I have chosen the first option to implement the syscall.  I have included a 
patch here regarding this mechanism.

Ok to commit?

-- Jeff J.

2003-11-04  Jeff Johnston  <jjohnstn@redhat.com>

	* config/ia64/nm-linux.h (CHILD_TO_XFER_PARTIAL): New macro to set up   		the 
ia64 linux native target to_xfer_partial method.
	(ia64_linux_xfer_partial): New prototype.
	* ia64-linux-nat.c (ia64_linux_xfer_partial): New function.
	* inftarg.c (init_child_ops)[CHILD_TO_XFER_PARTIAL]: Set up xfer partial 
method if one provided via macro.
	* target.c (init_dummy_target): Initialize to_xfer_partial to default.
	* target.h (target_object): Add new TARGET_OBJECT_UNWIND_TABLE enum.


Andrew Cagney wrote:
>> Nothing which involves a syscall is acceptable in a tdep file.  That's
>> what the t means - target support.
> 
> 
> ("tdep" mysteriously means "architecture vector support".  That "t" 
> really no longer makes sense :-()
> 
> Yes, architecture vector shouldn't be directly making syscalls.  Instead 
> the architecture specific code should use the target vector to obtain 
> this system information.  Here I think the best option is to add another 
> TARGET_OBJECT_xxxx variant and then use the target_read() method to pull 
> in the data.
> 
> As for the native target side, ia64-linux-nat should export something 
> like ia64_linux_child_read_partial that performs the syscall.  The 
> tricky [er messy] part is wiring it into child_ops, I see there are lots 
> of choices :-(
> 
> - define a nm-*.c macro and have that enable the assignment (ex #define 
> NATIVE_TO_READ_PARTIAL ia64_linux_child?) (ref KILL_INFERIOR)
> 
> - have a callback set the to_read_partial method in child_ops 
> (exec_set_find_memory_regions)
> 
> - modify all the targets so that each implements the new method
> 
> - others?
> 
> Is this information available via /proc?  In a core file?
> 
> Andrew
> 
> PS: Note this pending patch.  Dependant on the timing you or I may need 
> to tweak the name.
> http://sources.redhat.com/ml/gdb-patches/2003-10/msg00795.html
> 
> 
>