Kernel progress

Hi,

I managed to get the kernel to compile, link and run (if having a early
panic() due to missing cache handling code counts as "running") for the
PlayStation 2 using gcc-mips-current.

The only thing working for now is barebones console output over the
semi-hidden serial port on the Emotion Engine (thanks PS2DEV). Almost
everything else is commented due to bitrot for now.

So far it has only being tested on a development build of PCSX2, as my
PlayStation 2 is currently disassembled and waiting for electronic
components for the serial port mod. I'll be able to try this on the real
hardware within a couple of days (if I don't kill the motherboard in the
process).

Due to issues with the linker in gcc-mips-current, I had to modify
sys/arch/mips/conf/kern.ldscript to use the elf32-ntradlittlemips output
format, so I probably broke the mips ports. Also, -V NOGCCERROR=1 is
required to compile.

What would be the best/correct way to share my work-in-progress? Since
git-format patch spits out a 1000 line file, it'd be rude to post it here
unannounced. In the meantime, I'm putting a backup of this on GitHub (it's
going to take a while though...).