Memory layout
-------------

Address  Size		Description
-------- --------	---------------------------------------
00000000 1k		Real-mode IVT
00000400 256		BIOS data area
00000500 256		"data area"
00000600 2k		IDT
00000E00 40 (to 64?)	GDT

00003000 512		Floppy DMA buffer
00003200 512		Module directory
00003400 512		Module loading order

00004000 15k		Stack
00007C00 <9k		Boat loader
0000A000 ?		Symbol table (for linking between modules)
0000B000 ?		Temporary segment table (used by rdf_link)

00010000 192k		Loadable modules
00040000		heap (available for .BSS, etc...)
