GNU Debugger

[Stolero]

Hello

I need to run a debugger on a UNIX machine . The problem is that my code is a 
combination of "C" source and assembly
for the Microcontroller from Motorola the 68HC11 . 
My question is : is it possible to use gnu debugging tools and modify them such that I 
will be able to debug a mixture of 
68hc11 "C" and assembly source .

Thanks Simon