Format of Extended DMA descriptor structure (EDDS):
Offset	Size	Description	)
 00h	DWORD	region size
 04h	DWORD	offset
 08h	WORD	segment/selector
 0Ah	WORD	reserved
 0Ch	WORD	number available
 0Eh	WORD	number used
 10h	DWORD	region 0 physical address
 14h	DWORD	region 0 size in bytes
 18h	DWORD	region 1 physical address
 1Ch	DWORD	region 1 size in bytes
	...