GDB speed using Remote Serial Protocol

GDB speed using Remote Serial Protocol

[David Mc Kenna]

Hi all,

At present I have an outline for a stub ( GDB RSP -> uController -> Jtag ) for
an Arm7TDMi. I have successfully implemented the GDB -> uController side of
the equation. Here I have two questions.

Is there another way of seeing what GDB sends to the serial port without enabling
debug info within GDB ?, i.e. without using the commands :
"set debug remote 1" & " set debug serial 1"

My second questions relates to the first. With debug info switched on ( "set
debug remote 1" & " set debug serial 1"), a single step talks < 1 second to
complete, including all the debug info being written to the screen. Yet when
I switch off this info the single step time starts at < 1 second but soon mushrooms
to ~ 5 seconds.

I have tried this on gdb v5 and gdb v5.2.1 with the same results.
GDB configured as arm-elf


Any ideas??

Thanks,
Dave
--
http://www.iol.ie

Re: GDB speed using Remote Serial Protocol

[Daniel Jacobowitz]

On Mon, Dec 02, 2002 at 05:27:04PM +0000, David Mc Kenna wrote:
> Hi all,
> 
> At present I have an outline for a stub ( GDB RSP -> uController -> Jtag ) for
> an Arm7TDMi. I have successfully implemented the GDB -> uController side of
> the equation. Here I have two questions.
> 
> Is there another way of seeing what GDB sends to the serial port without enabling
> debug info within GDB ?, i.e. without using the commands :
> "set debug remote 1" & " set debug serial 1"
> 
> My second questions relates to the first. With debug info switched on ( "set
> debug remote 1" & " set debug serial 1"), a single step talks < 1 second to
> complete, including all the debug info being written to the screen. Yet when
> I switch off this info the single step time starts at < 1 second but soon mushrooms
> to ~ 5 seconds.
> 
> I have tried this on gdb v5 and gdb v5.2.1 with the same results.
> GDB configured as arm-elf
> 
> 
> Any ideas??

Sounds like something is being sent more quickly than your
stub/controller/whatever is ready to handle it.

What I recommend in this case is writing (or getting; rproxy may be
able to do this?) a stub which just connects a TCP port and a serial
port; forwards data from one to the other, and logs.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

Re: GDB speed using Remote Serial Protocol

[David Mc Kenna]

I would agree with this except that with debug info switched on it is much faster
than with it switched off. What is the difference in code execution within GDB
with debug info switched off?

Cheers,
Dave

>On Mon, Dec 02, 2002 at 05:27:04PM +0000, David Mc Kenna wrote:
>> Hi all,
>> 
>> At present I have an outline for a stub ( GDB RSP -> uController -> Jtag
) for
>> an Arm7TDMi. I have successfully implemented the GDB -> uController side
of
>> the equation. Here I have two questions.
>> 
>> Is there another way of seeing what GDB sends to the serial port without
enabling
>> debug info within GDB ?, i.e. without using the commands :
>> "set debug remote 1" & " set debug serial 1"
>> 
>> My second questions relates to the first. With debug info switched on ( "set

>> debug remote 1" & " set debug serial 1"), a single step talks < 1 second
to
>> complete, including all the debug info being written to the screen. Yet when

>> I switch off this info the single step time starts at < 1 second but soon
mushrooms
>> to ~ 5 seconds.
>> 
>> I have tried this on gdb v5 and gdb v5.2.1 with the same results.
>> GDB configured as arm-elf
>> 
>> 
>> Any ideas??
>
>Sounds like something is being sent more quickly than your
>stub/controller/whatever is ready to handle it.
>
>What I recommend in this case is writing (or getting; rproxy may be
>able to do this?) a stub which just connects a TCP port and a serial
>port; forwards data from one to the other, and logs.
>
>-- 
>Daniel Jacobowitz
>MontaVista Software                         Debian GNU/Linux Developer
>
>
--
http://www.iol.ie

Re: GDB speed using Remote Serial Protocol

[Daniel Jacobowitz]

No, you missed my gist.  With debug info printing, GDB takes a little
bit longer (because it has to do the printing).  Something is being
sent too quickly, and being dropped and then eventually retried.

On Mon, Dec 02, 2002 at 06:51:23PM +0000, David Mc Kenna wrote:
> I would agree with this except that with debug info switched on it is much faster
> than with it switched off. What is the difference in code execution within GDB
> with debug info switched off?
> 
> Cheers,
> Dave
> 
> >On Mon, Dec 02, 2002 at 05:27:04PM +0000, David Mc Kenna wrote:
> >> Hi all,
> >> 
> >> At present I have an outline for a stub ( GDB RSP -> uController -> Jtag
> ) for
> >> an Arm7TDMi. I have successfully implemented the GDB -> uController side
> of
> >> the equation. Here I have two questions.
> >> 
> >> Is there another way of seeing what GDB sends to the serial port without
> enabling
> >> debug info within GDB ?, i.e. without using the commands :
> >> "set debug remote 1" & " set debug serial 1"
> >> 
> >> My second questions relates to the first. With debug info switched on ( "set
> 
> >> debug remote 1" & " set debug serial 1"), a single step talks < 1 second
> to
> >> complete, including all the debug info being written to the screen. Yet when
> 
> >> I switch off this info the single step time starts at < 1 second but soon
> mushrooms
> >> to ~ 5 seconds.
> >> 
> >> I have tried this on gdb v5 and gdb v5.2.1 with the same results.
> >> GDB configured as arm-elf
> >> 
> >> 
> >> Any ideas??
> >
> >Sounds like something is being sent more quickly than your
> >stub/controller/whatever is ready to handle it.
> >
> >What I recommend in this case is writing (or getting; rproxy may be
> >able to do this?) a stub which just connects a TCP port and a serial
> >port; forwards data from one to the other, and logs.
> >
> >-- 
> >Daniel Jacobowitz
> >MontaVista Software                         Debian GNU/Linux Developer
> >
> >
> --
> http://www.iol.ie
> 

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer