You will also need some software patches. Three of these contain added
support for the internals of the PS2, specifically for the EE, as well
one adding support for newer versions of binutils and gcc to ps2lib.
I especially like reading this part at the top of that tutorial:
*************
** WARNING **
*************
This guide is now obsolete and shouldn't be used. Instead, you should
grab the autobuild script from my site (http://www.oopo.net/consoledev)
and use that for your building needs. This guide remains as it explains
the process of building a cross-compiling toolchain and can thus be
interesting to the curious. That is all.