compiling system binutils as cross tools

[xorquewasp at googlemail.com]

Hi.

How do I compile the system binutils (contrib/binutils) as i386 ->
x86_64 cross utils? That is, binutils that will run on an i386 host but
will produce x86_64 binaries?

I'm trying to produce a bootstrapping compiler for a port and need to
get these working. I've spent a while reading Makefiles but would rather
get information from someone who actually knows rather than waste
*another* week on this stuff.

I'd rather not compile the entire world if it can be avoided.

cheers,
xw