80219/iop321/iop331
===================
00000000 - 0000003f	memoryless boot registers (iop331)
00000000 - 7fffffff	ATU outbound direct adressing window
80000000 - 83ffffff	ATU memory window 0
84000000 - 87ffffff	ATU memory window 1
88000000 - 8fffffff	free
90000000 - 9000ffff	ATU I/O window
90010000 - ffffdfff	free
ffffe000 - ffffe8ff	peripheral memory-mapped registers
ffffe900 - ffffffff	reserved