How to create gcc cross compilers?

[lazer1 <lazer1@blueyonder.co.uk>]

Hello,

I am interested in generating 68k AmigaOS hosted gcc cross compilers 
from existing gcc's for some other platforms,

on AmigaOS we have "Geekgadgets" which provides a Unix environment 
with pdksh, and all the standard GNU build tools,

currently I use 68k AmigaOS native gcc-2.95.3-4 (ie runs on 68k AmigaOS 
and generates code for 68k AmigaOS)

say for a general scenario:

external platforms A and B, with A-hosted gcc cross compiler for 
generating B binaries,

(ie you run gcc on A and it generates code for B),

I want to port or transform this already existing gcc into a 
68k-AmigaOS hosted gcc cross compiler for generating B binaries,

How do I go about doing this?

Is there a standard procedure?

I think its not enough to specify:

configure --host=m68k-unknown-amigaos --target=B

do I need to port some other things as well such as binutils??

thanks for any help on this,

lazer1