cross-compilation documentation

[Peter Barada]

>  Why would decoupling the libgcc build make building glibc any easier or
>more difficult?  Don't quite see it myself.
>
>  Anyway, does the old "--without-headers --with-newlib" trick still work
>for making a bootstrap compiler these days?  I haven't tried it since 2.95.x
>days.

Because right now to build a full linux cross-compiler requires
building a bootstrap compiler which needs a set of headers installed
to build libgcc.  Once a bootstrap compiler is built, then glibc can be built
and installed, and then go back and build up the full compiler.

Since the headers are needed *before* a compiler is built, its a
chicken and egg process.  The current method convinces glibc to just
install its headers which are used to build libgcc as part of the
bootstrap compiler creation.

The newer versions of glibc don't have an easy method to just install
the headers so if the requirement of building libgcc as part fo the
compiler can be relaxed(at least for the bootstrap compiler), then the
process would look like:

1) build/install binutils
2) build/install bootstrap compiler
3) build/install glibc
4) build/install full compiler(w/c++, etc).
5) build/install libgcc for full compiler.

-- 
Peter Barada
peter@the-baradas.com