@jazzbiker: About your "he tells something interesting about for example kick-starting the new platform without writing the cross-compiler? Or the point is not to use gcc as the cross-compiler?"
Rob Landley is the pioneer of tempfs (init in RAM) and busybox. He hit and solved many corner-cases (in cross compiling) in reducing the "build from itself from scratch" of linux, with minimum original tools (kernel, shell, libc, compiler-tools).
He actually
provides a mini/trimmed-
kernel and a
shell (toybox, static compiled), plus the static-compiled
GCC, FOR EVERY architecture you want (supported by qemu simulator). It is READY to use it.
So YOU can compile everything you want. ex: using a x86-64 OS host, to compile for an ARM guest, etc.
He (already) compiled (the a mini-host OS, smaller than TC) so that you do NOT need to cross-compile
http://landley.net/toybox/downloads/binaries/toolchains/latest/ Basically you start qemu and load the desired HOST OS in qemu as the SAME architecture you want to compile for. ex: on TC14_64 host you run qemu with "OS" of 32 bits to compile for 32 bits; you can ever compile, inside that qmeu, a NEW kernel version, a new shell (busybox), a new licb (musl), because you
natively compile, in an isolated "host".