>        I am trying to implement trace in my port. Can anyone point me 
> where in
>        gdb source I can refer to? Any helpful documents.

What do you mean by "trace"?

Have you looked at gdb tracepoints?  Is this close to what
you are looking for?  See the url:
http://sourceware.org/gdb/current/onlinedocs/gdb_14.html#SEC95


> 
>        Once my trace is implemented , I have data in trace buffer. How 
> can I convert the data
>        from trace buffer and display it to user. Heard there are 3rd 
> party tools which comes in handy .

If you are talking about tracepoints (see above), and if
you can make your trace buffer talk to gdb according to the
published API, you can use gdb to display your trace results.

If not, you need to tell us more about what you're trying to do.


>        If any , please mail me. (preferably some gdb gui).
> 
> PS: I am novice in gdb implementation .
> 
> Thanks,
> Sumanth G
> 

Re: TRACE implementation

[sumanth]

Hi ,

       I am talking about "gdb tracepoints" only. I am asking for "How 
can I implement them in GDB ?"
       means, where I can start with. Heard something about remote stubs 
.....

       Michael , Can you be a bit more brief on "published API" which 
you mentioned in your last response.

Thanks,
Sumanth G

Michael Snyder wrote:
> sumanth wrote:
>> Hi,
>>        I am trying to implement trace in my port. Can anyone point me 
>> where in
>>        gdb source I can refer to? Any helpful documents.
>
> What do you mean by "trace"?
>
> Have you looked at gdb tracepoints?  Is this close to what
> you are looking for?  See the url:
> http://sourceware.org/gdb/current/onlinedocs/gdb_14.html#SEC95
>
>
>>
>>        Once my trace is implemented , I have data in trace buffer. 
>> How can I convert the data
>>        from trace buffer and display it to user. Heard there are 3rd 
>> party tools which comes in handy .
>
> If you are talking about tracepoints (see above), and if
> you can make your trace buffer talk to gdb according to the
> published API, you can use gdb to display your trace results.
>
> If not, you need to tell us more about what you're trying to do.
>
>
>>        If any , please mail me. (preferably some gdb gui).
>>
>> PS: I am novice in gdb implementation .
>>
>> Thanks,
>> Sumanth G
>>
>
>
>

Re: TRACE implementation

[Michael Snyder]

sumanth wrote:
> Hi ,
> 
>        I am talking about "gdb tracepoints" only. I am asking for "How 
> can I implement them in GDB ?"

Great.  Thanks for the clarification.
Partial answer: you don't have to implement them in gdb.
They're already implemented in gdb.

>        means, where I can start with. Heard something about remote stubs 

Yes, that's correct.  GDB already knows how to tell a stub
to collect trace data.  You need to implement a stub that
understands the trace commands that gdb will send to it.

>        Michael , Can you be a bit more brief on "published API" which 
> you mentioned in your last response.

Sure.  First, if you haven't seen this already, you probably
want to look at it: http://sourceware.org/gdb/talks/esc-west-1999
There is a white paper, a slide presentation, and other documents.
It's all old, but not obsolete, since very little additional
development has been done since then.

Second, the remote protocol messages that your stub will
need to implement are specified here:

http://sourceware.org/gdb/current/onlinedocs/gdb_37.html#SEC683

I should let you know that some folks at Code Sourcery have
recently been doing some work with tracepoints.  If you were
interested in hiring someone to do the work for you on contract,
either I or one of the other maintainers could probably put you
in contact with someone privately.

Good luck,
Michael

Re: TRACE implementation

[Nicholas Mc Guire]

On Wed, 21 Oct 2009, Michael Snyder wrote:

> sumanth wrote:
>> Hi ,
>>
>>        I am talking about "gdb tracepoints" only. I am asking for "How  
>> can I implement them in GDB ?"
>
> Great.  Thanks for the clarification.
> Partial answer: you don't have to implement them in gdb.
> They're already implemented in gdb.
>
>>        means, where I can start with. Heard something about remote 
>> stubs 
>
> Yes, that's correct.  GDB already knows how to tell a stub
> to collect trace data.  You need to implement a stub that
> understands the trace commands that gdb will send to it.

One implementation for GDB 6.3-6.6 is available at

ftp://dslab.lzu.edu.cn/pub/gdb_tracepoints

this is the stubs in gdbserver and a few (bug)fixes in the core
gdb routines that were needed.

thx!
hofrat

Re: TRACE implementation

[sumanth]

Hi Michael,
                    Very pleased with the information you provided. 
Still I have certain doubts in mind.
                    Tracepoints can b implemented through either remote 
stubs or gdbserver or gdb agents (byte-coding).
                     Is this 
true?..................................................
                     which can be best suited to me as I am accessing my 
fpga/processor through a parallel port jtag. I dont want to
                    burden my processor by running a server on it.
                    The problem here , I googled in net and I didn't 
even find a single prototype to have a fell of how to trace data(trace 
points)  on my target .

Thanks,
Sumanth G                           

Michael Snyder wrote:
> sumanth wrote:
>> Hi ,
>>
>>        I am talking about "gdb tracepoints" only. I am asking for 
>> "How can I implement them in GDB ?"
>
> Great.  Thanks for the clarification.
> Partial answer: you don't have to implement them in gdb.
> They're already implemented in gdb.
>
>>        means, where I can start with. Heard something about remote stubs 
>
> Yes, that's correct.  GDB already knows how to tell a stub
> to collect trace data.  You need to implement a stub that
> understands the trace commands that gdb will send to it.
>
>>        Michael , Can you be a bit more brief on "published API" which 
>> you mentioned in your last response.
>
> Sure.  First, if you haven't seen this already, you probably
> want to look at it: http://sourceware.org/gdb/talks/esc-west-1999
> There is a white paper, a slide presentation, and other documents.
> It's all old, but not obsolete, since very little additional
> development has been done since then.
>
> Second, the remote protocol messages that your stub will
> need to implement are specified here:
>
> http://sourceware.org/gdb/current/onlinedocs/gdb_37.html#SEC683
>
> I should let you know that some folks at Code Sourcery have
> recently been doing some work with tracepoints.  If you were
> interested in hiring someone to do the work for you on contract,
> either I or one of the other maintainers could probably put you
> in contact with someone privately.
>
> Good luck,
> Michael
>
>
>
>

Re: TRACE implementation

[Michael Snyder]

sumanth wrote:
> Hi Michael,
>                     Very pleased with the information you provided. 
> Still I have certain doubts in mind.
>                     Tracepoints can b implemented through either remote 
> stubs or gdbserver or gdb agents (byte-coding).
>                      Is this 
> true?..................................................
>                      which can be best suited to me as I am accessing my 
> fpga/processor through a parallel port jtag. I dont want to
>                     burden my processor by running a server on it.
>                     The problem here , I googled in net and I didn't 
> even find a single prototype to have a fell of how to trace data(trace 
> points)  on my target .

Sumanth,

How does gdb talk to your jtag device?  Is it
a) directly to the parallel port, or
b) through a serial connection to an agent that controls the parallel port?

If b, and if using the gdb remote serial protocol, then there's your
agent into which you can add the tracepoint smarts.

Michael

Re: TRACE implementation

[sumanth]

Hi Michael,
                   My gdb talk to jtag device  directly through parallel 
port.  There is no agent and no serial
                   protocol implemented in mine. So, challenge now is, 
how can I proceed in order to achieve
                   the task ( enabling trace point data collection  
feature in my toolchain's debugger)
Your response is deeply appreciated.

Thanks in advance,
sumanth G

   
Michael Snyder wrote:
> sumanth wrote:
>> Hi Michael,
>>                     Very pleased with the information you provided. 
>> Still I have certain doubts in mind.
>>                     Tracepoints can b implemented through either 
>> remote stubs or gdbserver or gdb agents (byte-coding).
>>                      Is this 
>> true?..................................................
>>                      which can be best suited to me as I am accessing 
>> my fpga/processor through a parallel port jtag. I dont want to
>>                     burden my processor by running a server on it.
>>                     The problem here , I googled in net and I didn't 
>> even find a single prototype to have a fell of how to trace 
>> data(trace points)  on my target .
>
> Sumanth,
>
> How does gdb talk to your jtag device?  Is it
> a) directly to the parallel port, or
> b) through a serial connection to an agent that controls the parallel 
> port?
>
> If b, and if using the gdb remote serial protocol, then there's your
> agent into which you can add the tracepoint smarts.
>
> Michael
>
>
>

RE: TRACE implementation

[Dominique Toupin]

You should see a reference implementation of GDB tracepoint for Linux (both in-process and with gdbserver) just in time for Christmas. The Eclipse CDT integration should also be available for Christmas. For CDT you will see the info just like a live debug session. In 2010 you should also see the integration with the Eclipse tracing framework in the Linux Tools project i.e. the GDB tracepoint can be merged with LTTng traces.

 
> -----Original Message-----
> From: gdb-owner@sourceware.org 
> [mailto:gdb-owner@sourceware.org] On Behalf Of sumanth
> Sent: Wednesday, October 21, 2009 1:07 AM
> To: Michael Snyder
> Cc: gdb
> Subject: Re: TRACE implementation
> 
> Hi ,
> 
>        I am talking about "gdb tracepoints" only. I am asking 
> for "How can I implement them in GDB ?"
>        means, where I can start with. Heard something about 
> remote stubs .....
> 
>        Michael , Can you be a bit more brief on "published 
> API" which you mentioned in your last response.
> 
> Thanks,
> Sumanth G
> 
> Michael Snyder wrote:
> > sumanth wrote:
> >> Hi,
> >>        I am trying to implement trace in my port. Can 
> anyone point me 
> >> where in
> >>        gdb source I can refer to? Any helpful documents.
> >
> > What do you mean by "trace"?
> >
> > Have you looked at gdb tracepoints?  Is this close to what you are 
> > looking for?  See the url:
> > http://sourceware.org/gdb/current/onlinedocs/gdb_14.html#SEC95
> >
> >
> >>
> >>        Once my trace is implemented , I have data in trace buffer. 
> >> How can I convert the data
> >>        from trace buffer and display it to user. Heard 
> there are 3rd 
> >> party tools which comes in handy .
> >
> > If you are talking about tracepoints (see above), and if 
> you can make 
> > your trace buffer talk to gdb according to the published 
> API, you can 
> > use gdb to display your trace results.
> >
> > If not, you need to tell us more about what you're trying to do.
> >
> >
> >>        If any , please mail me. (preferably some gdb gui).
> >>
> >> PS: I am novice in gdb implementation .
> >>
> >> Thanks,
> >> Sumanth G
> >>
> >
> >
> >
> 
> 
>