Using libgcj with different memory management library.

Hi,

I have a few questions regarding the memory management of libgcj.

1. As per my understanding libgcj uses boehm garbage collector for
memory allocations. Are there any allocations in libgcj which are not
routed to the garbage collector ? specially the parts of the library
written in C++. From what I understand is that the memory allocated
with the 'new' operator are routed to the gc . Is it necessary that
the class of object being allocated should be derived from the
'object' class for it to be allocated on the gc ? or all the
allocations with new get routed to gc ?
http://gcc.gnu.org/onlinedocs/gcj/Object-allocation.html#Object-allocation

2. I have a memory manager which allocates memory from a specific
memory pool. I want to port boehm gc to use this memory manager for
its allocations. Can someone give me some pointers as to where I can
make the necessary modifications ? I can see the gcconfig.h and
os_dep.c is the file containing the final system memory allocation
calls.  Is there some other place I need to look at ? Are there any
tricky issues I need to look at while doing the porting ?

Just for information I am using an ancient version of gcc (version 3.4.6).

Regards,
Abhishek