How to build FreeBSD entirely from sources?

[Geert Hendrickx]

Hello,

"FreeBSD from Scratch" describes a method for REbuilding a FreeBSD system
entirely from sources, starting from an existing FreeBSD system.

But I want to build a new FreeBSD system on a machine currently NOT
running FreeBSD.  How can I do this?

I'm used to doing this with Gentoo Linux:
With Gentoo, one extracts a "stage" tarball to the target partition, which
contains gcc, glibc and some other binary programs, just enough to rebuild
itself, using a "bootstrapping" script.  Then one does "emerge system"
which fetches sources for the entire base system, compiles them and
installs them.  After that, other applicantions can be installed with
"emerge packagename" (comparable to Ports system).

Can I install FreeBSD in a similar way?  Sysinstall only installs binary
packages.

I am new to FreeBSD but not to building stuff from sources (I've been
using Gentoo Linux for quite a while now).

Thanks in advance,

GH