Re: [Kgdb-bugreport] [PATCH] Kill kgdb_serial

[George Anzinger <george@mvista.com>]

Tom Rini wrote:
> On Tue, Mar 02, 2004 at 04:36:11PM -0800, George Anzinger wrote:
> 
>>Tom Rini wrote:
>>
>>>Regardless, it's not that we offer (nor does the -mm version, from what
>>>I read of it) eth or serial at any point, it simply allows for serial to
>>>be used and a switchover to eth.  And if kgdb is attached at the time,
>>>it's a 'fun' gdb session (or at least is was when I was trying it out in
>>>-mm and then in my own version).
>>
>>I am not really suggesting a live switch capability, more like something 
>>that is set a boot time.
> 
> 
> That's still not, AFAICT, what's offered in -mm or kgdb.sf.net.
> 
> 
>>>The real problem is that you start getting quite complex when you allow
>>>for a system to be kgdb eth, or 8250, or some arch serial driver, or
>>>some other I/O driver, and so on.  PPC has 3, and I don't see it getting
>>>smaller from there.
>>
>>I had imagined that it would be rather like a file system.  The stub would 
>>pass (or it could be a global if you prefer) the index to use into an array 
>>of interface structures.  Something like:
>>
>>struct kgdb_interface {
>>	void (*kgdb_in)(*char)
>>	:
>>	:
>>}
>>
>>struct kgdb_interface kgdb_io_array[N];
> 
> 
> And how do you pick a default?

A config option.
> 
> 
>>>And with both of those points, I don't think it's worth the trouble that
>>>point 2 is, given the limitations of point 1.
>>
>>I imagine that I would like this.  I would use the eth interface until 
>>required to use the serial.  I would rather not have to rebuild the kernel 
>>to do this....
> 
> 
> Then you're talking about live switching again, or some sort of control
> from userland.
> 

No, I would still choose this at boot time, it is just that I have to reboot the 
same kernel, not a new one.  It would be frozen once kgdb sees the command line. 
  Prior to that it would be the default chosen at config time.

-- 
George Anzinger   george@mvista.com
High-res-timers:  http://sourceforge.net/projects/high-res-timers/
Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml