GDB stubs question

GDB stubs question

[Lars Poeschel]

Hi!

I am trying to port eCos/Redboot to a new architecture. I am up to 
implementing GDB stubs now. Is there a list of functions which have to be 
implemented minimally ?
For the macros HAL_GET_GDB_REGISTERS() and HAL_SET_GDB_REGISTERS() the 
reference manual says they should translate between HAL_SavedRegisters and 
a "GDB array". Where do I know the layout of this "GDB array" from ?

Thanks,

Lars

Re: GDB stubs question

[Gary Thomas]

Lars Poeschel wrote:
> Hi!
> 
> I am trying to port eCos/Redboot to a new architecture. I am up to 
> implementing GDB stubs now. Is there a list of functions which have to be 
> implemented minimally ?
> For the macros HAL_GET_GDB_REGISTERS() and HAL_SET_GDB_REGISTERS() the 
> reference manual says they should translate between HAL_SavedRegisters and 
> a "GDB array". Where do I know the layout of this "GDB array" from ?

The GDB sources, I'm afraid.

What's the architecture?

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------

Re: GDB stubs question

[Lars Poeschel]

Am Dienstag, 6. Februar 2007 13:43 schrieb Gary Thomas:
> Lars Poeschel wrote:
> > Hi!
> >
> > I am trying to port eCos/Redboot to a new architecture. I am up to
> > implementing GDB stubs now. Is there a list of functions which have to be
> > implemented minimally ?
> > For the macros HAL_GET_GDB_REGISTERS() and HAL_SET_GDB_REGISTERS() the
> > reference manual says they should translate between HAL_SavedRegisters
> > and a "GDB array". Where do I know the layout of this "GDB array" from ?
>
> The GDB sources, I'm afraid.

Why afraid ?

I am not sure, because HAL_SavedRegisters is per thread structure and GDB 
seems to deal only with function call frames (struct frame_saved_regs). Is it 
the same for that case ?

> What's the architecture?

It is Fujitsu FR30.

Re: GDB stubs question

[Gary Thomas]

Lars Poeschel wrote:
> Am Dienstag, 6. Februar 2007 13:43 schrieb Gary Thomas:
>> Lars Poeschel wrote:
>>> Hi!
>>>
>>> I am trying to port eCos/Redboot to a new architecture. I am up to
>>> implementing GDB stubs now. Is there a list of functions which have to be
>>> implemented minimally ?
>>> For the macros HAL_GET_GDB_REGISTERS() and HAL_SET_GDB_REGISTERS() the
>>> reference manual says they should translate between HAL_SavedRegisters
>>> and a "GDB array". Where do I know the layout of this "GDB array" from ?
>> The GDB sources, I'm afraid.
> 
> Why afraid ?

Just because you have to go lumbering through the code to figure it out.

> 
> I am not sure, because HAL_SavedRegisters is per thread structure and GDB 
> seems to deal only with function call frames (struct frame_saved_regs). Is it 
> the same for that case ?

That's what the macros are for :-)  The CPU only understands CPU state (registers),
but this is duplicated across each thread in eCos.  The macros take the state of
the current thread/environment and put it into a form well known to GDB.  When
the thread is to be resumed, then GDB passes back the well formed state and the
macro needs to put that back into the appropriate thread information.

> 
>> What's the architecture?
> 
> It is Fujitsu FR30.

How different is it from the FRV400 (already in eCos)?  You
might get some pointers by looking at that HAL.

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------

Re: GDB stubs question

[Lars Poeschel]

> >> What's the architecture?
> >
> > It is Fujitsu FR30.
>
> How different is it from the FRV400 (already in eCos)?  You
> might get some pointers by looking at that HAL.

Unfortunately FR30 and FRV do not have too much in common, but looking at FRV 
eCos port at that point gives me a good idea how it works and how it should 
look like.

Re: GDB stubs question

[Lars Poeschel]

Am Dienstag, 6. Februar 2007 19:31 schrieb Mark Salter:
> On Tue, 2007-02-06 at 14:07 +0100, Lars Poeschel wrote:
> > It is Fujitsu FR30.
>
> That's a blast from the past. I wrote some gdb stub support for FR30
> back in 1998/99. Here are some sources you may find useful.

Thanks a lot!!
This is indeed very useful for me!

Lars