remote serial protocol

remote serial protocol

[Raja Saleru]

Dear all,



I have a question related remote serial protocol used in gdb and gdbserver
communication.

The command

                            Read Registers (g)

                            Ex:

                                          [gdb]  $g#67

                                          [target]
+0123456789abcdef0123456789..#xx



issued by gdb to request the values of all target registers. The target
replies with a single message containing ordered register values packed
end-to-end.



I wanted to know the ordering of the registers. Where it is documented?

Re: Remote Serial Protocol

[Andrew Cagney]

> Thanks for the quick reply,
> 
> Where are the macros for REGISTER_RAW_SIZE and REGISTER_NAME located ?


Either gdb/config/xyz/tm-xyz.h (legacy architectures) or gdb/xyz-tdep.c. 
  In the latter case they are functions (xyz_register_raw_size et.al.).

The dependence on those internal methods is acknowledged as a bug.

enjoy,
Andrew

Re: Remote Serial Protocol

[David Mc Kenna]

Thanks for the quick reply,

Where are the macros for REGISTER_RAW_SIZE and REGISTER_NAME located ?

Thanks,
Dave McKenna
>The answer used to be in remote.c but now its at the end of the
>documentation:
>read registers g 
>Read general registers. 
>reply XX... 
>Each byte of register data is described by two hex digits. The bytes with 

>the register are transmitted in target byte order. The size of each register

>and their position within the `g' packet are determined by the GDB 
>internal macros REGISTER_RAW_SIZE and REGISTER_NAME macros. 
>
>For instance, if your target had 4 32bit registers (for simplicity) and all
the 
>values were 0xdeadbeef, then the string your target would send back would
>look like:
>deadbeefdeadbeefdeadbeefdeadbeef
>
>(With all the packet info stripped off.)
>
>Tim.Combs@motorola.com
>
>On Wed, Jan 23, 2002 at 01:18:49PM +0000, David Mc Kenna wrote:
>> A question about the Remote Serial Protocol
>> 
>> When gdb issues the command : "+$g#67" , which reads the general registers,

>> what is the format of the expected return.
>> 
>> 
>> Debugging with gdb gives a vague reference but no solid info.
>> 
>> Thanks,
>> Dave Mc Kenna
>> 
>> 
>> 
>> 
>> --
>> http://www.iol.ie
>
>


--
http://www.iol.ie

Re: Remote Serial Protocol

[Tim Combs]

The answer used to be in remote.c but now its at the end of the
documentation:
read registers g 
Read general registers. 
reply XX... 
Each byte of register data is described by two hex digits. The bytes with 
the register are transmitted in target byte order. The size of each register 
and their position within the `g' packet are determined by the GDB 
internal macros REGISTER_RAW_SIZE and REGISTER_NAME macros. 

For instance, if your target had 4 32bit registers (for simplicity) and all the 
values were 0xdeadbeef, then the string your target would send back would
look like:
deadbeefdeadbeefdeadbeefdeadbeef

(With all the packet info stripped off.)

Tim.Combs@motorola.com

On Wed, Jan 23, 2002 at 01:18:49PM +0000, David Mc Kenna wrote:
> A question about the Remote Serial Protocol
> 
> When gdb issues the command : "+$g#67" , which reads the general registers,
> what is the format of the expected return.
> 
> 
> Debugging with gdb gives a vague reference but no solid info.
> 
> Thanks,
> Dave Mc Kenna
> 
> 
> 
> 
> --
> http://www.iol.ie

Remote Serial Protocol

[David Mc Kenna]

A question about the Remote Serial Protocol

When gdb issues the command : "+$g#67" , which reads the general registers,
what is the format of the expected return.


Debugging with gdb gives a vague reference but no solid info.

Thanks,
Dave Mc Kenna




--
http://www.iol.ie